ATC-13 Conference Proceedings Volume 2 by ATC-13

Volume 2

Table of Contents - Bold Content is in this Volume

Online link to: International Scientific Committee Volume 1: Invited Speakers Volume 1: Fashion and Clothing Science Volume 1: High Performance Fibres and Composites Volume 2: Nanofibres Volume 2: Natural Fibres Volume 2: Technical Textiles and Non-Wovens Volume 3: Textile Performance / Testing / Evaluation Volume 3: Textile Processing and Treatments

Page 3

Page 11 Page 14 Page 16

Title: Asian Textile Conference (ATC-13) Conference Proceedings Editor: Christine Rimmer Abstracts and manuscripts have been submitted in accordance with the Terms and Conditions stated on the ATC-13 webpage https://atc-13.org/about/terms-and-conditions/. â&#x20AC;&#x153;ATC-13 organisers reserve the right to publish the title and abstract of your presentation / poster in various conference marketing materials and other products. Provided abstracts and manuscripts were peer reviewed. It was the responsibility of the Author(s) to amend the Abstract and Manuscript in response to the Review feedback provided by the International Scientific Committee. Occassionally the abstract and manuscript titles do not match. Copyright 2015 Asian Textile Conference Published by Deakin University. 2015 ISBN: 978-0-7300-0039-6

International Scientific Committee Name Chair: Prof Xungai Wang Mr. Sean Bassett Dr. Jeff Church Dr. Floreana Coman Professor Raul Fangueiro Professor Bronwyn Fox Mr Michael Gerakios Dr. Stuart Gordon Prof. Jinlian HU

Affiliation

Institute for Frontier Materials, Deakin University, Australia AWTA Product Testing, Melbourne, Australia Advanced Fibre Innovation Manufacturing Flagship, CSIRO Fabrics & Composites Science & Technologies, Melbourne, Australia School of Engineering, University of Minho, Portugal Institue of Frontier Materials, Deakin University, Australia Metis Technologies, NSW, Australia Advanced Fibre Innovation Manufacturing Flagship, CSIRO Institute of Textiles and Clothing, The Hong Kong Polytechnic University, Hong Kong Advanced Fibre Innovation Manufacturing Flagship, CSIRO Dr. Mickey Huson Dept. of Organic and Polymeric Materials, Graduate School of Science and Professor Takeshi Kikutani Engineering,Tokyo Institute of Technology, Japan Clothing and Textile Sciences, Head of Department Applied Sciences, University Professor Raechel M Laing of Otago, New Zealand Institue for Frontier Materials, Deakin University, Australia Professor Tong Lin Advanced Fibre Innovation Manufacturing Flagship, CSIRO Dr. Rob Long Division of Materials Science and Engineering, CSIRO Dr. Menghe Miao Professor Textile Engineering, Chemistry and Science, College of Textiles, North Carolina Stephen Michielsen State University, USA Dr. Keith Millington Advanced Fibre Innovation Manufacturing Flagship, CSIRO A/Prof Rajiv Padhye School of Fashion & Textiles, RMIT University, Australia A/Prof Joselite Razal Institute for Frontier Materials, Deakin University, Australia Department of Textile Technology, KSR College of Technology, Nadu, India Professor O.L. Shanmugasundaram Professor Sachiko Sukigara Department of Advanced Fibro Science, Graduate School of Science and Technology, Kyoto Institute of Technology, Japan Mr Brendan Swifte Geofabrics Australasia Pty Ltd Prof. Mangesh D. Teli Professor of Textile Chemistry, Institute of Chemical Technology, India Professor Dong Wang Wuhan Textile University, China Professor Qufu Wei Professor of Textile Sciences & Engineering, The Graduate School of Jiangnan University, China Lee Family Professor in Fashion and Textiles Prof John H Xin Institute of Textiles and Clothing, The Hong Kong Polytechnic University, Hong Kong President of the Asian Society of Protective Clothing Professor Kee Jong Yoon Chair Dept. of Fiber System Engineering, Dankook University Director of Personal Protective Equipment Center, Dankook University, Korea National Engineering Laboratory for Modern Silk Professor Ke-Qin Zhang College of Textile and Clothing Engineering, Soochow University, China

Volume 1: Invited Speakers Page

Abstract Title

Acoustic Fibre Board Screens for Office Speech Privacy

Fibrous Materials and Wearable Technologies in a Nonlinear Interactive World

Volume 1: Fashion and Clothing Science Page 34 38 46 51 56 61 65 70

89 93

Abstract Title A Novel Nonlocal Self-similarity Technique for Fabric Defect Detection

WONG Wai Keung Calvin | JIANG Jielin Institute of Textiles and Clothing | The Hong Kong Polytechnic University

Brief Introduction On Uyghur Traditional Headwear--Doppa

Gulistan IGEMBERDI | Xiaoming YANG Textile College of Donghua University, Shanghai China | Textile College of Donghua University, Shanghai China

Characteristic on Colour Expression of Luxury Brand’s Garments

Conditions for Laccase Immobilization onto Modified Polyamide Fabric

Design of Leg Compression Stockings Adaptable to Leg Size for Prophylaxis Against Deep-vein Thrombosis

Dynamic Manipulation of Repeat Formation for Engineered Printing of Graded Garments

Olga Gavrilenko School of Fashion & Textiles, RMIT University, Melbourne

Effect of Compression Deformation of Body Surface on Back Silhouette When Wearing a Brassiere

Yuhi Murasaki | Miyuki Nakahashi | Harumi Morooka Kyoto Women's University | Kyoto | Japan

Effect of Different Pigment Colorants on Inkjet Printing Performance

Effects of Acculturation on Acceptance of Cultural Apparel in the Global Fashion Consumption: A Case 2014 APEC Costume Le Xing | Hui-e Liang | Chuanlan Liu Han Nationality Costume Culture and Non-material Culture Heritage Base | Jiangnan University | Wuxi

Evaluation and Simulation of Clothing Assembly Line

Finite Element Modeling of Women’s Breasts for Bra Design

Handle Durability of Reusable Cloth Diapers after Use

Hiroko Yokura | Sachiko Sukigara Shiga University | Kyoto Institute of Technology

Optimization of Producing Bacterial Cellulose used for Fashion Fabrics

Su Min Yim | So Hee Lee | Hye Rim Kim Department of Clothing and Textiles | Sookmyung Womenâ€™s University | Research Institute of women's health

Relation among Three-dimensional Shapes of Women's Trunk, Breast, and Abdomen

110

Research on Suitability of Women's Jacket for Various Body Types

114

Scenario in BRICS Region and Textile Potential

118

Seam Pucker Evaluation of Fused Fabric Composites Based on Subjective Method

Volume 1: Fashion and Clothing Science Page

Abstract Title

122i

Study on the Model of Feature Points of Bust Curve

123

Sustainability Challenges in Fashion Business

127

The Application of Nvshu Pattern in the Modern Women's Apparel Design

132

Virtual Draping by Mapping and Manipulation

Gao Peipei | Xing Xiaoyu | Shang Xiaomei Soochow University | Hong Kong

Philip KW Yeung and Kit KY Li Clothing Industry Training Authority | Hong Kong

Volume 1: High Performance Fibres and Composites Page 136 139 143 147 152

Abstract Title A Study on the Thermal Properties of Polyhydroxyamide Derivatives

Analyzing the Tensile Behavior of Woven-Fabric Reinforced Composites using Fiber Orientation Theorem F Hasanalizadeh | H.Dabiryan | A.A. Jeddi Amirkabir University of Technology | Amirkabir University of Technology | Amirkabir University of Technology

Biodegradable Composites from Natural Bamboo Fibres

Erwan Castanet Institute for Frontier Material and Carbon Nexus

Biosynthesis of Bacterial Cellulose/Carboxylic Multi-Walled Carbon Nanotubes for Enzymatic Biofuel Cells Application

Characterization of Polyimide/Poly(VDF-co-HFP) Composite Membrane prepared by Electrospinning Il Jae Lee | Chan Sol Kang | Doo Hyun Baik Chungnam National University | Korea | Chungnam National University

155

Chemical Resistance of Polyphenylene Sulfide Needle Non-Woven Fabric

163

Cost-Efficient and Flexible Production of High Quality Fabrics for Composite Applications

168

Crystallization Kinetics and Structural Features of Polyarylate/Nylon6 Island-In-The-Sea Fibers used for Thermoplastic Composites

WENJUN DOU Wuhan Textile University

Dr. Josef Klingele Lindauer DORNIER GmbH

172

176 180

Development of Composite Technical Filament for Smart Applications

Development of Hydrophilic Polyamide and its Applications on Functional Textiles

Wei Hung Chen | Wei Peng Lin | Ta Chung An Taiwan Textile Research Institute | Taiwan Textile Research Institute | Taiwan Textile Research Institute

Effect of Cross-sectional Configuration on Fiber Formation Behavior in the Vicinity of Spinning Nozzle in Bicomponent Melt Spinning Process Yiwen Chen | Wataru Takarada | Takeshi Kikutani Tokyo Institute of Technology | Tokyo Institute of Technology | Tokyo Institute of Technology

184 189 193 197

201

Effects of Bonding System on the Interfacial Adhesion Between Polyketone Fiber and EPDM Rubber

Evaluating Acoustic and Climatic Ageing Properties of Natural Fiber Based Nonwovens for Automotive Applications

Dr. Asis Patnaik CSIR Materials Science and Manufacturing

Fabrication and Characterization of Flexible Polyaniline-Decorated Fiber Nanocomposite Mats for Supercapacitors

Danyun Lei | Tae Hoon Ko | Ji-young Park | Yong Sik Chung | Byoung-Suhk Kim Department of BIN Convergence Technology, Chonbuk National University | Department of Organic Materials and Fiber Engineering, Chonbuk National University | Department of Organic Materials and Fiber Engineering, Chonbuk National University | Department of Organic Materials and Fiber Engineering, Chonbuk National University | Department of Organic Materials and Fiber Engineering, Chonbuk National University

Fabrication of Core-Shell Conducting Fibers and their Characteristics

Volume 1: High Performance Fibres and Composites Page

Abstract Title

205

Fabrication of Superionic Conductive Nanofiber

209

Fiber-Reinforced Rigid Polyurethane Foam Composite Boards: Manufacturing and Property Evaluations

Young Ah Kang | Yang Hun Lee | Kyoung Hou Kim Dong-A University | Dong-A University | Shinshu University

213

217

Growth of Zinc Oxide Nanorodes with Respect to Surface Condition of Carbon Fiber and Post Annealing

Seung A Song | Seong Su Kim Chonbuk National University | Chonbuk National University

Heat and Moisture Transfer Properties of Natural Silkworm Cocoons

221

High Spatial Resolution Confocal Raman Mapping: New Frontiers in Carbon Fibre Research

225

High-speed Melt Spinning Behaviors of Flame-retardant PET Fibers Containing Antibacterial Deodorant Function

229

Hybridization of Preforms for Textile Composites

233

Improvement of Flexural Properties of FRP by Filament Cover Method

237

Mechanical and Open Hole Tensile Properties of Self-Reinforced Recycling PET Composites

242

Mechanical Properties of Poly(lactic acid)/Hemp Hurd Biocomposites using Glycidyl Methacrylate

246

Mechanical Properties of Woven Jute - Carbon Fiber Cloth Hybrid-Reinforced Epoxy Composite

Hireni Mankodi Department of Textile Engineering

Ryo Sakurada | Limin Bao Mechanical Robotics Course | Graduate School of Science and Technology

Zhili Zhong | Manyi Li | Zhendong Liao Tianjin Polytechnic University | Tianjin Polytechnic University| Tianjin Polytechnic University

250

Modeling of Tensile Mechanics of 3D Woven Orthogonal Composites

257

Modification of Chemically Stable Polymeric Materials 61. Improvement in the Adhesive Property of Polymeric and FRP Materials

262 266

270

Ashwini Kumar Dash | B.K.Behera Indian Institute of Technology Delhi, India | Indian Institute of Technology Delhi, India

Hitoshi Kanazawa | Aya Inada Dept. of Industrial Systems | Faculty of Symbiotic Systems Science

Morphology and Thermal Property of Neoprene Textiles Coated with CNF/polymer Composite Sunhee Lee Dept. Fashion Design

pH- / Temperature-responsive Materials Prepared from Amino Acid Ester Carrying Polymerizable Vinyl Group

Pitch-based Carbon Fiber Prepared by Melt Spinning Using Screw Type Extruder

Tae Hwan Lim | Sang Young Yeo | So Hee Lee Korea Institute of Industrial Technology | Korea Institute of Industrial Technology | Sookmyung Women`s University

Volume 1: High Performance Fibres and Composites Page 273

277

282 286 290

Abstract Title Preparation and Characteristics of Carbon Nanotube/Carbon Fiber Composite Paper

Wan Jin Kim | Yong Sik Chung | Han Jin Jang | Hyun Myung Kwon Department of Organic Materials & Fiber Engineering, Chonbuk National University, Jeonju 561-756, Korea | Department of Organic Materials & Fiber Engineering, Chonbuk National University, Jeonju 561-756, Korea | Department of Organic Materials & Fiber Engineering, Chonbuk National University, Jeonju 561-756, Korea | Department of Organic Materials & Fiber Engineering, Chonbuk National University, Jeonju 561-756, Korea

Preparation and Characteristics of Thermoplastic Composite Sheet using Recycle Carbon Fibers

Yong Sik Chung | Yun-Seon Lee | Wan Jin Kim | Jae Ho Shin | Chul Ho Lee Department of Organic Materials & Fiber Engineering, Chonbuk National University, Jeonju 561-756, Korea | Department of Organic Materials & Fiber Engineering, Chonbuk National University, Jeonju 561-756, Korea | Department of Organic Materials & Fiber Engineering, Chonbuk National University Jeonju 561-756, Korea | Department of Organic Materials & Fiber Engineering, Chonbuk National University, Jeonju 561-756, Korea | Department of Organic Materials & Fiber Engineering, Chonbuk National University, Jeonju 561-756, Korea

Preparation and Characterization of Aramid Copolymer Fibers Including Ester and Cyano Group

Preparation and Characterization of High Temperature Carbon/Silica Composite by Sol-gel Process

Preparation and Properties of Polyetherimide(PEI)-MWCNT Composite Nanofibers A-Rong Kim | Young-Ah Kang | Jong S. Park* Dong-A University | Dong-A University | Pusan National University

294

Preparation and Thermal Properties of Polybenzoxazole Precursors Containing Sulfone Group

298

Preparation of Helical Crystals of Poly(ester-imide) by Crystallization during Polymerization - Influence of Oligomer Structure on Helical Morphology -

302

Preparation of Rigid Polymer Nanofiber by using Crystallized from Dilute Solution and its Application Tetsuya Uchida | Masashi Furukawa | Haruka DoDo Okayama Univ. | JAPAN | Okayama Univ.

306

Preparation of Well-Defined Polyacrylonitrile Fiber-Forming Polymer via New Controlled Radical Polymerization Techniques Xiaohui Liu Tianjin Polytechnic University

310

Properties of Cellulose Regenerated Fibers Spun from Ionic Liquid Solutions

312

Property Evaluations of Composite Films made of Polyvinyl Alcohol and Graphene Nano-Sheets by Using the Solution Mixing Method

Jiaping Zhang | Keita Tominaga | Yasuo Gotoh Faculty of Textile Science and Technology | Shinshu University | Faculty of Textile Science and Technology

316 320

PVA-Gel with Colossal Dielectric Constant can Deflect Laser Beam Toshihiro Hirai | Hiromu Satou | Chizuru Sakaguchi Shinshu University | Shinshu University | Shinshu University

Rheological Investigation of PAN-based Polymer Solutions to Determine the Wet Spinning Parameters for Continuous Fibre Production

324

Stability of Red Rare Earth Luminous Fiber Emission Spectra Yanan Zhu | Mingqiao Ge School of Textile and Clothing | Jiangnan University

Volume 1: High Performance Fibres and Composites Page 329

332

Abstract Title Structure and Properties of Fibers Manufactured from Liquid Crystalline Poly(2-Cyano-1,4-Phenylene Terephthalamide)Based Copolymers Seong Jun Yu Chugnam University

Studies on Tensile and Flexural Properties of Hemp/PBTG Biocomposites

336

Study on Solid Erosion Properties of Fiber-Reinforced Thermoplastics with High Heat-Resistant Properties

339

Synthesis and Characterization of Poly (L-lactide) Poly (caprolactone) Segmented Block Copolymers

343 346

349

353 357

366

371 375 378

Liu Bing | Bao Limin Shinshu University | Shinshu University

Synthesis and Characterization of Polyacrylonitrile-based Terpolymers as Carbon Fiber Precursors Eunbin Lee | Won Ho Park | Young Gyu Jeong Chungnam National University | Daejeon 305-764 | Korea

The Chemical Modification of Oxy-PAN Nanofibrous Web by Sodium Hydroxide Solution

The Effect of Carbonization Temperature on Properties of PAN-Based Carbon Fiber

The Effects of Heat-Treatment Temperature on Carbonization Behavior of Heterocyclic Aromatic Polymer

The Functional Properties of PET/ Rayon Staple Fiber Made Woven Fabrics with ACC@Ag Powders

The Heating and Cooling Behaviours of Needle Punched Nonwoven Fabrics with Wool and Silver Coated Polyamide Fibres

Thermal Protective Performance of the Air Layer in Firefighterâ&#x20AC;&#x2122;s Protective Clothing

Three Dimensional Composite Prepared by Vacuum-Assisted Resin Transfer Molding

Transverse Modulus of Carbon Fibre by Compression and Nanoindentation

Volume 2: Nanofibres Page 383

Abstract Title A Comparison of the Influence of Superhydrophobic Surfaces and the Wetness on the Colours, Near-Infrared (IR) and Shortwave IR Properties of Uniform Jie Ding | Bin Lee Defence Science and Technology Group | Defence Science and Technology Group

387

Adhesion of Electrospun PVA/ES Composites using Spiral Disk Spinnerets

392

Application of the Synthesized Magnetic TiO2Nanofibres in Dye Removal from Effluent

396

Cellulose-Based Co-Axial Nanofiber Membrane for Separator of High Performance Lithium-Ion Battery from Waste Cigarette Filter Tips

407 412 416

Chuchu Zhao | Yao Lu | Zhijuan Pan Soochow University | Soochow University | Soochow University

Elmira Pajotan | M.Rahimdokht | N. Noormohammadi Amirkabir University of Technology | Amirkabir University of Technology | Amirkabir University of Technology

Fenglin Huang Jiangnan University

Characterisation of Nanofibres Fabricated by Meltblowing using various Fluids Rajkishore Nayak RMIT and CSIRO

CNTs and Graphene Oxide Coated Electrode for Anionic Dye Removal by Heterogeneous Electro-Fenton Process Z. Eshaghzadeh | h. Bahrami | A. Gholami Akerdi. Amirkabir University of Technology | Amirkabir University of Technology | Amirkabir University of Technology

Continuous Manufacturing Process of Carbon Nanotube-Grafted Carbon Fibers

420

Drug Loaded Porous Silica Nanoparticles Composites Nanofiber and Evaluation of Characteristics

423

Electrical Properties of Polypyrrole Coated Nanofibers on PET Fabric with Potential for Flexible Heating Element Applications

Ke Ma | Mayakrishnan Gopiraman | KimIck Soo Shinshu University,Japan | Shinshu University,Japan | Shinshu University, Japan

427

Electrospun Hybrid Poly(Lactic Acid)/Titania Fibrous Membranes with Antibacterial Activity for Fine Particulate Filtration

431

Electrospun PVA/PE Nanofiber Mask

436 440

443 447

451 456

Wang Zhe | Pan Zhijuan Soochow University | Soochow University YAMASHITA Yoshihiro The University of Shiga Prefecture

Examining Thermal Properties of Nano Surfaces Formed with Electro Spinning Method from Shape Memory Polymers Erkan Isgoren | Sinem Gulas | Metin Yuksek | Marmara University, Turkey

Fabrication and Evaluation of Bi-layered Matrix Composed of Human Hair Kratin Nanofiber and Gelatin Methacrylate Hydrogel Min Jin Kim | Su Jung Ryu | So Ra Lee | Chang Seok Ki | Young Hwan Park Seoul National University

Fabrication of Electrospun Juniperus Chinensis Extracts loaded PVA Nanofibers Jeong Hwa Kim | Jung Soon Lee | Ick Soo Kim Chungnam National University | Chungnam National University | Shinshu University

Fabrication of ZnO Nanowires on Fabrics Based on Biomimetic Adhesion of Seeds onto Fiber Surfaces and Hydrothermal Growth Chao-Hua Xue | Xue-Qing Ji | Shun-Tian Jia Shaanxi University, China

Hydrophobic Functionalization of Textiles using Atmospheric Pressure Pulse Plasma

Raghav Mehra | Manjeet Jassal | Ashwini K. Agrawal Indian Institute of Technology

Modification of Graphene Oxide and Halloysite Nanotubes by Poly(Propylene Imine) Dendrimer to Improve the Dye Removal Efficiency F. Shahamati Fard | , A. Ghasempour | H. Bahrami | S. Akbari Amirkabir University of Technology | Amirkabir University of Technology | Amirkabir University of Technology | Amirkabir University of Technology

Volume 2: Nanofibres Page 461

464 467 470

Abstract Title Morphologies of Colloid-Electrospun Sulfonated Polyetheretherketone Nanofiber

Morphologies of Electrospun Polyacrylonitrile/Polyvinylpyrrolidone Composite Nanofiber

Sheng-Yin Peng | Chien-Lin Huang | Chih-Kuang Chen Department of Fiber and Composite Materials | Feng Chia University | Department of Fiber and Composite Materials

Morphologies of HDPE/PA6/GNS Composites Chien-Lin Huang* Department of Fiber and Composite Materials

474

Polyvinyl Alchol/Water Soluble Chitosan Electrospun Fiber Membranes: Process and Property Assessment

478

Preparation and Characterization Nanofibres from Poly(Îľ-caprolactone) poly(vinyl alcohol) Gum Tragacanth Hybrid Scaffolds

Zare Khalili | M. Ranjbar Amirkabir University of Technology | Bonab University

486

Preparation and Characterization of Electrospun PCL/Gelatin Nanofibers containing Graphene Nanoparticles

489i

Preparation of Antibacterial Nano-silver Sol

490 493 497 505

M.Ranjbar | Mina Heydari Bonab University | Amirkabir University of Technology

Preparation of Beta-Chitin Nanofibers from Squid Pen by Water Jet Machine

Preparation of Nanoparticle Fluorescent Pigment Dispersions by Miniemulsion Polymerization and itâ&#x20AC;&#x2122;s Properties

Jie Liu | Shaohai Fu Jiangnan University | Jiangnan University | Jiangnan University

Preparation of Polyvinyl Butyral/Titanium Dioxide Composite used for UV Blocking

509

Proof-of-Concept Fabrication of Photoactive Tio2-PU Composite Nanofibers for Efficient Dye Degradation

513

Reexamination of the Polymerization of Amino Acid NCA 69. A New Type Topochemical Polymerization of Amino Acid N-Carboxy Anhydrides

Xiaowen Wang | Huawen Hu | Chenxi Liu | John H Xin Institute of Textile & Clothing at The Hong Kong Polytechnic University - Hong Kong | Institute of Textile & Clothing at The Hong Kong Polytechnic University - Hong Kong | Institute of Textile & Clothing at The Hong Kong Polytechnic University - Hong Ko |

Hitoshi Kanazawa | Aya Inada Dept. of Industrial System | Faculty of Symbiotic Systems Science

518

Sericin Separation from Silk Degumming Waste Water by Magnetic Nanoparticles: A Feasible Approach

523

Strain Sensitive Cotton Fabric with a Graphene Nanoribbon Layer

527

Synthesis of Ag3VO4 TiO2 CNT Hybrids with Enhanced Photocatalytic Activity under Visible Light Irradiation

Esfandiar Pakdel | Jinfeng Wang | Xungai Wang Australian Future Fibres Research and Innovation Centre | Institute for Frontier Materials | Deakin University

Lu Gan | Songmin Shang The Hong Kong Polytechnic University | The Hong Kong Polytechnic University

Chang-Mou Wu | Ching-Kai Wang Department of Materials Science and Engineering | National Taiwan University of Science and Technology

Volume 2: Nanofibres Page 531

Abstract Title Synthesis of Silver Nanoparticles Stabilized with DOPA and their Application to Colorimetric Sensor for Heavy Metal and Catalyst Reduction of Methylene Blue Ja Young Cheon | Hun Min Lee | So Yeon Jin | Won Ho Park Chungnam National University | Chungnam National University | Chungnam National University | Chungnam National University

535

The Effect of Chelidonium Majus var. Asiaticum Extract Concentration o PVA Nanofiber Web Diameter

539

The Thermal and Functional Properties of PU/CC@Ag Composite Films

544

Ultrathin Hierarchically Structured Poly(Vinyl Alcohol-Co-Ethylene) Nanofirous Separator for High Rate Lithium-Ion Battery

Heong Yeol Choi | Jung Soon Lee | Ick Soo Kim Chungnam National University | Chungnam National University | Shinshu University

Volume 2: Natural Fibres Page

Abstract Title

548

An Investigation on Cellulose-Based Carbon Composite Materials Fabricated by 3D Printing

553

Animal Fibre Diameter-Length Relationship and Its Effects on Yarn Properties

Saeed Dadvar Deakin University

557

Back to the Nature in Future

563

Brief Analysis of Uyghur Traditional Textile Technology

569 571 576

Effect of Licl/Dmac Solution Treatment on Solubility and Mechanism of Native Hemp Fibers Min Zhu | Zhili Zhong | Zhendong Liao | Qi Weng Tianjin Polytechnic University

Facile Manipulation of Silk Fibroin Hydrogel Property by Molecular Weight Control

579

Functional Modification of Coir Fibre for Enhanced Oil Absorbency

584

In-Situ Analysis of Fiber Structure Development in CO2 Laser-Heated Drawing of Syndiotactic Polystylene Fiber

588

Investigating Drug Delivery Properties of Silk Fibres and Particles Mehdi Kazemimostaghim | Rangam Rajkhowa | Xungai Wang Deakin University | Deakin University | Deakin and Wuhan Textile University

592

595

Modification of Chemically Stable Polymeric Materials 62. Improvement of the Hydrophilic Property of Wool Fibers and Preparation of Water-Wettable Polypropylene and Silicone Ruber

Hitoshi Kanazawa | Aya Inada Dept. of Industrial Systems | Faculty of Symbiotic Systems Science

Plasma Assisted Finishing of Cotton Fabric with Chitosan

Maryam Naebe | Aysu Onur | Xungai Wang Institute for Frontier Materials (IFM), Deakin University, Geelong, Australia | Institute for Frontier Materials (IFM), Deakin University, Geelong, Australia | Institute for Frontier Materials (IFM), Deakin University, Geelong, Australia |

599

Preparation and Characterization of TLCP/PA6 Island-Sea Type Bi-Component Fibers by Melt Spinning Process

602

Preparation and flame retardancy of 3-(hydroxyphenylphosphinyl)-propanoic acid esters of cellulose and their fibers

607

Preparation of Kapok/Tio2 UV-Blocking Fiber by in-Situ Deposition

612

Shrink Proofing of Wool Fibers: Effect of Pretreatments with Shellac and Keratinase

616

Silk Modification Through In-Situ Polymerization and Crosslink under Visible Light

620

The Effect of Copper and Iron on Wool Photostability

Volume 2: Natural Fibres Page

Abstract Title

624

The Glass Transition Temperature (Tg) of Cotton

628

The Role of Various Fabric Parameters on the FAST Results of Wool and Wool Blend Worsted Fabrics

633 637

Chantal Denham CSIRO/Deakin

Sweta Das Department of Textile Science

Use of Bamboo Fibre in Textile

Varinder Kaur | D P Charropadhyay Guru Nanak Dev University, India | The M. S. University of Baroda, India

641

Using Micro-Electron Spin Resonance to Study Free Radicals in Protein Fibres

645

Water-free Chemical Treatment and Enzymatic Treatment of Wool to Change the Fiber Surface Morphology and Mechanical Properties

Keith Millington CSIRO

Chendi Tu | Sachiko Sukigara | Satoko Okubayashi | Fusako Kawai | Kunihiko Watanabe Department of Advanced Fibro-Science, Kyoto Institute of Technology, Japan | Department of Advanced Fibro-Science, Kyoto Institute of Technology, Japan | Department of Advanced Fibro-Science, Kyoto Institute of Technology, Japan | Center for Fiber and Textile Science, Kyoto Institute of Technology, Japan | Division of Applied Life Sciences, Kyoto Prefectural University, Japan

Volume 2: Technical Textiles and Non-Wovens Page

Abstract Title

649

A Theoretical Model for Thermal Resistance of Single Layer Cotton/Nylon-Kermel Blended Fabrics

657

Application of Regenerated Animal Fibers for Scaffold Preparation

661 665

669

673

Ali Kakvan | Saeed Shaikhzadeh Najar Amirkabir University of Technology Kazuya Sawada Osaka Seikei College

Coated Fabric Geomembranes

Mike Sadlier | Steve Aggenbach | Geosynthetic Consultants Australia | Infrastructure Technologies Australia |

Development of 3-Dimensional Fibrous Scaffolds using draw Texturing and Tubular Knitting Process

Effect of Tensile Properties of Layers on the Performance of Geocells made from Woven Fabrics in Bearing Capacity of Reinforced Soil Hadi Dabiryan | Mohammad Maroufi | Ghazal Ghamkhar Amirkabir University of Technology | Amirkabir University of Technology | Amirkabir University of Technology

Effects of Different Extraction Conditions on the Efficacy of Shatterstone

677

Effects of Recycled Kevlar Fibers on Physical Properties of Nonwoven Geotextiles

681

Geotextiles Made by Different Nonwoven Fabric Manufacturing Conditions: Manufacturing Techniques and Property Evaluations

685

Highly Precise Nanofiber Web-based Dry Electrodes for Long-term Biopotential Monitoring

690

Preparation and Characterization of N-Octadecane Microcapsules used for Textile Coating

694

Preparation and Characterization of Super Absorbent Nonwoven Fabrics for Chronic Wound Care

698 702

Tae-Hee Kim | Jung-Nam Im KITECH | KITECH

Preparation of Chitosan/Polyvinyl Alcohol Fibers without the use of Acetic Acid

Preparation of PET Non-woven Mats using High Voltage Dosing of Thermoplastic Polymer Powders and Melt-Fixing Process and Characteristics thereof

Sun Young Moon | Young Ho Kim | Chang Woo Nam Soongsil University | Soongsil university | Korea Institute of Industrial Technology

706 710

Study on Mixed media composed of UHMWPE Filaments and Microfibers

Zhang Heng | Qian Xiaoming Tianjin Polytechnic University

Study on Production of Non-woven Fabric and Mesh Type Knit Fabric used for Medical Products using Biodegradable Polyester Yoon Cheol Park | Jae Yun Shim | Young Hwan Park Korea Institute of Industrial Technology | Korea Institute of Industrial Technology | Korea Institute of Industrial Technology

714

Superhydrophobic Nonwoven Prepared from Biopolymer Derivatives

717

Synthesis and Characterization of Bio-Polyurethanes using Vegetable Oil-Based Polyols for Breathable Textile Coatings

Hiroaki Yoshida Shinshu University

Volume 2: Technical Textiles and Non-Wovens Page

Abstract Title

721

Synthesis and Characterization of UV Curable Oligomer for Pressure-Sensitive Adhesives

725

Synthesis and Fluorescent Properties of Water-Soluble Chitosan Oligomer with Fluorophore

728

The Effect of Structure of Socks on Plantar Pressure Distribution

Volume 3: Textile Performance / Testing / Evaluation Page

Abstract Title

732

A Study on Tencel and Polylactic Acid Fibres Based Nonwoven Structure Properties

735

A Study on the Preparation and Characterization of Wet-laid Nonwoven Based on Poly ketone

739 743

748

Gyudong LEE | Song Jun DOH Technical Textile and Materials R&D Group | KITECH | Korea Institute of Industrial Technology

A study on the Reliability Evaluation of Industrial textile Hwan Kuk, Kim Korea Textile Machinery Research Institute

Analysis of 19 SVHCS in Textiles using Liquid Chromatography Coupled with LTQ/Orbitrap Mass Spectrometry

Anti-aging Properties of PP / PET Acupuncture Filter Material Cherry Wuhan Textlie Univercity

755

Application of Phase Change Materials in Motorcycle Helmets for Heat-Stress Reduction

759

Comparison General Turnout Gear to Various Special Turnout Gear for Firefighters using the Flash Fire Testing Methods

763

767

Sinnappoo Kanesalingam | Lachlan Thompson | Rajiv Padhye RMIT University | RMIT University | RMIT University

Composite Environmentally Protective Sandwich Insulation Material Design

Composite Nonwovens Composed of Viscose Rayon and Super Absorbent Fibers for Incontinence Pad Yoonjin Kim | Jung Nam Im | Ga Hee Kim Korea Institute of Industrial Technology | Korea Institute of Industrial Technology | Korea Institute of Industrial Technology

771

Compression and Recovery Behavior of 3-D Composite Nonwovens Fabricated by Different Web-laying Methods

775

Cotton Bale Laydown Management Using Fuzzy C-Means Algorithm

779

Degradable Chitosan/Polyvinyl Alcohol Coronary Stents: Effects of Genipin Cross-Linking on Structure and Mechanical Properties

784

789 793 797

Chang Whan Joo | Dong Su Park Chungnam National University | Daejeon

Subhasis Das | Anindya Ghosh | Abul Hasnat Government College of Engineering & Textile Technology | Berhampore | West Bengal

Determination of Nonylphenol Ethoxylate and Octylphenol Ethoxylate Surfactants in Textiles by Liquid Chromatography High-Resolution Mass Spectrometry Xiwen Ye | Xin Luo | Zengyuan Niu | Li Zhang Shandong Entry-Exit Inspection and Quarantine Bureau | Shandong Entry-Exit Inspection and Quarantine Bureau | Shandong Entry-Exit Inspection and Quarantine Bureau | College of Chemistry and Chemical Engineering, Ocean University of China

Developing a Meltstick Test Method Ahmed Bhoyro Defence Science and Technology Organisation

Development Of Conductive Wire Reinforced Cotton Yarns For Protective Textile Applications

Development of Rain Test Equipment(Rain Tower) and Waterproof Performance Evaluation Criteria

Volume 3: Textile Performance / Testing / Evaluation Page

Abstract Title

800

Effect of Adhesive Interlinings on Creep Behavior of Woven Fabrics under low Stress in Bias Direction

804

Effect of Needle-Punching Conditions on the Fiber Orientation in the Nonwoven Fabric Characterized by X-Ray Micro Computed Tomography

KyoungOk Kim | Ken Ishizawa | Masayuki Takatera Shinshu University | Shinshu University | Shinshu University

808

815

819

Effects of Fabric Structures and Yarn Constitutions on the Functional Properties of Knitted Fabric

Effects of Twisting Coefficients on Properties of Coolplus/Zinc Ion Yarns and Knitted Fabrics

Evaluation of Effective Permittivity of Nonwoven Fabrics Using Two-layer Microstrip Transmission Line Method

823

Exploring Phase Change Materials in Firefighter Hood for Cooling

826

Facile Synthesis of Core/Shell-like NiCo2O4-Decorated MWCNTs and its Electrocatalytic Activity for Methanol Oxidation

830

Far-Infrared Nonwoven Fabrics Made of Various Ratios of Bamboo Fiber to Far-Infrared Fiber: Far-Infrared Emissivity and Mechanical Property Evaluations

835

High Elastic-Recovery Metal/Polyester Knitting Fabric: Manufacturing Techniques and Property Evaluations

839

Investigating the Dimensional Properties of the Spectral Reflectance of the Woolen Yarns used in Persian Carpet

843

Sarvenaz Ghanean | Mansoureh Ghanbar Afjeh Textile Engineering Department | Amirkabir University of Technology

Investigation of Electromagnetic Shielding Effectiveness of the Nonwoven Carbon Mat Produced by Wet-Laid Technology

847

Knitted Strain Sensors for Monitoring Body Movements

851

Manufacture of PAN-Based Anode Fibers for Lithium Ion Battery through Wet Spinning

Volume 3: Textile Performance / Testing / Evaluation Page

Abstract Title

855

Manufacturing Techniques and Property Evaluations of PVA/LE Nano-fibrous Membranes

859

Moisture Management and Thermo-Physiological Properties of the Multi-Layered Clothing System Containing SuperAbsorbent Materials

864

868

872 877

881 885 890 894 898 903 910 914 920 924

A Prof Rajiv Padhye | Dr Shadi Houshyar | Dr Rajkishore Nayak RMIT University Australia | RMIT University Australia | RMIT University Australia

Organic/Inorganic PP-Coated Heating Wire and Composite Knitted Fabrics: Processing Technology and Property Evaluations

Performance Evaluation of Commercial and Test Textiles and Analysis of their Behavior against Washing Machine Parameters during Laundering Muhammed Heysem Arslan | Ikilem Gocek | Ilkan Erdem | Umut Kivanc Sahin | Hatice Acikgoz Tufan Istanbul Technical University | Istanbul Technical University | ARCELIK Incorporation Washing Machine Plant | Istanbul Technical University | Istanbul Technical University

Physical Properties and Manufacturing Process Evaluation of Complex Stainless Steel Wire/Bamboo Charcoal Nylon/ Spandex Piled Yarn and Knitted Fabric Chin-Mei Lin | Pei-Chen Hsiao Asia University | Asia University

Preparation and Characterization of Wet-Laid Nonwoven for Secondary Battery Separator

Seung Woo Han | Sung Won Byun | Chang Whan Joo Korea Institute of Industrial Technology | Korea Institute of Industrial Technology | Chungnam National University

Preparation and Property Evaluations of Electrically Conductive Composite Fabrics Ting An Lin | Ching-Wen Lou | Jia-Horng Lin Feng Chia University | Central Taiwan University of Science and Technology | Feng Chia University

Property Evaluations of Sodium Chloride/Polyvinyl Alcohol Hydrogels Prepared by Different Drying Methods

Strength Forecasting of Spun Yarns at Different Gauge Lengths Using Weibull Distribution Parameters Anindya Ghosh Government College of Engineering & Textile Technology | Berhampore | West Bengal | India-742101

Study on the Influence of Tight-Fitting Sports Socks on Human Legâ&#x20AC;&#x2122;s Pressure Distribution Chen Ling Soochow University

Study on Warm Moisture Heating UNIQLO Brand Thermal Underwear Jingjing Zheng | Xiaofen Ji | Chen Pang College of Fashion Zhejiang Sci-Tech University

The Characteristic Evaluation of Electric yarn coated with Electroconductive Material

Un-Hwan Park | In-Sung Lee | Kwang-nyun Cho Korea Textile Machinery Research Institute | Korea Textile Machinery Research Institute | Korea Research Institute For Fashion Industry

The Comparative Evaluation of Car Carpet Material Including Hollow Fiber for Sound Absorbing Performance

The Design of New Jacquard Fabric Based on Four-Needle Jacquard Technology Md Anwar Jahid | Deng Zhongmin Wuhan Textile University | Wuhan Textile University

The Effect of Elastic Strain on Tribological Characteristics of Fabrics Suitable for Therapeutic Gloves Siti Hana Nasir | Olga Troynikov School of Fashion and Textiles | RMIT University | School of Fashion and Textiles | RMIT University

Volume 3: Textile Performance / Testing / Evaluation Page 928

932

936 940 945 950

Abstract Title The Effect of Structural Parameters on Air Permeability of Bifacial Fabrics

Licheng Zhu | Maryam Naebe | Ian Blanchonette | Xungai Wang Australian Future Fibres Research & Innovation Centre, Institute for Frontier Materials, Deakin University | Australian Future Fibres Research & Innovation Centre, Institute for Frontier Materials, Deakin University | CSIRO Manufacturing, Geelong | Australian Future Fibres Research & Innovation Centre, Institute for Frontier Materials, Deakin University, School of Textile Science of Engineering, Wuhan Textile University

The Interaction between UV Light and Fibres with different Cross-Sectional Shapes within the Yarns

The Life Test and Analysis of the Fabric Switch

The Research on Feature Recognition of Raw Cotton Defects and Impurities based on Image Processing Technology

Yong Zhang | Md Anwar Jahid | Deng Zhongmin Wuhan Textile University | Wuhan Textile University | Wuhan Textile University

Unsupervised Fabric Defect Segmentation using Local Dictionary Approximation

Jian Zhou | Weidong Gao Jiangnan University | Jiangnan University

Visual Impression of Fabric Texture at Different Viewing Distance

Aya Goto | Aki Kondo | Sachiko Sukigara Department of Advanced Fibro-science | Kyoto Institute of Technology | Department of Advanced Fibro-science

Volume 3: Textile Processing and Treatments Page

Abstract Title

954

A Study of One-Direction-Moisture-Conducting Laminated Fabric

958

Antibacterial Cellulose Containing Triazine N-halamine

963

Application of Genetic Algorithm Optimisation in Bleaching Treatment of Cellulosic Fibers

968

Catechinone Hair Dyestuff Preparation by Chemical Oxidation Method in Water/Alcohol Mixed Solution -Solvent Effect and Reaction Mechanism-

972

Comparison of Dyeing Behaviors of Reactive Dyes according to different Sodium Sulfate Addition Method

976

Design of Safer Flame Retardant Textiles Through Inclusion Complex Formation with Beta-Cyclodextrin: A Combined Experimental and Modeling Study

Seokil Hong | Heecheol Cha Korea Institute of Industrial Technology | Korea Institute of Industrial Technology

981

Development of New AOX-free Processing Method Extended to Wool

986

Discoloration of Kapok Indigo Denim Fabric by Using Carbon Dioxide Laser with Different parameters

991

Durability of Antibacterial Efficacy for Atmospheric Plasma-Treated Knitted Fabrics with Metal Salts against Laundering

995

Dyeing and Fastness Properties of Wool Yarns Dyed with Sunflower Seed Hulls

999

Dyeing Properties and Energy Saving Ratios according to Dyeing Conditions of S Type Disperse Dyes

1003

Dyeing Properties of Poly(Ethylene Terephthalate)/Poly(Ethylene Glycol) Block Copolymer Fibers

1007

Masukuni Mori | Illya Kulyk Mori Consultant Engineering Office | Veneto Nanotech SCpA

zahra Ahmadi | fateme Gholami Art university of tehran faculty | master student

Seokil Hong | Beomsoo Lee Korea Institute of Industrial Technology | Korea Institute of Industrial Technology Shekh Md. Mamun Kabir | Joonseok Koh Konkuk University | Konkuk University

Dyeing Textiles by Using Extracts from Mulberry Branch/Trunk I. Dyestuff Fluorescence Property

1010

Effects of Roller Drafting and Twisting on the Structural and Mechanical Properties of Nano-fibrous Bundles

1014

Effects of Variety, Growth Location, Scouring Treatments, and Storage Conditions on Dye Uptake by Cotton Fabric

1018

Efficacy of Torque Adjustment to the Roller Draft Process

Volume 3: Textile Processing and Treatments Page 1022 1026 1031 1035

Abstract Title Elimination of Dyestuff using scCO2

Yao CHEN | Satoko OKUBAYASHI | Teruo HORI | Ryoma FUKUMOTO | Toya BANNO

Enhancing UV Protection of Green Bamboo Textiles during Bio-processing

Dr. Jayendra N Shah The M. S. University of Baroda

Evaluation on Dyeability and the Reproducibility of Natural Indigo Dyeing

Fabrication of Robust Superhydrophobic Fabrics through Roughening of Fibers by Chemical Etching and Hydrophobization via Thiol-Ene Click Chemistry

1039 1043 1047

1052

Glycerol 1,3-Diglycerolate Diacrylate - A Unique Surface Modifier for Keratin Fibres

Hemin-Fixed Non-Woven Fabrics for Removing a Trace of CO Gas Contained in H2 Gas

Teruo Hori | Koji Miyazaki University of Fukui | University of Fukui

Investigation on Structural and Physical Properties of N/CoPET and PET Nonwovens by Processing Steps

Manufacturing the Continuous Electro-spun Bundle and its Battery Application

JungHo, Lim | Tumen Ulzii Ganbat | You Huh Department of Textile Engineering,Graduate School, KyungHee University | Department of Textile Engineering, Graduate School, KyungHee University | KyungHee University

1057

Multi-Objective Self-Optimization of the Weaving Process

1061

Novel Oxidation Hair Dyeing by Using Bio-Catechol Materials

1065

Marco Saggiomo | Yves-Simon Gloy | Thomas Gries Institut fur Textiltechnik der RWTH Aachen University (ITA) | Institut fur Textiltechnik der RWTH Aachen University (ITA) | Institut fur Textiltechnik der RWTH Aachen University (ITA)

Production Technology Selection for the Development of Technical Fabrics

1069

Research of the Electroless Copper-Plating on Wool Fabrics through Supercritical CO2 Pretreatment

1073

Study on Water-Repellent Property of Multi-Layer Fabric by using Melt-Blown Nonwovens

1076

Superphobicity/philicity Fabrics with Switchable, Directional Transport Ability to Water and Oil Fluids

Hua Zhou | Hongxia Wang Deakin University | Deakin University

Volume 3: Textile Processing and Treatments Page 1080 1084

1088

Abstract Title Sustainable Fibre Production and Textile Wet Processing for Better Tomorrow

1092

Synthesis of Nanofibrillar Para-aramid Aerogel through Supercritical Drying

1097

Synthesis of Novel Cationic Gemini Surfactants having Benzene Dicarboxylic Ester Structures in the Spacer Group and the Solubilization of Non-Ionic Dyes in their Micellar Solutions

Yuichi Hirata | Misato Sakakibara | Kunihiro Hamada Shinshu University | Shiunshu University | Shinshu University

1100

Ultrasonic Dyeing of Cotton with Natural Dye Extracted from Marigold Flower

1106

Wool and Hair Dyeing by Using Saccharides and Amino Acids I. Dyeing Conditions and Dyeability

Page 383 of 1108

The 13th Asian Textile Conference Geelong, Australia, November 3 - 6, 2015

A comparison of the influence of superhydrophobic surfaces and the water content on the colours, near-infrared (NIR) and shortwave Infra-red (SWIR) properties of uniform Jie Ding + and Bin Lee Defence Science and Technology Group

Abstract. Uniforms often get wet from rain, snow or even sweat. This not only causes discomfort to the wearer, but also has an impact on the signature management performance of the uniforms. Here we have investigated the effect of fabric wetness on the camouflage colours, Near Infra-red (NIR), Shortwave Infra-red (SWIR) properties of the Disruptive Pattern Combat Uniform (DPCU) fabrics. It was found that the colours, NIR and SWIR properties of DPCU fabric can be significantly different under wet conditions. In order to maintain signature management performance under wet conditions, we developed superhydrophobic surfaces on DPCU fabric. Such coated fabrics possess water/ice/snow repellent and anti-contaminating properties. A simple wet-chemical process based on the nanocoating was used to generate transparent superhydrophobic surfaces on the DPCU fabric. The superhydrophobic property of the coated fabric and the effect of the superhydrophobic coating on the colours, NIR and SWIR have been studied. Stable superhydrophobic surfaces with water contact angles over 150 degrees and sliding angles below 10 degrees were obtained. The coating itself showed no effect on the camouflage colours, but slightly changed the NIR and SWIR absorption of the coated fabrics.

Keywords: DPCU, Signature management, Colour, NIR, SWIR reflectance, superhydrophobic coating

1. Introduction Moisture content plays a very important role in textile properties. The effects of moisture content changes on textile properties, such as, heat transfer, thermal comfort, physical, mechanical and electrical properties [1], colour [2,3] have been extensive investigated. Colour is one of the most fundamental aspects of uniform design and contributes greatly to the overall visual effect of the camouflage. It is reported that water content affects the colour of fabric significantly [2,3]. Uniforms are treated with NIR signature management technology to protect wearers from detection by NIR sensors. Usually, NIR absorption increases with increasing moisture content of materials [4]. In this work, we investigate the effect of moisture content changes on the camouflage colours, NIR and SWIR of DPCU fabrics. A water repellent nano-coating was applied on DPCU to prevent water absorption. In recent years, researchers have made significant progress in applying superhydrophobic surfaces on fabrics for potential applications in a variety of areas. A superhydrophobic surface can be produced by either roughening the surface, lowering the surface free energy, or both. We have previously reported a one-step nano-coating method to create a superhydrophobic surface on various of fabric substrates [5,6]. The durability of the coating has been extensively studied [7,8]. Here, a simple wet-chemical process based on the nanocoating [5] was used to generate transparent superhydrophobic surfaces on the DPCU fabric.

2. Experiments 2.1 Colours, Near Infra-Red (NIR) and Short Ware Infra-Red (SWIR) properties Baseline DPCU fabric samples were conditioned at standard laboratory conditions (20oCÂą2 oC and 65%Âą5% R.H.) for more than 24 hours. They were then measured for weight, colour coordinates, NIR and SWIR properties, and used as the baseline reference. Baseline samples were also evenly soaked with tap water to have different moisture water content (from low to high, Wet1, Wet2 and Wet3). BYK Spectro-guide +

Corresponding author. Tel.: + 61 3 96260863 E-mail address: Jie.Ding@dsto.defence.gov.au

Page 384 of 1108

D65/10o was used to measure the CIE L*a*b* color coordinates. ASD FieldSpec 4 Hi-Res spectroradiometer was used to measure the spectral reflectance between 350nm and 2500nm. DPCU fabric contains 5 colour elements (Khaki, Light orange brown, Dark brown, Dull leaf green and Dark grey green). Three measurements for each colour element were carried out at random locations the fabric sample. The results presented in the next section are the average on three measurements.

2.2 Coating and characterizations One-step chemical coating of fluoro-containing silica nanoparticles was used based on the previous coating method [5].The solution containing silica nanoparticles was prepared by co-hydrolysis and condensation of two silane precursors, tetraethyl orthosilicate (TEOS) and tridecafluorooctyl triethoxysilane (FAS), in NH 3 _H 2 O–ethanol solution. This solution was coated onto the DPCU fabric to form a transparent film by dipping method. A scanning electron microscope (SEM) Leo 1530 was used to observe the elemental mapping at the microstructural level by SEM with Energy Dispersive X-ray spectrometry (EDX).

3. Results 3.1 Effect of moisture content changes on the camouflage colours, NIR and SWIR of DPCU fabrics Table 1 shows the colour shift of 5 DPCU colour elements due to fabric surface wetness. ∆E CMC(2:1) is used to indicate the colour difference between baseline (dry) and different water contents. A ∆E CMC(2:1) greater than1 implies a noticeable perceptual difference in colour. Clearly, it can be observed that the value of ∆E CMC(2:1) between the baseline and the wet samples is influenced by the amount of water in the fabric sample. There is a distinctive difference both in terms of ∆E CMC2:1 value and visual perception with the increase of water content. Wet 1 was the lowest whilst Wet3 was the highest in water content. Table 1: Effect of water content on the DPCU colours Fabric colour L* a* b*

∆E

L* a* b*

L* a* b* CMC(2:1)

Wet1 39.55 -0.42 16.52 5.16

Light Orange Brown Wet 2 33.60 -0.13 16.42 7.77

Wet3 32.89 0.03 15.15 8.34

Dry 38.14 8.43 25.31

Dark Brown Dry 33.59 5.56 15.96

CMC(2:1)

Fabric colour

∆E

Dry 49.58 -1.28 20.07

CMC(2:1)

Fabric colour

∆E

Khaki

Wet1 26.75 4.70 13.21 4.39

Wet1 30.95 6.34 20.60 4.74

Wet2 27.1 6.36 15.65 7.99

Wet3 27.03 5.39 12.69 9.18

Dull Leaf Green Wet2 23.40 4.21 9.74 7.33

Wet3 23.84 3.75 8.08 7.89

Wet2 22.06 -1.45 6.28 6.6

Wet3 22.81 -1.17 5.13 6.84

Dry 40.47 -7.73 24.07

Wet1 33.14 -6.35 19.23 4.67

Wet2 28.98 -5.17 15.70 7.59

Wet3 28.46 -4.35 13.54 8.62

Dark Green Dry 30.85 -2.94 10.88

Wet1 25.26 -2.02 8.77 3.88

Figure 1a shows the spectral reflectance profiles of Khaki colour with different water content. It is apparent that the reflectance decreases with the increase of water content in the NIR and SWIR regions. Visually it appears darker in relevant spectral regions. It was also interesting to observe that the NIR reflectance (up to 1400nm) was similar between the water content Wet 1 and Wet 2 whilst the SWIR reflectance (between 1400nm and 2500nm) behaved similarly to the water content Wet 2 and Wet 3. The presence of water in the fabric shows deep drops in spectral reflectance at 1450nm and 1900nm respectively.

Page 385 of 1108

Figures 1b shows a comparison of the spectral reflectance profiles of DPCU colour elements with different water content. It is clear that the separation gaps between colour elements diminish with the increase of water content, in particular in SWIR regions.

Figure 1a: Spectral reflectance of Khaki with different water content

Figure 1b: Spectral reflectance of DPCU colours with different water content

3.2 Effect of superhydrophobic coating on the camouflage colours, NIR and SWIR of DPCU fabrics We have previously reported that a coating solution prepared by co-hydrolysis/co-condensation of TEOS and a fluorinated alkyl silane under alkaline condition can effectively generate superhydrophobic surfaces on a wide range of substrates, including textile fabrics [5]. Figure 2 shows the SEM image and corresponding element mapping of the coated DPCU. It is clear from these images that a uniform nano-coating layer was formed. Water contact angle measurements were used to evaluate the wetting properties of the prepared surfaces. Figure 3 clearly shows a nearly spherical water droplet can stay on the treated DPCU fabric surface for a long period of time. The contact angle (CA) measurements indicated that the surface has a water contact angle of ~1500 and sliding angles below ~100. In contrast, the uncoated DPCU fabric surface cannot support the formation of any spherical water droplets.

Figure 2: SEM and EDX mapping of elements C, O,F and Si for the coated DPCU fabric

Page 386 of 1108

Figure 3: Water droplets on the uncoated fabric and coated DPCU Table 2 shows the total color difference ∆E

based on L*, a*, b* in the visible region between the uncoated and coated DPCU. The results indicate that the colours remained virtually unchanged after the coating. Figure 4 shows the spectral reflectance of coated and uncoated DPCU fabric. No significant difference could be observed. CMC(2:1)

Table 2. Measurement of the total color difference ∆E CMC(2:1) based on CIE 1976 L*, a*, b* Fabric colour L* a* b* ∆E

CMC(2:1)

Khaki uncoated coated 48.79 48.91 -0.45 -0.44 20.54 21.31 0.464

Light Green uncoated coated 41.00 41.50 -8.88 -8.56 25.15 25.69 0.496

Light Brown uncoated coated 38.41 39.14 8.05 8.09 26.66 27.10 0.458

Dark Brown uncoated coated 34.17 34.51 6.63 6.65 17.42 18.03 0.489

Dark Green coated uncoated 31.76 31.18 -3.42 -3.14 11.28 10.83 0.559

Figure 4: Spectra reflectance of coated and uncoated DPCU colour elements

4. Conclusion Water content has a detrimental impact on the colours, NIR and SWIR properties of DPCU fabric. The superhydrphbic coating provides a simple and effective approach to minimize the effect of water content on the camouflage effectiveness.

5. References 1. B. P. Saville, “Physical testing of textiles”, Woodhead Publishing Ltd. ISBN 1 85573 367 6, (1999). 2. M. Senthikumar, N. Selvakumar, “Parameters involved in assessment of dry state colour of fabrics from their wet state colour –A review”, Ind. J. Fibre Text. Res. (2007) 32. 126-134. 3. M. Senthikumar, N. Selvakumar, “A study on the effect of bulk water content and drying temperature on the colour of dyed cotton fabrics”, Color. Tech, (2011) 127, 145-152. 4. T. Giordanengo, et al.. “Correction of moisture effects on near infrared calibration for the analysis of phenol content in eucalyptus wood extracts” Annals of Forest Science, Springer Verlag, (2008), 65. 5. H. Wang, J. Fang, T. Cheng, J. Ding, L. Qu, L. Dai, X. Wang, T. Lin, “One-step coating of fluorocontaining silica nanoparticles for universal generation of surface superhydrophobicity” Chem. Comm. (2008) 7, 877-879. 6. H. Wang, J. Ding, L. Dai, X. Wang, T. Lin, “Directional Water-Transfer through Fabrics Induced by Asymmetric Wettability”, J. Mater. Chem. (2010) 20, 7938–7940. 7 H. Wang, J. Ding, L. Dai, X. Wang, T. Lin, “Super Water Repellent Fabrics Produced by Silica Nanoparticle”, RJTA, (2010) 14, 30-37. 8. H. Wang, J. Ding, Y. Xue, X. Wang, T. Lin, “Superhydrophobic fabrics from hybrid silica sol-gel coatings: Structural effect of precursors on wettability and washing durability”, J. Mater. Res. (2010) 25, 1336~1343.

Page 387 of 1108

The 13th Asian Textile Conference Geelong, Australia, November 3 - 6, 2015

Adhesion of electrospun PVA/ES composites using spiral disk spinnerets Chuchu Zhao1 Yao Lu1 and Zhijuan Pan1,2 1

College of Textile and Clothing Engineering, Soochow University, Suzhou 215021, PR China 2 National Engineering Laboratory for Modern Silk (Suzhou), Suzhou 215123, PR China

Abstract. Electrospun polyvinyl alcohol (PVA) nanofibrous mats on ethylene-propylene side by side (ES) nonwowen were prepared using spiral disk spinnerets. Electrospun PVA/ES composite membranes were fabricated by laminating of nanofibrous web onto nonwoven substrate via hot-press method. Adhesion properties between PVA nanofibrous mats and ES nonwowen were studied. The results showed that adhesion properties were significantly affected by temperature, pressure and function time. The resultant composite membranes, When treated at 145â&#x201E;&#x192; with the pressure of 100 Pa for 10 minutes, manifested the preferable adhesion energy of 7.95 J/m2 and the maximum peeling strength of 20.17 cN with the best air permeability of 73.92 mm/s.

Keywords: polyvinylalcohol, needleless electrospinning using spiral disk spinnerets, hot-press laminate, adhesion

1. Introduction The conventional single needle electrospinning is not widely adopted in industrial scale due to its low productivity. The multi-needle would lead to interfering electric fields. Recently more and more attention has been put on various needleless eletrospinning using rotating cylinder/disk [1,2] spiral coil [3] and spiral disk [4] spinnerets, the production of which could enhance by 10~1000 times compared to single needle electrospinning. Although electrospun webs exhibited exciting characteristics, it has been reported that they have limited mechanical properties [5]. To compensate this drawback and use them in protective field, electrospun nanofibers could be laminated to supporting substrate. Hot-press laminate is environmentally friendly processing method. One major challenge of this approach is to ensure good adhesion between nanofibrous mat and substrate without sacrificing the advantages of nanofibers. Mohammadian, etal [6,7] investigated the effects of laminating temperature on the morphology, air transport properties and the adhesive force of nanofibrous web/ Poly-Propylene Spun-bond Nonwoven multilayer. Results showed that the adhesive force between layers increased, while the air permeability decreased with temperature rising. In this essay, needleless electrospinnning with spiral disk spinnerets were used to produce nanofibers productivity. PVA/ES composite membranes were prepared by laminating of nanofibrous web onto nonwoven substrate via hot-press method. Effects of temperature, pressure and laminated time on air permeability and

Corresponding author: Zhijuan Pan. Tel.: +86-13625273222. E-mail address:zhjpan@suda.edu.cn.

Page 388 of 1108

adhesion properties were investigated.

2. Materials and methods 2.1. Materials Two different kinds of PVA (average molecular weight (M w ) 95 000 g/mol, percent hydrolyzation 95%; M w 20 000 ~ 30 000 g/mol, percent hydrolyzation 88%) were obtained from J&K scientific Co.Ltd. PVA was dissolved in deionized water using magnetic stirrer of water bath at 90 ℃ for2h. least at Solution of PVA-h (10wt%, M w 95 000 g/mol) and solution of PVA-l (25wt%, M w 20 000 ~ 30 000 g/mol) were stored at room temperature before electrospinning. Ethylene-propylene side by side (ES) nonwoven (25g/m2, melt temperature 130℃) was used as the substrate.

2.2. Fabrication of PVA/ES composites In the preliminary experiment, the precursive solutions were mixed in ratio of 3/7 PVA-h/PVA-l to get uniform nanofibrous mat and it was called PVA in the following experiment. Nanofibers were deposited on the rotating collector wrapped by ES substrate of 100 cm length and 30 cm width. It generated constantly with rotate speed of spinnerets 10r/min, spinning distance 180 mm and applied voltage about70 KV. After removing ES substrate covered with electrospun PVA nanofibers (PVA/ES) from collector, hot-press laminate process performed using pieces of flat glass (one piece of glass equal to 100 Pa or N/m2 pressure) placed above the composites at temperatures above softening point of ES substrate for more than 10 minutes. Three factors and three levels (temperature 135, 140, 145℃; pressure 100, 300, 500 Pa; time 10, 20, 30 min ) orthogonality experiment were carried out to find out a hot-press parameter which has the least effect on nanofibrous mat during process.

2.3. Characters Adhesion properties between PVA nanofibrous mat and ES substrate were characterized by means of photographs and field emission scanning electron microscope (FE-SEM, Hitachi S-4800, Japan) images qualitatively. They were also characterized by peeling test using the Instron 3365 tensile testing machine at a holding distance of 30 mm with a crosshead speed of 100 mm/min and a constant peeling length (elongation) of 60 mm quantitatively. Five strip samples of 20mm width and at least 80mm length were randomly cut from each laminated PVA/ES composites for peeling test, which were maintained under standard conditions (20±2℃, 65±2% RH) for 24 h before testing. Maximum strength (cN) is the maximum peak of the strengthelongation curve. Adhesion energy (J·m-2) is the ratio of area under the curve and area of strip sample. Air permeability, which used YG461E-Ⅲ according to GB/T5453-1997 standard under air pressure of 100 Pa, was measured to evaluate the effect of breathability on nanofibrous mat during laminating process.

3. Results and discussion Table 1 is the header of three factors and three levels orthogonality experiment and table 2 displays the detailed scheme and results. The morphology of resultant composites was shown in Fig.1 and Fig.2. The nonadhesion (NA) result of PVA/ES composite membrane was invalid laminating process. The resultant composite membrane, in which nanofibers could be peeled off from ES nonwoven easily, is called partial adhesion (PA)(Fig.2 a). This could be attributed to the partially melted ES fibers when treated at lower temperature. Fig.2 (b) showed that nanofibrous mat could be peeled off from substrate, but a thin nanofibrous mat was leaved on it. The membrane above was called good adhesion (GA). The ES fibers were completely melted and began to penetrate into the nanofibrous mat, which can be observed by SEM image in Fig.1(b).The resultant PVA/ES composited membrane, in which nanofibers could not be peeled up from the substrate, was called excessive adhesion (EA) (Fig.2 c). The SEM image of EA in Fig.1 (c) showed that the melted ES nonwoven penetrated into the nanofibrous mat completely, which clogged the porous of nanofibers and

Page 389 of 1108

affected the air permeability. Table1:Header of three factors and three levels orthogonality experiment A

A×B

A×C

B×C

Table2: Project and results of three factors and three levels orthogonality experiment Temp

Pressure

Time

/℃

/Pa

/min

135

100

135

100

135

100

135

300

135

300

135

300

sample

result

135

500

135

500

135

500

140

100

140

100

140

100

140

300

140

300

sample

Temp

Pressure

time

/℃

/Pa

/min

140

300

140

500

140

500

140

500

145

100

145

100

145

100

145

300

145

300

145

300

145

500

145

500

145

500

result

Page 390 of 1108

(a)

(b)

melted ES fiber

Fig.1 SEM images of PVA/ES composites (a) partial adhesion (b) good adhesion (c) excessive adhesion

(a)

ES substrate

PVA nanofibrous mat

(c)

(b)

ES substrate PVA nanofibrous mat with little nanofibers

PVA nanofibrous mat ES substrate

Fig.2 Photographs of PVA/ES composites (a) partial adhesion (b) good adhesion (c) excessive adhesion

It is observed that the adhesion of PVA/ES composite membranes enhanced with the increase of laminating temperature and time, which is consistent with the study of Mohammadian, etal[6].While it decreased with the addition of pressure especially laminated for a short time, which contradicts the traditional theory, wherein pressure usually facilitates the permeation of melt into the layer which is in favor of adhesion. This phenomenon may be due to the relative small thermal conductivity of glass, which go against the PVA/ES composite membranes to reach the setting temperature when laminated under more than one block of glass for a short time. Five kinds of GA membranes were selected to analysis the adhesion between nanofibrous mat and substrate quantitatively. Table 3 displays the maximum adhesion strength and adhesion energy of the selected composite membranes. When the PVA/ES composite membranes were treated at 145℃ with the pressure of 300 Pa for 20 minutes, the resultant composites manifested the best adhesion of maximum adhesion strength 20.56 cN and adhesion energy 13.4 J·m-2 at the expense of air permeability of 52.54 mm/s, which is more than 10 times compared to untreated sample. The composite membranes, which is laminated at 140℃ with the pressure of 100 Pa for 10 minutes, manifested the best air permeability of 73.92 mm/s slightly less than untreated sample and the preferable adhesion properties. The optimized parameter was 145℃ under 100 Pa for just 10 minutes, which is also a high efficiency and energy saving laminating method. Table 3: Results of peeling test of stick PVA/ES composites Air permeability

sample

laminate

maximum strength/cN

adhesion energy/(J·m-2)

untreated

2.04±0.22

0.41±0.09

76.57

135℃100Pa30min

10.04±1.14

6.22±0.93

57.05

140℃300Pa20min

7.21±2.6

3.93±1.03

62.68

140℃300Pa30min

18.27±4.16

10.08±0.73

55.18

/(mm·s-1)

145℃100Pa10min

20.17±5.14

7.95±3.03

73.92

145℃300Pa20min

20.56±6.16

13.4±2.25

52.54

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4. Conclusion The PVA/ES composite membranes were fabricated by laminating of nanofibrous web onto nonwoven substrate via hot-press method. The composite membranes with good adhesion between nanofiber mat and substrate could be applied in protective fields. The adhesion of PVA/ES composite membranes enhanced with the increase of laminating temperature and time, while it decreased with the addition of pressure especially laminated for a short time. The preferable adhesion of resultant composites, which was laminated at 140â&#x201E;&#x192; with the pressure of 100 Pa for 10 minutes, manifested the maximum adhesion strength of 20.17cN and adhesion energy of 7.95 JÂˇm-2 with the best air permeability of 73.92 mm/s.

5. Reference [1]

Huang, Chen, et al. "Needleless Electrospinning of Polystyrene Fibers with an Oriented Surface Line Texture." Journal of Nanomaterials (2012).

[2]

Niu, Haitao, and Tong Lin. "Fiber Generators in Needleless Electrospinning." Journal of nanomaterials (2012).

[3]

Wang, Xin, et al. "Needleless Electrospinning of Uniform Nanofibers Using Spiral Coil Spinnerets." Journal of Nanomaterials (2012).

[4]

Zhao Shuguang. a device of electrospinning. Patent 104099679A. (2014).

[5]

Sumin, Lee, et al. "The Effects of Laundering on the Mechanical Properties of Mass-Produced Nanofiber Web for Use in Wear." Textile Research Journal 79.12 (2009): 1085-90.

[6]

Kanafchian, Mohammad, Masoomeh Valizadeh, and Akbar khodaparast Haghi. "A Study on the Effects of Laminating Temperature on the Polymeric Nanofiber Web." Korean Journal of Chemical Engineering 28.2 (2011): 445-48.

[7]

Mohammadian, M, and A K Haghi. "Some Aspects of Multilayer Chitosan Electrospun Nanofibers Web." Bulgarian Chemical Communications 45.3 (2013): 336-46.

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The 13th Asian Textile Conference Geelong, Australia, November 3 - 6, 2015

Application of the Synthesized Magnetic TiO 2 Nanofibers in Dye Removal from Effluent Navid Noor Mohammadi1, Mehdi Rahimdokht1, Elmira Pajootan1, Hajir Bahrami1, ∗ 1

Textile Engineering Department, Amirkabir University of Technology, 424 Hafez Ave, Tehran, Iran

Abstract. This study have focused on the synthesis of magnetic hydrogen-titanate nanofibers and their application in dye removal process. The hydrogen-titanate nanofibers were synthesized by peroxide method. In this respect, TiO 2 nanoparticles were well dispersed in a solution containing hydrogen peroxide and sodium hydroxide at pH: 13. Then the solution was moved to a Teflon reactor at 80°C for 24 h. The prepared H-TiO 2 was treated with a hydrochloric acid (HCl) solution and then calcinated at 500 °C for 6 h to obtain the anatase nanofibers. FESEM images confirmed the formation of TiO 2 fibrous nanostructure with an average diameter of 51 nm. The magnetization process was carried out via electrochemical method at pH: 11 for 2 h using iron electrodes as anode and cathode. The synthesized magnetic H-TiO 2 nanofibers were separated from the aqueous solution by applying magnetic field. The photocatalytic activity and adsorption potential of the synthesized magnetic H-TiO 2 nanofibers were studied for the degradation of C.I. Basic Blue 9 (methylene blue). The effect of important parameters including TiO 2 dosage, initial dye concentration and pH of the solution was investigated on both adsorption and photocatalytic performances. The great advantage of the synthesized material is the facile separation by magnetic field from the treated wastewater.

Keywords: Magnetic Hydrogen-Titanate Nanofibers; Peroxide Method; Photocatalytic Activity; Adsorption.

1. Introduction Water, food, and energy are the three major resources issues facing the world today. Wastewater is now being looked at more as a resource than as a waste, a resource for water. Textile dyeing industry demands large quantities of water, which results in large amounts of wastewater containing contaminants from different steps of textile industry processes. Textile wastewater has strong color, high value of chemical and biochemical oxygen demand (COD and BOD) [1]. Therefore, advanced treatment is necessary to upgrade the treated wastewater quality to be reusable. Advanced oxidation processes (AOPs) are considered as effective alternatives for converting the colored wastewater contaminants into less harmful or lower-chained compounds [2]. AOPs are based on the formation of highly reactive hydroxyl radical. Among the AOPs, the photocatalytic process is one of the most promising processes due to its advantages, which include the use of inexpensive chemicals and high oxidation performance. Although TiO 2 nanoparticles have appropriate properties as photocatalyst, they have several environmental problems such as negative effects on microbial biomass, soil bacterial community shifts, etc., and they mustn’t be released into the environment [3]. The uses of magnetic nanoparticles or relatively larger nano-structured TiO 2 have increased the separation possibility of nanoparticles. The nano-structured titanates have been attractive for scientist because of their remarkable photocatalytic activity and larger structure rather than TiO 2 nanoparticles [4]. In this study, hydrogen-titante nanofibers (H-Titanate) were synthesized by a peroxide method. Then they were magnetized by electrochemical method using iron as electrodes. The magnetic synthesized TiO 2 nanofibers were characterized by FESEM images and FTIR analysis. The adsorption and photocatalytic

∗

Author to whom all correspondence should be addressed: 424 Hafez Ave, Tehran, Iran, 15875-4413. Tel: +98 //2164542614, Fax: +98 2166400245, Email: hajirb@aut.ac.ir.

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degradation of methylene blue (MB) dye molecules were investigated and the effect of pH, MB concentration and H-Titanate dosage was investigated.

2. Materials and Methods 2.1.

Chemicals and Material

C.I. Basic Blue 9 (MB) as the synthetic model dye was purchased from Ciba Co. TiO 2 nanoparticles (Degussa P25, average particle size: 30 nm, purity> 97% with 80:20 anatase to rutile) were used as photocatalyst. All reagents were of analytical grade. Hydrogen peroxide (30%), hydrochloric acid (HCl) and sodium hydroxide (NaOH) were purchased from Loba Chimie.

2.2.

Synthesis of Magnetic H-Titanate

H-Titante nanofibers were synthesized employing the peroxide method. TiO 2 nano powder (2 g) was disperesed in a solution containing hydrogen peroxide and NaOH at pH: 13. Then the solution was poured in a Teflon reactor for 24 h at 80°C for hydrothermal treatment. HCl (1 N) was used to reduce the pH of solution to 2 and it was stirred for 60 min. The synthesized H-Titanate was washed with deionized water until pH: 7 was reached. The nanofibers were annealed at 550°C for 6h to obtain the anatase nanofibers. The H-Titanate was magnetized by electrochemical method applying the current of 0.3 (A) for 2h to the dispersed solution containing 0.02 g of HTNF at pH: 11. The synthesized magnetic material was washed with distilled water and ethanol for five times.

2.3.

Adsorption and Photocatalytic Processes

Both photo degradation and adsorption processes were carried out in the batch mode. The UV lamp (Philips, 9 W) in the quartz tube was placed at the center of reactor for UV irradiation. The dark adsorption of MB was performed for 30 min without UV irradiation. Samples were taken over the specific time intervals, the magnetic H-Titanate were separated by applying a magnetic field, and finally, the absorbance of samples were measured using UNICO 2100 Spectrophotometer at 665 nm.

3. Results and Discussions 3.1.

Characterization

The FESEM images in Fig.1 show the successful formation of larger nano-structured TiO 2 as microspheres with nanofibers (diameter of ~56 nm) on their surface. FTIR spectra of H-Titanate and magnetic H-Titanate are also presented in Fig. 2. The broad peak at 3417 cm-1 is corresponding to the O–H stretching bond due to the absorption of water. The peak at 1632 cm-1 can be assign to the bending vibration of water. The stretching vibration of Fe–O in Fe 3 O 4 lattice is appeared at 563 cm-1 confirming the successful magnetization of H-Titanate [5].

Fig. 1: FTIR spectra of H-Titanate and magnetic H-Titanate, and FESEM images of TiO 2 nanoparticles (a) and HTitanate.

3.2.

Effect of Parameters on Removal Process

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The effect of pH on adsorption and photocatalytic activity is shown in Fig. 2. The results indicate that by increasing the pH of solution, the efficiency increases. This can be related to the negatively charged surface of H-Titanate at high pH values, which attract the positively charged MB dye molecules [6]. It can also be seen that the removal efficiencies of photocatalytic process are significantly higher than the adsorption process due to the formation of active hydroxyl radicals which oxidize the MB dye molecules.

Fig. 2: Effect of pH on (a) photocatalytic and (b) adsorption efficiencies.

The effect of H-Titanate dosage on the performance of both adsorption and photocatalytic removal processes was investigated and the results are illustrated in Fig. 3. According to these results, increasing the H-Titanate dosage from 0.2 to 0.4 g/L has increased the removal efficiency considerably, but further increasing of dosage up to 0.6 g/L, did not affect the removal (%), probably due to the aggregation of H-Titanate and less available surface area for the adsorption or UV irradiation to produce hydroxyl radicals [6].

Fig. 3: Effect of H-Titanate dosage on (a) photocatalytic and (b) adsorption efficiencies.

The effect of initial dye concentration on the efficiency was studied at values of 5, 10 and 20 mg/L. The results are shown Fig. 4. Increasing the initial dye concentration decreases the removal percentages. This can be explained by the fact that at constant dosage of adsorbent or photocatalyst, the available adsorption sites or the amount of hydroxyl radicals produced in the solution are not sufficient for the removal of higher concentrations of MB molecules and consequently the removal efficiencies decrease [6].

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Fig. 4: Effect of initial dye concentration on (a) photocatalytic and (b) adsorption efficiencies.

4. Conclusion In this study, the large nano-structured H-Titanate nanofibers were synthesized from TiO 2 nanoparticles by peroxide method. Then the synthesized nanofibers were magnetized by a simple and facile electrochemical method. FESEM images and FTIR analysis were used for the characterization purposes and confirmation of the synthesis processes. Magnetic H-Titanate was employed as adsorbent and photocatalyst for the removal of MB dye molecules, and the effect of operating parameters such as initial dye concentration, pH and H-Titanate dosage was investigated on the removal efficiencies. The promising results for the removal of MB using HTitanate and facile separation by a magnetic field can propose the synthesized magnetic H-Titanate as a proper material for wastewater treatment.

5. References [1]

[2] [3] [4]

[5]

[6]

D.E. Kritikos, N.P. Xekoukoulotakis, E. Psillakis, D. Mantzavinos, Photocatalytic degradation of reactive black 5 in aqueous solutions: Effect of operating conditions and coupling with ultrasound irradiation, Water research 41(10) (2007) 2236-2246. S. Esplugas, J. Gimenez, S. Contreras, E. Pascual, M. Rodrı́guez, Comparison of different advanced oxidation processes for phenol degradation, Water research 36(4) (2002) 1034-1042. Y. Ge, J.P. Schimel, P.A. Holden, Evidence for negative effects of TiO 2 and ZnO nanoparticles on soil bacterial communities, Environmental science & technology 45(4) (2011) 1659-1664. I. El Saliby, L. Erdei, J.-H. Kim, H.K. Shon, Adsorption and photocatalytic degradation of Methylene Blue over hydrogen–titanate nanofibers produced by a peroxide method, Water research 47(12) (2013) 4115-4125. S.-J. Bao, C.M. Li, J.-F. Zang, X.-Q. Cui, Y. Qiao, J. Guo, New Nanostructured TiO 2 for Direct Electrochemistry and Glucose Sensor Applications, Advanced Functional Materials 18(4) (2008) 591599. C. Sahoo, A.K. Gupta, Optimization of photocatalytic degradation of methyl blue using silver ion doped titanium dioxide by combination of experimental design and response surface approach, Journal of Hazardous Materials 215–216(0) (2012) 302-310.

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The 13th Asian Textile Conference Geelong, Australia, November 3 - 6, 2015

Cellulose-Based Co-axial nanofiber membrane for separator of high performance lithium-ion battery from Waste Cigarette Filter Tips Fenglin Huang 1, Yunfei Xu1, Bin Peng1, Yangfen Su1, Feng Jiang2, You-Lo Hsieh2, Qufu Wei1 1

Key Laboratory of Eco-Textiles, Ministry of Education,Jiangnan University, Wuxi 214122, China 2

Fiber and Polymer Science, University of California, Davis, CA95616, USA

Abstract: An investigation into eco-friendly polymer, cellulose acetate (CA), extracted from waste cigarette filter tips is undertaken to explore its potential application for promising separator of highperformance lithium ion battery. Cellulose/PVDF-HFP nanofiber membrane is prepared by a co-axial electrospinning technique, in which the shell material is PVDF-HFP and the core is cellulose acetate, whereby the membrane is hydrolyzed by LiOH solution. It is demonstrated that cellulose-based nanofiber membrane shows good mechanical performance (33.2 MPa, tensile strength), high porosity (69.69%), excellent thermal stability (over 200 °C) and super electrolyte compatibility (355%, electrolyte uptake). It has a lower interfacial resistance (98.5 Ω) and higher ionic conductivity (6.16 mScm-1) than those of commercial separator (280.0 Ω and 0.88 mScm-1). In addition, the rate capability (138 mAh·g-1) and cycling performance (76.7% after 100 cycles) are also superior to those for the commercial separator. These excellent performances endow cellulose-based nanofiber membrane a promising separator for high-power and more secure lithium-ion battery.

Keywords: electrospinning, nanofiber, separator, cellulose

1. Introduction Lithium-ion batteries (LIBs) with high specific energy and long cycle lifetime are highly desirable because of their wide applications in smart electronic devices, portable electronics and electric vehicles [1-4]. Furthermore, the development of sustainable energy has attracted more and more attentions due to environmental pollution and exhausted fossil oil [5]. However, various safety issues of LIB, with internal short-circuits being one of the most critical threats, are difficult to avoid. A separator in LIB is considered a key component to prevent such failures, because it can isolate cathode and anode to prevent electrical short circuits and at the same time allow rapid transport of ionic charge carriers [6, 7]. Commercial separator materials used in LIBs are polyolefin, for instance polyethylene (PE) and polypropylene (PP), because of their superior properties such as electrochemical stability and considerable mechanical strength [8, 9]. However, due to the low polarity, these materials show poor liquid electrolyte retention and have difficulty in absorbing electrolytes with high

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dielectric constants, such as cyclic carbonates [10]. These disadvantages lead to lower ionic conductivity and higher electrolyte leakage. Semi-crystalline polyvinylidene fluoride (PVDF) and its copolymer, Poly (vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP) have received special attentions as promising host polymers for separators of LIBs due to higher polarity and ionic conductivity [11-13]. Nevertheless, recent researches show that PVDF and PVDF-HFP separators have some disadvantages, such as the inferior thermal stability due to their low softening or melting temperature [14, 15]. So it is difficult to perform the critical function of electronic isolation between cathode and anode in large-sized batteries at elevated temperature or under vigorous conditions. A few studies have pointed out that poor liquid electrolyte retention due to their intrinsically hydrophobic character would restrict applications in high performance lithium-ion batteries [16, 17]. Recently, with exhausted fossil oil and severe environmental pollution, renewable polymers are highly motivated as alternatives to polyolefin or PVDF-based materials. Natural cellulose, the most important skeletal component in plants, is an inexhaustible and renewable raw material with many fantastic properties. Cellulose-based membrane might be a promising LIB separator due to its super thermal stability and hydrophilic property. Cellulose based materials have found massive industrial applications, with most being disposed after usage, such as cigarette filter tips made from cellulose acetate, posing severe environmental threat. Therefore, recycling cigarette filter tips and applying as LIB separator not only alleviate environmental pressure but also produce more value-added product. Meanwhile, separators should consist numerous fine pores for lithium ion to pass through to perform charge窶電ischarge behavior, which could be controlled by tuning the fiber diameters of fiber-based membrane. In fact, porous nanofiber membrane with fine pores could be facily obtained via electrospinning [18, 19]. Our group has proved that coaxial electrospinning is a simple and low-cost approach to achieve a core/shell nanofiber and the structure of core/shell nanofiber can be manipulated by selectively adjusting solution properties and operating parameters [20]. Here, cellulose acetate was extracted and purified from waste cigarette filter tips, and was co-axially electrospun with PVDF-HFP to prepare a cellulose-based core/shell nanofiber membrane. The thermal stability and hydrophilicity were further improved by converting cellulose acetate to cellulose via LiOH hydrolysis. The environmentally friendly, cost-effective, good mechanical property, super thermal stability and excellent electrochemical properties of this cellulose-based co-axial nanofiber membrane would endow it as a very promising separator for high performance lithium-ion batteries.

2. Experimental Section 2.1 Materials Schematic illustration for the cellulose-based co-axial nanofiber separator preparation was shown in Scheme 1. Poly (vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP) (Mw 50000 g/mol) was purchased from Shanghai 3F New Materials Co., Ltd (Shanghai, China). Commercial separator (PP, 2300) was supplied by Celgard LLC. Dimethylacetamide (DMAc) and acetone were supplied by Sinopharm Chemical Reagent Co., Ltd (Shanghai, China) and used without further purification. Waste cigarette filter tips were collected from ashtrays in Jiangnan University. The wrapping paper and solid impurities on the tips were manually wiped off firstly. The tips were soaked in distilled water at room temperature for 12 h, followed by sonicating in ethanol for 5hwith an ultrasonic processor UP400S. The washing solution was decanted, and the tips were sonicated in ethanol for three more times. The cleaned tips were then dried in a hot-oven at 80ﾂｰC for 6 h prior to use. The electrolyte was composed of 1 M LiPF6 dissolved in ethylene carbonate, dimethyl carbonate, and ethylene methyl carbonate (1:1:1, v/v/v).

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Scheme 1: Illustration of the preparation process of cellulose-based co-axial nanofiber separators forlithium ion battery.

2.2 Co-axial electrospinning of cellulose/PVDF-HFP nanofiber membrane The two polymer solutions were independently fed through concentrically configured needles with outer and inner diameters of 1.3 and 0.3 mm, respectively. The shell solution was prepared by dissolving PVDF-HFP in a mixture of DMAc and acetone (3/7, w/w) to 10 wt%. The core solution was prepared by dissolving extracted cellulose acetate into DMAc and acetone (2/1, w/w) to 15 wt %. Coaxial electrospinning was carried out at 15 kV with 150 mm needle-to-collector distance with fixed flow rates of 0.9 mL/h for PVDF-HFP solution. To obtain different core/shell morphologies, different flow rate ratios (1:3, 2:3, 3:3) of the core and shell solutions were used. The as-prepared electrospun nanofibers were then dried in a vacuum oven at 60°C for 12 h. Hydrolysis of cellulose acetate/PVDF-HFP membrane was performed in 0.05 M LiOH aqueous solution at ambient temperature for 10 h to produce cellulose/PVDF0HFP membrane. Then the obtained membrane was rinsed in distilled water and dried under vacuum at 60 °C for 12 h.

2.3 Characterizations and electrochemical evaluation The surface morphology of cellulose acetate/PVDF-HFP nanofibers was observed by a field emission scanning electron microscope (FE-SEM, Hitachi) and transmission electron microscope (TEM; JEM-2100HR, JEOL). Fiber diameter was measured from over 50 individual fibers using PHOTOSHOP (Adobe, San Jose, CA).The specimens for the SEM micrographs of the cross-section of membranes were prepared by fracturing in liquid nitrogen. FT-IR measurement was carried out on a Nicolet IS10 spectrometer. The mechanical strength was examined using KD-0.05 universal testing at a stretching speed of 1.5 mms-1. Atomic force microscopy (AFM, CSPM 4400) was used to analyze the surface property of nanofiber. The membrane wettability to the liquid electrolyte was performed by carefully depositing a drop (5μL) of the electrolyte on the membrane and the contact angle between membrane and liquid electrolyte was measured (DSA100, KRUSS) in 30 S. The thermal stability was evaluated by analyzing the shape change of separators after heating at 200 °C for 1 h. Differential Scanning Calorimetry（DSC）of the membrane was carried out by TA Q200 from 30 to 300 °C at 10 °C /min heating rate under N 2 atmosphere. The separator porosity was determined by immersing the membrane in n-butanol for 1 h [21]. The porosity of the membrane was calculated using the equation: (1) P=(m b /ρ b )/(m b /ρ b +m s /ρ s )×100%

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Where P indicates the separator porosity, m b and m s are mass of n-butanol and the separator, ρ b and ρ s are the density of n-butanol and the separator, respectively. The electrolyte uptake (η) was calculated by measuring the weight of separator before and after soaking in liquid electrolyte for 2 h based on equation: η=[(W-W 0 )/W 0 ]*100% (2) Where W 0 and W indicate the separator weight before and after liquid electrolyte absorption, respectively. The excess solution (n-butanol or electrolyte) at the surface of the separator was absorbed with a filter paper before measuring the weight. The testing cells had a typical three-electrode construction using lithium foils as both counter electrode and reference electrode. The cells were assembled in an argon-filled glove box. Charge–discharge tests were carried out at a current density from 0.2 C-5.0 C in a range of 2.8–4.2V versus Li/ Li+. All the tests were performed at 20 °C. Commercial separator (Celgard 2300) was assembled and tested at the same condition. The interfacial resistances between two lithium plates were investigated by electrochemical impedance spectroscopy (EIS) measurement. The ionic conductivity of cellulose-based and reference separator were evaluated using EIS measurement in combination with an Electrochemical Workstation (CHENHUA, CHI710b). The electrochemical stability of the separators was measured by a linear sweep voltammograms (LSV) on a working electrode of stainless-steel and a counter electrode of lithium metal at the potential range between 2.5 and 6.0 V under the scan rate of 1.0 mV·s-1 at 20 °C.

3. Results and Discussion 3.1 Core-shell structure and mechanical property of cellulose/PVDF-HFP nanofiber membrane The core-shell cellulose acetate/PVDF-HFP nanofibers were fabricated by co-axially electrospining cellulose acetate and PVDF-HFP at respective 15 and 10 wt% concentrations, serving as core and shell solutions respectively. The surface morphologies of electrospun nanofibers with varying core and shell solution flow rate ratios (1:3, 2:3 and 3:3) were shown in Figs 1a-c. The diameter of nanofibers fabricated with 1:3 flow rate ratio ranges from 412 nm to 1920 nm, averaging at 692 ± 127 nm (Fig. 1a). The average diameters of nanofibers fabricated with 2:3 and 3:3 flow rate ratios are 710 ± 198 nm (Fig. 1b) and 689 ± 138 nm (Fig. 1c), respectively, showing very little variations among all three samples. The cross-sectional structures of the three membranes show clear core-shell structures with apparently different core and shell thicknesses (inset in Figs 1a-c), consistent with the biphasic fibers with a darker cellulose acetate core and lighter PVDF-HFP shell in the TEM images (Figs. 1e-g). As the core and shell solution flow rate ratio increases, it is clear that the shell becomes more and more thinner, indicative of increased cellulose acetate amount. The ratios of core to shell diameters increased from 0.61, 0.72 and 0.79 at 1:3, 2:3 and 3:3 flow rate ratios, respectively, which are very close to their respective theoretical values of 0.58, 0.71 and 0.78 calculated from core and shell flow rate ratios. Both SEM and TEM images indicate that core-shell structures could be obtained by co-axially electrospinning and the fiber diameters are independent of the core and shell solution flow rates ratio, whereas the core/shell diameter ratios are. FTIR spectra of cellulose acetate (CA, washed cigarette filter tips), CA/PVDF-HFP membrane, and cellulose/PVDF-HFP membrane were used to monitor the chemical structural changes during alkaline hydrolysis (Fig. 1g). The CA/PVDF-HFP spectra showed a small shoulder at 1200 cm-1 and a prominent peak at 1425 cm−1, which are characteristic C-F and CH wagging peaks from PVDF-HFP, respectively. The presence of cellulose acetate in CA/PVDF-HFP was confirmed by the sharp peak at 1730 cm-1 from the carbonyl (C=O) stretching of cellulose acetate, as well as the shoulder at 1374 cm-1 and a major peak at 1238 cm−1, which could be ascribed to the C-H bond in -O(C=O)-CH 3 group and –CO- stretching of acetyl group, respectively. After alkaline hydrolysis, the carbonyl stretching peak (1730 cm-1) completely disappeared, along with the disappearance of the peaks at 1374 and 1238 cm-1, indicating successful conversion of cellulose acetate to cellulose. This conversion was further confirmed by the increased O-H stretching vibration at 3300 cm-1 to 3500 cm-1, indicating hydrolyzing acetate groups to hydroxyls.

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Fig.1: SEM (a-c) and TEM (d-f) images of co-axial CA/PVDF-HFP nanofibers with varying core/shell

flow rate ratios: 1:3 (a, d), 2:3 (b, e) , and 3:3 (c, d); Insets in a-c are SEM images of cross section of nanofiber; FTIR spectra of nanofiber membrane (g).

The stress-stain curves of cellulose/PVDF-HFP membrane with varying flow rate ratios are depicted in Fig.2a, along with electrospun PVDF membrane and commercial separator Celgard 2300 for comparison. The maximum stress of the electrospun cellulose/PVDF-HFP separator at 3:3 flow rate ratio is up to 34.1 MPa, which is close to the 35.9 MPa for commercial separator, but showing distinct difference fort he stress-strain behaviours. The Celgard 2300 curve displays a typical characteristic stress-stain curve, showing a sharp stress drop after reaching the maximum stress point. In contrast, the cellulose/PVDF-HFP curves declines steadily after the maximum stress point with a plateau on the stress-stain curve, indicating no abrupt breakage under stress. The maximum stress increased from 27 to 32.4 and 34.1 MPa with increasing flow rate ratios from 1:3 to 2:3 and 3:3, indicating the nanofibers membrane become much stronger with increased cellulose content, suggesting cellulose could significantly improve the mechanical properties oft he membrane. Besides, all maximum stress for the co-axial cellulose/PVDF-HFP separators are much higher than pure PVDF-HFP separator (20 MPa) with similar appearance, diameter and thickness, further comfirming the reinforcing contribution of cellulose. It has been indicated that bonding point

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Fig.2: Stress-strain curves of separators (a), inset is SEM image of co-axial cellulose/PVDF-HFP nanofibers with 3:3 flow rate ratio. AFM topography (b) and phase (c) images of co-axial cellulose /PVDF-HFP nanofibers with 3:3 flow rate ratio.

between fibers could enhance the mechanical property of fiber membrane. In cellulose/PVDFHFP composite, cellulose is easier to form bonding point during electrospinning due to the abundant polar groups, therefore providing reinforcement for the composite nanofibers membrane (inset in Figure 2a). The AFM topography and phase images of the cellulose/PVDFHFP nanofibers electrospun at 3:3 flow rate ratios were shown in Figure 2b&c. The topography images showed smooth surface with occasional convex shapes on the surface of nanofiber (circled and arrowed in Figure 2b&c), which showed more obvious contrast in the phase image, possibly suggesting biphasic surface morphologies due to the different properties of cellulose and PVDF-HFP. Consequently, it could be deduced from AFM images that a compound with a different composition (PVDF-HFP and cellulose) is formed on the surface of nanofiber, which could be due to the diffusion of cellulose into PVDF-HFP phase considering the thinner shell structure at higher flow rate ratio. Considering ist better mechanical property, co-axial cellulose/PVDF-HFP nanofiber membrane electropsun with flow ratio of 3:3 is chosen for thermal and electrochemical investigation.

3.2 Thermal stability and flame retardant property of co-axial nanofiber membrane Thermal stability is an important property for separator during application in LIBs. The photographs of the separators before and after thermal treatment in oven at 200 째C for 1 h were shown in Figure 3a&b. PVDF-HFP nanofiber membrane shows an apparent shrinkage after heating, whereas pure cellulose nanofiber membrane shows no shrinkage but a browning effect. However, the co-axial cellulose/PVDF-HFP nanofibers membrane exhibits negligible

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dimensional change and color variation, manifesting its excellent thermal dimensional stability, much superior to commercial separator (Celgard 2300) with significant shrinkage (85%) upon heating to 200 °C. The flame retarding ability of the separators is another important factor related to the safety of the LIBs. The combustion tests of PVDF/HFP membrane, Celgard 2300, cellulose and cellulose/PVDF-HFP are shown in Fig.3c. Both Celgard 2300 and cellulose nanofiber membrane separators immediately catch on fire in less than 2 s when being put on fire. Although PVDF-HFP nanofiber membrane shows good flame retarding ability without catching fire, severe shrinkage of the membrane could be observed when contacting with fire, consistent with its response to heat as shown previously. In contrast to the burning and severe shrinkage for all other separators, cellulose/PVDF-HFP separator presents best flame retarding ability and dimensional stability, which could be attributed to the core-shell structure, with the shell PVDFHFP acting as flame retardant and the core cellulose providing dimensional stability. Thermal shrinkage of commercial separator at high temperature could cause internal shot-circuits, and more seriously, lead to fire outbreaks and even explosions. The superior dimensional stability of cellulose-based co-axial nanofiber membrane should be beneficial to enhance safety characteristics of lithium-ion battery. DSC measurement is employed to further investigate the thermal stability of separators (Figure 3d). Celgard 2300 separator starts to melt at 150 °C and shows an endothermic peak at 161.8 °C, corresponding to its melting point. Though the heating curve of PVDF-HFP shows a low melting peak at 146.4 °C, the curve of cellulose/PVDF-HFP composite does not show any obvious endothermic peak below 300 °C, suggesting that cellulose/PVDF-HFP co-axial nanofiber membrane possess better thermal stability than Celgard separator, possible due to the core cellulose materials, which has high melting point of over 300 ℃. It can be suggested from the results that at temperatures above 161.8 °C, LIBs assembled with cellulose/PVDF-HFP is safer than that with Celgard 2300 separators.

Fig.3: Photographs of the separators before and after thermal treatment in oven at 200 °C for 1h (a, b), combustion photos (c) and DSC curves (d) of various separators.

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3.3 Electrochemical and battery performance It is well known that ionic conductivity and interfacial compatibility are the two key factors that affect the electrochemical performance of separators [22-24]. The Nyquist plots of the liquid electrolyte-soaked separators and a lithium metal anode are characterized by electrochemical impedance spectroscopy and shown in Fig. 4. It is well known that the semicircle at high frequency zone represents the charge-transfer resistance accompanied with migration of lithium ion between the electrode and electrolyte interface[25]. The straight slopping line corresponds to the diffusion of lithium ion in the active material of electrode. It can be seen from Fig 4 that interfacial resistance are 98.5, 280, and 235 Ω for cellulose/PVDF-HFP, Celgard 2300 and PVDF-HFP nanofiber membrane separators, respectively. Obviously, the interfacial property between anode and separator can be significantly improved in the case of cellulose/PVDF-HFP separator, indicating better interfacial compatibility with electrode material. The lower chargetransfer resistance is related to the higher electrolyte uptake and better interface compatibility which are beneficial to improve cycle performance and rate capability. Table 1 shows the contact angle, porosity and electrolyte uptake of Celgard 2300, cellulose/PVDF-HFP, cellulose nanofiber and PVDF-HFP nanfiber membrane. The contact angle between separator and electrolyte is known to correlate to electrolyte uptaking. The contact angles of Celgard 2300 separator and PVDF-HFP membrane are 69.29° and 55.38°, leading to low electrolyte uptake of 140 and 242%, respectively. Both cellulose nanofiber and cellulose/PVDF nanofiber membranes immediately absorb electrolyte upon contacting due to the hydrophilic nature of cellulose bearing numerous hydroxyls, making it impossible to measure the contact angle, suggesting the better interfacial compatibility between the separator and electrolyte. Besides interfacial compatibility, separator porosity is another critical factor for electrolyte uptake. [25] The porosity of cellulose/PVDF-HFP nanofiber membrane (66.36%) is fairly higher than that of Celgard 2300 separator (47.88%) and a little lower than that of cellulose nonwoven (69.69%). Both higher interfacial compatibility and porosity of cellulose-based co-axial nanofiber membrane lead to the higher electrolyte uptake of 355%, ca. 154% and 47% higher than those of of Celgard 2300 separator (140%) and PVDF-HFP nanofiber membrane (242%). Fig.4 Nyquist plots of Li/electrolyte-soaked separator/Li cells at 20 °C, insets are magnified Nyquist

plot and ionic conductivity of separators. Table 1 Porosity, electrolyte uptake and contact angle of separators Sample Porosity（%） Electrolyte uptake（%） Contact angle（°） Celgard 2300 47.88 140 69.29 Cellulose 69.69 397 / PVDF-HFP 62.33 242 55.38 Cellulose/PVDF-HFP 66.36 355 /

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The electrochemical stabilities of the cellulose/PVDF-HFP separator and other reference separators are evaluated by observing linear sweep voltammograms and its corresponding voltammogram (Fig. 5). It can be seen from the voltammogram that the decomposition voltage of the cellulose nanofiber membrane is around 3.8 V versus Li/Li+, indicating what? However, no appreciable decomposition of PVDF-HFP and cellulose/PVDF-HFP separators takes place below 5.0 V vs. Li/Li+, which is almost comparable to that of the Celgard 2300 separator. This result demonstrates the good electrochemical stability of the cellulose/PVDF-HFP separator, revealing that it could be as a promising alternative to the commercial separator for high-voltage lithium-ion batteries.

Fig.5: Linear sweep voltammogram curve of Celgard 2300, cellulose, PVDF-HFP and cellulose/PVDF at a scan rate of 1.0 mV s−1.

To evaluate the performance of cellulose/PVDF-HFP separator, electrochemical properties are investigated by charge and discharge testing and cycling performance characterization (Fig. 6). The discharge capacity of batteries assembled with cellulose/PVDF-HFP is around 138 mAh·g-1 at 0.2 C, approximately 20% higher than the 114.8 mAh·g-1 for Celgard 2000 separators, and is superior to those in references (130 mAh·g-1 [25], 120 mAh·g-1 [26],] and 130 mAh·g-1 [27], etc.). The improved electrochemical performance of cellulose/PVDF-HFP separator could be due to the increased ionic conductivity and transference number of Li+ ions. As another important parameter for rating LIB, the cycling stability of the LiCoO 2 cells using celgard 2300 separator and cellulose/PVDF-HFP separator at 0.2 C/0.2 C were tested for up to 100 cycles (Fig. 6a). The discharge capacity for the cell with Celgard 2300 maintains over 102.6 mAh·g-1 after 40 cycles, then starts to fade at a rapid rate to 30.1 mAh·g-1, with a retention ratio of only 27.28%. However, the cell with cellulose/PVDF separator shows better cycling performance with minimal discharge capacity fading until 80 cycles, after which more rapid fading could be observed but still keeps a high discharge capacity of 105.8 mAh·g-1 and retention ratio of 75.94% after 100 cycles, much superior than most commercial separators that only have discharge retention ratios of 61% after 100 cycles.29, 30 The corresponding chargedischarge curves for some selected cycle numbers are shown in Figs. 6b-c. It is clear that severe discharge capacity fading could be observed for Celgard 2300 cell after 50 cycles, whereas the discharge capacity fading was minimal for cellulose/PVDF-HFP cells. With increased current densities of 0.2, 0.5, 1, 2 and 5 C, the discharge capacities decrease from 138 to 121, 104.1, 96, 62 and 32.9 mAh·g-1 for cellulose/PVDF-HFP cells, respectively; however, these discharge capacities are all much higher than the respective 114.8, 94.5, 72.8, 83, 32 and 12.9 mAh·g-1 for Celgard 2300 cells. The superior discharge capacity and cycling performance could be ascribed to higher ionic conductivity and better interfacial compatibility of electrolyte-soaked cellulose/PVDF nanofiber membrane. Considering the excellent discharge capacity and cycling performance, as well as aforementioned better thermal dimensional stability, the electrospun co-axial cellulose/PVDF-HFP is very promising material for high performance and safe LIB separator.

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Fig.6: Cycle performance of the LiCoO2 cells using Celgard 2300 and cellulose/PVDF-HFP separators (a), first charge and discharge curves (inset in a ); 1st, 25th and 50th charge and discharge curves for Celgard2300 (b) and cellulose/PVDF-HFP separators (c); rate performance of cells using Celgard2300 and cellulose/PVDF-HFP.

4. Conclusions An environmentally friendly polymer material, cellulose acetate was successfully extracted from waste cigarette filter tips and skillfully electrospun with PVDF-HFP into co-axial core/shell composite nanofiber membrane. Following alkaline hydrolysis to convert cellulose acetate to cellulose, the membrane demonstrated good mechanical property, superior flame retardancy, excellent thermal stability and good electrolyte wettability. The ionic conductivity of the cellulose/PVDF separator was much higher than that of the commercial separator (Celgard 2300) saturated with liquid electrolyte. Moreover, cells assembled with cellulosebased co-axial nanofiber separator exhibited high storage, better cycling and enhanced rate performances compared to the battery using commercial separator. All these results suggested that this composite nanofiber membrane from wasted cigarette filter tips would be a promising separator for high performance and safe lithium ion battery.

Acknowledgements Authors are grateful to the following financial supporters: The National Natural Science Foundation of China (51203064), Industry-Academia-Research Joint Innovation Fund of Jiangsu Province (BY2014) and National High-tech R&D Program of China (863 Program 2012AA030313).

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References [1] J.H. Kim, J.H. Kim, E.S. Choi, H.K. Yu, J.H. Kim, Q.L. Wu, S.J. Chun, S.Y. Lee, S.Y. Lee, J. Power Sources 242 (2013) 533. [2] X.Zuo, X.M. Liu, F. Cai, H. Yang, X.D. Shen, G. Liu, J. Mater. Chem. 22 (2012) 22265. [3] Q. Xu, Q.S. Kong, Z.H. Liu, J.J. Zhang, X.J. Wang, R.Z. Liu, L.P Yue, G.L. Cui, RSC Adv. 4 (2014) 7845. [4] J.B. Goodenough, Y.Kim, J.Power Sources 196 (2011) 6688. [5] M.G. Adsul, A. J. Varma, D. V. Gokhale, Green Chem. 9 (2007)58. [6] H.P. Zhang, S.S Liang, B.P Sun, X.J. Yang, X. Wu, T. Yang, J. Mater. Chem. A 1 (2013) 14476. [7] X.Y. Zhang, S.A. Cheng, X. Huang, B. E. Logan, Energy Environ. Sci. 3 (2010)659. [8] S.S Zhang, J. Power Sources 164 (2007) 351. [9] P. Arora, Z.M. Zhang, Chem. Rev. 104 (2004) 4419. [10] X.S. Huang, J. Solid State Electrochem. 15 (2011) 649. [11] M. Deka, A. Kumar, J. Power Sources 196 (2011) 1358. [12] F. L. Huang, Q. Q. Wang, Q. F. Wei, W. D. Gao, H. Y. Shou, S. D. Jiang. Express Polym. Lett. 9 (2010) 551. [13] B. S. Lalia, Y. A. Samad, R. Hashaikeh, J. Appl. Polym. Sci. 126 (2012) E441. [14] M.Y. Li, I. Katsouras, C. Piliego, G. Glasser, I. Lieberwirth, P. W. M. Blom and D. M. de Leeuw, J. Mater. Chem. C, 1 (2013) 7695. [15] W.P. Wei, H.M. Zhang, X.F. Li, H.Z. Zhang, Y. Li, I. Vankelecom, Phys. Chem. Chem. Phys. 15 (2013) 1766. [16] C. M. Costa, M. M. Silva, S. Lanceros-MĂŠndez, RSC Adv. 3 (2013) 11404. [17] A.M. Stephan, Eur. Polym. J. 42 (2006)21. [18] D. W. Li, L. Luo, Z.Y. Pang, L. Ding, Q.Q. Wang, H.Z. Ke, F.L. Huang and Q. F. Wei, ACS Appl. Mater. Interfaces, 6 (2014) 5144. [19] F.L. Huang, Y.F. Xu, S.Q. Liao, D.W. Yang, Y.L. Hsieh, Q.F. Wei, Materials 6 (2013) 969. [20] X. Wang, T.T. He, D.W. Li, F.L. Huang, Q.F. Wei, X.L. Wang, Int. J. Mater. Prod. Tec. 46 (2013) 95. [21] X. Xia, X. Wang, H.M. Zhou, X. Liu, L.G. Xue, X.W. Zhang, Electrochim. Acta 121 (2014) 345. [22] M. Kumari, B.Gupta, S. Kram, Radiat. Phys. Chem. 81 (2012) 1729. [23] M.K. Wang, F. Zhao, S.J. Dong, J. Phys. Chem. B 108 (2004) 1365. [24] J. Malathi, M. Kumaravadivel, G.M. Brahmanandhan, M. Hema, R. Baskaran, S. Selvasekarapandian, J. Non-Cryst. Solids 356 (2010) 2277. [25] S.Y. Xiao, F.X. Wang, Y.Q. Yang, Z. Chang and Y.P. Wu, RSC Adv. 4 (2014) 76. [26] Y.S Zhu, F.X Wang, L.L Liu, S.Y. Xiao, Z. Chang, Y.P Wu, Energy Environ. Sci. 6 (2013) 618. [27] J.J. Zhang, Z.H. Liu, Q.S. Kong, C.J. Zhang, S. Pang, L.P. Yue, X.J. Wang, J.H. Yao, G. Cui, ACS Appl. Mater. Interfaces 5 (2013) 128. [28] J.J. Zhang, L.P. Yue, Q.S. Kong, Z.H. Liu, X.H. Zhou, C.J. Zhang, Q. Xu, B. Zhang, G.L. Ding, B.S. Qin, Y.L. Duan, Q.F. Wang, J.H. Yao, G.L. Cui, L.Q. Chen, Sci. Rep. 4 (2014) 3935.

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The 13th Asian Textile Conference Geelong, Australia, November 3 - 6, 2015

Structural properties of polypropylene nanofibres fabricated by meltblowing Rajkishore Nayak1, 2, Rajiv Padhye1, Lyndon Arnold1, Ilias Louis Kyratzis2 and Yen Bach Truong2 1

School of Fashion and Textiles, RMIT University, Brunswick, Victoria 3056, Australia 2 CSIRO Materials Science and Engineering, Clayton, Victoria 3168, Australia

Abstract. In this paper the structural properties of polypropylene (PP) nanofibres fabricated by meltblowing process by injecting fluids such as air and water at different flow rates in an extruder during meltblowing have been discussed. The nanofibres were characterised by differential scanning calorimetry (DSC), thermo gravimetric analysis (TGA), X-ray diffraction (XRD) and nuclear magnetic resonance (NMR). DSC results indicated that the PP polymer and the as-spun fibres (fabricated without any fluid) exhibited a higher melting point than the nanofibres. The lowering of the melting endotherm indicated a change of the crystalline phase which may be due to the thermal degradation caused by the higher temperature during meltblowing. This was verified by thermo gravimetric analysis (TGA) which showed that the PP polymer and as-spun fibres have higher thermal stability (indicated by the weight loss starting at higher temperature) compared to the nanofibres. The XRD results indicated that the nanofibres possess relatively lower and broader peaks compared to the higher and sharper peaks of PP polymer and as-spun fibres. This indicated that the nanofibres have a very low degree of crystallinity, which could be due to the rapid cooling after exiting the die allowing limited time for crystal formation. NMR results showed that the nanofibres fabricated with the fluids do not change in molecular structure. Keywords: nanofibres, meltblowing, fluids, structural properties

1. Introduction Over the last 20 years, most of the research on meltblowing has mainly focused on the factors influencing web properties, improving web quality and modeling of the process. Limited work has been done on the fabrication and characterization of nanofibres by meltblowing [1]. Hence, an attempt was made in this paper to fabricate and characterize the nanofibres by meltblowing process. The approach of the research was to utilise PP of high melt flow index (MFI) in combination with fluids to provide a platform for the fabrication of nanofibres. Two different fluids (air and water) were introduced at the vent port of a meltblowing equipment. The structural properties of the nanofibres have been analysed in this study. The nanofibres were characterised by differential scanning calorimetry (DSC), thermo gravimetric analysis (TGA), X-ray diffraction (XRD) and nuclear magnetic resonance (NMR).

2. Materials and methods PP of high MFI (100 and 300) was used for the meltblowing experiments. These high MFI polymers were synthesised by the chain scission of the base polymer (Moplen 241R with a MFI of 30 from Lyondellbasell) using radical initiator in an extruder as described in the reference [2]. The polymer MFI and the molecular weights are listed in Table 1. Table 1: List of polymers used for meltblowing experiments Polymer MFI Mw (g/mol) 100 100875 300 77590 Meltblowing experiments were performed on the horizontal JSW (Model: Tex 30) extruder with 40/1 (l/d) ratio. It consisted of polymer feeder, melt pump, a single-hole die of 0.5 mm orifice diameter and 4 vent ports [3]. The temperature of these heating zones was regulated independently. Deionised water was supplied at 5 and 10 ml/min (W5 and W10) whereas compressed air was supplied at 10 g/min at the vent port. The extruder was stabilised for approximately 1 hour prior to collecting the samples. Initially, the experiments were performed with all the polymers without any fluid supply. The as-spun fibres were directly collected over a

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conveyor belt without any further attenuation by drafting rollers. The samples fabricated with the use of fluids were collected onto aluminium foils supported on a glass screen. The thermal behaviour of the PP polymers, as-spun fibres and nanofibres were analysed by DSC (Mettler Toledo-DSC-821e). About 5–10 mg of the sample was heated from room temperature to 250 °C at a heating rate of 10 °C/min followed by cooling to the room temperature at the same rate. The samples were subjected to the second heating and cooling cycle similar to the first. Thermal degradation of the polymers and meltblown fibres were investigated by thermo gravimetric analysis (TGA). The samples were heated from room temperature to 800 °C at a heating rate of 10 °C/min with nitrogen purge. The crystalline properties of the polymers and meltblown fibres were analysed by X-ray diffraction (XRD) using a Bruker D8 Advance Diffractometer with CuKa radiation (40 kV, 40 mA). The samples were scanned over the 2θ range of 5° to 30° with a step size of 0.02° and a count time of 0.4 seconds per step. Analyses were performed on the collected XRD data using the Bruker XRD search match program “EVA™”. The crystalline phases were identified using the ICDD-PDF4+ 2010 powder diffraction database.

3. Results and discussion 3.1 DSC and TGA results Fig.1 shows the SEM images of the meltblown fibres fabricated using different fluids. The type of polymer and fluid not only affected the web morphology, but also affected the fibre diameter. The SEM images indicate that the fibres are not uniform, irrespective of the polymer MFI and fluid types. The coefficient of variation was very high, indicating high variation of the fibre diameter.

(a) (b) (c) (d) (e) (f) Fig. 1: SEM micrographs of meltblown PP fibres showing the effect of MFI and fluid type on fibre morphology and diameter: (a, c & e) 100 MFI & W10, W5 & air; (b, d & f) 300 MFI & W10, W5 & air. The detailed description of nanofibres can be found from the reference [3, 4]. This paper discusses the structural properties of the nanofibres fabricated. As the results received for 100 and 300 MFI were almost similar in nature, only the results for 300 MFI PP will be discussed here. The DSC thermograms of PP polymer and meltblown PP fibres (for 300 MFI) are shown in Fig. 2. The DSC thermogram in Fig. 2 (a) indicate that the PP polymer exhibited a melting point of 164.5 °C, the as-spun fibres exhibited a melting point of 165 °C whereas the fibres produced with various fluids exhibited the melting points in the range of 151–155.5 °C depending on the type of fluid. The melting points shifted towards lower values while the fluids were used compared to the PP polymer and the as-spun fibres. This change in the melting endotherm indicates a change of the crystalline phase. This may be due to the thermal degradation caused by the higher temperature during the meltblowing process. The cold crystallisation peak was observed at 113.5 °C for the PP polymer, 112 °C for the as-spun fibres and 107.5 °C for all the fibre samples fabricated with different fluids (Fig. 2(b)). It can be observed from Fig. 2 (a) and Fig. 2 (c) that single melting peaks were obtained in the first heating cycle whereas double melting peaks were obtained for the second. This can be attributed to the re-crystallisation or re-organisation by heating during the DSC experiments. The higher melting endotherm in the double peak correspond to the fusion of lamellar crystals formed during the process of primary crystallisation, whereas the lower melting endotherm correspond to the fusion of crystals grown mainly in the inter-fibrillar regions during the secondary crystallisation process [5]. The temperatures corresponding to the double peaks are 155 and 161.5 °C for both the PP polymer and as-spun fibres; and 140.5 and 151 °C for all the fibres fabricated with different fluids. The melting points in the second heating cycle were also shifted towards lower values while the fluids were used compared to the PP polymer and the as-spun fibres. The TGA curves (Fig. 3) reflect the degree of thermal degradation during meltblowing. The TGA curves show that the PP polymer has higher thermal stability (indicated by the weight loss starting at higher temperature) compared to the fibres fabricated with the supply of various fluids. Therefore, the decrease in the melting point (in DSC experiments) after meltblowing with the fluids is because of the decrease of the chain entanglements as a result of decrease in the molecular weight. The fibres produced with air supply degraded the most as the weight loss started at the lowest temperature.

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Fig. 2: DSC curves of meltblown PP fibres of 300 MFI: (a) 1st heating cycle (b) 1st cooling cycle and (c) 2nd heating cycle. Polymer As-spun fibre

Mass loss (%)

100 80 60 40

Air W5 W10

20 0 300

400

500

600

Temperature (°C)

Fig. 3: TGA thermogram of PP polymer and meltblown fibres from 300 MFI.

3.2 XRD results The diffraction patterns of PP polymer and meltblown PP fibres (for 300 MFI) are shown in Fig. 4. It can be observed that all the meltblown fibres produced with the fluid supply contain relatively lower and broader peaks compared to the higher and sharp peaks of PP polymer and as-spun fibres. This indicates that the fibre samples fabricated with fluids contain very low degree of crystallinity compared to the polymer and as-spun fibres. This can be attributed to the rapid cooling of the fibres after exit from the die prevent the crystalisation. The low degree of crystallinity is in accordance with the previous result for the meltblown web of PP [6]. It can be observed that the fibre samples fabricated with air supply are more amorphous than water supply. It can also be observed that all the meltblown fibres contain a mixture of smectic and monoclinic αform crystals. The Bragg reflection peaks at 14°, 17°, 18.5°, 21° and 22° correspond to the monoclinic crystals of PP (α-form) with the indexed plane of (110), (040), (130), (111) and (041) [7] and a space group of P2 1 /c. In the case of PP polymers and as-spun fibres, the α-form crystals are predominant, whereas the fibre samples produced by fluids are more of smectic. No β-form and γ-form was found in any of the meltblown samples. Thus the double peaks in DSC are related to the process involving α-crystals only. During the second heating cycle of DSC, the double endotherm has been attributed to the transitions between different modifications of α-crystal form (i.e. α 1 to α 2 ).

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Fig. 4: XRD diffractograms of PP polymer and meltblown fibres from 300 MFI.

3.3 NMR results The process of meltblowing involves the application of high temperature to the polymer. The application of high temperature can lead to chemical changes in the polymer by oxidation with atmospheric oxygen. This can lead to chemical changes in the structure of PP by the formation of carboxylic acids, aldehydes or esters [8]. NMR spectra of the polymers and fibres fabricated with the fluids were recorded to determine the chemical structure. Fig. 4 shows the 13C NMR spectra of 300 MFI polymer, as-spun fibre (fibres fabricated without fluids) and fibres fabricated using the fluids in meltblowing. The fibres fabricated from 100 MFI also showed identical NMR spectra.

Fig. 4: 13C NMR spectra of the fibres fabricated by meltblowing from 300 MFI PP. The chemical shifts a, b, c in the figure correspond to the –CH 3 , –CH and –CH 2 groups of PP, respectively. The comparison of NMR spectra indicated that the spectra of the polymer, as-spun fibre and fibres fabricated with different fluids are similar. Therefore, the injection of fluids did not change the chemical structure of the fibres at high temperature. The chemical shifts for PP polymers and fibres are listed in Table 2. Table 2: Chemical shifts of PP polymers and fibres Code a b c

Chemical shift (ppm) 23.6 28.4 43.2

Group –CH 3 –CH –CH 2

4. Conclusions Nanofibres of PP have been successfully fabricated by meltblowing process with the injection of two different fluids: air and water. DSC results indicated that the PP polymer and the as-spun fibres exhibited a higher melting point than the nanofibres, which indicated a change of the crystalline phase due to thermal degradation caused by the higher temperature during meltblowing. This was verified by TGA, which showed that the PP polymer and as-spun fibres have higher thermal stability, which is indicated by the weight loss starting at higher temperature compared to the nanofibres. Single melting peaks were obtained in the first heating cycle of DSC whereas double melting peaks were obtained for the second due to the re-crystallisation by heating during the experiments. The XRD results indicated that the nanofibres possess relatively lower and broader peaks compared to the higher and sharper peaks of PP polymer and as-spun fibres. This indicated that the nanofibres have a very low degree of crystallinity, which could be due to the rapid cooling after exiting the die allowing limited time for crystal formation. NMR results showed that the nanofibres fabricated with the fluids do not change in molecular structure.

5. References 1. 2. 3. 4.

Nayak, R., et al., Recent advances in nanofibre fabrication techniques. Textile Research Journal, 2012. 82(2): p. 129-147. Machado, A., et al., Evolution of peroxide induced thermomechanical degradation of polypropylene along the extruder. Journal of Applied Polymer Science, 2004. 91(4): p. 2711-2720. Nayak, R., Fabrication and characterisation of polypropylene nanofibres by melt electrospinning and meltblowing, in School of Fashion and Textiles. 2012, RMIT University: Melbourne. Nayak, R., et al., Fabrication and characterisation of polypropylene nanofibres by meltblowing process using different fluids. Journal of Materials Science, 2013. 48(1): p. 273-281.

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5. 6. 7. 8.

Paukkeri, R. and A. Lehtinen, Thermal behaviour of polypropylene fractions: 2. The multiple melting peaks. Polymer, 1993. 34(19): p. 4083-4088. Lee, Y. and L.C. Wadsworth, Effects of melt-blowing process conditions on morphological and mechanical properties of polypropylene webs. Polymer, 1992. 33(6): p. 1200-1209. Broda, J. and A. Wochowicz, Influence of pigments on supermolecular structure of polypropylene fibres. European Polymer Journal, 2000. 36(6): p. 1283-1297. Gugumus, F., Re-examination of the thermal oxidation reactions of polymers3. Various reactions in polyethylene and polypropylene. Polymer Degradation and Stability, 2002. 77(1): p. 147-155.

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The 13th Asian Textile Conference Geelong, Australia, November 3 - 6, 2015

CNTs and Graphene Oxide Coated Electrode for Anionic Dye Removal by Heterogeneous Electro-Fenton Process Zahra Eshaghzade, Abdollah Gholami Akerdi, Elmira Pajootan, S. Hajir Bahrami â&#x2C6;&#x2014; Textile Engineering Department, Amirkabir University of Technology, 424 Hafez Ave, Tehran, Iran

Abstract. In this study, carbon nanotubes (CNTs) and graphene oxide (GO) nano-sheets were uniformly electrodeposited on the surface of carbon electrodes at the voltage of 25 V for 30 min assisted by a cationic surfactant (CTAB, Cetyl Trimethyl Ammonium Bromide). FESEM images confirmed the formation of a uniform layer on the surface of the carbon electrode. On the other hand, magnetic Fe 3 O 4 nanoparticles were synthetized electrochemically in aquatic ambiance under moderate conditions. The characterization of the generated nanoparticles was performed by vibrating sample magnetometer (VSM) and Fourier transform infrared (FTIR) spectra. In order to exhibit the environmental application of the fabricated electrode, they were used as cathodes in a heterogeneous electro-Fenton process using the synthesized Fe 3 O 4 as the catalyst to degrade C.I. Acid Red 14 (AR14). The degradation of AR14 by has been carried out at different experimental conditions such as pH and initial dye concentration. From the result it is found that at pH= 3, dye concentration of 50 mg/L, electrical current of 0.15 (A), the best electrochemical degradation of AR14 could be obtained. Keywords: Carbon nanotubes (CNTs), Graphene Oxide (GO), Magnetic Fe3O4, Electro-Fenton.

1. Introduction Nowadays, contamination of water resources is one of the most dangerous global menaces. Water resources can be polluted by discharging of colored wastewaters from different industries such as textile, paper, food, printing, cosmetics, pharmaceutical, etc [1]. There are different conventional methods for the treatment of contaminated wastewaters including physical, chemical and biological methods. Electrochemical oxidation technique is among the advanced oxidation processes (AOPs), which can degrade various organic pollutants especially dyes. This promising technology is based on the production of free radicals (such as đ?&#x2018;&#x201A;đ?&#x2018;&#x201A;đ?&#x2018;&#x201A;đ?&#x2018;&#x201A;â&#x20AC;˘ and đ?&#x2018;&#x201A;đ?&#x2018;&#x201A;2â&#x20AC;˘â&#x2C6;&#x2019; ) by coupling of electron transfer reaction when electrodes are dipped in electrolyte solution at a definite potential difference. Free hydroxyl radicals are very powerful oxidizing agents with an oxidation potential of 2.80 (V) [2]. electro-Fenton process is based on the safe and facile in situ electro generation of H 2 O 2 from dissolved oxygen and consequently the formation of destructive active oxygen species like OH â&#x20AC;˘ in sufficient quantities in presence of iron ions. Despite of conventional Fenton process the heterogeneous Fenton applies various iron source catalysts to overcome the main drawbacks of using soluble iron such as narrow operating range of pH, iron hydroxide sludge generation and further treatment. In addition, the separation and recycling of this catalyst like iron oxides are more facile [3, 4]. In this research, electrodeposition method was applied to coat carbon electrodes (CE) with a uniform carbon material. The modified electrodes by graphene oxide (GO) and CNTs, the two new exclusive carbon based nanoparticles, were used as cathode in electro-Fenton decolorization of an azo dye (C.I. Acid red 14 and the electrochemically synthesized magnetic iron oxide nanoparticles (Fe 3 O 4 ) were added as heterogeneous Fenton catalyst. Dye removal efficiency of electro-Fenton process was investigated at different values of pH and initial dye concentration using modified cathodes by CNTs and GO.

â&#x2C6;&#x2014;

Author to whom all correspondence should be addressed: 424 Hafez Ave, Tehran, Iran, 15875-4413. Tel: +98 //2164542614, Fax: +98 2166400245, Email: hajirb@aut.ac.ir.

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2. Materials and methods 2.1.

Chemicals and materials

2.2.

Synthesis of GO

CNTs (degree of purity≥ 95%) were supplied from Neutrino Co., Iran. All chemicals were purchased from Merck co.

GO was synthesized by the modified Hummer’s method. In brief, graphite powder (3 g) was dispersed into a mixture of concentrated H 2 SO 4 (360 mL), H 3 PO 4 (40 mL) and KMnO 4 (18 g). Then, H 2 O 2 (30%, 3mL) was added to the mixture at room temperature and filtered by a Nylon film. The solid material was washed with 200 mL HCL 30% and filtered, then it was washed with ethanol. Finally, the product was washed twice with deionized water.

2.3.

Synthesis of Fe 3 O 4 magnetic nanoparticles

The environmentally friendly electrochemical route was applied to synthesize magnetite nanoparticles under mild conditions at room temperature and aquatic ambiance. The modified carbon electrodes by CNT’s layer were applied as cathode and the utilized anode was iron electrode and the electro generation of Fe 3 O 4 was performed by applying the voltage of 25 V.

3. Result and discussion 3.1. Characterization Field emission scanning electron microscopy (FESEM) images were used to analyse the surface morphology of CE (a), GO-CE (b), CNTs-CE(c) samples which are shown in Fig. 1. FESEM images confirm that thin films of GO and CNTs are deposited on the surface of CE. (a)

(b)

(c)

Fig.1. FESEM images of CE (a) before, (b) after modification by CNTs, and (c) after modification by GO.

Characterization study on the synthetized magnetite nanoparticles was carried out using vibrating sample magnetometer (VSM) to obtain the ferromagnetic properties of nanoparticles and FESEM analyses in order to confirm the generation of spherical nanoparticles of Fe 3 O 4 with a mean particle size of about 45 nm (Fig. 2).

Fig.2. FESEM image, and VSM analysis of the synthesized Fe 3 O 4 magnetic nanoparticles.

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3.2. Effect of operating parameters According to Fig. 3, the removal efficiency increased after the deposition of CNTs and GO. This is probably due to the formation of higher amounts of H 2 O 2 at the surface of cathode, which results in the formation of more hydroxyl radicals and consequently higher dye removal (%).

Fig.3. Effect of CE modification on AR 14 removal

3.2.1. Effect of initial Dye concentration Dye solutions with different AR14 initial concentrations (C o ) (25-100 ppm) were used to evaluate the electro-Fenton process. The treatment efficiency decreased from 99% to 81% with an increase of C o from 25 to 100 ppm. This is due to the fact that at high C o , redox species produced via electrode dissolution are insufficient to interact with a large number of dye molecules (Fig.4 (b)). Also this trend can be observed about decolorization by CNTs covered cathode, but by comparing initial concentration diagrams (Fig.4.(a)), no impressive difference was noticed. This result could indicate the proper dye removal of AR14 dye molecules at determined different dye concentrations.

Fig.4. Effect of initial dye concentration on removal (%) at different times: (a) CNTs-CE, (b) GO-CE.

3.2.2. Effect of pH Electro-Fenton experiments were performed at pH range of 3 to 11 at optimum current (0.1 (A) for GO and 0.18 (A) for CNTs). Decolorization efficiencies were found to be dependent upon initial pH. By using magnetite catalyst as Fenton reagent, wide pH range seems to be efficient for dye removal. As it is shown in Fig. 5, both acidic and basic pH demonstrates remarkable dye removal efficiencies. It can be related to no Fe(OH) 3 sludge generation in basic pH due to the structure of Fe 3 O 4 nanoparticles with stabilized Fe3+ ions [5-7].

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Fig.5. Effect of pH on removal (%) for different times, (a) CNTs-CE, (b) GO-CE

4. Conclusion In the present study, the electro-Fenton discoloration of AR14 dye molecules was investigated by CNTs and GO fabricated carbon electrode. For this purpose, GO and CNTs were deposited on the surface of carbon plates by the simple electrodeposition method. The modified plates were successfully used to decolorize AR14 dye molecules with the advantage of remarkable removal at broad range of pH and higher discoloration compared to the unmodified carbon plates. Approximately 30% and 29% higher degradation (%) were obtained for GOCE and CNTs-CE rather than CE (at pH 3 and 50 mg/L AR14), because of the higher electro generation of hydrogen peroxide at the surface of the modified cathodes.

5. References [1]. Sharma, P. and M.R. Das, Removal of a cationic dye from aqueous solution using graphene oxide nanosheets: investigation of adsorption parameters. Journal of Chemical & Engineering Data, 2012. 58(1): p. 151-158. [2]. Radha, K., V. Sridevi, and K. Kalaivani, Electrochemical oxidation for the treatment of textile industry wastewater. Bioresource technology, 2009. 100(2): p. 987-990. [3]. Babuponnusami, A. and K. Muthukumar, A review on Fenton and improvements to the Fenton process for wastewater treatment. Journal of Environmental Chemical Engineering, 2014. 2(1): p. 557-572. [4]. Huang, R., et al., Heterogeneous sono-Fenton catalytic degradation of bisphenol A by Fe3O4 magnetic nanoparticles under neutral condition. Chemical Engineering Journal, 2012. 197(0): p. 242-249. [5]. Pajootan, E., M. Arami, and M. Rahimdokht, Discoloration of wastewater in a continuous electro-Fenton process using modified graphite electrode with multi-walled carbon nanotubes/surfactant. Separation and Purification Technology, 2014. 130: p. 34-44. [6]. Raghu, S., et al., Evaluation of electrochemical oxidation techniques for degradation of dye effluentsâ&#x20AC;&#x201D;A comparative approach. Journal of hazardous materials, 2009. 171(1): p. 748-754. [7]. He, Z., et al., Electro-Fenton Process Catalyzed by Fe3O4 Magnetic Nanoparticles for Degradation of C.I. Reactive Blue 19 in Aqueous Solution: Operating Conditions, Influence, and Mechanism. Industrial & Engineering Chemistry Research, 2014. 53(9): p. 3435-3447.

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The 13th Asian Textile Conference Geelong, Australia, November 3 - 6, 2015

Continuous manufacturing process of carbon nanotube-grafted carbon fibers Geunsung Lee 1, Ji Ho Youk 2, Jinyong Lee 1 and Woong-Ryeol Yu 1 + 1

Department of Materials Science and Engineering and Research Institute of Advanced Materials (RIAM), Seoul National University, Gwanak-ro, Gwanak-gu, Seoul, 151-744, Korea 2 Department of Applied Organic Materials Engineering College of Engineering Inha University In-cheon 402-751, Korea 3 Agency for Defense Development Daejeon 305-600 Korea

Abstract. Hybridization of carbon nanotubes (CNTs) with carbon fibers (CFs) through their direct growth has been suggested as an effective means to upgrade the material properties of CFs because grafted CNTs improve the shear stiffness and the surface roughness of CFs. Such a hybridization method is free from CNT dispersion problem. For the mass production of CNT-grafted CFs, a continuous process was developed using a bimetallic catalyst and chemical vapor deposition process that did not degrade microstructures and mechanical properties of CFs. The lowering of growth temperature of CNTs was key to manufacture continuously CNT-grafted CFs without any degradation of their mechanical properties. Water vapor-assisted CVD was adopted to accelerate CVD process and T-zone furnace was designed to minimize shade effect. Finally, unidirectional composites were prepared using CNT-grafted CFs manufactured in this study and expoxy matrix to investigate the effect of the CNT and CF hybridization on their mechanical properties.

Keywords: carbon nanotube, carbon fibers, continuous grafting process, chemical vapor deposition.

1. Introduction Due to their excellent mechanical, electrical and thermal properties, carbon fibers (CFs) have been used in nearly all-engineering fields, promoting vast research to improve their mechanical properties. However, the improvements of the mechanical properties of CFs are now saturated; thereby researchers pursue a new direction for improving the mechanical properties of the CF reinforced composites. On the other hand, carbon nanotubes (CNTs) have been emerged to a new generation reinforcement material and stimulated a considerable amount of research. However, the application of CNTs as reinforcement has brought many problems related with aggregation of CNTs and their macroscale continuity. Thus, concept of hybridization between CNTs and CFs has been developed to solve problems on CNTs and CFs and there have been numerous researches for hybridization. Among them, hierarchical structure, so called CNT-grafted CFs, already showed its advantages on mechanical and electrical performances on several researches.[1-3] Their increased surface area comes from nano-micro hierarchical structure contributed to the interfacial shear strength [3, 4] and electrochemical performance [5] and radially grown CNTs on the surface of CFs toughened interlaminar properties of composites [6]. In this study, a continuous manufacturing process was developed that can manufacture CNT-grafted CFs using floating-catalyst chemical vapour deposition (FCVD) without mechanical degradation. Bimetallic catalysts [7] and water-vapour [8] were used to low the manufacturing temperature and accelerate the process speed. Decreased process time and lowered CVD temperature prevented inter-diffusion between catalyst particles and CFs, maintaining the mechanical properties of CFs. For continuous process, we established a compartment with slit at the jacket of the furnace to supply CF bundle from outside of the furnace. CFs were allowed to pass the slit but gas from side of the compartment prevented infiltration of outer atmosphere. Finally, unidirectional composites were prepared using CNT-grafted CFs manufactured in this study and expoxy matrix to investigate the effect of the CNT and CF hybridization on their mechanical properties. +

Corresponding author. Tel.: + 82-2-880 9096. E-mail address: woongryu@snu.ac.kr

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2. Experimental 2.1.

Continuous process using T-shaped two zone furnace

(a) (b) Fig 1: (a) Schemes of continuous process for CNT-grafted CFs; (b) T-shaped two zone furnace for process We used T-shaped two-zone furnace to maximize the contact area between CFs and chemical vapour and to minimize the shade effect. To prevent inter-diffusion between CF and catalyst particles which causes degradation of mechanical properties of CFs, we lowered CVD temperature from 750℃ to 500℃ by introducing Ni-Fe bi-metallic catalysts. Nickelocene (Ni(η 5 -C 5 H 5 ) 2 , Sigma-Aldrich) and ferrocene (Fe(η 5 –C 5 H 5 ) 2 , Sigma-Aldrich) were used as catalysts precursors and toluene was used as carbon source.

The first zone of the furnace was preheated to 200ºC to vaporize/sublimate the catalyst precursor– toluene solution. Then, CNTs were grown on the CF substrate in the second zone at 500ºC. In addition, we applied water-vapor assisted CVD to boost manufacturing speed of CNT-grafted CFs. We injected water to the first zone and vaporized water vapour was carried to the second zone which CNT growth occurred. We developed a compartment with a slit on the jacket of the furnace to supply bundle of CFs from outside of furnace without disturbance in the CVD atmosphere. Spread CFs (Toray T700SC, 12K) were continuously supplied from reel and collected by lab-made take up reel. 2.2.

Characterization

The morphology and microstructure of the CNTs, CF substrate, and conducting wires were observed using field-emission scanning electron microscopy (FE-SEM) (JEOL JSM 7600F), high-resolution transmission electron microscopy (HR-TEM) (JEOL JEM 3000F), and Raman spectroscopy (HORIBA, T64000). To verify the mechanical properties of CNT-grafted CFs, single fiber tensile test was conducted using lab-made ultimate tensile machine. The surface potential of the furnace was measured using an electrostatic field meter (SIMCO FMX-003) during the FCVD growth process.

3. Results & discussion 3.1.

The effects of bimetallic catalysts on the mechanical properties of CNT-grafted CFs

Figure 2 shows the morphology of the CNT-grafted CFs using monometallic (Figure 2 (a)) and bimetallic catalysts (Figure 2 (b)). CNTs were uniformly grown on CF surface in both cases but their tensile strength (Figure 3) shows big difference. CNT-grafted CFs using the Fe-only catalysts at the high temperature CVD show severe degradation while CNT-grafted CFs using bimetallic catalyst maintained their own mechanical

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properties. The cross sections of CNT-grafted CFs were observed using TEM to investigate the mechanism behind such damages on tensile strength of CNT-grafted CFs prepared by the Fe-only catalysts FCVD process. In Figure 4 (a) catalyst particles are seen on the CF surface and most of CNTs seem to grow in the tip growth mode. In Figure 4 (b), however, catalyst particles are observed in the CFs, implying that catalyst particles were diffused into the CFs at high temperature. These nanoparticles seem to act as defects bringing about the mechanical degradation of CNT-grafted CFs prepared by the Fe-only catalysts FCVD.

(a) (b) Figure 2: Morphology of CNT-grafted CFs prepared from different FCVD process (a) Fe-only catalysts CVD at 750째C; (b) bimetallic catalysts CVD at 500째C

Figure 3: Tensile strength of CNT-grafted CFs

(a) (b) Figure 4: The internal structure of CNT-grafted CFs prepared from different FCVD process. (a) FCVD using the Fe-only catalysts at 750째C (b) FCVD using bimetallic catalyst at 500째C

3.2.

Manufacturing of CNT-grafted CFs using water-vapor assisted CVD

Although the problems on mechanical properties of CNT-grafted CF had been solved, there were several obstacles for successful continuous process. The growth of CNTs was accelerated using water vapour in the

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CVD atmosphere. By adopting water vapour in the CVD atmosphere, we could accelerate manufacturing speed of CNT-grafted CFs by 4 times (6mm/min to 24mm/min) without mechanical degradation of CFs.

4. Summary In this study, we demonstrated a continuous process for manufacturing the CNT-grafted CF. Bimetallic catalysts and water-vapour assisted CVD were applied to prevent the mechanical degradation of the CNTgrafted-CFs and to accelerate the CNT growth. Using CNT-grafted CFs, unidirectional composites were manufactured and their mechanical properties are under investigation.

5. References [1] Kim KJ, Kim J, Yu W-R, Youk JH, Lee J. Improved tensile strength of carbon fibers undergoing catalytic growth of carbon nanotubes on their surface. Carbon. 2013;54(0):258-67. [2] Lee G, Kim KJ, Yu W-R, Youk JH. The effect of the surface roughness of carbon fibres on CNT growth by floating-catalyst chemical vapour deposition. Int J Nanotechnology. 2013;10(8):800-10. [3] Sager R, Klein P, Lagoudas D, Zhang Q, Liu J, Dai L, et al. Effect of carbon nanotubes on the interfacial shear strength of T650 carbon fiber in an epoxy matrix. Compos Sci Technol. 2009;69(7):898-904. [4] Kim KJ, Yu W-R, Youk JH, Lee J. Factors governing the growth mode of carbon nanotubes on carbon-based substrates. Phys Chem Chem Phys. 2012;14(40):14041-8. [5] Le VT, Kim H, Ghosh A, Kim J, Chang J, Vu QA, et al. Coaxial Fiber Supercapacitor Using All-Carbon Material Electrodes. ACS Nano. 2013;7(7):5940-7. [6] Kepple K, Sanborn G, Lacasse P, Gruenberg K, Ready W. Improved fracture toughness of carbon fiber composite functionalized with multi walled carbon nanotubes. Carbon. 2008;46(15):2026-33. [7] Chiang WH, Sankaran RM. Synergistic effects in bimetallic nanoparticles for low temperature carbon nanotube growth. Adv Mater. 2008;20(24):4857-61. [8] Yun Y, Shanov V, Tu Y, Subramaniam S, Schulz MJ. Growth mechanism of long aligned multiwall carbon nanotube arrays by water-assisted chemical vapor deposition. The journal of physical chemistry B. 2006;110(47):23920-5.

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The 13th Asian Textile Conference Geelong, Australia, November 3 - 6, 2015

Drug loaded porous silica nanoparticles composites nanofiber and evaluation of characteristics Ma Ke1, Suzuki2, Mayakrishnan Gopiraman3, 1

Ick Soo Kim

Abstract. First, we report drug loaded-porous silica nanoparticles immobilized polycaprolactone nanofiber composites for drug release properties. The PSNs with average particles diameter of about 200nm, specific surface area of about 300 m2/g and small mean pore size of about 3 nm were successfully derived from rice husk. A high loading of about 20% of drug was achieved with the resultant PSNs. The PCL-based electrospun nanofibers loading with different weight percentages of drug/PSNs were successfully prepared and investigated for their releasing properties. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) results of PSNs/PCL composite mats showed homogeneous incorporation of Allenton-loaded PSNs into the electrospun PCL fibers. After complete characterization, the release profiles of resultant PSNs/PCL composites were investigated. The usefulness of the PSNs/PCL composites was acknowledged from its highly sustained release behavior. Moreover, the release rate could be tuned by the different weight percentages of drug-loaded PSNs in the electrospun PCL nanofibers.

Keywords: husk, silica porous particle, composite nanofiber, drug release.

1. Introduction Electrospun polymer nanofibers have attracted much attention in various fields due to its simple preparation, easy handling, large specific surface area, and high porosity with an interconnected pore structure. Although there are several methods have been developed to produce polymer nanofibers and their composites, electrospinning is one of the simple and prime routes for the fabrication of polymer nanofibers. The electrospun nanofibers are often employed in various fields such as catalysis, chemical and biological sensors, nanofiber reinforcement and drug delivery. Particularly, as carriers, the electrospun nanofibers showed good potential for drug delivery due to its unique structure and properties. Moreover, the drug release behavior can be easily controlled by the morphology and composition of the fibers [1,2], and the drug-loaded electrospun mat could also be easily fabricated into various shapes (e.g. membrane, tube) for different applications, such as wound dressing and nerve conduits. Porous silica nanoparticles (PSNs) have attracted much attention as a sustained release material owing to its high specific surface area, large pore volume biocompatibility, and chemical protection for the payloads. The PSNs have often used as an efficient material in heterogeneous catalysts, adsorbents, electronic materials, and drug delivery systems. The surface of PSNs is highly composed of silanol groups of having the properties of weak acids. Thanks to the exits of silanol group, it can be easily modified with various silylating agents. In this paper a method of make nanofiber mat coating drug filled porous silica nanoparticle to sustain drug release will be introduced. This study composited the porous silica particles and nanofiber through electrospinning method in order to drug releaseďź&#x17D; The product of this study is assumed as the use of sustained-release material which can be used for wound dressing, as the filled drug (Allantoin) which be widely used into Pharmaceuticals and cosmetics has an effect of cell proliferation and anti-inflammatory. In addition, polycaprolactone(PCL) one kind of polymer which be used in this study as nanofiber mat is praised as its outstanding biocompatibility and biodegradability which can be used in medical materials and tissue engineering, such as sutures.

2. Materials and methods

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2.1.

Materials

PCL(Mn:70,000-90,000 ， Sigma-Aldrich ， USA), Dichloromethane(DCM ， Wako ， Japan) and Dimethylformamide (DMF，Wako，Japan).Husks of rice from Aichi Prefecture of Japan, the husks are be considered as a kind of waste. Allantoin (Wako，Japan) which be used as the drug filled into the porous silica particles. Hydrochloric acid(Wako，Japan)

2.3.

Preparation of Silicon

The procedure employed for the synthesis of Silicon was as follows. First, Cleaned the husks with tap water to remove the other things which mixed into husks. Then，rice husk ash was prepared by heating the rice

husk in amuffle furnace from 100 to 550°C. 2.2.

Electrospinning process

The electrospinning apparatus (Har-100*12, Matsusada Co., Tokyo, Japan) and grounded rotary drum collector were used in this experiment. Solution was add into 5 mL plastic syringe and capillary tip (inner diameter; 0.6 mm). Plug a copper wire which can connected to the anode in the solution. Rotary drum collector which covered with aluminum foil was used to collect nanofiber. In this case, the distance between the chip and collector was 15 cm, applied voltage: was the 10 kV.

For survey the spinning conditions, mixed solvent of DCM and DMF. = 8 ： 2(w/w). PCL concentration was changed with of 8 wt%. 5, 15, 25wt% drug filled silica particles were added into PCL solution.

3. Results and discussion 3.1 Elemental analysis In order to affirm the product which was processed with hydrochloric acid and burned was porous silica, we used XPS and EDS to do Elemental analysis. We can see the result from Fig.1ad Fig.2. Through the result of XPS, we can see in all of the samples the peak of O 1s，Si 2p，and Si 2swhich are in 530 eV， 100 eV and 145 eV, respectively. Due to fig.1.b the component content of rusk, we can see the peaks of C 1s and K 2s, in 280 eV and 400 eV, respectively. But in fig.1.a. the peaks of C 1s and K 2s did’t exist. This can prove that Potassium and organic component was removed from husk.

Fig. 1. XPS spectra of porous silica(a) and rice husk(b).

We also got similarly result through EDS, in Fig.2 we can see the carbon decreased, and an obviously increased in silicon and oxygen.

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Fig. 1. EDS spectra of porous silica (A) and rice husk(B).

3.2. Sustained-release test It is considered the sustained-release rate of drug filled porous silica particles obvious slower compared to that without drug filled porous silica particles PCL nanofiber. After the 40 hours, the sample directly added Allanto in to the PCL nanofiber released fastest, and sample added drug filled porous silica particles to the PCL nanofiber was much slower. The sustained-release rate changed obviously as the amount of drug filled porous silica particles changed.

Fig. 3.(A) The cumulative Allantoin release from Porous silica nanoparticles.(B) The cumulative Allantoin release from Porous silica nanoparticles composite nanofiber (a)Porous silica nanoparticles 0wt%, (b)Porous silica nanoparticles 5wt%, (c)Porous silica nanoparticles 15wt%, and (d)Porous silica nanoparticles 25wt%.

4. References [1] Bansal V, Ahmad A, Sastry M J Am, Fungus-Mediated Biotransformation of Amorphous Silica in Rice Husk to Nanocrystalline Silica, Chem Soc 128(2006), 14059â&#x20AC;&#x201C;14066 [2]

V. Thavasi, G. Singh, S. Ramakrishna, Electrospun nanofibers in energy and environmental applications, Energy Environ Sci, 1 (2008), 205â&#x20AC;&#x201C;221

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The 13th Asian Textile Conference Geelong, Australia, November 3 - 6, 2015

Electrical properties of Polypyrrole coated nanofibers on PET Fabric with potential for flexible heating element applications Yuedan Wang, Haiqing Jiang, Yifei Tao, Tao Mei, Qiongzhen Liu, Dong Wang * College of Materials Science and Engineering, Wuhan Textile University, Wuhan, 430200, China

Abstract: Heating elements are widespread products in many applications for private and industrial use. While carbonbased materials such as carbon nanotube and fibers have previously been used in conducting polymer composites, no study has been conducted on the conducting polymer and nanofibers composites. In this study, polypyrrole coated PVAco-PE nanofibers/PET non-woven fabric are prepared by spray coating and in situ polymerization, and their electric heating behavior is also investigated as a function of the composition of polypyrrole and nanofibers. Scan electron microscope (SEM) images and Infrared spectrum (IR) confirm that the polypyrrole formation and was well dispersed on the PVA-co-PE nanofibers. The electrical resistivity of the composite films is decreased significantly with increasing the polypyrrole content coated on the nanofibers. In addition, maximum temperature attained at a given applied voltage for the nanocomposite films can be finely adjusted by the content of polypyrrole and nanofibers. The polypyrrole coated PVA-co-PE nanofibers/PET composites also exhibit excellent electric heating performance in terms of rapid temperature response and outstanding heating-cooling cyclic performance, which was associated with operational stability in actual electric heating applications. For the composite film with double side nanofibers, a maximum temperature is stably maintained over a cyclic voltage variation of 6-20V. It is believed to be owing to the presence of PVA-co-PE nanofibers induce more polypyrrole formed and improve the conductivity and heating behavior of composites. The extensive experimental results that may lead to a better understanding of structure, electrical and thermal properties of polypyrrole/nanofiber composites for practical applications as heating devices and/or conducting composites.

Keywords: Nanofibers; Polypyrrole; Electrical property; Functional composites; Thermal property

1. Introduction Electric heating materials are a kind of electrical resistors that convert electrical energy into thermal energy. Recently, heating elements are used widely for advanced applications including floor heating, mirror/window defrosting, road deicing, medical instruments, functional textiles, industrial processes, and so on1-4. Light weight, processibility, as well as flexible heating elements attract more attention by the increasing demand of society. Accordingly, the electric heating composites based on polymer composites reinforced with carbonbased fillers have already been investigated5-6. Another approach utilize conducting polymers (CP), many papers on the functionalization of textiles with CP were published7-8. Such conducting polymer materials are formed according to oxidative polymerization of aniline, pyrrole, thiophene, and their derivatives9. Polypyrrole (PPy) is one of the most promising electrically conducting polymers for multifunctional applications. Meanwhile, there have been no reports on electric heating behavior consisting of polymer matrix and conducting polymer with nanofibers up to now, which is a crucial design consideration for practical applications. In this study, the structural features of polypyrrole/PVA-co-PE nanofibers deposited on PET nonwoven fabrics have investigated, and the electrical properties of the materials with potential for flexible heating element applications have also studied.

2. Experimental PVA-co-PE nanofibers were prepared according to previous methods reported in paper11. The typical procedure was that PVA-co-PE nanofibers (NFs) were dispersed in an aqueous solution with a high speed shear mixer to form a stable suspension. The suspension was then coated onto the clean surface of the PET nonwoven fabric to form PVA-co-PE nanofibers/PET and NFs/PET/NFs films by spurting method. Then, *

Corresponding author. Tel.: + 86-027-59367691. E-mail address: wangdon08@126.com.

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PPy/PVA-co-PE nanofibers/PET fabric was fabricated according to In Situ Polymerization. The PPy/PVA-coPE composites were prepared with different bath ratios. The bath ratio was defined as the volume of pyrrole solution to that weight of substrate. The polymerized PPy/PVA-co-PE/PET fabric were taken out and cleaned by water and ethanol for 3 times, then dried in air. The prepared samples were then cut into pieces for further tests.

3. Results and discussion The morphology of PPy/PVA-co-PE nanofibers composite was investigated to elucidate the physical properties–structure relationship. The optic image and SEM images of PPy coated PET or PVA-co-PE/PET, PVA-co-PE/PET, and non-woven PET substrate as shown in Figures 1(c), 1(d), and 1(a)–1(b), respectively. The color of PET fabric and PVA-co-PE/PET are white. After polypyrrole coating, the color of composites change to black. The surface of PVA-co-PE and PET are very clean and smooth without any defects (Figure 1a, b). For the PPy/PVA-co-PE composite films, the polypyrrole are found to be uniformly and randomly dispersed on the surface of PET fabric or PET after nanofibers treatment (Figure 1c, d). It indicates that with the nanofibers treatment, more particles can be found on the nanofibers surface compare with PET. From the following IR image, it confirms the particle attribute to the formation of polypyrrole.

Fig. 1: (a)–(d) Digital image and SEM images of PET fabric, PVA-co-PE nanofiber/PET, PPy/PET and PPy/NFs/PET composite films.

FTIR experiments were conducted to confirm the formation of the polypyrrole as well as PVA-co-PE nanofiber. The FT-IR spectra of spunlace PET non-woven fabrics, PVA-co-PE nanofibers on PET non-woven fabrics, the composites, and polypyrrole are presented in Fig. 2, respectively. The absorption peak of the PVA-co-PE nanofiber/PET at 3308 cm-1 corresponded to the stretching vibration of hydroxyl groups. Two absorption bands were observed at 1327 cm-1 and 1456 cm-1 were associated to the bending vibrations of C-H bond. Besides, the stretching vibrations of C-H bond were shown at 2881 cm-1 and 2689 cm-1. The peaks at 1089 cm-1 and 1142 cm-1 were attributed to the stretching vibrations of C-O bond. For the PPy/PVA-co-PE composites, the peaks at 1697, 1533, and 1470 cm-1 indicate the presence of pyrrole, whereas the peaks in the 792-837 cm-1 range and at 1025 cm-1 originate from C-H absorption12. Further, the peaks at 1139 cm-1 were attributed to CH in-plane deformation. The peaks at and 1286 cm−1 were due to C-N bond stretching vibrations in the ring. Compared with the pristine PVA-co-PE membrane, all of those characteristic peaks confirmed the formation of PPy on the surface of the PVA-co-PE nanofibers.

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Fig. 2: FT-IR spectrum of spunlace PET non-woven fabrics, polypyrrole and the composites.

The electrical properties of PPy/nanofiber composite films were investigated as a function of pyrrole content are represented in Figures 3, the change in bath ratio from 20 to 140 indicated that more pyrrole was used for polymerization. It should be noted that resistivity decreased significantly with increasing bath ratio, while the slopes of the curves decrease positively for the composites with double side nanofibers treatment. The resistivity of prepared PPy/PVA-co-PE composites with the bath ratio 140 was less than 1 ÎŠÂˇcm, demonstrating excellent conductivity. This result manifests that the electrical resistivity was strongly dependent on PPy and nanofiber content by showing a typical percolation behavior, the added pyrrole amount and nanofiber for in situ polymerization plays an important role in determining the electrical conductivity of PPy/PVA-co-PE nanofibers composites.

Fig. 3: Electrical resistivity of the composite films as a function of the pyrrole content with different bath ratio.

Electric heating behaviors of the composite films with double nanofibers treatment were investigated by applying different constant voltages from 1 to 6 V (Fig.4). There were apparent temperature changes for the composite films, while the temperature increased steeply once a voltage above response point as applied at 0 s, reached a maximum value within 50 s, and decreased slowly to room temperature when an applied voltage was off at 570 s. Time-dependent temperature curves can be divided into three regions: the temperature growth (heating) region (5â&#x2C6;&#x2019;150 s), the equilibrium (maximum temperature) region (150-1100 s), and the temperature

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decay (cooling) region (1100−1500 s). It was found that the electric heating behavior of the PPy/nanofibers composite films was strongly dependent on the pyrrole contents as well as the applied voltages. The maximum temperature increased with the increment of the applied voltage. In addition, the infrared images at different time for electric heating experiment are also present in Figure 4. When a voltage was applied, the infrared image of the composite film changed from purple to green to red with time, which confirms the existence of the electric heating behavior. By supplying a voltage of 1-6 V on in such a way coated textile materials and the use of an optimized composite design, an uniform evolution of heat can be achieved with average temperatures up to 170℃. Moreover, the obvious relationship between voltage and maximum temperature offers the possibility of a simple adjustment of the desired heat evolution by voltage control.

Fig. 4: Thermal infrared images of PPy/nanofibers/PET of different time by applying constant voltage and timedependent temperature changes of the composite film at different applied voltages.

4. Summary We have prepared polypyrrole coated nanofibers on PET fabric with various polypyrrole contents by spray coating and in situ polymerization. The electric heating behavior is investigated as a function of the composition of polypyrrole and nanofibers by correlating with microstructure and electrical resistivity. In summary, the polypyrrole coated nanofibers on PET fabrics exhibit excellent electric heating performance, which is extraordinary capable for the production of textile-based flexible, durable and strong-heating heating elements for manifold technical application areas. Furthermore, it has to be pointed out that the electric property and electric heating behaviors exhibit better performance with nannofibers treatment compare with composites without it. Overall, it is valid to conclude that the polypyrrole coated nanofibers on PET fabric with potential for flexible heating element applications.

5. References [1] Y. H. Yoon, J. W. Song, D. Kim, J. Kim, J. K. Park, S. K. Oh, C. S. Han, Adv. Mater., 2007, 19, 4284-4287. [2] Y. G. Jeong, G. W. Jeon, ACS Appl. Mater. Interfaces, 2013, 5, 6527-6534. [3] C. Yu, K. Choi, Y. Yin, J. C. Grunlan, ACS Nano, 2011, 5, 7885-7892. [4] S. H. Park, E. H. Cho, J. Sohn, P. Theilmann, K. Chu, S. Lee, Y. Sohn, D. Kim, B. Kim, Nano Res., 2013, 6,389398. [5] E. S. Park, Macromol. Mater. Eng., 2005, 290, 1213-1219. [6] Y. Ryu, L. Yin, C. Yu, J. Mater. Chem., 2012, 22, 6959-6964. [7] K. H. Hong, K.W. Oh, T. J. Kang, Journal of applied polymer science, 2005, 97, 1326-1332. [8] J. Wu, D. Zhou, M. Looney, P. Waters, G. Wallace, C. Too, Synthetic Metals, 2009, 159, 1135-1140. [9] A. Malinauskas, Polymer, 2001, 42, 3957-3972. [10] L.X. Wang, X. G. Li, Y. L. Yang, Reactive and Functional Polymers, 2001, 47, 125-139. [11] P. Pötschke, K. Kobashi, T. Villmow, T. Andres, M.C. Paiva, J.A. Covas, Composites Science and Technology, 2011, 71, 1451-1460. [12] K. Cheah, M. Forsyth, V.T. Truong, Synthetic Metals, 1998, 94, 215-219.

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The 13th Asian Textile Conference Geelong, Australia, November 3 - 6, 2015

Electrospun hybrid poly(lactic acid)/titania fibrous membranes with antibacterial activity for fine particulate filtration Zhe Wang 1, Zhijuan Pan1, 2, * 1

College of Textile and Clothing Engineering, Soochow University, Suzhou 215123, PR China 2 National Engineering Laboratory for Modern Silk (Suzhou), Suzhou 215123, PR China * Corresponding author at: Soochow University, No. 199 Renai Road, Suzhou, PR China, Tel.:+86 13625273222, E-mail address: zhjpan@suda.edu.cn

Abstract. Hybrid poly(lactic acid)/titania (PLA/TiO 2 ) fibrous membranes exhibit excellent air filtration performance as a filter media with good antibacterrial activity was prepared via electrospinning technique. By simply varying the composition of precursor solutions and relative humidity, the morphology of hybrid PLA/TiO 2 fibers, including nanopore and nanometer-scale protrusions on the surface of fibers, could be can be regulated. SEM and TEM analysis methods were used to investigate the distribution of nanopore and TiO 2 NPs on the surface of hybrid PLA/TiO 2 fibers. Nitrogen adsorption-desorption analysis revealed that nanopore and nanometer-scale protrusions play a key role in improving the BET specific surface area of relevant PLA/TiO 2 fibrous membrane. Filtration performance tests by measuring the penetration of sodium chloride (NaCl) aerosol particles with a 260nm mass median diameter indicated that high fiber’s surface roughness, large specific surface area greatly improved particle capture efficiency and facilitates the penetration of air flow. Furthermore, the introduction of TiO 2 NPs also endows the relevant fibrous membrane with antibacterial property. The asprepared PLA/TiO 2 fibrous membrane loaded with 1.75 wt% TiO 2 NPs content formed at the relative humidity of 45% showed a high filtration efficiency (99.996%) and a relatively low pressure drop (128.7 Pa) at the face velocity of 5.3 cm/s and a high antibacterial activity of 99.5%. Keywords: hybrid nanofiber, nanopore, nanoparticle, air filtration, antibacterial activity

1. Introduction Particulate matter pollution has drawn increasing attention for it may cause dramatic health problems to the public, such as respiratory diseases, cardiovascular illness, and allergies, and low visibility [1, 2]. The particles suspend in the air with the diameters smaller than 2.5 μm were considered to be particularly harmful since it can penetrate human bronchi, lungs, and even extrapulmonary organs [3]. Thus, the filter mediums, which can effectively capture these harmful fine particles, are greatly desired. Besides particulate matter, bacteria matter can also impact health [4]. Thus, it is very important for the fibrous filter medium to possess antimicrobial property, especially when they were used as respiratory protection and indoor air purification. Titanium dioxide (TiO 2 ) is one of the most popular antibacterial materials, which has been widely used in many fields due to its strong photo-oxidation activity, long-term chemical and physical stability and cost-effective preparation. Previous study shows that the antibacterial activity of TiO 2 can be significantly enhanced when TiO 2 particle is in nanoscale because of its large specific surface area [5]. In this paper, we report the development of hybrid PLA/TiO 2 fibrous membrane with hierarchical structures, including nanopres, nanometer-scale protrusions and high roughness surface, which is able to effectively remove particles and bacteria in one step.

2. Materials and methods 2.1. Materials Poly(lactic acid) (PLA W m =1.0×105), N, N-dimethylacetamide (DMAC), Dichloromethane (DCM), and TiO 2 NPs (with average diameter of 21nm) were of analytical grade and used without further purification.

2.2. Preparation of the polymer solutions and electrospinning PLA solutions at concentrations 7 wt% were prepared by dissolving PLA in a mixture of DCM/DMAC

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(10/1, w/w) by stirring for 24 h. Additionally, 7 wt% of PLA solutions containing 0.5, 1, 1.5, 1.75, and 2 wt% of TiO 2 NPs were prepared using the DCM/DMAC mixtures with weight ratio of 10/1.The prepared PLA/TiO 2 solution was loaded into glass syringe and ejected at a feed rate of 1ml/h through a metal needle operated by a syringe pump. A high voltage (23kV) was applied to the needle tip through a high-voltage supply. The hybrid PLA/TiO 2 fibers were deposited on a grounded metallic rotating roller at 5.5 m/min, which was positioned 12 cm from the tip of the needle.

2.3. Characterization The viscosity and conductivity of the PLA and PLA/TiO 2 solutions were measured with a viscometer and a conductivity meter, respectively. The morphology of the electrospun fibers were examined using SEM and TEM. The BET surface area of the fibrous membranes was measured using a ASAP-2020 analyzer.The aerosol filtration efficiency and airflow resistance were measured with a TSI Corp. model 8130 automated filtration testing unit. NaCl aerosol particles of 260 nm mass median diameter were prepared by an aerosol particle generator. Every NaCl aerosol test was conducted with the continuous face velocity of 5.3 and 14.1 cm/s. The antibacterial activity of the hybrid PLA/TiO 2 fibrous membranes against Staphylococcus aureus was evaluated by using the viable cell-counting method according to GB/T 20944.3-2008.

3. Results and Discussion 3.1 Preparation of hybrid PLA/TiO 2 fibers with different morphology Fig. 1 shows the SEM and TEM images of hybrid PLA/TiO 2 fibers obtained by varying the TiO 2 concentration and relative humidity and the detailed parameters were listed in Table 1. It was clearly observed that all the fibers showed densely packing nanopores on the surface of the fibers (SEM images) due to the phase separation and breath figure induced by fast solvent evaporation and vapor penetration and condensation. By increasing the TiO 2 content, the surface structure of the hybrid PLA/TiO 2 fibers was remarkably changed by creating nanometer-scale rough structures with more TiO 2 NPs attached onto the surface of fibers (the inset Fig. 1TEM b, c, d, e, and f) and the fiber diameters gradually increased, which were due to the weakened conductivity and enhanced viscosity of the composite solutions (Table 1). Noteworthy, when TiO 2 concentration reached 2 wt%, micron-sized agglomerates formed on fiber’s surface (Fig. 1f), which was related to the agglomeration of TiO 2 NPs. By increasing the relative humidity, The nanopores distributed on the surface of the fibers increased (Fig. 1SEM e, g, h, and i), which could be due to that a high relative humidity allows much more vapor in the air to form more water droplets on the surface of jet and is also conducive to the penetration of much more vapor into the fluid jet. While the protuberances attached onto the surface of fibers decreased (Fig. 1 TEM e, g, h, and i), which may be attributed to that the increase of fiber diameter(Table 1)provided more opportunity for the TiO 2 NPs to be coated inside the fibers. The nitrogen adsorption-desorption analysis method was carried out to investigate the specific surface area of PLA/TiO 2 fibrous membrane with different morphology as shown in Table 1. It can be find that the BET surface area increased with increasing TiO 2 content (as the concentration of TiO 2 NPs was less than 2 wt%), which indicate the key role of TiO 2 NPs in improving the specific surface area. However, the BET surface area slightly decreased when TiO 2 concentration reached 2 wt% due to the formation of large agglomerates on relevant fiber’s surface. The BET surface area of the PLA fibrous membrane loaded with 1.75 wt% TiO 2 NPs increased with the relative humidity increased from 15% to 45%, which can be ascribed to the significant increase of nanopores on the surface of fibers. However, the BET surface area slightly decreased as the relaticve humidity reached 60% due to the decrease of protuberances the slight increase of fiber diameter. Sample

PLA-45 PT/0.5-45 PT/1-45 PT/1.5-45 PT/1.75-45 PT/2-45 PT/1.75-15 PT/1.75-30 PT/1.75-60

Table 1: Compositions and properties of different solutions and the corresponding fibers Concentration Concentration Viscosity Conductivity Humidity Fiber of PLA of TiO 2 (mPa. s) (µs/cm) (%) diameter (wt%) (wt%) (μm) 7 0 135 2.65 45 1.29±0.15 7 0.5 144 1.21 45 1.31±0.17 7 1 158 0.86 45 1.33±0.20 7 1.5 178 0.71 45 1.34±0.22 7 1.75 202 0.62 45 1.36±0.24 7 2 236 0.54 45 1.40±0.30 7 1.75 202 0.62 15 0.76±0.34 7 1.75 202 0.62 30 0.98±0.26 7 1.75 202 0.62 60 1.43±0.30

BET surface area (m2/g) 21.86 23.75 26.11 27.89 30.54 28.84 19.27 25.36 28.06

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Fig. 1: SEM images of (a) PLA-45, (b) PT/0.5-45, (c) PT/1-45, (d) PT/1.5-45, (e) PT/1.75-45, (f) PT/2-45, (g)PT/1.7515, (h)PT/1.75-30, and (i) PT/1.75-60. The insets are the corresponding TEM images of each sample.

3.2 Air filtration performance and antibacterial activity of hybrid PLA/TiO 2 fibers with different morphology The hybrid PLA/TiO 2 fibrous membranes, FM1 (PLA), FM2 (PT/1-45), FM3 (PT/1.75-45), FM4 (PT/1.75-15), FM5 (PT/1.75-60), with different morphology, possessed fairly similar basis weights were selected to study their air filtration performance and antibacterial property, as shown in Fig. 2. As seen in Fig. 2a, the hybrid PLA/TiO 2 fibrous membranes exhibited increased filtration efficiency, increased from 99.979 to 99.990% at the face velocity of 14.1cm/s and increased from 99.991% to 99.996% at the face velocity of 5.3cm/s, and significantly decreased pressure drop, decreased from 360.2 to 326.9Pa at the face velocity of 14.1cm/s and decreased from 140.8 to 128.7Pa at the face velocity of 5.3cm/, with the increase of the concentration of TiO 2 NPs. This results were due to the increase of nanometer-scale protrusions and roughness of fiber surface, resulting in high specific surface area and large friction coefficient, which enhanced the trapping capacity of fibers on particles; furthermore, the relative large pore size induced by thicker fiber may be conducive to the penetration of air flow through the membranes. Fig. 2b presents the filtration performance of hybrid PLA/TiO 2 fibrous membranes containing 1.75wt% TiO 2 formed at various relative humidity. It is shown that the fibrous filter FM4 exhibited the lowest filtration efficiency (99.965%) and the highest pressure drop (375.5Pa) at the face velocity of 14.1 cm/s, which could be attributed to that relative low specific surface area and few nanopores on fiber surface weaken the fiberâ&#x20AC;&#x2122;s capture efficiency of fine particles and small pore size due to small fiber diameter may go against the air penetration. This is also the reason why FM4 showed the worst filtration performance at the face of 5.3cm/s. It worth noting that the filtration efficiency of FM5 were 99.972% at the face velocity of 14.1cm/s and 99.994% at the face velocity of 5.3cm/s, which were slightly lower than that of FM3 at the corresponding face velocity due to somewhat small specific surface area, few protrusions, and large fiber diameter. Furthermore, the pressure drop of FM5 were 313.8Pa and 119.7Pa at the face velocity of 14.1cm/s and 5.3cm/s, respectively. Fig. 2c displays the antibacterial activity of FM1, FM2, FM3, FM4, and FM5 against S. Aureus. It was observed that the antibacterial activity of PLA fibrous membranes significantly increased from 10.1% to 99.5% by increasing the TiO 2 NPs content. This results can be attributed to that more TiO 2 NPs distributed on the surface of PLA fibers and the reactive hydroxyl radicals generated by the photocatalysis of TiO 2 NPs under light irradiation causes the peroxidation of the polyunsaturated phospholipid of the cell membrane of the

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bacteria and also lead to a loss of respiratory activity of the bacteria, which in turn kills the bacteria. It is worth to note that the hybrid FM4 possesses antibacterial activity of 99.8%, which was slightly higher than that of FM3. In addition, the antibacterial activity of FM5 is 97.4%, which is slightly lower than that of FM3. This phenomenon is well agreed with the previous study (Fig.1) that more TiO 2 NPs distributed on the surface of fibers with the increase of relative humidity.

Fig. 2: Filtration performance and antibacterial activity of FM1, FM2, FM3, FM4, and FM5: (a) filtration efficiency and pressure drop of FM1, FM2, and FM3; (b) filtration efficiency and pressure drop of FM3, FM4, and FM5; (c) antibacterial activity of FM1, FM2, FM3, FM4, and FM5 against S. Aureus.

4. Conclusions In summary, a hierarchical structure of PLA/TiO 2 hybrid fibers for enhanced air filtration performance with a good antibacterial activity was prepared via one-step electrospinning technique. The microstructure, including nanopores and nanometer-scale protrusions on the surface of fibers, of the hybrid PLA/TiO 2 fibers can be regulated by tuning the concentration of TiO 2 NPs in PLA solution and relative humidity. Furthermore, the nanopores and nanometer-scale protrusions on PLA fiber significantly enhanced the surface roughness structure, specific surface area of relevant fibrous membrane, which greatly improved particle capture efficiency and facilitates the penetration of air flow. In addition, the introduction of TiO 2 NPs also endowed the relevant fibrous membrane with antibacterial property induced by photocatalysis and more TiO 2 NPs distributed on the surface of fibrous membrane indicated a higher antibacterial activity. The as-prepared PLA/TiO 2 fibrous membrane loaded with 1.75 wt% TiO 2 NPs content formed at the relative humidity of 45% exhibited excellent filtration performances: a high filtration efficiency (99.996%) and a relatively low pressure drop (128.7 Pa) at the face velocity of 5.3 cm/s and good antibacterial property: a high antibacterial activity of 99.5%. This work provided a versatile way to further design and develops multifunctional filters for respiratory protection, indoor air purification, and other filtration applications.

5. Acknowledgments This work is supported by the Nanotechnology Special Project of the Suzhou Science and Technology Program Project (ZXG2012043), the Priority Academic Program Development of Jiangsu Higher Education Institutions [PAPD], and the Graduate Student Innovation Project of Jiangsu Province (KYLX15_1245).

6. References [1] Kyunghwan Yoon, Benjamin S. Hsiao, Benjamin Chu, Functional nanofibers for environmental applications, J. Mater. Chem. 18 (2008) 5326â&#x20AC;&#x201C;5334. [2] Yildiz O, Bradford P D, Aligned carbon nanotube sheet high efficiency particulate air filters, Carbon, 64 (2013) 295-304. [3] Chong Liu,Po-Chun Hsu,Hyun-Wook Lee, Meng Ye, Guangyuan Zheng, Nian Liu, Weiyang Li,Yi Cui, Transparent air filter for high-efficiency PM2.5capture, Nat. Commun. 2015. [4] Vanangamudi, Anbharasi, Sakinah Hamzah, and Gurdev Singh, Synthesis of hybrid hydrophobic composite air filtration membranes for antibacterial activity and chemical detoxification with high particulate filtration efficiency (PFE).CHEM. ENG. J. 260 (2015) 801-808. [5] Lee, Won Seok, Yang-Seok Park, and Yoon-Kyoung Cho, Significantly enhanced antibacterial activity of TiO 2 nanofibers with hierarchical nanostructures and controlled crystallinity, Analyst, 140.2 (2015) 616-622.

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The 13th Asian Textile Conference Geelong, Australia, November 3 - 6, 2015

Development of the nanofiber filter having the PM2.5 particles separating function Yoshihiro Yamashita The University of Shiga Prefecture 2500 Hassaka Hikone 5228533, JAPAN yoshihiro_yamashita1958@goo.jp

Abstract. By using the polyolefin emulsion solution, nanofiber nonwoven fabric having a fiber diameter of 100-300nm was obtained. Mask using nanofibers are also possible supplement PM0.3 particles well PM2.5 particles. Future is a problem that reducing the pressure loss.

Keywords: nanofiber, electrospinning, PM2.5, polyolefin emulsion, mask, filter

1. Introduction Harmful particles floating in the cause of air pollution in the atmosphere is causing a serious social problem. Fine particle size 2.5Îźm contained in the exhaust gas from factories and automobiles is said the cause of air pollution in China. From the day before the Beijing Olympic Games and anti-Japanese 70 anniversary parade, hey had regained the blue sky by closed the factory. Research of heat resistance of the filter to collect the dust (bag filter) is urgently needed. This PM2.5 particles are also flying to the Japan along with the yellow sand on the spring. Flying information of this PM2.5 has been published on the Web. Viewed from an aircraft, it is possible to find the thin dark drift PM2.5 layer on the sunny sky. Mask corresponding to the PM2.5 are numerous sold in Japan, but the product is only with nanofiber. It is urgent to develop a mask that made full use of nanotechnology in the future.

2. Experiment Nanofibers can be easily prepared by using the electrospinning method. When electrospinning to apply a high voltage of 10-30kV to the polymer solution, it is a phenomenon that the tip of the droplets of the nozzle is sprayed to the fibres, it can be made very easily nanofibers. Figure 1 is a schematic diagram of the production of nanofiber by electrospinning. Nozzle inner diameter is 0.5mm, the distance between the nozzle and target is 5-20cm, voltage is 10-30kV. Fibre diameter of the nanofiber is dependent on the concentration of the polymer solution. Figure 2 is a relationship between solution concentration and the fibre diameter of the nylon nanofiber. Varying the viscosity and the evaporation rate of solvent of the solution is to design the optimal nanofiber diameter. 2.1 Manufacture of the nanofiber nonwoven fabric for PM2.5 We chose following polymer and solvent to make a nanofiber mask corresponding to PM2.5 from electro spinning process. Polymer: Polyolefin PE emulsion /PVA, Solvent: water/alcohol As for the nonwoven for PM2.5, the solvent used a mixed of water / alcohol = 4/1 where there were few adverse effects to the body to touch the direct human mouth and nose. These solvents are not necessary to the recovery when creating nanofibers, it is possible to reduce manufacturing costs. Excellent water resistance, water-dispersible PE emulsion was used. The average particle size of the emulsion is 50nm. PVA is to stabilize the dispensability in water of the PE emulsion, which facilitates the fabrication of nanofibers. The prepared PE nanofiber nonwoven fabric it is shown in Figure 3. It has been shown also to commercial melt blown PP non-woven fabric, as well as general-purpose PP non-woven fabric for comparison in Figure 3. The magnification is all the same, and, in the top, 500 times, a bottom are 5,000 times. The average fibre diameter of PE nanofiber is 300nm, average fibre diameter of the melt blown PP is 1.5Îźm and generic PP fibre is 5Îźm. Evaluation method of PM2.5 particle separation performance was carried out using a particle supplemental

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evaluation apparatus of Kochi Prefecture Paper Technology Centre. The particles were determined initial trapping efficiency by utilizing JIS11 powder.

3. Result and discussion Performance comparison between commercial mask and nanofiber mask for PM2.5 1) Capture particle performance I show a commercial mask for PM2.5, a melt blown PP nonwoven fabric, the result of the nanofiber nonwoven fabric in figure 4 and figure 5. Nanofibers only one layer is very significantly lower performance in order to empty is wounded during the measurement holes for thin. Nanofibers two ply can barely withstand practical use. Because the strength of the nonwoven improved by pressing two pieces of nanofiber sheets at 50 ℃ for five seconds, the mesh was clogged up, the performance improved markedly. Nanofiber two-layer pressed product not only PM2.5, PM0.3 also has a collection efficiency of 99% or more. The nanofibers as well as PM0.3 capture performance is excellent, commercially available PM2.5 corresponding mask, an average fiber diameter of 0.8μm melt blown nonwoven fabric. 2) Pressure loss and air permeability Since the measure of pressure drop is required a large system, to a simple translation is possible in air permeability tester. As a result it is shown in the figure 5. Relationship in the pressure loss (PL) and the air permeability (AP) from the figure 9, I have found that can be approximated by the following equation (Fig.6). AP �Pa ∙

s � = 15.4 × PL(Pa) m

Pressure loss is less desirable 100Pa. Commercially available mask is 70Pa or less. Originally, although the benefits of nanofibers is that pressure loss is small, it does not unfortunately can achieve it. The reason is that the nanofiber diameter thick and 100-300nm, sequences are considered to be random. Even greater distribution of the fiber diameter is also a factor that increase the pressure loss. In the future it requires a refinement and homogenization of the fiber diameter. 3) Pressure loss and weight per unit area Figure 7 represents the relationship between the pressure loss and the basis weight. Basis weight because there is no correlation with the denseness of the non-woven fabric, pressure loss and the basis weight is not correlated. This fact shows that the thickness of the mask is not related to performance. This is also confirmed from figure 7. Figure 8 shows the relationship between the removal rate of pressure loss and particle. Removal rate as the pressure loss increases was improved.

Fig.1 Electrospinning conditions

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Fig.2 solution concentration and nanofiber diameter

(a)

(b)

Relationship between the

(c)

(a) PE nanofibers (b) melt blown PP non-woven fabric (c) general-purpose PP non-woven fabric Fig.3 Micrograph of pM2.5 mask

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Fig.4 Relationship of PM2.5 particle removal rate and mask materials

Fig.5 Performance evaluation of different materials nanofiber mask

Fig.6 Relationship of air permeability and pressure loss

Fig.7 Relationship between the pressure loss and

Fig.8 Relationship between the removal rate

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the basis weight

and the pressure loss

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The 13th Asian Textile Conference Geelong, Australia, November 3 - 6, 2015

Examining Thermal Properties of Nano Surfaces Formed With Electro Spinning Method From Shape Memory Polymers Erkan Isgoren 1, Sinem Gulas 1 and Metin Yuksek 1 + 1

Marmara University, Technology Faculty, Department of Textile Engineering, Istanbul, Turkey

Abstract. Shape memory polymers belong to \"active dynamic polymer\" group, which are able to have more than one shape. Besides having permanent shape properties, they obtain a second shape with mechanic deformation and, long term stabilization of this deformation and then they return to their permanent shape with an external stimuli application. In shaping shape memory polymers by piece; moulding methods such as, casting, compression, pour water, injection, and extrusion are used (permanent shaping). After giving permanent shape to material, with a process called memorialization or programming, desired second or third temporary shapes can be instructed to the component. Material heated above glassy transition temperature is deformed and then, deformed shape is cooled to very low temperatures. After it is completely cooled, the load application is removed and shape remains constant. This is temporary shape. In this state, polymer is extremely durable and rigid. Temporary state can be removed with heating above transition temperature. Shape memory property provides self-regulation ability to materials under changing temperature conditions. According to these findings, by using shape memory materials in nano-web production, it is predicted that surfaces that can change properties such as visibility under different temperatures, air permeability, water vapour permeability can be obtained. In is study, shape memory polyurethane is used and nano-web productions in different concentrations are made from this material. From the obtained nano-webs; shape memory properties, resistance properties, and physical properties are examined.

Keywords: Shape Memory Polymers, Shape Memory Effect, Nano Fibers, Nano Webs

1. Introduction Shape memory polymers (SMPs) are a kind of shape memory materials, which are defined as polymeric materials capable of feeling and responding external stimulus in a predetermined shape. Shape memory polymers are first developed in France and become commercial in Japan in 1984 [2]. First commercial shape memory polymers are; polinorbo developed by Nippon Zeon Company, trans-isoprene-based shape memory polymer developed by Kuraray Company, and styrene-butadiene based shape memory polymers developed by Asahi Company. Processability problems have been seen in first developed shape memory polymers [3]. Later, Mitsubishi Heavy Industries (MHI) had successfully developed polyurethane based thermoplastic polymers (SMPU). Tg values of MHI SMPU has a wide range of -30C째 to 65C째 and materials are more processable than the former SMP materials. Due to its improved processability feature, SMPU materials have a widespread interest. They also have extensive and comprehensive application areas [1]. In this study, from shape memory polymer materials at different solution concentrations and different voltages of electro spinning method nano surfaces are produced. Microscopic images of obtained nano surfaces are captured and surface thickness, porosity and contact angle values were examined.

2. Experimental Studies 2.1.

Material

The shape memory polymer material (MM3520) which is used as a raw material in the study and has Tg at 35째C, was obtained in granular form Diaplex, Tokyo, Japan. For electro spinning; which N stirred in volume ratio of 50/50, N- dimethylformamide (DMF), and tetrahydrofuran (THF) are used as a solvent, shape memory polymer solutions were used at different concentrations (in 5%, 10%, 15%, 20% ratios). +

Corresponding author. Erkan Isgoren Tel.: + 90-216-3365770 ext.1408 E-mail address: eisgoren@marmara.edu.tr

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2.2.

Preparation of Samples

Electro spinning processes are done at Marmara University Nanotechnology and Biomaterials Application and Research Center, and performed with NS24 laboratory type electro spinning unit of Invenso Company. Because it is expected that the fiber fineness and surface properties can create differences; different samples are produced by making variation in feed amount, distance between needle and collector, and voltage rates. Then, these samples were coded according to their suitability for production parameters. Production parameters and sample codes for the electro-spinning process are given in the table below. In all productions, environment humidity 70% (± 2) and temperature 26°C (± 1) were kept constant. Table 1: Electro spinning production parameters made polymer solution

2.3.

Sample 1

Sample 2

Sample 3

Sample 1

Sample 2

Sample 3

Sample 1

Sample 2

Sample 3

20% Solution

Sample 3

15% Solution

Sample 2

10% Solution

Sample 1

5% Solution

Voltage (kV) Feed Amount (ml/hr) Collector Distance (cm) Used Material Amount (ml) Amperage (mA)

38.9 0.80 29.5 3 0.007

35 1.00 24.5 5 0.000

30 1.00 24.5 5 0.000

38.9 0.80 29.5 5 0.005

35 1.00 24.5 5 0.000

30 1.00 24.5 5 0.000

38.9 0.80 29.5 3 0.010

30 1.00 24.5 5 0.000

35 1.00 24.5 5 0.001

38.9 0.80 29.5 5 0.011

35 1.00 24.5 5 0.004

30 1.00 24.5 5 0.000

Roller Speed (rpm)

Examination of Microscopic Images of Fibers and Determination of Fiber Finesses

All samples produced in NS24 laboratory type electro spinning unit were analyzed in JSM-5910 LV model scanning electron microscope of JEOL brand (SEM). SEM images of the samples has been captured in x1000, x2000, X5000, and x10.000 magnification ratios. X2000 magnificated SEM images of samples produced in different concentrations are given in the table below. Fineness determination of obtained nanofiber was measured with Image J program via SEM images of the nano surfaces. Average fiber fineness obtained from the results of measurements was given in the table below. Table 5: SEM images of nano surfaces Y5K39

Y5K35

Y5K30

Y10K39

Y10K35

Y10K30

Y15K39

Y15K35

Y15K30

Y20K39

Y20K35

Y20K30

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2.4.

Thickness Determination of Nano Surfaces

Fineness testing of nano-surfaces is made by Mitutoyo thickness measuring device at Marmara University laboratory. Average thickness values of surfaces were given in the table below. Table 9: Thickness Values of nano surfaces Sample Code Y5K39 Y5K35 Y5K30

2.5.

Thickness (nm) 0.0132 0.0093 0.0115

Sample Code Y10K39 Y10K35 Y10K30

Thickness (nm) 0.0266 0.0387 0.0424

Sample Code Y15K39 Y15K35 Y15K30

Thickness (nm) 0.0394 0.0561 0.0712

Sample Code Y20K39 Y20K35 Y20K30

Thickness (nm) 0.0468 0.0656 0.0675

Contact Angel Measurements

Contact angle is measured with water dripping onto the surface to be measured, and profile photographing the occurred angel and then by analysing this photograph in computer. In profile photographs which are required for contact angel measurement it is important that parts where contact axis and angles are calculated is clear [4]. Contact angle measurements of shape memory nano surfaces were carried out with contact angle measurement device (Pocket Goniometer PG-X). Surface angle of 3 Îźl distilled water spread on sample surface was measured with computerâ&#x20AC;&#x2122;s software (PG software) by measuring first 10 profile photographs captured at 100 measures/min speed. In the literature; when nano surface with high surface roughness was compared with nano surfaces with low surface roughness it is observed that high contact angle was achieved. Surface roughness and porosity of the film where electro-spinning was made can be improved by changing fiber diameter or size of bead-like structures. Porosity and bead structure increases the contact angle of nano fibers [5]. Contact angle values obtained from made measurements are given in Table 10. When contact angle and structures of nano surfaces are examined, it is observed that factors such as fiber formation on nano surface and placement of fibers are associated with contact angle. Table 10: Contact Angle Analysis Results Sample Code Y5K30 Y5K35 Y5K39

2.6.

Contact Angle(Î¸(Â°)) 74.53 92.63 77.27

Sample Code Y10K30 Y10K35 Y10K39

Contact Angle(Î¸(Â°)) 73.63 102.47 78.57

Sample Code Y15K30 Y15K35 Y15K39

Contact Angle(Î¸(Â°)) 70.87 78.33 81.00

Sample Code Y20K30 Y20K35 Y20K39

Contact Angle(Î¸(Â°)) 72.33 71.60 71.57

Porosity Measurements

Porosity ratio in nano surfaces is important in areas such as filtration and tissue engineering particularly. Moreover, porosity is an important factor in determining the air and water permeability properties of nano surfaces. Therefore, porosity rate of the produced nano surfaces were calculated. Porosity of nano surfaces which thicknesses have been determined previously were calculated with below formula: đ?&#x2018;&#x192;đ?&#x2018;&#x192;đ?&#x2018;&#x192;đ?&#x2018;&#x192;đ?&#x2018;&#x192;đ?&#x2018;&#x192;đ?&#x2018;&#x192;đ?&#x2018;&#x192;đ?&#x2018;&#x192;đ?&#x2018;&#x192;đ?&#x2018;&#x192;đ?&#x2018;&#x192;đ?&#x2018;&#x192;đ?&#x2018;&#x192;đ?&#x2018;&#x192;đ?&#x2018;&#x192; = ďż˝1 â&#x2C6;&#x2019;

đ?&#x2018;?đ?&#x2018;? ďż˝Ă&#x2014; đ?&#x2018;?đ?&#x2018;?0

100

(2.1)

Wherein, â&#x20AC;&#x153;Ď â&#x20AC;? is apparent density of membrane (calculated by dividing the membrane weight to membrane volume) and â&#x20AC;&#x153;Ď â&#x2014;Ś â&#x20AC;? is density of polymers in chip state [6]. Porosity results obtained with the above formula were given in the table below.

Table 11: Porosity measurement results

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Sample Code Y5K39 Y5K35 Y5K30

Porosity (%) 37.76 55.16 38.93

Sample Code Y10K39 Y10K35 Y10K30

Porosity (%) 51.04 29.09 31.74

Sample Code Y15K39 Y15K35 Y15K30

Porosity (%) 42.70 20.34 27.92

Sample Code Y20K39 Y20K35 Y20K30

Porosity (%) 25.38 30.74 40.54

3. Results In the study, from shape memory polymer material, shape memory nano surfaces are produced in different surface thickness and fiber fineness, then, contact angle and porosity properties were evaluated. When obtained fiber fineness is examined, in concentration changes it is observed that different voltage rates have different effects on the fiber fineness. Therefore each sample should be evaluated within its own terms. In studies which was made with solution having 20% concentration it is observed that smooth fiber formation is not occurred but when it is reached to peak voltage rate smooth fiber formation is began. In the solutions with 15% and 20% concentration, which are high-density solutions, it is observed that initial voltage increase (from 30kV to 35kV) increased the fiber fineness, but when voltage is raised more (to 38.9kV) surface morphology began to deterioration and fiber thickness seems to be increased. In low-density solutions, unlikely, voltage increase (from 30kV to 35kV) first decreased the fiber fineness, but when it is continued to increase voltage (to 38.9kV) it has seen that there is an increase in fiber fineness. Considering the nano surface thickness it can be said that, concentration increase is effective on surface thicknesses due to surface material increase. However, during production, factors such as device running behavior, shape of Taylor cone, scattering of jets have effect on surface thickness. Taking the average thicknesses of surfaces, it is calculated that, average thickness of sample prepared with 5% solution is 0.011mm, average thickness of sample prepared with 10% solution is 0.036mm, average thickness of sample prepared with 15% solution is 0.056mm, and average thickness of sample prepared with 20% solution is 0.060mm. As can be seen, when solution concentration increased the thickness of the produced nano surface also increased. When examining the results of the contact angle measurements; it is seen that there are two contact angles measured above 90°, which are surfaces appears to be produced with 5% solution and 35kV voltage, and 10% solution and 35kV voltage. When SEM images of both surfaces are examined, it can be said that, proper nano fiber formation and good surface morphology increases the contact angle. It can be stated that, formation of fine fibers increases the amount of fiber on surface and reduces the pore size and this increases the contact angle. Moreover, it is also thought that, bead-like surface seen on surfaces produced by 5% solution and applying 35kV voltage can be effective in increasing the contact angle. When the porosity results of nano surfaces are examined; it is observed that, the highest porosity value belongs to the 5% solution and 35kV voltage sample and the sample appear to have a beaded fiber structure. In addition, smooth surface morphology and increase in fiber fineness increases the porosity, but in structures with damaged morphology increase in fiber thickness also increases porosity.

4. References [1] Hu, J. (2007) Shape Memory Polymers and Textiles, The Textile Institute-Woodhead Publishing Limited, Cambridge, England [2] Mondal S., Hu J., Yang Z., Liu Yan., Szeto Y. (2002), Shape Memory Polyurethane For Smart Garment, The Research Journal of Textile and Apparel Vol. 6 No.2, 2002 (www.rtja.org) [3] Karataş C., Katmer S., (2014), Şekil Hafızalı Plastik Parça Üretimi, Türk-Alman Endüstriyel Kalıp Tasarım ve İnovatif İmalat Teknolojileri Paylaşım Çalıştayı, 8-9 Mayıs 2014 www.turk-alman-bilimyili.com.tr [4] Özkan A. (2011) Plazma Polimerizasyon Tekniği ile Farklı Yüzey Kararlılığı Oluşturulan Tip 4 Titanyum İmplant Materyaline 2 Farklı Yüzey Enerjisine Sahip Oral Streptokokların İn Vitro Adezyonunun İncelenmesi, Doktora Tezi, Baskent Üniversitesi Saglık Bilimleri Enstitüsü, Ankara [5] Dinç H. (2013) Polivinil Borat Sentezi ; Elektrospin Yöntemiyle Nanofiber Hazırlanması Ve Karakterizasyonu, Yüksek Lisans Tezi, Selcuk Üniversitesi Fen Bilimleri Enstitüsü, Konya [6] Liu Y. (2012) Electrospun Nanofibrous Membrane: Studies on Processing Parameters, Pore Sizes and Applications, Doktora Tezi, Stony Brook Üniversitesi, ABD

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The 13th Asian Textile Conference Geelong, Australia, November 3 - 6, 2015

Fabrication and Evaluation of Bi-layered Matrix Composed of Human hair keratin Nanofiber and Gelatin methacrylate Hydrogel Min Jin Kim, Su Jung Ryu, So Ra Lee, Chang Seok Ki and Young Hwan Park + Department of Biosystems and Biomaterials Science and Engineering, Seoul National University, Seoul, Republic of Korea

Abstract. As skin serves primarily as a protective barrier, the treatment of skin lesions is a critical issue, requiring the variety of researches about tissue-engineered skin substitutes. For skin tissue engineering, various materials that are biocompatible and biodegradable have been used. For example, human hair keratin is a natural biomacromolecule and it has Leu-Asp-Val (LDV) sequence that can bind to cell surface integrins. Gelatin, a natural protein derived from denatured collagen, also contains peptide sequence for cell surface receptor recognition. Therefore, human hair keratin and gelatin can be used to improve cell attachment, through physical adsorption on the surface of a matrix. In addition to the cell affinity, gelatin can be cleaved by various proteases and methacrylate-functionalized gelatin (GelMA) can be photo-crosslinked. Therefore, cell affinity and protease sensitivity make methacrylated-gelatin hydrogel suited for cell encapsulation studies. In this contribution, we manufactured bi-layered composite matrix that mimic epidermal and dermal layers of the skin. Keratin was extracted from human hair and blended with chitosan and poly(ethylene oxide) for improvement of mechanical properties and electrospinnability, and the electrospun keratin/chitosan nanofiber forms the upper layer of the construct. Also, we synthesized collagen-derived gelatin functionalized with methacrylate groups (GelMa) and crosslinked though UV irradiation to create hydrogel for bottom layer of the construct. Physical morphology of electrospun nanofiber is characterized using field emission scanning electron microscopy (FESEM). Our results revealed that keratin/chitosan electrospun nanofiber was well-formed and maintained its fibrous morphology after crosslinking. We cultured keratinocyte, composing epidermal layer, on the keratin/chitosan electrospun nanofiber and evaluated the reproductive integrity using Alamar Blue assay. We also cultured fibroblast cell, composing dermal layer, encapsulated GelMA hydrogel and evaluated cell viability and reproductive integrity. Bi-layered composite matrix, composed of keratin/chitosan electrospun nanofiber and GelMA hydrogel and resembling double layer structure of skin, is attractive as alternative templates for tissue regeneration. Keywords: Keratin, Chitosan, Gelatin methacrylate, Electrospinning, Bi-layer.

1. Introduction As skin serves primarily as a protective barrier, the treatment of skin lesions is a critical issue, requiring the variety of researches about tissue-engineered skin substitutes. Human hair keratin is a protein taken from human source noninvasively and it has Leu-Asp-Val (LDV) sequence that can be recognized by cell surface integrins [1]. Chitosan is a polysaccharide widely used for biomedical application because of its excellent biocompatibility and biodegradability [2]. In this study, we designed bi-layer composite matrix that mimics epidermal and dermal layers of the skin. Human hair keratin was blended with chitosan and poly(ethylene oxide) for improvement of mechanical properties and electrospinnability of electrospun nanofiber as a epidermal layer construct. Also, we synthesized gelatin methacrylate and cross-linked it though UV irradiation to create hydrogel for dermal layer construct. Keratinocyte and fibroblast were used to evaluate the biological functions of bi-layered matrix composed of hair keratin nanofiber and gelatin methacrylate hydrogel as a skin replacement.

Corresponding author. Tel.: + 82-2-880-4622. E-mail address: nfchempf@snu.ac.kr

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2. Experimental Keratin was extracted from human hair according to the Shindai method [3]. In brief, hair was intensively washed with water and then treated with chloroform/methanol mixture to remove the external lipid. Pre-treated hair was cut into small pieces and mixed with 500 ml of extraction medium containing 5 M urea, 2.6 M thiourea, 25 mM Tris-HCl and 5% mercaptoethanol. The mixture was kept at 50 ℃ for 72h. Then dialyzed keratin solution was freeze-dried. Dope solution for electrospinning was prepared by dissolving keratin and chitosan powder in formic acid with following ratios; keratin:chitosan = 2:0 (K2C0), 1:1 (K1C1) and 0:2 (K0C2). Poly(ethylene oxide) was added to dope solution for improvement of electrospinnability. Electrospinning was performed at a constant feed rate and voltage. Electrospun nanofibers were crosslinked using glutaraldehyde. Morphology of electrospun nanofibers were analysed using a field emission scanning electron microscope (FESEM) and fiber diameter were measured using Image J program. Attenuated total reflection-Fourier transform infrared spectroscopy (ATR-FTIR) was performed to determine the chemical composition of the electrospun nanofiber. Tensile test was performed to determine the tensile properties of electrospun nanofiber in dry and wet conditions. Gelatin methacrylate (GelMa) was synthesized according to the previously described method [4]. Then, GelMa powder was dissolved with photoinitiator in PBS at 60 ℃. Finally, GelMa solution was exposed to UV light for hydrogel crosslinking reaction. For biological evaluation, keratinocyte cells were cultured on the electrospun keratin/chitosan and fibroblast cells were encapsulated in the GelMa hydrogel. Alamar Blue assay was conducted to measure the metabolic activity of each cells.

3. Results and Discussion 3.1. Characterization of electrospun keratin/chitosan nanofiber Human hair keratin/chitosan nanofiber was successfully fabricated and maintained its fibrous morphology after crosslinking (Fig. 1A). Average fiber diameter decreased after crosslinking and all samples had similar average fiber diameter about 150 ~ 200 nm (Fig. 1B).

Fig. 1: (A) FESEM images and (B) average fiber diameter of as spun and crosslinked keratin/chitosan nanofiber.

FTIR spectrum of K2C0 consisted of the characteristic absorbance peaks of protein like amide A, amide I, and amide II peaks. The spectrum of K0C2 had a C-O-C stretching peak which is a typical peak of polysaccharides. The spectrum of K1C1 had typical peaks of both keratin and chitosan (Fig. 2A). Tensile properties of the electrospun keratin nanofiber was improved by blending with chitosan (Fig. 2B). In both dry and wet conditions, ultimate tensile strength and Young’s modulus of K1C1 were improved compared to K2C0.

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Fig. 2: (A) ATR-FTIR spectra and (B) S-S curve of keratin/chitosan nanofiber in dry and wet conditions.

3.2. Biological evaluation Keratinocyte cells cultured on K1C1 had the highest metabolic activity (Fig. 3A). This effect could be explained by synergetic effect of the biological activity of keratin due to the cell adhesion motif (i.e., LDV sequence) and mechanical property of chitosan for stable cell growth. GelMa hydrogel could support the proliferation of fibroblast cells (Fig. 3B). These results suggest that bi-layered matrix composed of keratin/chitosan blend nanofiber and GelMa hydrogel can provide a favourable environment for skin cells.

Fig. 3: Metabolic activity of (A) keratinocyte cells cultured on keratin/chitosan nanofiber and (B) fibroblast cells cultured in the GelMa hydrogel for 10 days.

4. Conclusion Keratin/chitosan blend nanofiber was successfully fabricated with electrospinning. FESEM images showed that nanofiber has uniform morphology. By blending with chitosan, mechanical property of keratin/chitosan nanofiber was improved. This keratin/chitosan nanofiber was designed as a matrix for skin epidermis substitute. GelMa hydrogel was chosen as a matrix for skin dermis substitute. Keratinocyte cells were cultured on the keratin/chitosan nanofiber and K1C1 sample showed highest metabolic activity. Fibroblast cells were cultured in GelMa hydrogel and metabolic activity of cells were gradually increased for 10 days. These results imply that bi-layered matrix composed of keratin/chitosan nanofiber and gelatin methacrylate hydrogel can be a good candidate for skin tissue engineering.

5. References [1] Vipin V., Poonam V., Pratima R., Alok R. R., Biomed. Mater., 3, 1-12 (2008). [2] Won H. P., Lim J., Dong I. Y., Sam H., Polymer, 45, 7151-7157 (2004). [3] Akira N., Makoto A., Keiji T., Toshihiro F., Biol. Pharm. Bull., 25, 569-572 (2002). [4] Jason W. N., Sandeep T. K., Hojae B., Chang M. H., Seda Y., Ali K., Biomaterials, 31, 5536-5544 (2010).

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The 13th Asian Textile Conference Geelong, Australia, November 3 - 6, 2015

Fabrication of Electrospun Juniperus Chinensis Extract-loaded PVA Nanofibers Jeong Hwa Kim 1, Jung Soon Lee 1 + and Ick Soo Kim 2 1

Department of Clothing and Textiles, Chungnam National University, Korea 2 Institute for Fiber Engineering Shinshu University, Japan

Abstract. The fabrication of PVA nanofibers containing Juniperus Chinensis extracts by electrospinning has been examined. PVA/Juniperus Chinensis extracts composite nanofibers were produced at different Juniperus Chinensis concentrations (0.25, 0.5, 1.5wt. %). The parameters of electrospinning including polymer contents, voltage and tip-to-collector distance (TCD) were optimized for fabrication process. The study show that 12wt.% PVA, 10kV applied voltage and 15cm TCD were the best condition to obtain uniform PVA/Juniperus Chinensis extracts composite nanofibers. It has been found that the average diameters of fibers increased by the adding of Juniperus Chinensis extracts. Morphologies of the electrospun composite nanofiber were observed by using a field emission scanning electron microscope. As the results, PVA/Juniperus Chinensis extracts composite nanofibers having a diameter in the range from 310~360nm were successfully prepared via an electrospinning. As the concentration of Juniperus Chinensis extracts increased, the diameter of fibers increased due to the hydrogen bonding interaction between the hydroxyl groups of PVA and phenolic ester/hydroxyl groups of Juniperus Chinensis extracts.

Keywords: fabrication, Juniperus Chinensis, extract, electrospinning, PVA.

1. Introduction Electrospinning is a simple and effective process for producing nanofiber with diameter range from nanometers to micrometers which have high specific surface area. Hence, medicated nanofibers can be readily fabricated using a solution containing a mixture of a plant-extracts and a polymer[1]. There have been several reports that Juniperus Chinensis has efficient ingredient of antifungal activity and house dust mite repellent effect[2-6]. Juniperus Chinensis extracts has been used for the treatment of wounds and various dermatological diseases due to its antidotal and sterilizing effects. It was proved that Juniperus Chinensis can be effectively used for the prevention of UV and SLS-induced adverse skin reaction such as radical production, inflammation and skin cell damage[7-9]. Therefore, the aim of this study was to prepare and characterize eletrospun polyvinyl alcohol (PVA) nanofibers loaded with Juniperus Chinensis extracts expecting for use in topical skin treatment and functional textiles.

2. Experimental Juniperus Chinensis(JC) heartwood was purchased from a dispensary of herbal medicine. PVA(degree of hydrolysis=88%, degree of polymerization(DP)=1,700) was supplied by the Kuraray Co. Ltd.(Japan). Distilled water and ethanol(99.9%) were used to prepare the solutions. All the chemicals were used without further purification. About 2kg JC heartwood was digested in 99.9% ethanol (0.02kl) and was kept for 48hrs in jar. Then the solution was filtered with filter paper repeatedly. Fine filtrate was concentrated on water bath evaporate solvent in rotary evaporator(RV10, IKAâ&#x201C;&#x2021;, Germany) to obtain the crude extracts. It was made stock solution that was diluted with 99.9% ethyl alcohol in a ratio of one to one. A weight amount of PVA was dissolved in distilled water to prepare PVA solutions at concentration of 11, 12, 13 and 14wt% respectively. JC extract was dissolved completely in PVA solution by stirring magnetically +

Corresponding author. Tel.: + 82-010-5312 8004. E-mail address: jungsoon@cnu.ac.kr

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using a magnetic stirrer at 400rpm at room temperature for up to 12 hours. Extract was mixed in PVA solution in different concentrations: 0.25, 0.5, 1.5 and 2.5wt% individually. In order to find optimum electrospinning condition for extract-loaded uniform nanofiber, some parameters were changed. These were concentration of polymer solution, applied voltage and distance between capillary and grounded plate. Four different polymer concentration (11, 12, 13, 14wt%), four distinct voltage(8, 10, 12, 14 KV) and three different distance(10, 15, 20cm). The solution were introduced into a standard 10ml plastic syringe attached to a blunt 21-gauge stainless steel hypodermic needle, which was connected to a high-voltage supply(high-voltage DC power supply unit, Matsusada Precision Inc.). A syringe pump (KDS 100) was used to control the flow rate of the solution. Once high voltage was applied to the needle of the syringe, a fluid jet was ejected was from the needle and accelerated toward a grounded collector aluminium sheet. The needle was placed at a distance away from the aluminum collector. The charged polymer fibers were deposited on the collector in the form of nanofibers. These steps were repeated with four different polymer concentrations, four distinct voltages, and three different distances. The viscosity of the PVA solution was obtained with a Brookfield LVDV Ⅱ+ Pro Viscometer(USA). The morphology of the electrospun nanofibers was characterized using field emission scanning electron microscope (JSM-6010LA, JEOL, Japan). The surface morphology of the electrospun nanofibers was obtained by SEM. The obtained images were further analyzed to examine fiber diameter. At least 50 fibers were measured for their fiber diameter s and the average and standard deviations were plotted.

3. Results and Discussion Prior to electrospinning, the pure PVA solutions were measured for their viscosity and the results were showed in Table 1. The concentration of PVA solution led to change on solution viscosity from 1152~4070cp. Both the viscosity of PVA solution and average diameter of the electrospun PVA nanofiber increased with an increase in PVA concentration. Table 1: Viscosity value of the pure PVA solutions and fiber diameter of PVA nanofibers PVA Solution concentration(wt%)

Viscosity(cP)

Fiber diameter(nm)

1152±8.37

248.4±27.42

1682±24.89

295.6±13.65

2262±40.87

327.7±49.83

4070±77.46

732.9±187.94

Morphology of the electrospun PVA nanofiber observed by field-emission scanning electron microscopy showed that uniform composite nanofibers were manufactured at 11~13wt% solution concentrations while wide ribbon-shaped fibers were observed at 14wt%, which were shown in Fig. 1. The average of fiber diameter increased with the increasing concentration of the polymer solution. Concentrations of 11wt%, 12wt%, 13wt% and 14wt% pure PVA nanofibers attained fiber diameters of 248±47nm, 295±42nm, 327±97nm and 732±193nm, respectively.

(a) (b) (c) (d) Fig.1: SEM images of electrospun pure PVA nanofiber prepared from different polymer solution concentrations: (a) 11wt%, (b) 12wt%, (c) 13wt%, (d) 14wt%.

It was found that 12wt% had the smallest standard deviation. From the surface morphology characterization, 12wt% of PVA polymer concentration displayed the optimum concentration for electrospinning. To

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investigate the effect of spinning voltage on the morphology and diameters of electrospun PVA fibers, a concentration of 12wt% PVA solution was prepared and electrospun with the spinning voltage varying from 8kV to 14kV. Table 2 showed the changes in average diameter of nanofiber according to voltages. After statistical analysis, the narrowest distribution of fiber diameters was obtained at a spinning voltage of 10kV. Table 2: Average nanofiber diameter of PVA according to voltages. Voltage(kV)

Fiber diameter(nm)

320.8±68.40

301.3±10.54

363.5±48.66

267.8±84.26

Table 3: Average nanofiber diameter of PVA according to TCD. TCD(cm)

Fiber diameter(nm)

300.9±14.13

349.5±12.04

375.7±17.57

Effect of applied distance can be seen in Table 3. The test was carried out with concentration of 12wt% PVA concentration under 10kV, the TCD was 10, 15 and 20cm. The average fiber diameters were found to have increase trend with increasing TCD. The standard deviation of fiber diameters at TCD 15cm was the smallest. Among those nanofiber conformations, one of them was chosen in order to load Juniperus Chinensis extracts. Selected characteristics of electrospun PVA were given below; polymer concentration: 12wt%, applied voltage: 10kV, TCD: 15cm. Table 4: Viscosity value of Juniperus Chinensis extract loaded PVA solutions and fiber diameter of PVA/JC nanofibers according to JC-extract concentration. PVA/JC Solution Fiber Viscosity(cP) concentration(wt%) diameter(nm) 0.25

1528±49.19

310.8±19.29

0.5

1902±50.19

346.4±21.97

1.5

2812±48.68

2.5

3894±58.57

362.3±30.07 Electrospinning impossible

Almost completely smooth nanofibers at 0.25, 0.5wt% of extract were formed, but the nanofibers had irregular morphologies at 1.5wt%. Electrospinning was impossible at 2.5wt% of extract. It may be that at 2.5wt% because of high viscosity electrospinning was suppressed because it prohibits flow of a polymer solution continuously to the capillary tip. It can be shown in Table 4 that average diameters of electrospun PVA/JC hybrid nanofibers were 310±21nm, 346±28 nm and 362±36nm, respectively, with Juniperus Chinensis extract weight ratios of 0.25, 0.5, and 1.5%. Fiber diameters increased with the increasing of Juniperus Chinensis extract content.

4. Conclusion In this study, composite nanofibers of PVA/Juniperus Chinensis extract were successfully fabricated by electrospinning. The study show that 12wt.% PVA, 10kV applied voltage and 15cm TCD were the best condition to obtain uniform PVA/Juniperus Chinensis extracts composite nanofibers. It has been found that the average diameters of fibers increased by the adding of Juniperus Chinensis extracts. The resulting fibers

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exhibited a uniform diameter ranging from 310~360nm. It can be expected that these nanofibers will be suitable for filtration, medical application and protection textiles.

5. Acknowledgements This research was supported by Basic Science Research Program through the National Research Foundation of Korea(NRF) funded by the Ministry of Education, Science and Technology(2014R1A1A3A04049595)

6. References [1] W. K. Son, J. H. Youk, and W. H. Park, Carbohyd. Polym., 2006, 65: 430. [2] Ki Yeon Nam and Jung Soon Lee, Korean Journal of Human Ecology, 2010, 19(4): 699-707. [3] Ohashi, H., T. Asai, and S. Kawai, 1994, Screening of main Japanese conifers for antifungal leaf components,172 sesquiterpenes of Juniperus chinensis var. pyramidalis. Holzforschung, 1994, 48: 193-198. [4] Clark, A. M., J. D. McChesney, and R. P. Adam, 1988, Phytother. Res. 4: 15-19. [5] Yarelis, O. N., S. S. Iraida, G. C. Isidro, and H. G.Rosario, Penz. & Sacc. and Botrytis cinerea Pers. J. Agric.Food Chem,. 2006, 54: 7517-7521. [6] Chi Hoon Lee, Joon Moh Park, Ha Yun Song, Eun Young Jeong and Hoi Seon Lee, Journal of Food Protection, 2009, 6: 1686-1691. [7] Y. A. Gherbawy and H. M. Elhariry, Life Science Journal, 2014, 11(2): 19-30. (ISSN:1097-8135) [8] A. Sher, Gomal journal of Medical Sciences, 2009, 7(1): 72-78. [9] Jin Hwa Kim, Sung Min Park, Gwan Sub Sim, Bum Chun Lee and Hyeong Bae Pyo, Journal of Society Cosmetic Scientists Korea, 2004, 30(1): 63-71.

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The 13th Asian Textile Conference Geelong, Australia, November 3 - 6, 2015

Fabrication of ZnO Nanowires on Fabrics Based on Biomimetic Adhesion of Seeds onto Fiber Surfaces and Hydrothermal Growth Chao-Hua Xue*, 1, 2 , Xue-Qing Ji1, Jing Zhang1, and Shun-Tian Jia1 1

College of Resource and Environment, Shaanxi University of Science and Technology, Xi’an 710021, China Shaanxi Research Institute of Agricultural Products Processing Technology, Shaanxi University of Science and Technology, Xi’ an 710021, China 2

Abstract. A novel biomimetic process to fabricate nanostructured ZnO on PET fabrics has been proposed. Inspired by the composition of adhesive proteins in mussels, conformal surface-adherent films of polydopamine on PET fibers were formed in a mild condition, and acted as reactive sites to immobilize ZnO seed crystals. Then ZnO nanowires on fibers were prepared by hydrothermal growth process. The effect of preparing conditions on the growth of ZnO nanostructures was systematically studied by scanning electron microscopy and X-ray diffractometer. It testified that the dopamine pre-treatment of PET fabrics plays a positive effect in the integration of seed layer, and imparts excellent UV-blocking property to the fabrics. By repeatedly immersing fabric samples into fresh precursor solution every 6 h, the growth time was prolonged to 24 h to obtain intertwined nanowires as long as several microns.

Keywords: Biomimetic, adhesive, polydopamine, intertwined nanowires, UV-blocking

1. Introduction Zinc oxide, as a wide band gap semiconductor with a large excitation binding energy, has been widely used in electrical or optical areas[1, 2]. In recent years, growing ZnO nanostructures on flexible substrates such as fabrics, plastics and papers has aroused significant interest in fundamental studies as well as in making optoelectronics devices and functional materials, wearable electronics and smart clothing with sensing and protection capabilities for instance[3-5]. As flexible substrates always have weak resistance to high temperature and harsh environments, hydrothermal growth method is recognized as an excellent procedure for the preparation of ZnO nanostructures on their surfaces. But growing ZnO nanostructures over a large area still poses severe challenges such as weak interaction between the ZnO nanolayers and the substrate surfaces, and non-uniform coating. During the growth of ZnO nanostructures on different substrates by hydrothermal method, seeding of the substrates is particularly important. Generally, seeding was carried out by dipping into the alcohol solution of zinc acetate[6, 7] ，spin or spray a colloidal solution of ZnO particles[8, 9], or pulsed laser deposition[10]. But the original interfacial interaction was so week that a great deal of studies has committed to solve these problems. For instance, the flexible substrates can be activated by alkaline solution to produce hydroxyl and carboxyl groups[11]，which can react as binding sites to integrate with ZnO relying on intermolecular hydrogen bonds. The observation of the adhesion of mussels to various substrates led to a big step to material science. It is reported that 3,4-dihydroxy-L-phenylalanine is the major origin of robust adhesion[12]. Dopamine, with a similar molecular structure to 3,4-dihydroxy-L-phenylalanine, can be oxidized and spontaneously selfpolymerize and stick on all kinds of organic and inorganic surface through strong covalent and noncovalent bonds under wet condition with oxygen, or metal ions as oxidant[13, 14]. More importantly, the molecular structures before and after polymerization all contain hydroxy and amino groups，which react as a secondary reactive sites to different molecules[15]. Therefore, coating fibers with dopamine might be a good Corresponding author. Tel.: + 86-029-86132768 E-mail address: xuech@zju.edu.cn

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way of modification to activate the fabric surfaces for further functionalization. In this work，we described the preparation of intertwined ZnO nanostructures of several micro meters long on poly(ethylene terephthalate) (PET) fabrics through bionic dopamine coating and two-step hydrothermal growth..

2. Experimental Section 2.1. Surface modification of fabrics with dopamine in Tris buffer The fabric was immersed in 150 mL 2.0 g/L dopamine solution in Tris buffer (10 mM, pH 8.5) for 8 h in a sealed container. During the reaction, the container was continuously rotated to keep the fabric evenly coated at 40 �. After that, the sample was removed from the dopamine solution, washed sequentially by anhydrous ethanol and deionized water until the solution was clear without apparent suspension, and air-dried for further use. The fabric sample was denoted as PET-PDA.

2.2. Growth of ZnO nanostructures on PET-PDA fabrics The ZnO seed solution was prepared following the procedure reported by Thushara J. Athauda et al [8]. Firstly, the substrates were sonicated in the seed solution for 10 minutes at 100 W, then heated at 150℃ for another 10 minutes to ensure the ZnO crystals were securely attached. Secondly, the seeded fabrics were immersed in 50 mL precursor solution containing a 25 mM aqueous solution of Zn(NO 3 )·6H 2 O and C 6 H 12 N 4 . The container was incubated at 93 ℃, fabric samples were repeatedly immersed into fresh precursor solution every 6 h and growth was prolonged to 24 h. After aging in the solution for some time, the fabrics were removed out, rinsed with deionized water and dried at 80 ℃, which was denoted as PET-PDA-ZnO. Besides, bare PET fabrics were also used for the growth of ZnO nanostructures, denoted as PET-ZnO.

3. Results and discussion 3.1. Effect of dopamine pre-treatment on the growth of ZnO nanostructures Comparing figure1(a) and (b), it can be seen that pre-treatment of fabrics with dopamine made the fibers rougher with coating of PDA nanoparticles. After the seeding and hydrothermal growth for 6 h, pristine and dopamine pre-treated fabrics were all covered by ZnO nanostructures (figure 1c and 1d), but the alignment and coverage of ZnO nanostructures on PET-PDA fabrics were significantly better than the pristine ones. These differences might be caused by the different interfacial interactions between the substrates and ZnO.

Figure 1. SEM images of fabrics before and after dopamine modification: (a) pristine PET; (b) PET-PDA; (c) PET-ZnO; (d) PET-PDA-ZnO; (e) X-ray diffraction patterns of fabrics; (e) Optical transmittance of fabrics.

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Polydopamine coated fibers with active groups showed good affinity for ZnO seeds, therefore ZnO grains were integrated on the polydopamine layer depending on such physical or chemical reactions after the seeding process. Then ZnO grows homoepitaxially from the grains to form different nanostructures. While for pristine PET fabrics, surface active groups were too less and too weak, the ZnO grains can just deposit on the surface by physical interactions. It is well known that the orientation of ZnO nanostructures mainly determined by the orientation of ZnO grains on the substrates[16], stronger interactions benefit the alignment and coverage.

3.2. Crystal structure and optical transmittance of modified fabrics Figure 1(e) shows the recorded XRD patterns demonstrating the crystalline-phase evolution of the fabric samples of PET, PET-PDA and PET-PDA-ZnO. By first immersing the PET fabrics in dopamine solution for 8 h, the crystal structure was almost unchanged. That is because after the fabric went through a polymerization modification procedure, polydopamine with amorphous structure uniformly coated on it, and which is undetectable[17]. According to the XRD pattern of PET-PDA fabrics with growth of ZnO structures, wurtzite is the only crystallographic phase detectable in the hexagonal ZnO nanorods. The colour of the fabric changed from white to brown, the transmittance sharply decreased in the wavelength range of 300 nm to 800 nm, the growth of ZnO nanostructures further increased its UV protection property, as shown in figure 1(f).

3.3. Preparation of intertwined ZnO nanowires on PET fabric surface To investigate morphological evolution of ZnO nanostructures along growth time, fabric samples were repeatedly introduced into fresh precursor solution every 6 h to ensure a high growth rate. The samples with growth time of 6 h, 12 h, 18 h and 24 h were characterized in figure 2. It indicates that the length of ZnO nanowires varied with the duration of reaction process. When duration time prolonged to 12 h, there appeared fusion trend on top of ZnO nanowires, then these fusion nanowires continued to incorporate with each other, culminating in the intertwined ZnO nanowires on the fabric surface. Their diameter was about 50 nm and up to several micro meters. Corresponding X-ray diffraction image (figure 2e) shows they are well consistent with hexagonal wurtzite ZnO crystal structure, sharp peaks indicating good crystal profiles.

Figure 2. Typical SEM images of ZnO nanostructures on fabric surface at different reaction time (a) 6 h; (b) 12 h; (c) 18 h and (d) 24h, and (e) Time-dependent crystal structures of PET-PDA-ZnO.

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4. Conclusion In summary, we have successfully fabricated intertwined ZnO nanowires on PET fabrics surface based on biomimetic adhesion of seeds onto fiber surfaces and hydrothermal growth using zinc nitrate aqueous solution. It is clearly shown that the dopamine pre-treatment greatly increased the interfacial interactions between fabric surface and ZnO seed crystals, and the dopamine coating imparts the fabric excellent UV-blocking properties. Repeatedly introducing fabric samples into fresh precursor solution guaranteed ZnO a faster growth rate, the wires of the second layer can grow on top of the first layer. Our investigation may pave a new way for the growth of ZnO nanostructures on various flexible substrates and the fabrication of functional materials.

Reference [1] Ting Guo, Yidong Luo, Yujun Zhang, et al. Controllable growth of ZnO nanorod arrays on NiO nanowires and their high UV photoresponse current[J]. Crystal Growth & Design, 2014, 14(5): 2329-2334. [2] Yang Bai, Hua Yu, Zhen Li, et al. In Situ Growth of a ZnO Nanowire Network within a TiO 2 Nanoparticle Film for Enhanced Dye-Sensitized Solar Cell Performance[J]. Advanced Materials, 2012, 24(43): 5850-5856. [3] Joonho Bae, Min Kyu Song, Young Jun Park, et al. Fiber Supercapacitors Made of Nanowire‐Fiber Hybrid Structures for Wearable/Flexible Energy Storage[J]. Angewandte Chemie International Edition, 2011, 50(7): 1683-1687. [4] Majid Montazer and Morteza Maali Amiri. ZnO nano reactor on textiles and polymers: ex situ and in situ synthesis, application, and characterization[J]. The Journal of Physical Chemistry B, 2014, 118(6): 1453-1470. [5] Lingling Wang, Xintong Zhang, Bing Li, et al. Superhydrophobic and ultraviolet-blocking cotton textiles[J]. ACS applied materials & interfaces, 2011, 3(4): 1277-1281. [6] Xiulan Hu, Xiaodong Shen, Hongtao Li, et al. Polyethylenimine-assisted synthesis of transparent ZnO nanowhiskers at ambient temperatures[J]. Thin Solid Films, 2014, 558: 134-139. [7] Chih Feng Wang, Fan Shiuan Tzeng, Houguang Chen, et al. Ultraviolet-durable superhydrophobic zinc oxidecoated mesh films for surface and underwater–oil capture and transportation[J]. Langmuir, 2012, 28(26): 1001510019. [8] Thushara J Athauda and Ruya R Ozer. Nylon fibers as template for the controlled growth of highly oriented single crystalline ZnO nanowires[J]. Crystal Growth & Design, 2013, 13(6): 2680-2686. [9] Sunandan Baruah, Chanchana Thanachayanont, and Joydeep Dutta. Growth of ZnO nanowires on nonwoven polyethylene fibers[J]. Science and Technology of Advanced Materials, 2008, 9(2): 025009. [10] Liqing Liu, Kunquan Hong, Xing Ge, et al. Controllable and rapid synthesis of long ZnO nanowire arrays for dyesensitized solar cells[J]. The Journal of Physical Chemistry C, 2014, 118(29): 15551-15555. [11] Chaohua Xue, Wei Yin, Shuntian Jia, et al. UV-durable superhydrophobic textiles with UV-shielding properties by coating fibers with ZnO/SiO 2 core/shell particles[J]. Nanotechnology, 2011, 22(41): 415603-415610. [12] Yanlan Liu, Kelong Ai, and Lehui Lu. Polydopamine and its derivative materials: synthesis and promising applications in energy, environmental, and biomedical fields[J]. Chemical reviews, 2014, 114(9): 5057-5115. [13] Falk Bernsmann, Vincent Ball, Frédéric Addiego, et al. Dopamine-melanin film deposition depends on the used oxidant and buffer solution[J]. Langmuir, 2011, 27(6): 2819-2825. [14] Matthew J Harrington, Admir Masic, Niels Holten-Andersen, et al. Iron-clad fibers: a metal-based biological strategy for hard flexible coatings[J]. Science, 2010, 328(5975): 216-220. [15] Qing Zhu and Qinmin Pan. Mussel-Inspired Direct Immobilization of Nanoparticles and Application for Oil-Water Separation[J]. ACS nano, 2014, 8(2): 1402-1409. [16] Lori E. Greene, Matt Law, Dawud H. Tan, et al. General route to vertical ZnO nanowire arrays using textured ZnO seeds[J]. Nano Letters, 2005, 5(7): 1231-1236. [17] F Bernsmann, V Ball, F Addiego, et al. Dopamine61Melanin Film Deposition Depends on the Used Oxidant and Buffer Solution[J]. Langmuir, 2011, 27(6): 2819-2825.

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The 13th Asian Textile Conference Geelong, Australia, November 3 - 6, 2015

Hydrophobic functionalization of textiles using atmospheric pressure pulse plasma Raghav Mehra, Manjeet Jassal * and Ashwini K. Agrawal ** Smart Materials and Innovative Textile Applications (SMITA) Research Lab, Department of Textile Technology, Indian Institute of Technology Delhi (IIT Delhi), Hauz Khas, New Delhi -110016, India

Abstract. Plasma technology has gained importance in recent years as it is a dry process and alters only the top surface of the material whereas bulk is not affected. In this study, hydrophobic functionalization of viscose fabric was carried out using He/dodecyl acrylate (He/DA) plasma at atmospheric pressure. The effect of various parameters such as duration of pulse (duty cycle), reaction time and monomer concentration were studied to impart hydrophobicity to cellulosic substrate. A comparison was made between continuous and pulse plasma. After the treatment, water absorbency time of more than 1h was observed for samples treated at low duty cycles as well as continuous plasma (duty cycle=1). However, water contact angle was found to be highest at low duty cycles and lowest in continuous plasma. The results indicate that pulsed plasma offer better control of precursor in in-situ reactions compared to continuous plasma. This may be due to monomer fragmentation and substrate activation during a plasma pulse, and subsequently, these may react together during the plasma off period. On the other hand, excessive fragmentation of precursor may occur in continuous plasma.

Keywords: Pulsed plasma, hydrophobicity, atmospheric pressure plasma

1. Introduction In-situ plasma reactions offer a unique way of surface modification of the textiles as it is a dry, environmentally friendly process and alters only the top surface of the material. However, to make them commercially viable, they are required to be made even more efficient. Studies [1-6] have shown that the structures formed in insitu plasma polymerization are better and more controlled using pulsed plasma than the conventional continuous wave (CW) plasma. However, very limited work [7] has been carried out on pulsed plasma for functionalization of textiles using various precursors. The present study is aimed at functionalizing cellulosic substrate using a nonfluoro, long chain hydrocarbon precursor (dodecyl acrylate) for enhanced hydrophobicity using pulsed plasma. The effect of pulse duty cycle, concentration of precursor and time has been investigated in order to improve reaction efficiency and obtain desired hydrophobicity with lower power and in lower reaction time.

2. Experimental 2.1 Materials Viscose fabric with plain weave and areal density 130 g/m2 was scoured and used. Dodecyl acrylate (DA) was procured from Sigma Aldrich, India and zero grade helium gas was supplied by Sigma Gases, India. Solvents n-hexane and acetone were procured from Merck, India.

2.2 Plasma Treatment The plasma reactor and method of plasma treatment of viscose fabric has been explained in detail in our previous study [8]. The duty cycle (DC), which determines the on and off period of the plasma was calculated

* **

Tel.: + 91 11 2659 1426; manjeet.jassal@smita-iitd.com Tel.: + 91 11 2659 1415; ashwini@smita-iitd.com

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using Equation 1 where t on and t off represent the on and off time of the plasma. The average power delivered to reactor was measured using Equation 2, where P o represents on-power of plasma. on Duty Cycle (DC) = tont+t

-Eq. 1

off

PAvg = P0 × �tonton � +t off

-Eq. 2

The frequency, power density (for CW plasma), electrode gap, helium flow rate and total treatment time for the reaction were kept constant at 15 kHz, 0.383 w/cc, 1.5 mm, 0.4 slpm and 2.5 minutes as it was found to give best results in terms of hydrophobicity as reported in our previous work on continuous wave plasma [8].

2.3 Characterization The plasma treated samples were thoroughly washed in n-hexane and acetone to remove unreacted and loosely deposited materials and dried, and then analysed. AATCC 79-2007 method was followed to measure the water drop absorbency time of the untreated as well as plasma treated-solvent washed fabrics. The drop absorbency time was observed for a maximum period of one hour. ASTM D 5946-04 static Sessile drop method was followed to measure the water contact angle (WCA) on both sides of the fabrics. The average of five drops placed at different positions on the fabric was recorded. The surface of the untreated and plasma treated samples was characterized using ATR–FTIR spectroscopy and field emission scanning electron microscopy (FE-SEM).

3. Results and Discussion 3.1 Effect of Process Parameters The effect of various process parameters such as duty cycle, precursor concentration and reaction time on the hydrophobicity of the fabric have been studied and are discussed below.

Effect of duty cycle The effect of duty cycle on the degree of hydrophobocity of viscose fabric was carried out by varying duty cycle from 0.1 to 1 while keeping other parameters constant. Duty cycle =1 represents continuous wave plasma, where there is no off time, while for 0.1, the plasma was on for 10% of the total reaction time. Table 1 shows the drop absorbency time of the samples. Reaction of viscose with DA precursor at duty cycle of 1 gave drop absorbency time of > 1 h. Interestingly, the drop absorbency time was not found to decrease as the duty cycle was gradually decreased to a very low value of 0.1. Thus, it can be inferred that pulsed plasma is capable of giving comparable hydrophobicity to that of CW plasma. This may happen because during the on-phase of a plasma pulse, precursor fragmentation and substrate activation could take place and these reactive species may continue to react together in the off-phase of the pulsed plasma. This implies that reaction of precursor with the fabric could be carried out at one-tenth the power used in CW plasma (duty cycle=1), thereby, making the process more energy efficient. Table1: Drop absorbency time of plasma treated fabric with different duty cycles Duty Cycle Untreated 0.1 0.3 0.5 0.8 1 (CW)

Drop Absorbency time < 1 sec >1h >1h >1h >1h >1h

Effect of precursor concentration Effect of precursor concentration on hydrophobic functionalization was carried out by varying the concentration of DA solution from 0.005 to 0.2 M for different duty cycles. The other parameters were kept constant. At all concentrations of DA and at all duty cycles, the drop absorbency time was found to be more than one hour as evident from Table 2. One significant observation made was sample treated with very low concentration of DA= 0.005M and with duty cycle = 0.1 was capable of exhibiting hydrophobicity of more than one hour, while, samples treated at very high concentrations of precursor also exhibited the similar effect. This further indicated that the pulse plasma was effective at very low concentrations of precursor thereby

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making the process more economical. Hydrophobicity was also evaluated with water contact angle (Table 3) and the results point out that samples treated at lower duty cycles had somewhat higher contact angles in comparison to CW plasma treated samples. This may be due to the formation of uniform and regular deposition of the precursor on the fabric treated at lower duty cycle. As the duty cycle increases, the contact angle decreases and is found to be lowest at duty cycle 1, which may be due to non-uniform deposition of precursor due to excessive etching in CW plasma. A clear difference in curvature of water droplet on viscose fabric treated with duty cycle= 0.1 and duty cycle= 1 can be seen in Figure 1. It may be inferred that pulse plasma with low duty cycle is not only capable of exhibiting comparable results but may even be better than CW plasma. Duty Cycle Untreated 0.1 0.3 0.5 0.8 1 (CW)

Table 2: Drop absorbency time of plasma treated fabric using varying concentrations of DA 0.005 M 0.01 M 0.05 M 0.1 M 0.15 M 0.2 M < 1 sec >1h >1h >1h >1h >1h

>1h >1h >1h >1h >1h

Table 3: Water contact angle (⁰)* of plasma treated fabric using varying concentrations of DA Duty Concentration (DA) Cycle 0.005 M 0.01 M 0.05 M 0.1 M 0.15 M 0.2 M Untreated Not measurable 0.1 143 143 150 149 148 148 0.3 143 142 145 147 147 147 0.5 140 140 143 147 143 148 0.8 139 141 142 146 145 144 1 ( CW) 139 139 143 146 143 142 *Standard Deviation of water contact angle ± 4⁰

Fig. 1: Water droplet on viscose fabric treated with a) duty cycle= 0.1 and b) duty cycle= 1

Effect of reaction time The above reactions were carried out for a total reaction time of 2.5 minutes. This time appeared to be sufficiently long for obtaining the desired functionality. In order to investigate the efficiency of reaction at different duty cycles, the reaction time was varied in the range of 30 s to 2.5 minutes for different concentrations of DA and duty cycles. The results of hydrophobicity of treated fabrics at two extreme concentrations of DA i.e. the lowest concentration of 0.05 M and highest concentration of 0.2 M are shown in Figure 2 and 3. 70

60 50

30 s

1 min

1.5 min

2 min

2.5 min

0 0.1

0.3

0.5

0.8

1 (CW)

Duty Cycle

Fig.2: Effect of reaction time on duty cycle for 0.05 M DA Concentration

Drop Absorbency Time(min)

60 50

30 s

1 min

1.5 min

2 min

2.5 min

0 0.1

0.3

0.5

0.8

1 (CW)

Duty Cycle

Fig.3: Effect of reaction time on duty cycle for 0.2 M DA Concentration

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From the results, it can be concluded that reaction time of 30 s was ineffective in giving hydrophobicity of greater than 1 h for all concentrations of DA and duty cycles. This may be due to less number of precursor molecules reacting with the substrate in the short reaction time of 30 s. However, reaction time of 1 min at duty cycle of 0.3 was found to be sufficient to provide water absorbency time of 1 h at low DA concentration of 0.05 M. On the other hand, at higher concentration of DA of 0.2 M, only long reaction times of 2.5 min could exhibit drop absorbency time of >1 h for all duty cycles. This suggests that higher concentration might not give desirable results at smaller reaction times which may be due to incomplete reaction of precursor with the substrate.

3.2 Chemical characterization of plasma treated viscose fabric ATR-FTIR Spectroscopy The ATR-FTIR spectra of plasma treated-solvent washed viscose fabrics treated with duty cycle =0.1 and 1 (CW) are shown in Fig. 3. In the spectra, two distinct peaks at 2918 cm−1 and 2850 cm−1 were observed for the symmetric and asymmetric stretching of CH 2 . A new peak at 1731 cm−1 was also observed for C=O stretching of ester groups. Appearance of these peaks shows the presence of long hydrocarbon chain of DA in the sample.

ATR-FTIR

FE-SEM Micrographs a) untreated fabric, fabric treated with b) duty cycle=0.1 and c) duty cycle=1

Fig. 3: Characterization of untreated and plasma treated viscose fabric

Scanning electron micrograph analysis Surface morphology of viscose fabric treated at duty cycle 0.1 and 1 is shown in Figure 3. From the micrographs, it can be clearly seen that the pores of the viscose fibres are masked with formation of a thin layer of the precursor or its fragments onto the fibres. However, the thin layer formed is uniform, regular and continuous in case of fabric treated with duty cycle=0.1. On the other hand fabric treated at duty cycle = 1 exhibited non-uniform, damaged and discontinuous layer on its surface. This may happen because during a plasma pulse of low duty cycle, short time of on-plasma appears to be enough for controlled activation of the precursor and the substrate followed by a long off-time, which may lead to uniform reaction and deposition of precursor on the fabric. As duty cycle is increased, plasma on-time increases, which may lead to excessive fragmentation of the precursor and greater etching of the deposited layers, thus giving non uniform deposition and poorer functionalization.

4. Conclusions This study was an attempt to obtain hydrophobicity of viscose fabric with the help of pulsed plasma. It is concluded that reaction of precursor with the fabric could be carried out at low duty cycle i.e. at low power, low concentrations of precursor and less reaction time. Thus hydrophobicity of cellulosic fabric could be obtained efficiently with lower energy, lesser chemicals at a faster rate with the help of pulsed plasma compared to the CW plasma. Hydrophobicity in terms of drop absorbency time and contact angle of fabric treated with pulse plasma has considerably better values than the fabric treated with continuous wave plasma, which is attributed to more uniform deposition of the precursor onto the fibres with pulsed plasma.

5. References 1. 2. 3. 4. 5. 6.

J. M. Tibbitt, M. Shen, A. T. Bell, J. Macromol. Sci. Chem., 1976, A10, 1623. D. D. Neiswender, Adv. Chem. Ser., 1969, 80, 338. F. J. Dinan, S. Fridman, P. J. Schirrmann, Adv. Chem. Ser., 1969, 80, 289. K. Nakajima, A. T. Bell, M. Shen, M.M. Millard, J. Appl. Polym. Sci., 1979, 23, 2627. J. G. Calderon, R. B. Timmons, Macromolecules, 1998, 31, 3216. J. Friedrich, G. Kühn, R. Mix, A. Fritz, A. Schönhals, J. Adhesion Sci. Technol., 2003, 17, 1591.

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7. K. H. Kale, S. S. Palaskar, J. Appl. Polym. Sci., 2012, 125, 3996 8. P. K. Panda, M. Jassal, A. K. Agrawal, Surf. Coat. Technol., 2013, 225, 97.

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The 13th Asian Textile Conference Geelong, Australia, November 3 - 6, 2015

Modification of Graphene Oxide and Halloysite Nanotubes by Poly(propylene imine) Dendrimer to Improve the Dye Removal Efficiency Farnaz Shahamatifard, Anahita Ghasempour, Elmira Pajootan, Somaye Akbari, Hajir Bahrami ∗ Textile Engineering Department, Amirkabir University of Technology, 424 Hafez Ave, Tehran, Iran

Abstract. In this research, the modification of Halloysite nanotubes (HNTs) as an aluminosilicate and the synthesized graphene oxide (GO) as a carbon-based adsorbent, employing Poly(propylene imine) dendrimer (PPI, generation 2) was studied. For this purpose, GO and HNTs were dispersed in distilled water in separate solutions. Then the solution containing PPI was added to the well dispersed adsorbent and they were sonicated for 60 min and stirred for 24 h. Then the prepared HNTs-Den and GO-Den were washed two times with distilled water and dried in oven at 30°C for 12 h. The adsorbents were characterized by field emission electron microscope (FESEM) images and Fourier transform infrared (FTIR) analysis. By this modification, the adsorbents will have the tendency to adsorb anionic dye molecules via the amino terminated functional groups of PPI. The adsorption process of each adsorbent, before and after the modification was investigated in aqueous solution in batch system for the removal of C.I. Acid Blue 92 (AB92). The parameters influencing the efficiency of the adsorption process like pH was evaluated. The results showed that the adsorption after the modification was a rapid process and equilibrium was rapidly integrated after 15 min of contact time. High removal efficiencies (> 88%) were achieved at pH: 3, due to the strong electrostatic attraction forces between the negatively charged dye molecules and positively charged amino groups on the surface of GO and HNTs.

Keywords: PPI Dendrimer; Halloysite Nanotubes (HNTs); Graphene Oxide (GO); Equilibrium Parameters.

1. Introduction Nowadays, by industrialization of societies, many contaminants such as synthetic dyes are bieng discharged into the water. Approximately 280,000 tons of industrial dye are discharged into the water, which are hazardous and toxic to the environment and possess significant side effect to the human life. Textile industry consumes large amount of water and synthetic dyes [1]. One of the most widely used dyes in textile industry is acidic dye, which is used for dying of wool, silk, cotton, nylon, etc. These dyes are mostly carcinogenic and cause damage to the nervous system, eyes and skin in a lone period of time [2]. Various methods have been employed for the removal of dyes from wastewaters including biological methods, filtration, membranes, chemical oxidation, coagulation and ion-exchange. Among the mentioned methods adsorption is popular and more effective due to low-cost, low energy requirement, high Availability and easy process [3]. Various types of adsorbent have been investigated such as chitosan [4], CNT [5], bentonite [6], zeolite [6], etc. Halloysite nano tube (HNTs) is a kind of aluminosilicate which has two layered structure. This mineral adsorbent contain tubular shape by two layers, octahedral and tetrahedral surrounded by OH groups especially at the end of tube. This functional group lead to negative charge for HNTs. As a result, HNTs has received more attention because of tubular structures and surface OH group and it has illustrated high affinity towards the cationic molecules [7]. Graphene is a new family member of carbon and it has a honeycomb structure and SP2 hybrid. These nanoparticles due to physical and chemical properties are highly regarded and one of graghene derivatives, is ∗

Author to whom all correspondence should be addressed: 424 Hafez Ave, Tehran, Iran, 15875-4413. Tel: +98 //2164542614, Fax: +98 2166400245, Email: hajirb@aut.ac.ir.

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graghene oxide. Graghene oxide (GO), has inclusive functional groups (epoxy- hydroxyl- carboxyl- keton). It has a large porous surface which is available and easily dispersible in water [8]. Dendrimers are highly branched macromolecules. Due to the high absorption capacity, unique physical and chemical properties and high compatibility with the environment High adsorptions cause having many reactive groups, and porous surface, made this hyper branched as a specific adsorbent about variety class of organic and inorganic pollutants. One of the most commonly used Dendrimers is polypropylene Imine. This type of dendrimer contains a core of D-amino butane, propylene interior and terminal amine groups. Investigations show that the adsorption of anionic dyes onto the HNTs and GO are comparatively low because of the charge distribution on the chosen adsorbents. Therefore in this study it has been decided to modify the surface of the reminded adsorbent by dendrimer because of amine functional groups at their terminal groups to retain remarkable dye removal. In this study, the absorption of C.I Acid Blue 92 (AB92) as Acidic dye has been studied, by GO and HNTs absorbents modified by PPI. The factors affecting the efficiency of the removal process such as initial pH solution were evaluated. To determine the absorption characteristics FESEM and FT-IR spectra was used.

2. Materials and Methods Preparation of graghene oxide (GO) Graphene oxide (GO), was prepared by the improved hummers method [9]. A 9:1 mixture of concentrated H 2 SO 4 /H 3 PO 4 (360:40 mL) was added to a mixture of graphite flakes (3.0 g). Then 18 g of KmnO4 was added slowly and in stages. The resulting mixture was disrupted on stirrer for 12 hours at 50 ° C. After 12 hours. 3 Ml of H 2 O 2 (30%) was poured in to solution slowly in the ice bath. The resulting solution was centrifuged (5000 rpm for 4 h), and the supernatant was decanted away. The remaining solid material was then washed in succession with 200 mL of water (3×), 200 mL of 30% HCl, 200 mL of ethanol (2×) and 200 mL deionized water. The solid obtained was dried at room temperature.

Preparation of GO-Den

Poly (propylene imine) (PPI) dendrimer (Generation 2, molecular weight: 770 g·mol−1, and molecular formula: C 40 H 94 N 14 ) was supplied by BVSYMO Chem. The GO-Den adsorbent was prepared by the addition of 300 mL PPI dendrimer of generation 2 (500 mg·L−1) solution and 0.1 g of GO to 150 mL of ethyl alcohol (98%) at pH 3. The resulted solution was sonicated for 60 min using Delta D68H Ultrasonic bath and then stirred at 200 rpm for 24 h. The solution was centrifuged at 5000 rpm for 10 min, and the adsorbent was dried in air at room temperature (25 °C).

Preparation of HNT s -Den The synthesized process started by HNTs acidification. Acidification of HNTs was performed via HCl (37%) solution and stirred for 24h, then filtered and washed with distilled water until the pH reached a constant value. The purified HNTs was dried in oven at 60 ℃ for 24h. The purified HNTs, toluene and APTES were refluxed for 12h at 60℃, then filtered and washed by methanol, ethanol and diethylether. HNTs-APTES, MA (methyl acrylate) and ethanol were refluxed at 60℃ about 24h to introduce the ester groups to HNTs structure. Last step of the synthesis was done by the combination of HNTs-MA by defined amount of dendrimer solution. The solution was stirred for 24h at room temperature by magnetic stirrer.

Adsorption Experiments The solution of dye (Acid blue92) was prepared, in the defined concentration of adsorbent dosage, pH value, dye concentration and temperature. pH value was adjusted with H 2 SO 4 and NaOH. The dye removal eﬃciency was calculated using eq1:  A − Ao  dye Re moval =  T  X 100  Ao 

(1.1)

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3. Results and Discussion 3.1. Characterization of Adsorbent Fig. 1 shows FTIR spectra for graphene oxide (a) and HNTs (b). In Fig. 6 (a), the peaks at 2924 and 2849 cm-1 represent the stretching of C-H groups of alkane. The absorption band at 1724 cm-1 is assigned to the double bond C=O stretching of carboxyl groups on the geraghene oxide surfaces. The peak at 1223 cm-1 and 3426 cm-1 are attributed to stretching C-O-C of epoxy groups and stretching OH. The peak of Fig. 6 (b) illustrated the main HNTs peak at 3696 cm-1 is related to stretching vibration of the inner surface Al−OH groups. The peak at 3618 cm-1 is assigned to the O−H stretching vibration of the inner Al−OH groups. The comprehensive range between 1633 and 3448 cm-1 notified the existence of water in HNTs structure. The peak at 1034 cm-1 links to the stretching vibration of the Si−O. The peak at 913 cm-1 is recognized the O−H deformation vibration of inner Al−OH connection. The 538 cm-1 is ascribed the Al−O−Si deformation.

HNTs

Absorbance

4000

3500

3000

2500

2000

1500

1000

500

4000

3500

wavenumbers (cm-1)

3000

2500

2000

1500

1000

500

-1

wavenumber (cm )

Fig.1: FT-IR spectra (a) GO, (b) HNTs.

FESEM images of graphene oxide, before and after the reformation of dendrimer (PPI) can be seen in Fig. 3 Graphene oxide (GO) and graphene oxide-PPI (GO-Den) showed porous and layer surface. But (GODen) surface PPI has grooves and more waves. As Fig. 3 Shows, by surface modification of the HNTs, the dimension increased. FESEM illustrated that the morphology of HNTs-Den does not change through the modification.

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Fig. 2: FESEM image (a) GO, (b) GO-Den, (C) HNTs, (d) HNTs-Den.

3.2.

Adsorption process

As experimental results show in Fig.3, The removal of AB92 is significantly improved after the modification of adsorbents with PPI dendrimer, due to the electrostatic attraction forces between the positively charged amine groups of PPI and negatively charged dye molecules. These results are obtained at optimum values of HNTs dosage of 0.3 g/L at pH 5 and AB92 concentration of 25mg/L. The optimum values for GO-Den are 0.06g/L of adsorbent dosage, pH 3 and 50 mg/L of AB92.

100 80

GO Dye Removal (%)

GO-PPI-G2

HNTs

60 40 20

(d)

HNTs-PPI.G2

70 60 50 40 30 20

0 0

Time (min)

10 0 0

30 40 Time (min)

Fig. 3: Comparison of removal graphene oxide and HNT s before and after the modification with dendrimer (PPI).

3.3. Effect of pH Dye removal was examined at various range of pH value. The optimum pH values for HNTs-Den and GODen were achieved 5 and 3. Acidic dye preformation at acidic pH was higher than basic pH values, due to the presence of H+, which increases the positive charge on the surface of the absorbent that leads to higher adsorption of dye molecules. As Fig.4 clarified, the affinity of AB92 in acidic pH is remarkable compared to others pH values. The dye removal of HNTs-Den and GO-Den have grown practically 42% and 84% compared to the unmodified substrates.

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Fig. 4: Effect of different pH value on AB92 removal by HNTs and HNTs-DenG2 (a) GO and GO-Den (b),

4. Conclusions In this study, the surface of GO and HNTs were successfully grafted by PPI dendrimer. FESEM analysis of HNTs and GO were presented before and after the modification process. Experimental results showed that the unmodified selected adsorbents have achieved low dye removal percentages compared to the modified ones. The reason is related to the higher accepted site for molecules due to the existence of amine groups in the structure of the modified adsorbents. The results illustrated that the acidic pH was the optimum value for AB92 removal. Approved pH for HNTs and GO were 5 and 3, respectively.

References [1] [2]

[3] [4] [5] [6] [7] [8] [9]

Wawrzkiewicz, M., et al., Adsorptive removal of acid, reactive and direct dyes from aqueous solutions and wastewater using mixed silicaâ&#x20AC;&#x201C;alumina oxide. Powder Technology, 2015. 278: p. 306-315. Nekouei, F., et al., Kinetic, thermodynamic and isotherm studies for acid blue 129 removal from liquids using copper oxide nanoparticle-modified activated carbon as a novel adsorbent. Journal of Molecular Liquids, 2015. 201: p. 124-133. Rong, X., et al., Adsorptionâ&#x20AC;&#x201C;photodegradation synergetic removal of methylene blue from aqueous solution by NiO/graphene oxide nanocomposite. Powder Technology, 2015. 275: p. 322-328. Ngah, W.W., L. Teong, and M. Hanafiah, Adsorption of dyes and heavy metal ions by chitosan composites: A review. Carbohydrate Polymers, 2011. 83(4): p. 1446-1456. Luo, X., et al., Synergic adsorption of acid blue 80 and heavy metal ions (Cu 2+/Ni 2+) onto activated carbon and its mechanisms. Journal of Industrial and Engineering Chemistry, 2015. Ghasemi-Fasaei, R., et al., Sorption characteristics of heavy metals onto natural zeolite of clinoptilolite type. International Research Journal of Applied and Basic Sciences, 2012. 3(10): p. 2079-2084. Liu, R., et al., Removal of methyl orange by modified halloysite nanotubes. Journal of Dispersion Science and Technology, 2012. 33(5): p. 711-718. Perreault, F., A.F. de Faria, and M. Elimelech, Environmental applications of graphene-based nanomaterials. Chemical Society Reviews, 2015. Marcano, D.C., et al., Improved synthesis of graphene oxide. ACS nano, 2010. 4(8): p. 4806-4814.

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The 13th Asian Textile Conference Geelong, Australia, November 3 - 6, 2015

The morphology of electrospun Polyacrylonitrile/polyvinylpyrrolidone composite nanofiber Sheng-Wei Mei1, Sheng-Yin Peng1, Yang-Chun Fan1, Zi-Xin Wei1, Chien-Lin Huang*1, WenCheng Chen1 1

Department of Fiber and Composite Materials, Feng Chia University, Taichung 40724, Taiwan

Abstract. Polyetheretherketone (PEEK) possesses good chemical resistance, radiolucency, and mechanical properties similar to those of human bones. As such, PEEK is particularly suited for nanofiber biomedical application. Porous biomaterials with the appropriate 3D surface network can enhance biological functionalities, especially in tissue engineering, but is difficult to accomplish this on an important biopolymer, such as PEEK, because of its inherent chemical inertness. However, PEEK can be sulfonated via concentrated sulfuric acid to disperse PEEK in organic solvent. To date, sulfonated polyetheretherketone (sPEEK) nanofibers are insufficiently understood. In addition, only a few studies on the proton exchange membrane have been published. In this study, a 3D porous and nanostructured network with bio-functional groups was produced on colloid-electrospun sPEEK. sPEEK powders were obtained by adding PEEK powder to concentrated sulfuric acid. sPEEK powders were re-dispersed as colloids in organic mixture solvent (dimethylacetamide). A systematic study of the effects of sPEEK on the solution properties and electrospinning process is necessary to obtain a better understanding of the manipulating of electrified jets to produce sPEEK nanofibers. The morphologies and thermal properties of sPEEK electrospun fiber mats were investigated. Results revealed that the high concentration sPEEK colloid solution could be electrospun to produce sPEEK nanofibers.

Keywords: sulfonated polyetheretherketone, electrospinnig.

1. Introduction Porous biomaterials with the proper three-dimensional (3D) surface network can enhance biological functionalities especially in tissue engineering, but it has been difficult to accomplish this on an important biopolymer, polyetheretherketone (PEEK), due to its inherent chemical inertness. In this study, a 3D porous and nanostructured network with bio-functional groups is produced on electrospun sulfonation-treated PEEK. Electrospun fibers with high surface area to volume ratio and structures mimicking extracellular matrix have shown great potential in tissue engineering[1]. The loose bonding between nanofibers is beneficial for tissue ingrowth and cell migration, promoting good nutrition distribution throughout whole fibrous scaffold. PEEK is a polyaromatic, semicrystalline, rigid, thermoplastic polymer with excellent mechanical properties and high resistance to various chemicals and radiation[2]. Besides, PEEK is non-cytotoxic and can be repeatedly sterilized using conventional steam, Îł-irradiation and ethylene oxide treatment without deterioration of its mechanical properties. All these benefits have rendered particulate reinforced PEEK attractive for biomedical applications, including use as material for orthopaedic implants.

2. Experimental PEEK (1 g) was stirred with 50 mL of concentrated sulfuric acid at 40 oC for 3 Day. Subsequently, the uniform suspension with 2% (w/v) was precipitated drop-by-drop into a 20-fold excess volume of Distilled water. sPEEK particles were washed via distilled water and then separated via centrifugation. sPEEK particles were washed via distilled water and then separated via centrifugation. Precipitated sPEEK powders were dried continuously in a oven at 60 and 150 oC, respectively. The preweighed sPEEK polymer was added in a dimethylacetamide (DMAc) solvent and vigorously stirred for several hours with the assistance of temperature. All of the prepared solutions were subjected to room temperature electrospinning, in which the needle size was Di/D 0 /length=63mm/0:53mm/4 mm, where D i and D 0 are the inner and outer diameters of the needle,

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respectively. The prepared solutions were delivered by a syringe pump (Cole–Parmer) to the needle at a controlled flow rate (Q). High electrical voltage (V) was applied to the spinneret by using a highvoltage source (MECC, HVU-40P100) to provide sufficient electric field for electrospinning. To construct a needle-to-plate electrode configuration, an aluminum board (30 × 30 cm2) was used as a collector for the electrospun fibers at a fixed tip-tocollector distance of 21 cm. The morphology of the fibers was observed under a scanning electron microscope (SEM, Hitachi S4100). The fiber diameters were measured form a collection of ~200 fibers, from which their average diameter (df) was determined.

3.Results and discussion Dynamic light scattering (DLS) experiments probed the solution structure of the sPEEK colloid in DMAc at 0.1 mg/mL-1 concentrations. The size of the aggregates for sPEEK was 140 nm. Fig. 1(a) and 2(a) shows the obtained products from the electrospinning process of the sPEEK solutions with 25 wt% and 26 wt% concentration, respectively. A beaded fiber-like structure was seen in the electrospun 25 wt% sPEEK/DMAc solutions. Mowever, a bead-free fibers was obtained in the electrospun 26 wt% sPEEK/DMAc solutions. To determine the fiber diameters of fibers, 200 measurements of fiber diameter were obtained for the sPEEK nanofibers. The d f distribution of the electrospun 25wt% sPEEK solution is shown in Fig. 1(b). The d f of the sPEEK fibers was 158 ± 49 nm, and no PVA fibers lower than 325 nm were noticed. The d f distribution of the electrospun 26wt% sPEEK solution is shown in Fig. 3(b). The d f of the PVA/GNS fibers was calculated to be 170 ± 50 nm. It should be noted that the d f of the sPEEK nanofibers was increased with increased sPEEK concentration.

(b)

(a) Percentage (%)

0 0

100

200

300

400

500

fiber diameter (nm)

Fig. 1. (a) SEM image of electrospun product prepared from 25 wt% sPEEK solution. (b) Histogram plots of the fiber diameters of electrospun 25 wt% sPEEK solution.

(a)

(b) Percentage (%)

0 0

100

200

300

400

fiber diameter (nm)

Fig. 2. (a) SEM image of electrospun product prepared from 26 wt% sPEEK solution. (b)

500

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Histogram plots of the fiber diameters of electrospun 26 wt% sPEEK solution..

4.Conclusions The sPEEK nanofibers are successfully prepared by electrospinning a collided DMAc solution that has various amounts of sPEEK. The fiber diameters of of the sPEEK nanofibers was increased with increased sPEEK concentration.

Acknowledgment The authors are grateful to the Ministry of Science and Technology , Taiwan (ROC) for the research grant (MOS T104-2622-E-035-014-CC2) that supported this work.

References [1] Y. Zhao, H. M. Wong, W. Wang, P. Li, Z. Xu, E. Y. W. Chong, C. H. Yan, K. W. K. Yeung, P. K. Chu, Biomaterials, 34, 9264 (2013) [2] K. Pielichowska and S. Blazewicz, Adv. Polym. Sci., 232, 97 (2010)

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The 13th Asian Textile Conference Geelong, Australia, November 3 - 6, 2015

The morphology of electrospun Polyacrylonitrile/polyvinylpyrrolidone composite nanofiber Sheng-Yin Peng 1, Chien-Lin Huang 1, Chih-Kuang Chen1 1

Department of Fiber and Composite Materials, Feng Chia University, Taichung 40724, Taiwan

Abstract. Producing a high surface area PAN-based carbon nanofiber (CNF) have been of immense interest beacuse of their potential for applications in various fields, ranging from chemistry to physics and to biotechnology. Electrospinning is remarkably simple and versatile technique to prepare nanofiber or composite nanofibers. In this study, the Polyacrylonitrile (PAN)/ polyvinylpyrrolidone (PVP) nanofiber are prepared by electrospinnig. After removing most of PVP from the PAN/PVP nanofiber, the porous PAN nanofiber, and ultra-fine PAN nanofiber can be obtain. Although literature is available on electrospun PAN/PVP nanofibers, little information is available on the effects of the ratio of PAN/PVP and molecular weight of PVP, solution morphologies, and microstructures. To obtain a better understanding on manipulating electrified jets to produce fibers with different structures, a systematic study of the effects of PVP on solution properties and electrospinning process is necessary. The effects of PVP addition on solution rheology, conductivity, and morphology were investigated. The PAN/PVP composite fibers were characterized via scanning electron microscopy, Brunauer-Emmett-Teller nitrogen adsorption, and Fourier transform infrared spectroscopy. The results revealed the effects of PVP with various concentration and molecular weight on the microstructure, and morphology of PAN/PVP composite nanofibers. Furthermore, the porous, and ultra-fine PAN nanofiber carbonized into CNF via high temperature furnace.

Keywords: Polyacrylonitrile , polyvinylpyrrolidone , electrospinnig.

1. Introduction Polyacrylonitrile (PAN) is a thermoplastic semicrystalline polymer. It is a hard, slow to burn, and low permeability to gases. About 90% of worldâ&#x20AC;&#x2122;s total carbon fiber productions are PAN-based. In addition to its well-known application as an excellent reinforcer for composites, PAN-based activated carbon fiber has also been receiving increasing attention in recent years as adsorbent for gas adsorption application and water treatment. Producing a high surface area PAN-based carbon nanofiber (CNF) have been of immense interest beacuse of their potential for applications in various fields, ranging from chemistry to physics and to biotechnology. Electrospinning is a simple and low cost method for the preparation of nano-fibers, and it can also be prepared different forms as hollow, porous fibers and beads, although the process is easy, but morphology and diameter of fiber by several polymer solution properties and processing parameters affected. However, electrospinning obtained diameter of fiber about 100 nm ~ 5 Îźm by the regulation of the above parameters. There are many studies hope to increase the surface area of the nanofiber. Preparing small holes on the fiber is the most effective way to increase the surface area of the nanofiber. Using two incompatible polymer components mixed phase separation method [1], liquid - liquid phase separation method [2] or added an inorganic nanoparticles methods [3]. However, phase separation method of making a porous fibrous most common method, whether by selection of different polymer phase separation, adjusting the ratio of the two polymer, molecular weight, etc., forming sea-island structure is similar to the two-component melt spinning, removing another component into ultra-fine nano-fibers [1]. If sufficient phase separation between two polymers in the nanofiber leads to dispersion of one in the matrix of the other, and, if the dispersed phase can be accessed and removed, internal pores and ultra-fine nanofiber can be created. In this study, the PAN/ polyvinylpyrrolidone (PVP) nanofiber are prepared by electrospinnig. After extracting with water, most of PVP from the PAN/PVP nanofiber can be selectively removed. Thus the porous PAN nanofiber, can be obtain.

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2. Experimental The polyvinylpyrrolidone (PVP, ALFA, Mw ~ 1,300,000) powders and polyacrylonitrile (PAN, sp2, Mw ~ 150,000) powders prepared to 8 wt% respectively and dissolved in N,N’-dimethylformide (DMF, ECHO) Stirred for 8 hours at room temperature.The PAN/PVP bicomponent nanofibers prepared weight ratio of 50/50 that also Stirred for 8 hours at room temperature. All of the prepared solutions were subjected to room temperature electrospinning, in which the needle size was Di/D 0 /length=63mm/0:53mm/4 mm, where D i and D 0 are the inner and outer diameters of the needle, respectively. The prepared solutions were delivered by a syringe pump (Cole–Parmer) to the needle at a controlled flow rate (Q). High electrical voltage (V) was applied to the spinneret by using a highvoltage source (MECC, HVU-40P100) to provide sufficient electric field for electrospinning. To construct a needle-to-plate electrode configuration, an aluminum board (30 × 30 cm2) was used as a collector for the electrospun fibers at a fixed tip-tocollector distance of 14 cm. The morphology of the fibers was observed under a scanning electron microscope (SEM, Hitachi S4100). The fiber diameters were measured form a collection of ~200 fibers, from which their average diameter (df) was determined.

3. Results and discussion The viscosity of 8 wt% PAN/DMF solution and 8 wt% PVP/DMF solution is 276.29 cP and 80.7 cP respectively. The molecular weight of PVP polymer was higher than that of PAN polymer; however, the viscosity of PVP/DMF solution was lower than that of PAN/DMF solution with the same concentration. This result was caused by higher molecular interaction between PAN polymer. Fig. 1(a) and 1(b) shows the obtained products from the electrospinning process of the 8wt% PVP/DMF solutions and 8 wt% PAN/DMF solution, respectively. A beaded fiber-like structure was seen in the electrospun 8 wt% PAN solutions. Moreover, a bead-free fibers was obtained in the electrospun 8 wt% PAN solutions. Fig 2(a) shows the SEM images of PAN/PVP = 50/50 bicomponent nanofibers, which was elecrospun from 8wt% PAN/PVP/DMF solution. A smooth fiber structure was obrained in PAN/PVP = 50/50 bicomponent nanofibers. Fig 2(b) shows the SEM images of PAN/PVP nanofibers, which was residual PAN fiber after selective removal of PVP via washing with ethanol/distilled water for one day. Continuous residual fibers was seen even if PVP is removed selectively from PAN/PVP = 50/50 fibers. Moreover, the nanofibers had bump and non-smooth surface structure on it.

(a)

(b)

Fig. 1: SEM images of electrospun (a) 8 wt% PVP, (b) 8 wt% PAN.

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(a)

(b)

Fig. 2: SEM images of electrospun (A) 8 wt% PVA/PVP 50/50 bicomponent nanofibers, (b) 8 wt% PVA/PVP 50/50 bicomponent nanofibers by washed one day.

4.Conclusions The PAN/PVP = 50/50 bicomponent nanofibers were successfully prepared by electrospinning a 8 wt% PAN/PVP/DMF solution. Continuous residual and bump fiber structures were obtained even if PVP is removed selectively from PAN/PVP = 50/50 fibers.

Acknowledgment The authors are grateful to the Ministry of Science and Technology , Taiwan (ROC) for the research grant (MOST 104-2221-E-035-081-) that supported this work.

References [1] C. Kim, Y.II. Jeong, B.T.N. Ngoc, K.S. Yang, M. Kojima, Y.A. Kim, M. Endo, J.W. Lee, Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim. 3, (2007) 91. [2] J.T. McCann, M. Marquez, Y.J. Xia, Am. Chem. Soc. 128, (2006) 1436. [3] B.H. Kim, K.S. Yang, Journal of Industrial and Engineering Chemistry 20, (2014) 3474â&#x20AC;&#x201C;3479

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The 13th Asian Textile Conference Geelong, Australia, November 3 - 6, 2015

Morphologies of HDPE/PA6/GNS composites Yang-Chun Fan1, Hao-Ping Yang1, Chien-Lin Huang*1, Jia-Horng Lin1 1

Department of Fiber and Composite Materials, Feng Chia University, Taichung 40724, Taiwan

Abstract. Blending polyamide 6 (PA6) with high density polyethylene (HDPE) can improve impact strength and absorbing water of PA6. However, HDPE has no thermodynamic miscibility with PA because HDPE is a non-polar polymer, whereas PA6 is a strong polar polymer. Graphene nanosheets (GNS) have attracted significant scientific attention because of their remarkable features, including exceptional electron transport, excellent mechanical properties, and high surface area. When dispersing GNS in blend of HDPE/PA6, GNS can be located either in one phase or both phases or at the interface. This study focused on the morphology change of immiscible polymer blends with the incorporation of GNS. The direct relationship between morphology change of the blends and network structure of the GNS was also attempted to determine. HDPE/PA6 composites filled with GNS were prepared by melt compounding. Highly exfoliated graphene oxide (GO) powders were prepared by the Hummers method prior to reduction and then combined by lyophilization. GNS was synthesized by thermal reduction of GO. Different contents of GNS were introduced into the immiscible HDPE/PA6 blend. The phase morphology of HDPE/PA6/GNS were analyzed in detail by using scanning electron microscopy and transmission electron microscopy. Moreover, the presence of the network structure of GNS was confirmed by its electrical conductivity.

Keywords: Polyamide 6, high density polyethylene, Graphene nanosheets.

1. Introduction Polymer blending is the way widely used to improve the existing polymer properties. Although slightly polymer blends can be completely into single-phase matrial, most polymer blends are immiscible and display multiple phase morphologies. It is well know, there are two most important and common phase morphologies in the immiscible polymer blends, i.e. sea-island morphology and co-continuous morphology. Moreover, when dispersing GNSs in the blends of two polymers that are immiscible, the GNSs can be located either in one or both of the polymers or at the interface. The resulting electrical properties will depend on the location of the GNS as well as on the blend morphology. Blending PA with high density polyethylene (HDPE) can improve the low impact strength and high absorbent water of PA6. However, HDPE have no thermodynamic miscibility with PA because they are non-polar polymers, while PA is a strong polar polymer. In this work, High density polypropylene(HDPE)/PA6 composites filled with graphene(GNS) were prepared by melt compounding. Therefore, the morphologies of HDPE/Polyamide 6 (PA6)/GNS composites will be investigated.

2. Experimental 2.1.

Sample preparation

All the materials used in this study were commercially available high density polyethylene (HDPE)ă&#x20AC; polyamide 6 (PA6) and GNS. HDPE/PA6/GNS composites were prepared using lab-scale mixer (Brabender, Tzung Wei plastic Machinery Co, Ltd, Taiwan, R.O.C.) with a 55 cm3 mixing chamber and a pair of roller blades. For all of the prepared samples, the compounding temperature was set to 250 oC, and the roller speed was 100 rpm. Blending of GNSs and PA6 was initially, and subsequently mixed with PA6. The weight ratio between HDPE and PA6 was set as 50/50, and the content of GNS was 1.0 wt.% of the blend. The blended compounds were then compressionmolded at 250 oC for 3 min and subsequently

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cooled to room temperature to obtain 1 mm thick samples for further investigation.

2.2.

Scanning electron microscopy (SEM)

The phase morphologies of the nanocomposites were investigated by using a Scanning electron microscopy (SEM, Hitachi S4100). The composites was first cryogenically fractured in liquid nitrogen. To investigate the phase morphology of HDPE in the nanocomposite, the cryogenically fractured surface was etched in formic acid (FA) for 2.5 h to remove PA6 phase from the sample.

2.3.

Differential scanning calorimetry (DSC)

The crystallization and melting behaviors of the samples were investigated by using a DSC (Q20, TA) under a nitrogen atmosphere. A sample of about 4-6 mg was first heated from 25 to 300℃ at a heating rate of 10 ℃/min and isothermal at 300℃ for 10 min to erase the thermal history, then the sample was cooled down to 25 ℃ at a cooling rate of 10℃/min, and then the sample was heated again to 300℃ at the heating rate of 10 ℃/min.

3. Results and discussion Figs. 1 show the SEM images of the immiscible HDPE/PA6 = 50/50 blend without GNS and it’s nanocomposites with 1wt% GNSs, which was residual HDPE after selective removal of PA6 via washing with FA. For the HDPE/PA6 blend, the HDPE/PA6 forms the co-continuous morphologies (Fig. 1(a)). Moreover, with GNSs addition to HDPE/PA6 blend, the co-continuous morphologies become less noticeable. This result indicated that GNSs addition to HDPE/PA6 blends lead to significant change in morphology. HDPE particles have merged into larger domains. The melt-crystallization behaviors of both HDPE and PA6 components were characterized by using DSC and the results are shown in Fig. 2. To study the melt crystallization, samples were held at 300 oC for 10 min, followed by cooling at a 10 oC/min rate. The crystallization peak temperature of HDPE and PA6 were denoted as T c,HDPE and T c,PA6 , respectively. A shift of T c,HDPE and T c,PA6 of 3.1 and 8.0 oC were obtained for composites with GNS content of 1 wt%, respectively. T c,HDPE and T c,PA6 were increased with increased GNS content, respectively. However, the increase of T c,HDPE was lower than that of T c,PA6 . This result could be caused by the GNS dispersion in HDPE and PA6 Phase. (a)

(b)

Fig 1. SEM images show the cryogenically fractured surface morphology and the distribution of FMWCNTs in the nanocomposites at different magnifications. The contents of GNS are 0wt%(a), 1.0wt%(b), 3.0wt%(c).

Endothermic

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1 wt% 0 wt%

100

150

200

250

300

350

T ( C)

Fig 2. DSC cooling curves show the crystallization behaviors of HDPE component and PA6 component in HDPE/PA6/GNSs nanocomposites with different contents of GNS.

Conclusions For the HDPE/PA6 blend, the HDPE/PA6 forms the co-continuous morphologies. GNSs addition to HDPE/PA6 blends lead to significant change in morphology. HDPE particles have merged into larger domains. The crystallization temperature of HDPE and PA6 were increased with increased GNS content, respectively.

Acknowledgment The authors are grateful to the Ministry of Science and Technology , Taiwan (ROC) for the research grant (MOST 104-2221-E-035-081-) that supported this work.

4. References [1] Dasari, Z. Z. Yu, Y. W. Mai, G. Cai, H. Song, Polym., 50, 1577 (2009). [2] P. Fabbri, E. Bassili, S. B. Bon, L. Valentini, Polym., 53, 879 (2012). [3] X. Fangming, S. Yunyun, L. Xiaoxi, H. Ting, C. Chen, P. Ya, W. Yang, European Polymer Journal, 48, 350(2012).

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The 13th Asian Textile Conference Geelong, Australia, November 3 - 6, 2015

Novel Nanoporous Networks Constructed by Cellulose Nanowhiskers and PAN electrospinning fibers Xinwang Cao 1,2, Sheng Li 1,2, Binding+ 3, 4, Jianyong Yu 3, 4 and Xungai Wang 1, 2 1

College of Textile Science and Engineering, Wuhan Textiles University, Wuhan 430073, China National engineering laboratory for advanced yarn and fabric formation and clean production, Wuhan Textile University, Wuhan 430073, China 3 School of textiles, Donghua University, Shanghai 620210, China 4 Nanomaterials Research Center, Research Institute of Donghua University, Shanghai 200051, China

Abstract. Cellulose nanowhiskers as a kind of renewable and biocompatible nanomaterials evoke much interest because of its versatility in various applications. Herein, a novel controllable fabrication of spider-weblike nanoporous networks based on jute cellulose nanowhiskers (JCNs) deposited on the electrospun (ES) PAN nanofibrous membrane by simple directly immersion-drying method is reported. Jute cellulose nanowhiskers were extracted from jute fibers with a high yield (over 80%) via a 2,2,6,6-tetramethylpiperidine-1-oxyl radical (TEMPO)/NaBr/NaClO system selective oxidization combined with mechanical homogenization. The morphology of JCNs nanoporous networks/ES nanofibrous membrane architecture, including coverage rate, pore-width and layer-by-layer packing structure of the nanoporous networks, can be finely controlled by regulating the JCNs dispersions properties and drying conditions. The versatile nanoporous network composites based on jute cellulose nanowhiskers with ultrathin diameters (3-10 nm) and nanofibrous membrane supports with diameters of 100-300 nm, would be particularly useful for filter applications.

Keywords: Jute Cellulose Nanowhiskers; Electrospun Nanofibrous Membrane; Nanoporous Networks; PAN Nanofibrous Membrane

1. Introduction Network structure materials with nanosized pores had great potential applications as high efficient filter in air, food, and medical fields [1]. During our previous work, we prepared nanofibers/nets membranes using different kinds of polymer solutions by one step elctro spinning/netting process [2]. Cellulose nanowhiskers with ultra-thin diameters are promising to prepare new bio-based and environmental friendly porous network materials with high performance. Through supercritical drying and freeze-drying, the porous nanofibril networks aerogels with high specific areas, low densities and better mechanical properties than those of other organic polymers, could be obtained from aqueous cellulose nanowhiskers suspensions [3]. However, both methods require special equipments and/or solvent exchange process, which is time consuming, costly, extremely low productive, and even harmful to the environment. Therefore, more simple and high productive processes would be desirable for the preparation of nanowhiskers porous networks. In the present investigation, cellulose nanowhiskers extracted from chemically pretreated jute fibers by the combination of TEMPO/NaBr/NaClO system selective oxidization and mechanical homogenization were deposited on PAN electrospun nanofibrous membranes and formed into ultrathin nanoporous networks by simple immersing-drying process. The morphologies of nanoporous networks in the composite membranes were investigated by field-emission scanning electron microraph.

Corresponding author. Tel.: + 86-027-5936 7572. E-mail address: B.Ding@dhu.edu.cn.

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2. Experimental Jute bast fibers (Redbud Textile Tech. Inc., Jiangsu, China) were sieved under 60 mesh and vacuum dried before used. The starting materials included polyacrylonitrile (PAN, Mw=90, 000, Spectrum Chemical Co., Ltd., USA) and all other chemicals were of laboratory grade (Aladdin Chemical Regents Co., Ltd., China) and used as received without further purification. Preparation of jute cellulose nanowhiskers (JCNs) suspension was performed according to the procedure described elsewhere [4]. 6 wt% PAN elctrospinning solutions were prepared by dissolving in DMF at 60 oC with vigorous stirring for 6 h. PAN nanofibrous membranes were prepared at 20 kV in a relative humidity of 40 % at 24 oC at a feed rate of 1 mL/h and with a constant tip to collector distance of 18 cm using DXES-1 spinning equipment (Shanghai Oriental Flying Nanotechnology Co., Ltd., China).The ES nanofibrous membranes were dipped into the dispersions of DTAB (0.05, 0.10, and 0.15 w/v%) and jute cellulose nanowhiskers (0.05, 0.10, and 0.15 w/v%) in a glass bottle. The bottle containing dispersions and membranes was then placed under reduced pressure for 5 min using a vacuum pump to remove air bubbles present in the dispersions. The membranes were vertically removed from the dispersions in the bottle and excess dispersions carried over in the lower part of the membranes were removed by filter paper. The wet membranes were dried. The surface tensions of cellulose nanowhiskers, DTAB solutions, and their mixtures were test by a surface tension tester (QBZY, Fangrui Instrument Co. Ltd., Shanghai, China). The top morphologies of ES nanofibrous composite membranes were examined using a field emission scanning electron microscopy (FE-SEM) (S-4800, Hitachi Co. Ltd., Japan).

3 Results and discussion 3.1 Surface tension test From the point of view of molecular force, the molecules in fluid are constantly in a Brownian motion. However, inside liquid, there is mutual attraction (including repulsive force) between the molecules of fluid. Therefore, the resultant molecular force on the molecules in the bulk of liquid is zero. The mutual attraction between the molecules of the same kind of substance is defined as cohesion. Liquid is prone to gradually narrow liquid surface area. Surface tension is refered to the force on the liquid surface which makes the liquid level contracted into a minimum area [5]. The surface tension of the solutions directly influences the distribution of cellulose nanowhiskers on the nanofibrous membranes when it dried. Table 1 lists the surface tension test results of different solutions. We could see that the surface tensions of the JCNs suspensions, DTAB solutions, and their mixture are smaller than that of pure water (72.8 mN/m) [6], and the introduction of DTAB sharply decreases the surface tension of cellulose nanowhiskers suspensions. With the increasing of concentration of cellulose nanowhiskers and DTAB, the surface tension of both decrease. This could be interpreted by the surface tension of solutions affected by solute. Gibbs equation suggested that, Γ= -(dσ/dc)*c/RT

(3.1)

Where Γ is the surface excess, σ is the surface tension, T is the thermodynamic temperature, R is the gas content, c is the concentration of solutions. When (dσ/dc) < 0, Γ>0, which was defined as surface active substance [7]. Because of its decreasing the surface tension of solutions, it was called surfactant. Table 1 Surface tension test results of different solutions.

Solutions

Concentration（w/v%）

Surface tension（mN/m）

0.05

22.95

0.10

21.97

DTAB

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JCNs

DTAB + JCNs

0.125

17.35

0.15

17.55

005

63.77

0.10

62.56

0.15

52.17

0.05 + 0.05

37.12

0.05 + 0.10

36.81

0.05 + 0.15

35.18

3.2 Morphology of nanoporous networks on PAN nanofibrous membranes Fig. 1 shows the FE-SEM images of the nanoporous JCNs networks on PAN nanofibrous membranes. It could be seen that two dimensional (2D) ultrathin nanoporous networks based on cellulose nanowhiskers with diameter less than 10 nm were fabricated on the PAN nanofibrous membrane supports. One thing should be pointed out that PAN is super-hydrophilic. It could also be seen that there are cellulose nanowhiskers not only between the nanofibers, but also on the surface of PAN (Fig. 1a and 1b), which make the fiber surface rough.

( a )

(b )

Fig.1 FE-SEM images of porous JCNs networks in PANnanofibrous membranes,(a,b)

3.3 Mechanism of nanoporous networks formation TEMPO oxidized cellulose nanowhiskers have high surface free energy for numerous carboxyl and hydroxy groups present on its surface [8]. Therefore, during the direct drying of the JCNs aqueous suspensions, the oxidized cellulose nanowhiskers would highly aggregate to obtain transparent films with good gas barrier properties. Hydrophobic groups were introduced into its surface to decrease the polarity and surface free energy of JCNs and finally to prevent its rapid aggregation during drying. As shown in Fig. 5, the reaction between DTAB and JCNs converted the carboxyl group of TEMPO oxidized cellulose to the hydrophobic group. The JCNs/DTAB suspensions maintained a stable dispersion without gelation or sedimentation for hours in the atmosphere environment. If DTAB completely reacted with equimolar to carboxyl group of TEMPO oxidized cellulose, there would be NaBr ions or molecules at a level equimolar to the carboxyl group of TEMPO oxidized cellulose. If only part of DTAB reacted with JCNs, the unbound DTAB and NaBr would coexist, which would influence the formation of nanoporous structures. This should be studied further in the future.

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CH3(CH2)11

CH3 + N CH3 Br-

COONa O

+ OH

CH3

NaBr + CH3(CH2)11

CH3 + N CH3

COOO O

CH3

OH OH

Fig. 2 Reaction between DTAB and TEMPO oxidized cellulose.

4 Conclusions In summary, JCNs nanoporous networks, similar in appearance to spider webs, were prepared by simple immersing-drying of JCNs/DTAB dispersions using PAN electrospun nanofibrous membrane supports containing submicrometer-sized pores. The porous JCNs networks were composed of a mixture of single JCNs with widths smaller than 10 nm and JCNs bundles. Additionally, the versatile nanoporous composites would be particularly useful for ultrafiltration applications. We believe that the method described here with much lower energy consumption could be easily extended to provide a route to produce high performance filter from cellulose nanowhiskers.

Acknowledgements This work is supported by the National Natural Science Foundation of China (No. 51503162), Natural Science Fund of Wuhan Textiles University (143024), and Science and Technology Iinnovation P project Fund of Wuhan Textiles University (153009).

References [1] Wang X., Ding B., Yu J., & Wang M. (2011). Engineering biomimetic superhydrophobic surfaces of electrospun nanomaterials. Nano Today, 6, 510-530. [2] Hu J., Wang X., Ding B., Lin J., Yu J. & Sun G. (2011). One-step electro-spinning/netting technique for controllably preparing polyurethane nano-fiber/net. Macromolecular Rapid Communications, 32(21), 1683-1734. [3] Saito T., Uematsu T., Kimura S., Enomae T., & Isogai A. (2011). Self-aligned integration of native cellulose nanofibrils towards producing diverse bulk materials. Soft Matter, 7, 8804-8809. [4] Cao X, Ding B., Yu J., & Al-Deyab S. S. (2012). Cellulose nanowhiskers extracted from TEMPO-oxidized jute fibers. Carbohydrate Polymers, 90(2), 1075-1080. [5] Tyson W. R., & Miller W. A. (1977). Surface free energies of solid metals: Estimation from liquid surface tension measurements. Surface Science, 62(1), 267-276. [6] Jan R., & Helmut C. (2004). Superstructures of temporarily stabilized nanocrystalline CaCO 3 particles: Morphological control via water surface tension variation. Langmuir, 20(3), 991-996. [7] Rotenberg Y., Boruva L., & Neumann A.W. (1983). Determination of surfacetension and contact angle from the shapes of axisymmetric fluid interfaces. Journal of Colloid and Interface Science, 93 (1), 169-183. [8] Okita Y., Saito T., & Isogai, A. (2010). Entire surface oxidation of various cellulose microfibrils by TEMPOmediated oxidation. Biomacromolecules, 11(6), 1696-1700.

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The 13th Asian Textile Conference Geelong, Australia, November 3 - 6, 2015

Polyvinyl Alchol/Water Soluble Chitosan Electrospun Fiber Membranes: Process and Property Assessment Meng-Chen Lin 1, Ching-Wen Lou 2, Chih-Kuang Chen 3, Chien-Lin Huang

and Jia-Horng Lin1, 5, 6 + 1

Laboratory of Fiber Application and Manufacturing, Department of Fiber and Composite Materials, Feng Chia University, Taichung City 40724, Taiwan, R.O.C. 2 Institute of Biomedical Engineering and Materials Science, Central Taiwan University of Science and Technology, Taichung City 40601, Taiwan, R.O.C. 3 The Polymeric Biomaterials Lab, Department of Fiber and Composite Materials, Feng Chia University, Taichung City 40724, Taiwan, R.O.C. 4 Department of Fiber and Composite Materials, Feng Chia University, Taichung City 40724, Taiwan, R.O.C. 5 School of Chinese Medicine, China Medical University, Taichung City 40402, Taiwan, R.O.C. 6 Department of Fashion Design, Asia University, Taichung City 41354, Taiwan, R.O.C.

Abstract. Nano techniques for materials have been well developed as a result of the advanced technology. There are plenty of techniques to prepare nanomaterials, and electrospinning is one simple and convenient method. Microcapsules, nano membranes, superfine fibers, different types of nanomaterials are featured by having a high specific area. This crucial feature thus in turn provides a greater efficiency of the drug delivery to the resulting biomedical material that serves as a carrier. In this study, water soluble chitosan is used as an antibacterial drug. Different amounts of water soluble chitosan solutions are then combined with polyvinyl alcohol (i.e., the carrier), and are then processed by electrospinning in order to form polyvinyl alchol/water soluble chitosan electrospun fiber membranes. Finally, the surface morphology and the bacteriostatic properties of the electrospun fiber membranes is observed and evaluated.

Keywords: Electrospinning, Polyvinyl alcohol (PVA), Water Soluble chitosan (WS-CS), Viscosity, Conductivity.

1. Introduction Nanotechnology has been used in various territories, and it can make different types of products, such as nano-crystals, pulverulent body, fibers, and carbon tubes [1]. Electrostatic spinning is a simple and convenient method to produce nanofibers that are tremendously used in biomedical field for filtration, drug propagation, wound dressings, and tissue engineering scaffold [2]. Because of having high specific surface area and a high porosity, nanofibers facilitate drug delivery speed and filtration effect, and are good candidate for drug carriers. In addition, nano-products made by using nanotechnology bring convenience to users. However, when being absorbed by the human body, nano-products can cause ill effects, such as rejection phenomenon and metabolism failure. They may also jeopardize the environment [3]. As a result, biomedical products have been made with natural or synthetic materials with avirulence and biocompatibility. Polyvinyl alcohol (PVA) is a synthesis polymer, and has satisfactory hydrophilicity, biocompatibility, and avirulence. Its molecular chain consists of numerous hydrophilic groups, and PVA thus can be made into solution with water as its solvent. In addition, when serving as an electrospinning solution, PVA solution is free from the evaporation and any follow-up treatment of a poisonous solvent [4].

Corresponding author. Tel.: + 886-4-2451-8672. E-mail address: jhlin@fcu.edu.tw

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Being a derivative of chitin and a natural material, chitosan has desired biocompatibility, avirulence, and bacteriostatic properties. However, chitosan does not easily dissolve in ordinary organic solvents, but only acid solvents, such as methanoic acid, acetic acid, citric acid, and propionic acid can undo the intermolecular and intramolecular hydrogen bond [5]. The use of chitosan thus requires a complete removal of the acidity in the solvent in order to prevent possible harms to creatures. Therefore, this study uses modified water-soluble chitosan (WS-CS) to give bacteriostatic properties to nanofibers. In this study, PVA has a specified concentration while WS-CS has different concentrations. PVA and WS-CS are blended with different volume ratios. The viscosity and electrical conductivity tests are conducted in order to examine the influence of volume ratio and WS-CS concentration on the diameter of PVA/WS-CS nanofibers. The bacteriostatic property against Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli) of nanofibers are evaluated to determine the influence of WS-CS concentration.

2. Experimental 2.1. Materials PVA (Sigma-Aldrich Co., Ltd. U.S.A.) has a molecular weight (Mw) of 89000-98000 Da and is 99+%hydrolyzed. Water soluble chitosan (WS-CS, Charming & Beauty Co., Ltd., Taiwan, R.O.C.) has a Mw of 30000.

2.2. Experimental Procedure PVA powder and deionized water are blended into a 14wt% PVA solution. WS-CS powder and deionized water are blended into 5, 10, and 15 wt% WS-CS solutions. With a specified total amount of 20 ml, PVA and WS-CS are blended with various volume ratios of 100/0, 90/10, and 70/30. These mixtures are then electrospun with settings: a voltage of 20 kV, a 10 cm distance between the jet and collector, and a velocity of 1 ml/hr. This electrospinning thus forms mixtures into PVA/WS-CS electrospun fiber membranes.

2.3. Tests Viscosity A rotational viscometer (Fungilab, Spain) is used to measure the viscosity of different PVA/WS-CS mixtures.

Conductivity A pH/conductivity meter (EC500, Extech Instruments, U.S.A.) is used to measure the electrical conductivity of PVA/WS-CS mixtures five times, and data are analyzed.

Scanning Electron Microscope (SEM) PVA/WS-CS electrospun fiber membranes are cut along with a release paper, and are dried in an oven for 24 hours in order to completely remove moisture. Samples are then coated with gold with an Ion Sputter (E1010, Hitachi, Japan) for 30 seconds, after which they are analyzed by using an SEM (S3000, Hitachi, Japan).

Image Analyses An analyzing image software (Image-Pro 6.2 illustration) is used to measure the diameter of PVA/WS-CS electrospun fiber membranes.

Bacteriostatic Property S. aureus and E. coli are separately formulated into bacterial suspension. 0.1 ml suspension is coated onto a solid medium, after which samples are attached to them for 24 hours. The inhibition zone is then observed.

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3. Results and Discussion 3.1. Effects of Viscosity and Electrical Conductivity on the Morphology of PVA/WS-CS Nanofibers The viscosity and electrical conductivity of PVA/WS-CS mixtures with various blending ratios are indicated in Table 1. Increasing WS-CS concentration causes viscosity and electrical conductivity of the mixtures to increase. The addition of more chitosan can also result in a higher viscosity than that of a pure PVA solution. The abundant OH groups of PVA’s molecular chains as well as OH groups and CH 2 OH groups of WS-CS molecular chains form a hydrogen bond force that is ascribed to an increasing viscosity [5]. However, this phenomenon is absent when the mixture consists of a low WS-CS concentration of 5 wt%. As a low WSCS concentration provides WS-CS molecules and PVA molecules with a lower possibility for their intermolecular hydrogen bond force, the viscosity of the mixtures thus decreases. In contrast, a combination of 10wt% chitosan significantly increases the viscosity of the mixtures. WSCS is a polymer that easily dissociates cations, which in turn increases the electrical conductivity and then the formability of the nanofibers. Figure 2 indicates the SEM images of PVA/WS-CS nanofiber membranes as related to various blending ratios. Figure 2 (a-c) shows that a PVA/WS-CS blending ratio of 90/10 results in a good fiber formation. A low WS-CS concentration (5 wt%) decreases the diameter of nanofiber to 100-200 nm whereas a high WS-CS concentration (15 wt%) results in a diameter between 500-600 nm. A high WS-CS concentration gives the mixture a higher viscosity that is not easily refined into fibers, but a low WS-CS concentration leads to a contrary result. The morphology of nanofibers made with a PVA/WS-CS blending ratio of 70/30 is indicated in Figure 2 (d-f). WS-CS concentration of 5 wt% or 10 wt% results in a diameter of nanofibers between 80-200 nm, and their SEM images also exhibit bead formation. A low viscosity allows the mixtures to be easily electrospun onto the collector. In addition, compared to pure PVA solution, the mixtures with a low viscosity also have a greater electrical conductivity that causes a higher electric field force. As a result, a higher spinning force also facilitates the electrospinning of the mixtures with a low viscosity. Table 1: The viscosity and electrical conductivity of PVA/WS-CS mixtures as related to various blending ratios PVA/WS-CS blending ratio 100/0 90/10-15 wt% 90/10-10 wt% 90/10-5 wt% 70/30-15 wt% 70/30-10 wt% 70/30-5 wt% 0/100-15 wt% 0/100-10 wt% 0/100-5 wt%

(a)

(b)

Viscosity (cP) 657.6 914.7 722.5 677.1 887.4 592.9 503.2 154.3 48.5 3.8

Electrical conductivity (μS/cm) 0.66×103 2.7×106 1.924×106 1.179×106 6.470×106 4.670×106 1.494×106 -(cannot measure) 1.9370×107 1.1860×107

(c)

(g) (d)

(e)

(f)

Fig. 1: SEM images (3000×) of PVA/WS-CS electrospun fiber membranes as related to various blending ratios (a) 90/10-5 wt%, (b) 90/10-10 wt%, (c) 90/10-15 wt%, (d)70/30-5 wt%, (e) 70/30-10 wt%, (f) 70/30-15 wt%, and (g) PVA. Three concentrations of WS-CS are 5 wt%, 10wt%, and 15 wt%.

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3.2. Effects of WS-CS Concentrations on the Bacteriostatic Properties of PVA/WS-CS Nanofiber Membranes The bacteriostatic properties against S. aureus and E. coli of nanofiber membranes as related to various WS-CS concentrations. Regardless of the concentrations of being 5, 10, or 15 wt%, inhibition zones are distinctly present, indicating that chitosan has bacteriostatic effect against S. aureus and E. coli. The molecular chains of chitosan are composed of amino groups that release cation groups and pericytes, and thereby cause the intracellular matter in cells to ooze and eventually apoptosis. As a result, chitosan has bacteriostatic effect.

Fig. 2: Bacteriostaic efficacy against (A) S. aureus and (B) E. coli of chitosan with a concentration of a) 5 wt%, b) 10wt%, and c) 15 wt%.

4. Conclusions This study successfully produces PVA/WS-CS nanofiber membranes. When PVA/WS-CS blending ratio is 90/10, the diameter of nanofibers increases as a result of increasing WS-CS concentration. The combinations of blending ratio of 70/30 and a WS-CS concentration of 5 wt% and 10 wt% lead to bead formation of nanofibers, and are thus not qualified for electrospinning. The bacteriostatic test results indicate that PVA/WSCS nanofiber membranes have desired bacteriostatic effects against S. aureus and E. coli.

5. Acknowledgements The authors would like to thank Ministry of Science and Technology of Taiwan, for financially supporting this research under Contract MOST 103-2622-E-166-001-CC2.

6. References [1] M. Loos, in "Carbon Nanotube Reinforced Composites" (M. Loos, Ed., pp. 1, William Andrew Publishing, Oxford, 2015. [2] I. S. Chronakis, in "Micromanufacturing Engineering and Technology (Second Edition)" (Y. Qin, Ed., pp. 513, William Andrew Publishing, Boston, 2015. [3] M.-F. Chen, Y.-P. Lin, and T.-J. Cheng, Technovation, 33, 88 (2013). [4] K. Paipitak, T. Pornpra, P. Mongkontalang, W. Techitdheer, and W. Pecharapa, Procedia Engineering, 8, 101 (2011). [5] M. Z. Elsabee, H. F. Naguib, and R. E. Morsi, Materials Science and Engineering: C, 32, 1711 (2012).

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The 13th Asian Textile Conference Geelong, Australia, November 3 - 6, 2015

Preparation and Characteristics of Thermoplastic Composite Sheet using Recycle Carbon Fibers Yong Sik Chung +, Yun-Seon Lee, Wan Jin Kim, Jae Ho Shin, Chul Ho Lee Department of Organic Materials & Fiber Engineering, Chonbuk National University, Jeonju 561-756, Korea

Abstract. Recently, the applications of carbon fiber reinforced plastics (CFRPs) composite are much broader than before when it comes to the industries of automobile, ship, aerospace and war military because of its lightness, and high mechanical properties. Thermosetting plastics like epoxy are frequently used as binding matrix of CFRPs due to their high hardness, wetting characteristics and low viscosity. However, thermosetting plastics with excellent properties cannot be melted and remolded. Due to this reason, a thermosetting plastic waste causes serious environmental problems with the production of fiber reinforced plastic composites. Thus, many studies have focused on the carbon fiber reinforced thermoplastics (CFRTPs) composite and recycled carbon fiber (RCF). In this study, RCF was prepared from CFRPs using a pyrolysis method for separated resin, and degree of decomposition for epoxy resin was sufficiently confirmed from analysis of thermal gravimetric analysis (TGA) and scanning electron microscope (SEM). The cutting and grinding methods of RCF was used to prepare the carbon fiber composite sheet (CFCS). CFCS was manufactured by applying recycle carbon fibers and various thermoplastic fibers and compared the morphologies of surface and cross-section, mechanical properties, and crystallization enthalpy of CFCS at the different cooling conditions.

Keywords: Carbon fiber, Recycled carbon fiber, Composite sheet, Carbon fiber reinforced thermoplastic composite, Sheet molding compound.

1. Introduction Carbon fiber consists of a few or numerous filaments which diameter is 5-15 Îźm. When carbon fiber is mainly used as composite material reinforcement, it performs a role bearing external loads with matrix. In this case, matrix plays the role of binder between fibers used as reinforcement in carbon fiber reinforced plastics (CFRPs) composite and thermosetting plastics have been used usually as the matrix [1-4]. Thermosetting plastics like epoxy are frequently used as binding matrix of CFRPs due to its properties such as hardness, wetting characteristics and low viscosity. However, thermosetting plastics with excellent properties cannot be melted and remolded. For this reason, a thermosetting plastic waste cause serious environmental problems with the production of fiber reinforced plastic composites [4]. Thermoplastics are environment-friendly material as there is the possibility of separation from carbon fiber and remolding process can be applied through simple heat treatment. In addition, various ways such as treatments with acid, organic solvent and supercritical fluid are suggested as recycling plan of waste carbon fiber. However, carbon fiber separated from carbon fiber reinforced thermoplastics (CFRTPs) composite is discarded or utilized as low-grade filler, because its length and type are so various and expensive for treatment process. In this research, an optimal treatment condition is suggested for recycling of carbon fiber from CFRPs composites through pyrolysis method. Recycled carbon fiber composite sheet (RCFCS) is also fabricated by mixture of RCF and thermoplastic fiber. And in the fabrication process, effects of each condition on the physical and chemical properties of RCFCS is compared and analyzed.

Corresponding author. Tel.: + 82-010-7247-2350 E-mail address: psdcolor@jbnu.ac.kr

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2. Materials and Experimental 2.1. Recycled carbon fiber (RCF) preparation RCF was obtained from CFRP (USN150 SK chemical, Korea) which is reinforced by one-way carbon fibers. Before pyrolysis, CFRP was cut by Cutter mill (Hankook crusher Co., Ltd.), and due to selection of optimal pyrolysis temperature, Thermogravimetric analyzer(TGA, Q50, TA Instruments) was utilized by applying the heating rate of 10 ℃/min at temperature of 400 ℃, 600 ℃ and 800 ℃. Pieces of CFRP were pyrolyzed at temperature of 400 ℃, 600 ℃ and 800 ℃ using a horizontal high temperature furnace (Jeon Heating Industrial Co., Ltd). Surface morphology of pyrolyzed CFRP was observed by scanning electron microscope (SEM, SU-70, HITACHI), Prepared RCF which removed resin from CFRP was cut by cutter (HC, Ham-cut) at 4000 rpm for uniform length.

2.2. Recycled carbon fiber composite sheet (RCFCS) fabrication RCFCS was fabricated by RCF prepared in 2.1. with PET(Polyethylene terephthalate, Huvis, Korea), PE/PP (Polyethylene/Polypropylene, Huvis, Korea) as thermoplastic fibers binder. Properties of thermoplastic fibers are listed in Table 1. RCF and thermoplastic fibers were dispersed in 3000 ml of water with different ratio. RCF/thermoplastic fiber slurries were agitated at 400 rpm of rotation speed, and then 100 ml of PAA(Poly(acrylic) acid. 0.5 wt.% in water) was added into slurries as dispersant. Using uniformly dispersed slurries, RCFCS were fabricated by paper making machine. Fabricated RCFCS was dehydrated by vacuum pump and then dried at 80 ℃ for 3 h. Hot-pressing process was performed for improvement of bonding strength with melting of thermoplastic fibers at 150 ℃ at 5 MPa for 3 min. And then RCFCS was cooled for variations of crystallinity according to different cooling methods. Temperature of hot-pressing and cooling method of RCFCS are showed in Fig. 1. The morphologies of RCFCS are explored using a SEM and the mechanical properties are measured by universal testing machine (UTM, INSTRON 5560). Thermal analysis measurement was performed for crystallinity characterization according to different cooling methods using a TGA. Table 1: Properties of thermoplastic fibers. Fineness (Denier)

Length (mm)

Melting point

Working temperature

(℃)

LM-PET

100/250

150

PE/PP

130/170

150

Fig. 1: Change of hot-pressing and cooling temperature of RCFCS as a function of time.

3. Result and Discussion 3.1. Recycled carbon fiber (RCF) The thermal decomposition behavior of CFRP was analyzed by heating rate of 10 ℃/min at temperature of 400 ℃, 600 ℃ and 800 ℃ respectively. As seen in Fig. 2, weight loss of CFRP was appeared to 55 %, 70 % and 72% at 400℃, 600℃ and 800℃, respectively. As the results of TGA analysis, epoxy resin was existed in CFRP at 400 ℃ and decomposed completely at more than 600 ℃. Therefore, the optimal pyrolysis temperature was determined to 600 ℃ for separation of the epoxy from CFRP

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CFRP pyrolyzed at 400 ℃, 600 ℃, 800 ℃ using the high-temperature furnace was observed through SEM (Fig. 3). Untreated CFRP showed that epoxy resin was coated on the surface of the carbon fiber (Fig. 3 a) and CFRP treated at 400 ℃ showed that residual amount of epoxy resin was partially present (Fig. 3 b). However, in the Fig 3 c and Fig 3 d, CFRPs treated at 600 ℃ and 800 ℃ indicated that surface of carbon fibers was oxidized partially and had rough appearance because of relative high pyrolysis temperature. But, epoxy resin deposited was completely removed on the carbon fiber.

Fig. 2: TGA analysis of RCF according to temperature condition.

Fig. 3: Surface observations of RCF according to pyrolysis temperature; (a) untreated, (b) 400 ℃, (c) 600 ℃, (d) 800 ℃.

3.2. Recycled carbon fiber composite sheet (RCFCS) RCFCS was fabricated by mixture of RCF and thermoplastic fiber using a paper making machine, and then hot-pressing was performed. Fabricated RCFCS was observed cross-section and surface through SEM. Fig. 4 shows SEM image on surface and cross section obtained from RCFCS according to CF-PET content ratio and cooling conditions. With increase of PET binder content, it was distributed uniformly in surface of RCFCS and the shape of surface could be seen smoother. Binding points between carbon fibers were increased with increase in PET binder content, and binder was penetrated uniformly into internal RCFCS. In addition, thickness of RCFCS fabricated in a slow cooling condition was thinner than that of natural cooling condition because pressure applied to the composite sheet was maintained until the binder was completely solidified. In the RCFCS fabricated by PE/PP binder, appearance and thickness of RCFCS were appeared tendency similar to those of RCFCS used by PET binder which is described above. Consequently, the amount of binder and cooling conditions affected the morphology and physical property of RCFCS. It is indicated that crystallinity of binder solidified in slow cooling condition is higher than that of natural cooling condition. In general, the cooling rate is known to affect the crystallinity of the molten polymer resin in the process of solidification. When the cooling rate is lowered rapidly from the melting point, crystalline polymer resin is presented in amorphous state at room temperature. However if the cooling rate is lowered slowly, the polymer resin is produced in crystal with heat at crystallization temperature (T c ). At this time, the crystallization temperature and degree of crystallinity can be determined by DSC measurement. Fig. 5 shows

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DSC analysis of RCFCS fabricated with PE/PP binder. Degree of crystallinity and crystallization temperature of PE/PP binder was calculated from area and temperature of exothermic peak appeared in Fig. 5. From these results of calculation, it was confirmed that degree of crystallinity of PE/PP binder was lower in the natural cooling condition than in slow cooling condition.

Fig. 4: SEM of surface and cross section obtained from RCFCS according to CF-PET content ratio and cooling conditions; (a) natural, (b) slow.

Fig. 5: DSC analysis of RCFCS (PE/PP) according to content ratio and cooling condition; (a) natural, (b) slow.

4. Conclusion In this paper, RCF was prepared after the epoxy resin was separated from carbon fiber composite using a pyrolysis method. Prepared RCF was used for fabrication of composite sheet with PET and PE/PP thermoplastic fiber as binder, and then cooling process of RCFCS was performed through the different temperature. From the TGA and SEM measurements, it was confirmed that epoxy resin was completely decomposed at more than 600 â&#x201E;&#x192; by pyrolysis method. Binding points of RCFCS were increased with increase in content of binder, which was penetrated uniformly into internal composite sheet. In addition, thickness of RCFCS fabricated in a slow cooling condition was thinner than that of natural cooling condition because pressure applied to the RCFCS was maintained until the binder was completely solidified. Increase of binder content led to higher tensile strength of RCFCS, which fabricated with PET binder had the highest tensile strength. In the slow cooling condition, crystallinity of binder was improved as result of sufficient crystal growth which has to have higher tensile strength.

5. References

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[1] Kim, Y.A., “Carbon Fiber Composite.” Physics & High Technology, Vol. 12, No. 3, 2003, pp. 31-35. [2] Schwartz, M.M., Composite Materials Handbook, McGraw Hill Higher Education, 1983. [3] Rosato, D., Designing with Plastics and Composites: A Handbook, Springer, 1991. [4] Gauthier, M.M., Engineered Materials Handbook, Asm International Handbook Committee, 1995.

Preparation and Characterization Nanofibers from Poly (εcaprolactone)/Poly (vinyl alcohol)/ Tragacanth Hybrid Scaffolds Zahra Zare Khalili 1, S.H.Bahrami1 + and Marziye Ranjbar Mohammadi2 1

Textile Engineering Department, Amirkabir University of Technology, Tehran, Iran 2 Polymer Engineering Department, Textile group, Bonab University, Bonab, Iran

Abstract. We report fabrication of poly (Ɛ-caprolactone) (PCL), poly (vinyl alcohol) (PVA) and gum tragacanth (GT) nanofiber blends through two nozzles electrospinning process for either skin tissue engineering or as a wound dressing patches. Aqueous solution of PVA/GT (blend ratio: 60:40) was injected from one syringe and polycaprolactone solution from the other one. Response surface methodology (RSM) was used with three-levels for optimizing the average diameter and morphology of nanofibers. Scanning Electron Microscopy (SEM), Fourier Transform Infrared (FTIR) and differential scanning calorimetry (DSC) were used to characterize the nanofibers. Hydrophilicity and mechanical strength properties of nanofibers were evaluated. Presence of PCL increased mechanical strength of the nanofibers. Therefore these scaffolds with three dimensional morphology, hydrophilic nature, and proper mechanical strength can simulate skin structure and can also be used as drug delivery carriers.

Keywords: Electrospinning, Nanofibrous scaffold, Gum Tragacanth, Poly (ε-caprolactone), Poly (vinyl alcohol)

6. Introduction Since 1990s, there has been a growing interest in the fabrication of nanofibers by Electrospinning processes. Electrospinning is a fiber spinning method carried out at room temperature by a high-voltage electrostatic field, using a polymeric solution or melt that produces polymeric fibers with diameters in the sub-micron range from natural and synthetic polymers [1]. Electrospun nanoscale membranes can be used in medical applications such as tissue engineering and drug delivery, which involves proper physical, mechanical and biological properties of nanofibers [2-3]. The combination of both synthetic and natural polymers is a convenient strategy to provide an ideal 3D porous scaffold for biomedical applications [4]. Tragacanth (GT) is an anionic natural polymer for scaffold derivation due to its favourable biocompatibility and biodegradability, non-toxicity, wound healing and antimicrobial properties while Electrospinning of tragacanth poses many challenges because of high viscosity of solution and repulsive interaction between the polyanions along the chains of GT [5]. Previous reports have shown that to overcome this drawback it is possible to blend this polymer with polymers such as PVA [5] and PCL [6] as these synthetic polymers can result in an improved electrospinning process. In this research, we explored a novel method for fabricating three dimensional biodegradable nanofibrous scaffolds include poly caprolactone, poly vinyl alcohol and tragacanth through two nozzles electrospinning process. Therefore mix solution of poly vinyl alcohol and tragacanth are feeded through one syringe and polycaprolactone solution from the other one. Poly-Caprolactone is semi-crystalline polyester with strong hydrophobicity property and this synthetic polymer can be used in biomedical applications because of its sufficient mechanical strength and biocompatibility [7]. Poly (vinyl alcohol) (PVA) is a semi-crystalline hydrophilic biopolymer with many characteristics such as non-toxicity, good mechanical properties and good chemical thermal stability [1]. Two nozzles electrospinning is a good way to take advantages of the inherent properties such as excellent biological properties of tragacanth and to obtain the appropriate strength of scaffold. The current study aims at the screening of important process variables followed by using a response surface methodology (RSM) method. This technique is an effective method for optimizing several variable parameters. +

Corresponding author. Tel.: +98-21-64542680. E-mail address: hajirb@aut.ac.ir

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7. Experimental 7.1. materials Poly (vinyl alcohol) (Mw= 94–120 kDa) was purchased from MERK, Co and PCL (Mw 80 kDa) was supplied from Sigma-Aldrich chemical company. Gum tragacanth used in this study prepared from the stems of Fluccosus species of Astragalus bushes, growing in central areas of Iran. N, N- dimethylformamide (DMF) and chloroform were purchased from Aldrich chemical and Merck companies, respectively.

7.2. Electrospun scaffold fabrication GT and PVA were dissolved in distilled water in ratio of 40/60 (w/w) [5] at concentration of 5 %( w/v) and stirred at room temperature until complete dissolution. PCL was dissolved in 1/1(v/v) solution of chloroform/DMF in order to get 12wt% concentration. GT/PVA and PCL solutions were co-electrospun simultaneously into nanofibers by generating electric field with a high voltage power supply (0-25kV), a needle with inner diameter of 0.40 mm and two pumps (MEDIFUSION, MS-2200). Resultant webs were collected on the grounded aluminum rotating drum (40 rpm) with 100 mm in diameter at room temperature.

7.3. Characterization of scaffolds Electrospun nanofibrous membranes were coated with a layer of gold, and the morphology was observed using a scanning electron microscope (SEM) model ALS2300C made in Korea. The average diameters of the resulting nanofibers were determined from the SEM images, using Microstructure Measurement software. Fourier transform infrared spectroscopy (FTIR) analysis (Thermo Nicolet, Nexus 670 made in USA) was used to study the chemical characteristics of PVA/GT-PCL nanofibers. The tensile properties of the electrospun nanofibers were examined with Instron (model 5566, USA). The hydrophilic/hydrophobic properties of the PVA/GT-PCL nanofibers were measured by the drop method, which a video contact angle instrument (Sony model SSC-DC318P, Japan) was used for capturing images. Thermal properties were examined by differential scanning calorimetry (model 2010, USA) and samples were heated from room temperature to 200 °C at a heating rate of 10 °C/min in N 2 atmosphere.

8. Results and discussion 8.1. Preparation and characterization of electrospun PVA/GT-PCL scaffolds In order to obtain nanofibers with the best morphology and diameter, Response surface methodology (RSM) was used to investigate the effect of electrospinning parameters such as flow rate of polymer solutions, distance between syringe tip/collector and applied voltage on the morphology and diameter of nanofibers at three levels -1, 0 and +1. However, nanofibers (Fig. 1) were selected as optimum nanofibers for further experiments because of higher amount of GT and The SEM images show that the fibers diameter was approximately 132 nm and a smooth bead-less morphology was obtained.

Fig. 1: Optimum nanofibers; feed rate PVA/GT and PCL, 1.6 and 0.4 ml/hr respectively, voltage 15 kV and distance electrospinning 15 cm.

8.2. FTIR results FTIR spectra of GT powder, PVA/GT and PVA/GT-PCL nanofibers were recorded (Fig. 2). In the case of GT, characteristic peaks in the spectra were at 3426, 2930, 1744, 1627, 1440 and 1079 cm-1. The strong absorption band of GT at 3426 cm-1 corresponds to the O-H groups. The peaks at 2930 cm−1 and 1744 cm−1 represent the characteristic sharp peaks for methylene and carbonyl stretching vibrations in ketones and carboxylic acids groups, respectively. The bands observed at 1627 cm−1 and 1440 cm-1 could be assigned to

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stretching vibrations of carboxylate groups in the gum tragacanth. The band at 1079 cm−1 corresponds to stretching vibrations of alcoholic groups. The FTIR spectra of PVA/GT indicated the characteristic peaks of GT and PVA such as 3396, 2938, 1733, 1615 and 1434 cm−1, which assign to characteristic O-H, C-H, carbonyl, asymmetrical and symmetrical stretch of carboxylate groups, respectively. The strong absorption bands of PCL at 2936 and 2865 cm-1 which corresponds to the C-H 2 groups observed at The FTIR spectra of PVA/GT-PCL.

Fig. 2: FTIR spectra, GT powder, PVA/GT and PVA/GT-PCL nanofibers.

8.3. Mechanical properties Figure 3 presents the stress–strain curves of both PVA/GT and PVA/GT-PCL hybrid nanofibrous scaffolds. The PVA/GT scaffolds showed mechanical strength and strain of 6.38 MP and 9%, respectively. However PVA/GT-PCL nanofibers exhibited strength and maximum strain of 6.65 MP and 84%, respectively. Increase in strain of PVA/GT-PCL scaffolds was mainly because of using PCL in the formulation.

Fig. 3: Stress-strain curves and mechanical properties of the PVA/GT, PVA/GT-PCL.

8.4. Hydrophilicity of nanofibers Results of hydrophilicity showed that PCL nanofiber was highly hydrophobic and the obtained contact angle was about 123°. However PVA/GT-PCL web showed interesting wettability characteristics with a contact angle of 55°, because the water soluble components (GT and PVA) enhance hydrophilicity of nanofibers. Fig 4 shows results of the Hydrophilicity of scaffolds. a

Fig. 4: Contact angle of electrospun nanofibers; a) PCL nanofibers, b) PVA/GT-PCL nanofibers.

8.5. DSC results Figure 5 gives the DSC profiles of the GT powder, PCL and PVA/GT-PCL nanofibers. The DSC thermogram for GT power shows a very broad endothermic peak corresponding to dehydration of the GT polymer starting from 48 °C and ending at 202°C with the peak temperature at 89 °C. The DSC curve of the PVA/GT nanofibers (not shown) reveals peak relative to dehydration at 78 °C. Gum tragacanth decomposes

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at 250-280°C. For PCL nanofiber the endothermic peak related to the melting of the crystalline phase is observed in a temperature range between 30 and 70 °C, with a maximum at 59.5 °C. The melting peak of PCL and dehydration of PVA/GT nanofibers shifts to lower temperature starting at 54 °C and ending at 68 °C with the peak temperature at 58.6 °C. This shows presence of these polymers affected the thermal behaviour of each other. C

Fig. 5: DSC curve of A: GT powder, B and C: PCL and PVA/GT-PCL nanofibers.

9. Conclusion In this paper three-dimensional biodegradable nanofibrous scaffolds containing poly (ε-caprolactone) (PCL), poly (vinyl alcohol) (PVA) and gum tragacanth (GT) were produced successfully, through two nozzles electrospinning process. Scanning electron microscopy (SEM) results showed that fabricated nanofiber with optimum diameter and morphology had a smooth and bead-less morphology with the diameter of 132nm. The FTIR spectra of hybrid nanofibers confirmed existence of three polymers in nanofiber composition. DSC analysis of hybrid nanofibers prepared shows shift to lower temperature for melting peak of PCL and dehydration of GT powder. Presence of PCL increased mechanical strength and elongation of fabricated hybrid nanofibers and hydrophilicity nature of GT and PVA showed that these scaffolds can be good candidate for being applied as skin tissue substitutes and drug delivery carriers.

10.References [5] Santos, C., Silva, C. J., Büttel, Z., Guimarães, R., Pereira, S. B., Tamagnini, P., Zille, A., 2014. Preparation and characterization of polysaccharides/PVA blend nanofibrous membranes by electrospinning method. Carbohydrate polymers, 99, 584-592. [6] Leung, V., Ko, F, 2011. Biomedical applications of nanofibers. Polymers for Advanced Technologies, 22(3), 350365. [7] Mohammadi, Y., Soleimani, M., Fallahi-Sichani, M., Gazme, A., Haddadi-Asl, V., Arefian, E. ..., Ahmadbeigi, N., 2007. Nanofibrous poly (epsilon-caprolactone)/poly (vinyl (alcohol)/chitosan hybrid scaffolds for bone tissue engineering using mesenchymal stem cells. International journal of artificial organs, 30(3), 204. [8] Torricelli, P., Gioffrè, M., Fiorani, A., Panzavolta, S., Gualandi, C., Fini, M., Bigi, A., 2014. Co-electrospun gelatinpoly (l-lactic acid) scaffolds: modulation of mechanical properties and chondrocyte response as a function of composition. Materials Science and Engineering: C, 36, 130-138. [9] Ranjbar-Mohammadi, M., Bahrami, S. H., Joghataei, M. T., 2013. Fabrication of novel nanofiber scaffolds from gum tragacanth/poly (vinyl alcohol) for wound dressing application: In vitro evaluation and antibacterial properties. Materials Science and Engineering: C, 33(8), 4935-4943. [10] Ranjbar-Mohammadi, M., Bahrami, S. H., 2015. Development of nanofibrous scaffolds containing gum tragacanth/poly (ε-caprolactone) for application as skin scaffolds. Materials Science and Engineering: C, 48, 7179.Polycaprolactone nanofibers for the controlled release of tetracycline hydrochloride. [11] Karuppuswamy, P., Venugopal, J. R., Navaneethan, B., Laiva, A. L., Ramakrishna, S., 2015. Polycaprolactone nanofibers for the controlled release of tetracycline hydrochloride. Materials Letters, 141, 180-186.

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The 13th Asian Textile Conference Geelong, Australia, November 3 - 6, 2015

Preparation and Characterization of Electrospun PCL/Gelatin Nanofibers Containing Graphene Nanoparticles Mina Heidari 1, S. H. Bahrami 1 + and Marziyeh Ranjbar Mohammadi 2 1

Textile Engineering Department, Amirkabir University of Technology, Tehran, Iran 2 Textile Engineering Department, Bonab University, Bonab, Iran

Abstract. In this paper, poly (ε-caprolactone (PCL))/gelatin/graphene composite nanofibers have been successfully fabricated by electrospinning. RSM methodology based on four-variables (applied voltage, PCL/gelatin blend ratio, solution feed rate, and graphene concentration) with three-levels was used to investigate the effect of these different parameters on the morphology of nanofibers. The morphology and functional groups analysis of nanofibers were investigated by Scanning Electron Microscopy (SEM) and Fourier transform infrared (FTIR) respectively. Nanocomposite nanofibers showed higher tensile strength compared with neat PCL/gelatin nanofibers. Contact angle results demonstrated that nanofibers embedded with graphene nanosheets are being more hydrophil which can result in increasing cell proliferation. According to these improved characteristics of PCL/gelatin/graphene nanofibers, they are a promising candidate for application in tissue engineering and drug delivery system.

Keywords: Electrospinning, Poly (ε-caprolactone), Gelatin, Graphene, Nanofibrous scaffold.

1. Introduction Graphene, a two dimensional carbon nanomaterial with a hexagonal lattice structure has evoked a great deal of interest as it exhibits a superior biocompatibility, great electron transport capability, excellent mechanical properties as well as exceptional electrical and thermal conductivity. Recently graphene and graphene oxide have emerged as an enormous platform in biomedical applications such as drug delivery and tissue engineering. Construction of graphene/polymer nanocomposite nanofibrous scaffolds has been lately reported in several researches. The incorporation of graphene nanoparticles serves in favor of having a scaffold which represents extraordinary features such as improved mechanical, biological, electrical and thermal properties in comparison to neat nanofibers [1-2]. Ardeshirzadeh et al developed electrospun PEO/chitosan/graphene oxide nanofibrous scaffolds for controlled release of doxorubicin. It had been revealed that an interaction was occurred between drug molecules and GO nanoparticles with the scaffold leading to higher drug loading of 98% [2]. Qi et al fabricated nanofibrous biocomposite scaffolds of poly (vinyl alcohol) and graphene oxide through electrospinning. They found that Mouse Osteoblastic Cells grew well on the surface of scaffold. Moreover the mechanical and elasticity properties of the scaffolds were increased significantly [3]. PCL is aliphatic polyester that has been recognized to be biocompatible and biodegradable with good mechanical properties. A lot of researches have been conducted on electrospun nanofibrous scaffolds, although it’s poor hydrophilicity in along with low degradation rate restricts its biomedical applications. On the other hand, among natural polymers gelatin is considered to be the most abundant one obtained from hydrolysis of collagen. In addition, gelatin is a biocompatible and biodegradable biopolymer which had been applied in various fields for instance tissue engineering, drug delivery and wound dressing; nevertheless, its poor mechanical performance is considered to be a barrier for its vast range of applications. Therefore blending PCL with gelatin opens up the opportunity to overcome the deficiencies of natural and synthetic polymers. Recently several studies have been carried out based on producing PCL/gelatin nanofibrous structures [4]. Gautam et al fabricated and characterized PCL/gelatin nanofibrous scaffold. They found that the weight ratio of PCL/gelatin considerably impacted on the morphology of nanofibers. Furthermore MTT assay results confirmed cell proliferation on the scaffold which makes it a good candidate for tissue engineering applications [5]. +

Corresponding author. Tel.: +98-21-64542680. E-mail address: hajirb@aut.ac.ir.

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In order to establish a correlation between electrospinning parameters and fiber diameter Response Surface Methodology was utilized in this study. RSM is based on these steps: selection of variables and their levels, design of required experiments, carrying out experiments, and determination of optimum operating condition and lastly validation of the model [6]. In the present study, PCL/gelatin/graphene nanofibrous scaffolds are prepared via electrospinning. The incorporation of graphene into PCL/gelatin blend, results in great improvements in the mechanical as well as hydrophilicity properties of the nanocomposite nanofibrous scaffold, which makes it an excellent candidate for tissue engineering applications.

2. Experimental 2.1. Materials PCL (Mw=80kDa) was prepared from Sigma-Aldrich. Gelatin and glacial acetic acid were purchased from Merck Co. Germany. Graphene nanoplatelets, grade C750 was obtained from XG Sciences, USA. Firstly, 15%w/v solutions of PCL and gelatin in acetic acid 90% v/v were prepared. Then gelatin solutions were added to PCL drop by drop and the mixture was stirred 30 minutes in order to have a homogenous solution. Then graphene powder was ultrasonicated in acetic acid 90% v/v for 1 hour and consequently graphene were mixed with PCL/gelatin solution under continuous stirring for 1 hour.

2.2. Electrospinning A horizental electrospinning setup was utilized consisting of a 20 ml syringe with a needle tip (gauge 19 mm), a syringe pump (Atom Medical Corp 1235N Tokyo Japan) and a high-voltage power supply (0-40kV). Several parameters considered to be as the most influential in electrospinning process. The parameters are as following: PCL/gelatin blend ratio 25/75, 50/50, 75/25 (w/w), applied voltage in the range of 10 to 20 kV, solution feed rate in the range of 0.2 to 1.8 ml/hr and the concentration of graphene in the range of 0 to 2wt%. Electrospinning distance was kept constant at 15 cm.

2.3. Characterization of scaffolds Scanning Electron Microscope (SEM) (Seron Technology, AIS2300C, Korea) was employed to investigate the morphology and diameter of electrospun nanofibrous scaffolds. The nanofibers were gold coated prior to scanning. Microstructure measurement software was used to measure the diameter of the nanofibers. For each experiment average nanofiber diameter was determined from 100 measurements of random fibers. The statistical software Design Expert was utilized for the regression analysis of the experimental data. Mechanical properties of the electrospun nanofibers were evaluated using an Instron (5566 Universal Testing Machine USA). The cross-head speed was set at 5mm/min. Contact angle measurement of the electrospun nanofibers was obtained from a video contact angle instrument (Sony model SSC-DC318P, Japan) and then calculated by image analysis software (Image J). The structure of graphene nanoplatelets, PCL/gelatin and PCL/gelatin/graphene electrospun nanofibers were characterized by Fourier transform infrared spectroscopy (FT-IR, Thermo Nicolet, Nexus 670, USA).

3. Results and discussion 3.1. SEM results of electrospun PCL/gelatin/graphene scaffolds PCL/gelatin/graphene nanocomposite nanofibers were prepared through electrospinning. Four parameters including PCL/gelatin blend ratio, applied voltage, solution feed rate and graphene concentration were chosen as the most dominant parameters. It was revealed that with increasing the gelatin concentration in blend, the nanofiber diameter decreases remarkably. This could be ascribed to higher charge density created by gelatin inside the solution, as gelatin is a polyelectrolyte. As a result enhances the conductivity of the solution which serves in favor of producing nanofibers with lower diameter. As the applied voltage increases, the electrostatic force on the surface of the jet increases, consequently. This results in the further elongation of the jet during the electrospinning process, leading to create smaller nanofiber diameter. It is deduced that a rise in the nanofiber diameter would appear with increasing the solution feed rate. This finding also evidenced that while the graphene concentration increases the average diameter of electrospun nanofibers decreases due to higher electrical conductivity of the solution. Nevertheless, with increasing graphene concentration above 1.5wt% a slight increase in average diameter of nanofiber would take place, which may be attributed to the aggregation of graphene nanosheets.

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PCL/gelatin blend ratio of 50/50, an applied voltage of 20kV, a feed rate of 1 and a graphene concentration of 1.5wt% was selected as optimum electrospinning conditions. From SEM results presented in Fig. 1 it can be clearly seen that smooth and bead-free nanofibers were obtained.

Fig. 1: SEM image of electrospun nanofibers with optimum electrospinning condition.

3.2. Mechanical properties The mechanical properties of the PCL/gelatin and PCL/gelatin/graphene nanocomposite nanofibers were evaluated using tensile test. As it is depicted in Fig. 2, we found that the ultimate tensile stresses and strains of graphene incorporated nanofibers were greater than that of PCL/gelatin nanofibers. The increment in tensile stress could be attributed to the good dispersion of graphene nanosheets in the polymer scaffold and improved interaction between graphene nanosheets and PCL/gelatin chains.

Tensile Stress (Mpa)

2.5 2 1.5

PCL/gelatin

1 PCL/gelatin/graphe ne

0.5 0 -0.5

Tensile Strain (%)

Fig. 2: Tensile stress-strain curve of the PCL/gelatin and PCL/gelatin/graphene nanofibrous scaffolds.

3.3. Contact angle The contact angle measurement results of PCL/gelatin and PCL/gelatin/graphene nanofibers are depicted in Fig. 3. A water contact angle of 54Ě&#x160; was observed for PCL/gelatin nanofibers, whereas PCL/gelatin/graphene nanofibers showed a lower contact angle of about 35Ě&#x160;, which indicates higher hydrophilicity of graphene incorporated nanofibrous scaffolds. This could be ascribed to improved surface polarity in presence of graphene hydroxyl groups. a

Figure 3: Contact angles of (a) PCL/gelatin (b) PCL/gelatin/ graphene nanofibers.

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3.4. FTIR results FTIR spectra of graphene powder, PCL/gelatin and PCL/gelatin/graphene nanofibers are presented in Fig. 4. In the IR spectrum of graphene powder the characteristic peaks were observed at 3431 (O-H), 2920 and 2851 (C-H) and 1630cm-1 (C=C). In PCL/gelatin nanocomposite nanofibers, characteristic bands at 2944 and 2867, 1731, 1294, 1241 and 1180cm-1, are assigned to asymmetric and symmetric CH 2 , C=O, C-O and C-C, asymmetric and symmetric C-O-C groups of PCL and bands presented at 3306cm-1, 1650cm-1, 1538cm-1 are due to N-H, amide I, amide II groups of gelatin, respectively. In the IR spectrum of PCL/gelatin/graphene nanocomposite the characteristic band at 3100-3600cm-1 could be ascribed to the reaction between O-H band corresponding to graphene and NH2 band corresponding to PCL/gelatin. In comparison to graphene powder, a characteristic band presented at 3431cm-1 assigned to O-H groups has intensified, which demonstrates that graphene functional groups have taken reaction with PCL/gelatin chains. On the other hand, the observed band at 1650cm-1 in PCL/gelatin has shifted to 1647cm-1 indicating the presence of graphene in the structure.

4000

3500

3000

2500

a) graphene

2000 1500 1000 Wavenumber (cm-1 ) b) PCL/gelatin/graphene

500

Figure 4: FTIR images of graphene powder, PCL/gelatin/graphene and PCL/gelatin nanofibers.

4. Conclusion In our study PCL/gelatin/graphene nanocomposite nanofibrous scaffolds were fabricated by electrospinning. The morphology, mechanical and hydrophilicity properties of the scaffolds were investigated. The SEM micrographs of the electrospun mat showed that smooth and bead-free nanofibers were obtained. Moreover, the tensile strength of mats containing 1.5% graphene was increased significantly in comparison to pristine PCL/gelatin nanofibers. The incorporation of graphene nanosheets led to effective enhancement of hydrophilicity properties which makes the scaffold a proper candidate for tissue engineering applications. References [1] Ramazani, S., & Karimi, M. (2014). Electrospinning of poly (ε‐caprolactone) solutions containing graphene oxide: Effects of graphene oxide content and oxidation level. Polymer Composites. [2] Ardeshirzadeh, B., Anaraki, N. A., Irani, M., Rad, L. R., & Shamshiri, S. (2015). Controlled release of doxorubicin from electrospun PEO/chitosan/graphene oxide nanocomposite nanofibrous scaffolds. Materials Science and Engineering: C, 48, 384-390. [3] Qi, Y. Y., Tai, Z. X., Sun, D. F., Chen, J. T., Ma, H. B., Yan, X. B., ... & Xue, Q. J. (2013). Fabrication and characterization of poly (vinyl alcohol)/graphene oxide nanofibrous biocomposite scaffolds. Journal of Applied Polymer Science, 127(3), 1885-1894. [4] Ghasemi-Mobarakeh, L., Prabhakaran, M. P., Morshed, M., Nasr-Esfahani, M. H., & Ramakrishna, S. (2008). Electrospun poly (ɛ-caprolactone)/gelatin nanofibrous scaffolds for nerve tissue engineering. Biomaterials, 29(34), 4532-4539. [5] Gautam, S., Dinda, A. K., & Mishra, N. C. (2013). Fabrication and characterization of PCL/gelatin composite nanofibrous scaffold for tissue engineering applications by electrospinning method. Materials Science and Engineering: C, 33(3), 1228-1235. [6] Hakkak, F., & Rafizadeh, M. (2013). Optimization of electrospun polyacrylonitrile/poly (vinylidene fluoride) nanofiber diameter using the response surface method. Journal of Macromolecular Science, Part B, 52(9), 1250-1264.

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The 13th Asian Textile Conference Geelong, Australia, November 3 - 6, 2015

Preparation of antibacterial nano-silver sol

Feng Chen1,a, Chen Xia Bian1,Chun Sheng Chen1, Hua Zhang2,Jian wei Cui1,b 1

School of Textile and Clothes, Nantong University, China,226019 2 Nan Tong SIDEFU Textile Decoration Co.,Ltd a 1035495179@qq.com, bcui.jw@ntu.edu.cn

Abstract: This paper adopted two methods to prepare the antibacterial properties of nano-silver sol, researching the influence of the reaction temperature, and the concentration of silver nitrate on the size, the morphology and the dispersion of the nano-silver particle. First of all, we tested the absorbance of the prepared nano-silver sol by uv-vis to characterize the distribution width of the diameter of the nano-silver particle. Next, we researched the particle size and the dispersion of nano particles through TEM testing. Finally, with a halo test, we tested the antibacterial properties of the nano-silver sol prepared by the above two methods. The results shows that: 1) the nano silver sol prepared by the above two different methods both have certain antibacterial properties, and which prepared by the first method is better the second one; 2) the size of the nano silver particles are both about 20 nm, while in the aspect of the dispersion, method 1 is better than method 2; 3) when the concentration of silver nitrate is 0.05 mol/l, the distribution of the nano silver particle size is relatively narrower; 4) when the reaction temperature is 60 degrees, both two methods can make the reaction most completely and get the nano silver sol most stable. Key words: Starch; nano- Silver sol; Preparation; Antibacterial properties

1. Introduction Because of the small size effect, quantum effect and great specific surface area, nano-silver, as a new type of antibacterial materials, has a lot of advantages, such as high efficiency, good safety, wide range of antibacterial and etc so that it has very high application value. There are various methods to prepare silver nanoparticles, in which liquid reduction method is not only simple, low requirements for equipment and environment but also easy to operate, easy to achieve mass production, and is currently one of the most practical method.1 Liquid reduction method is to use Ag ion in silver salt reduced to Ag atom through chemical redox reaction to prepare silver nanoparticles. In reduction process, we often use polyethylene glycol, sodium hypophosphite, sodium citrate, glucose and so on as reduction agents, which are all relatively environment friendly. At the same time, we also use some organic protective agent, such as starch and polyvinyl alcohol and etc to prevent the reunion. These protective agents are rich in hydroxyl which can form coordination bonds with silver ions so that they will be wrapped on the surface of the silver nanoparticles, effectively preventing or reducing their reunion, dispersing and stablizing silver nanoparticles. We used two methods to prepare the antibacterial properties of nano-silver sol, researching the influence of the reaction temperature, and the concentration of silver nitrate on the size of, the morphology of and the dispersion of the nano-silver particle. First of all, we tested the absorbance of the prepared nano-silver sol by uv-vis to characterize the distribution width of the diameter of the nano-silver particle. Next, we researched the particle size and the dispersion of nano particles through TEM testing. Finally, with a halo test, we tested the antibacterial properties of the nano-silver sol prepared by the above two methods.

2. Experimental 2.1 Experiment materials and apparatus Materials: Silver nitrate (analytical pure, Guangdong Guanghua Sci-tech Co., Ltd ); Two hydrated sodium citrate (analytical pure, Xilong Chemical Co., Ltd ); Homemade modified starch; 2-3 Polyethylene glycol 2000 (PEG2000, analytical pure, Guangdong Guanghua Sci-tech Co., Ltd); Deionized water; Beef extract (biochemical reagent); Peptone(biochemical reagent); Agar powder (biochemical reagent); Pure sodium hydroxide (analytical pure); Sterile fibre sheep off whole blood(biochemical reagent); Anhydrous ethanol (analytical pure); Escherichia coli. Apparatus: magnetic stirrer; Electronic balance; KTR type ultraviolet disinfection car; thermostat oven; JEM-1230 type transmission electron microscope (TEM) (Japanese electronics co., LTD); TU-1901 ultraviolet-visible absorption spectrometer; FT-IR650 Fourier infrared spectrometer.

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2.2 Preparation of silver nanoparticles 2.2.1 Method one Use starch, kind of natural biodegradable polymer, as a protective agent and dispersant, and sodium citrate as reducing agent to prepare silver nanoparticles environmentally.

2.2.1.1 Experimental scheme The scheme is showed as following Table 1: Table 1: Experimental scheme of method one Sample

0.01

0.025

0.05

0.07

0.05

Starch : Silver nitrate (mol:mol)

2:1

Reaction time (min)

120

Reaction temperature(℃)

AgNO3 Concentration (mol/L)

2.2.1.2 Experimental progress

Pore certain amount of water into three flasks, and then mix some starch in, heat temperature to 95 ℃ and stir thirty minutes constantly to make starch gelatinized. Next, add the configured silver nitrate solution with certain concentration to the above three flasks, cool the temperature to 70 ℃, and keep stirring the mixture for reaction 10 minutes. Afterwards, add the sodium citrate solution with the speed of 1 drop per second into the above mixture until fully reacted. At this time, remove the prepared sol from the reaction flasks and make it cooling naturally.

2.2.2 Method two Use Polyethylene glycol as dispersant, protective agent and reducing agent to preparation silver nanoparticles

2.2.2.1 Experimental scheme The scheme is showed as following Table 2: Table 2: Experimental scheme of method two Sample

10#

11#

12#

13#

14#

AgNO3 Concentration (mol/L)

0.01

0.025

0.05

0.07

0.05

PEG:AgNO3 (g:g)

40:1

Reaction time (min)

120

Reaction temperature (℃)

2.2.2.2 Experimental process Add certain amount of polymer polyethylene glycol in distilled water, heating to appropriate temperature and stirring the mixture until the polymer polyethylene glycol had been dissolved. Then, drop into quantitative AgNO3 solution within a certain time, continuing stiring the mixture until fully reacted. At this time, remove the prepared sol from the reaction flasks and make it cooling naturally.

2.3 Characterization of silver nanoparticle Use TEM testing to research the size of, the morphology of and the dispersion of the silver nanoparticles. Adopt TU - 1901 ultraviolet - visible absorption spectrometer (absorption range of 200 ~ 800 nm, resolution 2 nm) analyze the distribution width of the diameter of nano silver sol with different silver nitrate concentration

2.4 Antibacterial property of silver nanoparticle

According to the AATCC Test Method 90 (Halo Test, also called AGAR AGAR Method),4 select of escherichia coli to test the antibacterial properties of silver nanoparticles.

3. Results and discussions 3.1 Influence of silver nitrate concentration on silver nanaoparticle

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Ultraviolet-visible absorption spectrum can roughly characterize the particle size, morphology, and the distribution of the particle size of silver nanoparticles. Ultraviolet-visible absorption spectra of sample 1 #, 2 #, 3 # , 4# were showed as following (Figure 1). Ultraviolet-visible absorption spectra of sample 8 #, 9 #, 10# , 11# were showed as following ( Figure 2). According to Figure 1 and Figure 2, we can find that every sample has a strong absorption peak at about 420 nm among the testing wavelength range (300-800), which is a typical spherical surface plasma resonance absorption characteristic peak of silver nanoparticles. 5 Moreover, the figure also showed that the absorbance of the sample solution gradually increased from with the increase of the concentration of silver nitrate, which indicates that there are more and more silver nanoparticles generated. After analyzing the shapes of the absorption peak, we can see that they are symmetrical and their half peak widths are narrower, which suggests that the prepared silver nanoparticles have good dispersion and a narrow particle size distribution under the protection of starch. 0.75

1.0

0.01molL 0.025molL 0.05molL 0.07molL Absorbance

Absorbance

0.01molL 0.025molL 0.05molL 0.07molL

0.5

0.50

0.25

300

400

500

600

700

800

300

400

Wavelength/nm

500

600

700

800

Wavelength/nm

Fig.1:Ultraviolet-visible absorption spectra of sample Fig.2:Ultraviolet-visible absorption spectra of sample 1 #, 2 #, 3 # , 4#(different concentration of AgNO3) 8 #, 9 #, 10 # , 11# (different concentration of AgNO3)

3.2 Influence of reaction temperature on silver nanaoparticle Basically, the action temperature mainly influenced three dimensions on the silver nanoparticles, reduction rate and completeness, crystal growth and stability of the nano-silver sol. Under atmospheric pressure, we recorded the change of the colors of the solution of 5#, 3#, 6#, 7#, 12#, 10#, 13#, 14#, from the preparation day, to one day, three days, a week, three weeks, a month after. Many experiments showed that when the temperature was low and the reaction speed was slow, only a small number of small particles of silver were generated and were easy to aggregate so that sample 12# had no significant color change, and poor stability. When the temperature was higher, it was easy to form silver mirror, which is contributed to the intensified Brownian motion under excessive temperature, increasing the opportunities of particle collision and leading to particles reunion.6 Based on our experiments and color variation of the solution of silver nanopartices prepared under different temperature, we can find that Sample 10# of method two, which are under 60 â&#x201E;&#x192;, is the most stable one, and has high reduction rate and completeness ,and the color changed least a month later.

3.3 TEM analysis The TEM images of sample 3# and sample 10# are showed in Fig3 and Fig4 respectively. From Figure 3. We know that the average size of the silver nanoparticles is about 20 nm, and that there is no reunion

Fig.3 TEM image of sample 3#

Fig.4 TEM image of sample 10#

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phenomenon when use starch as protective agent and dispersant. Meanwhile, Figure 4 shows that although the average size of the silver nanoparticles is also about 20 nm, silver nanoparticles, prepared by polyethylene glycol as the reducing agent and protective agent, form a large aggregate. Therefore, it indicate that the coating effect of starch promotes the dispersion of silver particles, preventing the reunion of the silver ions so that it can play role into a stabilizer and dispersant. However, the amount of the starch granule coated on the surface of the silver ions are different, the particle size present different.

3.4 Antibacterial properties analysis Place the sample in the inoculated agar medium culturing in the constant temperature incubator for 24 hours, and then observe the antibacterial effect. The diameter size of bacteriostasis circle around can directly show the strength of the antibacterial properties. The antibacterial effect of sample 3# and sample 10# are showed in Figure 5 and Figure 6 respectively. According to Figure 5, we know that the diameter size of bacteriostasis circle is larger than 7mm and almost unchanged over time so that realize a good antibacterial effect. In Figure 6, there is no bacteriostasis circle and also no bacteria breeding, which means having certain antibacterial effect but not the best. Hence, the results showed that starch coated silver nanoparticles have better and durable antibacterial effect.

Fig.5 The antibacterial effect of sample 3#

Fig.6 The antibacterial effect of sample 10#

4. Conclusion 1) The nano silver sol prepared by the above two different methods both have certain antibacterial properties, method one is much better than method two; 2) The size of the nano silver particles are both about 20 nm, while in the aspect of the dispersion, method 1 is better than method 2; 3) When the concentration of silver nitrate is 0.05 mol/l, the distribution of the particle size of silver nano is relatively narrower; when the reaction temperature is 60 degrees, both two methods can make the reaction most completely and get the nano silver sol most stable. 4) Starch coated silver nanoparticles have better and durable antibacterial effect.

Acknowledgements The research is supported by The industry-academy-research joint innovation fund of jiangsu Provincial Science and Technology Bureau (item No. BY2013042-07) and enterprise authorized item (item No. 13H018)

References 1. X. H. Gao, H. F. Wang, H. X. Zhang, Simple preparation of silver nanoparticles coated by starch and its antibacterial property, Rare Metal Mater. Eng. 42 (2013) 2098–2010. 2. C. P. Qian, L. Lu, J. W. Cui, Optimization of grafted oxidized starch process conditions, Cotton Text. Technol. 39 (2011) 625–627. 3. C. P. Qian, Q. Shi, L. Liu, Analysis of the influence factors of grafted oxidized starch, Cotton Text. Technol. 8 (2010) 681–683. 4. C. P. Gao, M. Gao, Y. Y. Liu, The test methods and standards of texile antibacterial performance, Text Dye. Finish J. 29 (2007) 38–42. 5. S. L. Li, J. Mao, Z. Chen, Study on stability of nano colloidal silver, Rare Metal Mater. Eng. 37 (2008) 1436–1440. 6. D. H. Yang, Preparation and study for antibacterial of nano-silver sol, J. Liaoning Unive. 37 (2010) 314–317. 7. Y. J. Dai, T. Deng, S. R. Jia, Preparation and characterization of fine silver powder with colloidal emulsion aphrons, J. Memb. Sci, (2006) 685–691. 8. W. Z. Zhang, X. L. Qiao, J. G. Chen, Synthesis and characterization of silver nanoparticles in AOT microemulsion system, Chem Phys, (2006) 495–500. 9. M. Barbic. Single crystal silver nanowires prepared by the metal amplification method, J. Appl. Phys, 91 (2002) 9341.

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The 13th Asian Textile Conference Geelong, Australia, November 3 - 6, 2015

Preparation of β-Chitin Nanofibers from Squid Pen by Water Jet Machine Mitsumasa Osada 1, Shin Suenaga 1, Kazuhide Totani 2 , Yoshihiro Nomura 3 and Kazuhiko Yamashita 4 1

Division of Chemistry and Materials, Faculty of Textile Science and Technology, Shinshu University, 3-15-1, Tokida, Ueda, Nagano, 386-8567, Japan 2

Department of Chemical Engineering, National Institute of Technology, Ichinoseki College, Takanashi, Hagisho, Ichinoseki, Iwate, 021-8511, Japan 3 Scleroprotein and Leather Research Institute, Faculty of Agriculture, Tokyo University of Agriculture and Technology, Saiwai, Fuchu, Tokyo 183-8509, Japan 4 YAEGAKI Bio-industry, Inc., Mukudani, Hayashida, Himeji 678‒4298, Japan

Abstract. In this work, we converted β-chitin in squid pen to nanofiber by wet pulverize treatment with a water jet machine just using water. β-Chitin nanofiber is expected as functional materials. XRD analysis of β-chitin powder and TEM observation of β-chitin nanofiber were conducted. We obtained the individualized β-chitin nanofibers 510 nm in cross-sectional width and at least a few microns in length. This study showed that a wet pulverize treatment with a water jet machine is a promising method for producing β-chitin nanofiber. Keywords: biomass, chitin, nanofiber.

1. Introduction Squid is a popular sea food in many parts of the world. However, squid pen is disposed as waste from processed marine products factories. Squid pen consists of 30% of -chitin, 70% of protein, and less than 1% of inorganic matter. Chitin is structural polysaccharides consisting of β-(14)-linked N-acetyl anhydroglucosamine units. At least two types of chitin crystal are known, - and β-chitins. Most natural chitins have the -type crystal structure, while the β-type chitin is present in squid pen. About 10 tons/year of the squid pen has been disposed in Sanriku coast, Tohoku region, Japan. In this work, we examined to produce β-chitin powder squid pen by acid and base treatments as shown in Figure 1. Then we converted the β-chitin power to nanofiber by wet pulverize treatment with a water jet machine just using water.

Water jet machine

-chitin powder Squid pen Fig. 1: -Chitin nanofiber preparation from squid pen

-chitin nanofiber

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2. Experimental 2.1.

Chitin nanofiber preparation

We purified β-chitin from a squid pen (Todarodes pacificus) by acid and base treatments. The purpose of acid treatment is to remove inorganic matter and that of base treatment is to remove protein content. The slurry of β-chitin powder was disintegrated by a water jet machine Star Burst system (Sugino Machine Co., Ltd., Japan). As shown in Figure 2, two slurry flows were ejected from a nozzle and collided with each other. The disintegrated samples were recovered as β-chitin nanofiber. An advantage of using the water jet machine is that we can produce nanofiber by just using water.

Slurry of β-chitin powder A stream high-pressure water jet

Collision at Mach 4

Slurry of β-chitin powder

-chitin nanofiber

Fig. 2: -Chitin nanofiber preparation by a water jet machine

2.2.

XRD analysis

Equatorial diffraction profile of β-chitin powder was obtained with Cu-Kα from a powder X-ray generator (Japan Electronic Organization Co. Ltd., JDX-3530), operating at 30 kV and 30 mA.

2.3.

Transmission Electron Microscope (TEM) β-Chitin nanofiber dispersions were was observed by TEM (FEI, Tecnai G2F20) operating at 200 kV.

3. Results & Discussion XRD pattern of chitin obtained in this work is shown in Figure 3. The XRD pattern is the same as that of β-chitin reported previously [1], indicating that the crystal structure of our chitin powder is β-type. The peak around 9° derived from the [010] plane and the peak around 19.5°derived from the [100] plane were observed. Crystallinity index of β-chitin was about 0.8.

Diffraction angle 2θ [º] Fig. 3: XRD pattern of -chitin powder obtained from squid pen

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Figure 4 shows TEM micrograph of β-chitin nanofiber. From TEM observation, the size of β-chitin nanofibers were 5-10 nm in cross-sectional width and at least a few microns in length. This result indicates that β-chitin could be converted to its nanofiber by the water jet because high pulverizing capability. During wet pulverize treatment, the water jet machine can accelerate β-chitin powder to over sonic speed. Then βchitin powder collides each other at about Mach 4 and they were fibrillated to nanofiber. This study showed that β-chitin nanofiber production is possible by using a wet pulverize treatment with a water jet machine.

1 mm Fig. 4: TEM micrographs of β-chitin nanofiber

4. References [1] Yimin Fan, Tsuguyuki Saito, and Akira Isogai, Preparation of Chitin Nanofibers from Squid Pen β-

Chitin by Simple Mechanical Treatment under Acid Conditions, Biomacromolecules, 9, 1919–1923, 2008

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The 13th Asian Textile Conference Geelong, Australia, November 3 - 6, 2015

Preparing of Multi-Layered PCL/Collagen/Elastin Nanofibrous Composite by Electrospinning Metin Yüksek 1, Ramazan Erdem 2 , Mehmet Akalın1 and Onur Atak 1 1

Marmara University, Technology Faculty, Department of Textile Engineering, Istanbul, Turkey 2 Serik Vocational School of Higher Education, Akdeniz University, Antalya, Turkey

Abstract. The main goal of this study is to prepare electrospun nanofibrous composites consisting of Polycaprolactone (PCL)/Collagen Type 1 and PCL/Elastin based layers. Layers were manufactured separately first, and then together to obtain the final form (three-layered) of the nanofibrous composite by using electrospinning technique. The morphologies and mechanical properties of each layer and the nanofibrous composite were compared to each other. The chemical composition and interactions between the polymers were found out by performing FTIR analysis. Scanning electron microscopy (SEM) observations were carried out for morphological analysis. Tensile and elongation properties of nanofibers were determined on Instron machine. Results revealed that the diameter and the tensile strength of nanofibers were decreased as the amount of biopolymers increased in the blends. Keywords: Nanocomposite, Electrospinning, PCL, Elastin, Collagen.

1. Introduction Electrospinning is a processing technique in which a high voltage is applied to a polymeric solution to produce small nanometer to micron diameter scale fibers that are ideal for a variety of applications[1]. PCL is aliphatic, semicrystalline polyester with a broad spectrum of practical or potential applications. Although the PCL has been known for a long time it is gaining an increased scientific interest only in the last 10–15 years [2]. Collagen is one of the most abundant ECM proteins in mammals. It has been reported that collagen has been utilized as a biomaterial for a breadth of medical devices and tissue engineered scaffolds [3]. Elastin is another major protein component of the ECM produced by fibroblasts and smooth muscle cells, which provide resilience to the skin and other tissues. It is abnormally expressed during skin wound healing which partially contributes to the impaired breaking strength of scars compared with unwounded skin [4]. In this study, PCL, Elastin and Collagen solutions for electrospinning were prepared in HFP with the different volume ratio. This altered the solutions characteristics as well as the nanofiber morphologies during the electrospinning process. The main purpose of this study is to explore the impact of polymer concentration on nanofiber formation and to investigate the mechanical properties of the final nanofibrous membranes.

2. Materials and Methods 2.1. Materials PCL with a molecular weight of 80,000 g mol_1 was purchased from Sigma Aldrich (USA). Collagen from bovine Achilles tendon was purchased from Sigma Aldrich (USA). Elastin from bovine neck ligament was purchased from Sigma Aldrich (USA). PCL (7% wt.) and Collagen (0,9% wt.) and Elastin (1,86 % wt.) were dissolved in 1,1,1,3,3,3-Hexafluoro-2-propanol (HFP) (Molecular Weight 168.04).

2.2. Preparation of blend solution Collagen and Elastin and PCL were dissolved in HFP. PCL weight concentration of 7%, Collagen 0.9 % and Elastin 1.86 % were prepared at room temperature for 6 hours by using laboratory type magnetic stirrer 1+

Corresponding author. Metin Yüksek Tel.: + 90-216-3365770 ext. 1684 E-mail address: myuksek@marmara.edu.tr

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(Stuart, SB 162). Before electrospinning, the three solutions were blended at different volume ratios of PCL/collagen/elastin. Mixing ratio of the solutions are given in Table 1.

Figure 1. Illustration of Three Layer Electrospun Scaffold Structures; Layer 1: PCL/COL (70/30%), Layer 2: PCL/ELS (60/40%), Layer 3: PCL/COL (70/30%). Table 1. Mixing ratio of the solutions and related electrospinning parameters. Polymers PCL PCL/COL PCL/ELS PCL/COL/ELS

Blend Ratio (%) 100 70/30 60/40 66/20/14

Feeding Rate (ml/h) 1.50ml/h 0.30ml/h 0.30ml/h 0.30ml/h

Applied Voltag e (kV) 30 28 24 30

Distance (cm) 25 25 30 25

Fed Solution (ml) 12 12 12 4-4-4

2.3. Electrospinning Electrospinning was performed in the laboratory spinning unit (NS24, NanoFMG), which was designed in terms of a vertical working principle. Each solution was placed in a 12 ml syringe and sent to the drum collector through a 20 gauge nozzle. The flow rate of the solution was also determined by setting up the syringe pump at 0.3 ml/hour for blend solutions and 1.50ml/ for pure PCL solution. The rotational speed of the drum collector was 35 rpm and its distance has been ranged from 25 to 30 cm away from the nozzle.

2.4. SEM and FTIR Analysis of Electrospun Nanofibers Electrospun fibers were characterized by SEM (JSM-5910 LV from JEOL). The fiber diameter distribution was calculated over 50 fibers with the Image J software (Image J, 2011) from the SEM images obtained at a magnification of 5000 x. FTIR analysis was also carried out in order to determine the chemical structures of the nanofibrous membranes. Fourier transform infrared spectroscopy (NEXUS 870, ThermoNicolet). The transmittance of each sample was recorded with five scans at a resolution of 4 cm-1 between 4000 and 380 cm-1.

2.5. Tensile Measurements of Electrospun Nanofibrous Membranes In order to determine the mechanical properties of the electrospun nanofibrous membranes, tensile and elongation tests were carried out by using an Instron Machine (Instron 4411). The specimens were cut into approximately 50 mm x 10 mm (length x width) in both machine direction and width direction in order to be loaded into the uni-axial testing machine. During the experiment, 50 N load cell under a cross-head speed of 10 mm/min was applied to the specimens. Three repetitions were taken for each specimen in order to calculate the tensile strength and elongation at break values.

3. Results and Discussion 3.1. Morphologies of electrospun Collagen, Elastin, PCL fibers Fig. 2 shows SEM micrographs of the electrospun nanofibers composed of Collagen, PCL, Elastin. In general, it can be stated that uniform and bead free nanofibers were fabricated through the mentioned (Table 1) electrospinning parameters. The fiber diameter distribution was quite large especially for PCL/COL and PCL/ELS membranes. On the other hand, pure PCL nanofiber diameters were close to each other. There are many thin fibers as well as larger diameter fibers were produced when the biopolymers blended with PCL. This situation created smaller pore size and more porous structure compared with the membrane that only included pure PCL. In addition, it was observed that the morphology of the PCL nanofibers was not an uniform round shape due to solvent that was not evaporated completely during the electrospinning process.

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Figure 2. SEM images of electrospunnanofibers with various solvents; (A) 100% PCL, (B)70/30% PCL/Collagen, (C) 60/40% PCL/Elastin, (D) Three layered scaffold.

The diameter measurements revealed that the largest fiber diameter was belonged to pure PCL (1536±293nm) and the smallest diameter was obtained for the blend of PCL/COL (197±101nm). The diameter of PCL/ELS blend nanofibers was calculated as 282±105nm. Our study proved that the diameter of the nanofibers decreased significantly by introducing the biopolymers to the blend solutions. This may be attributed to the gradual decrease in the solution viscosity which is a highly influent parameter for determining the nanofiber diameter and morphology during electrospinning. Furthermore, in the case of fabrication of the pure PCL nanofibers, the feeding rate was 1.50ml/h, although the feeding rate was set as 0.30ml/h for the blend solutions containing biopolymers. This may be another explanation for the huge decrease in fiber diameters since the feeding rate of pure PCL solution was five times greater than the blend PCL/COL and PCL/ELS solutions.

3.2. FTIR Analysis of the Nanofibrous Membranes Figure 3 displays the spectrums of pure PCL, PCL/COL (70/30%), PCL/ELS (60/40%) and three layered nanofibrous membranes. According to the diagram, some characteristic peaks are illustrated related to PCL. Although the curves for all specimens are similar to each other, intensities of the curves alter especially in 2943cm-1 and 2864cm-1 regions. It is consistent that these alterations might occur due to the interaction between Collagen and PCL as well as Elastin and PCL during the mixing of solutions before electrospinning. Peaks at 2943cm-1 and 2864cm-1 indicate asymmetric and symmetric CH 2 strechnings. Also, some specific peaks are belonged to following chemical structures; carbonyl (C=O) streching at 1720 cm-1, asymmetric COC stretching at 1239 cm-1 and symmetric COC stretching at 1165 cm-1. In addition, peaks at 1640 cm-1 and 1530 cm-1 are belonged to amide I and amide II which proves the existence of collagen in the blend [5].

Figure 3. FTIR spectrums of electrospun nanofibrous membranes.

3.3. Mechanical Properties of Electrospun Nanofibrous Membranes Figure 4 presents the tensile strengths of the electrospun nanofibrous membranes. According to the results, the greatest value was obtained for PCL/COL blend in both machine and width directions. This situation could

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Strain (%)

Stress (MPa)

be explained by the fiber diameter and high volume ratio to surface area. Above findings exhibited that the smallest fiber diameters produced from PCL/COL blend that means more fibers were laid per unit area. Therefore when the external force applied to such structures, more amount of fibers bear the applied force so that the tensile strength of such structures increases. PCL/ELS blend nanofibrous membranes showed the least tensile strength performance among others. This is due to the amount of biopolymers used in the blend. It is confirmed that synthetic polymer perform much better mechanical properties compared with the biopolymers. Hence, when the ratio of the biopolymer increases in the blend, tensile strength of the structure decreases. Tensile strength of the three layered nanofibrous membranes was found greater than the PCL/ELS blend; however, it was less than the pure PCL and PCL/COL blend membranes. This is acceptable because three layered membrane is a combination of PCL/COL and PCL/ELS, and it contains the mechanical characteristics of both blend structures. 5 0

Machine Direction

Width Direction

Figure 4. Tensile strength of the membranes.

1500 1000 500 0 Machine Direction

Width Direction

Figure 5. Strain properties of the membranes.

Figure 5 illustrates the strain properties of the electrospun nanofibrous membranes. Findings exposed that greatest strain value was belonged to pure PCL electrospun nanofibrous membrane since PCL is an elastic polymer. PCL/COL and three layered nanofibrous membranes exhibited the weakest performance in terms of strain properties. It can be concluded that increase in biopolymer level in the blends causes a significant decline in strain properties.

4. Conclusion In this study, pure PCL, one layer of PCL/COL and PCL/ELS, and three layers of PCL/COL/ELS nanofibrous membranes were successfully fabricated by electrospinning technique. Fiber morphology and diameters were dramatically influenced by the solution concentration and feeding ratio during electrospinning. Largest fiber diameter was obtained from pure PCL solution, on the other hand, finest fiber diameter was produced from PCL/COL blend. Mechanical properties of the nanofibrous membranes were affected by fiber diameter, amount of fiber laid in per unit area and the amount of biopolymer included in the blends. By preparing such blend membranes and multilayer structures, potential functional biomaterials such as tissue scaffolds could be produced that may contribute fundamentally to future researches.

5. References [1] Cheryl L. Casper, Weidong Yang, Mary C. Farach-Carson, and John F. Rabolt, “Coating Electrospun Collagen and Gelatin Fibers with Perlecan Domain I for Increased Growth Factor Binding”, Biomacromolecules 2007, 8, 11161123 [2] Jing, Z.; Xu, X. Y.; Chen, X. S.; Liang, Q. Z.; Bian, X. C.; Yang, L. X.; Jing, X. B. J. Controlled Release 2003, 92, 227-231. [3] MiroslavHuskic´, IrenaPulko, “The synthesis and characterization of multiarm star-shaped graft copolymers of polycaprolactone and hyperbranched polyester”, European Polymer Journal 70 (2015) 384–391 [4] RuiLiu, ZhengtuoZhao, LuweiZou, QiyinFang, Lin Chen, Alan Argento, Joe F. Lo, “Compact, non-invasive frequency domain lifetime differentiation of collagens and elastin”, sorsandActuators B: ChemicalVolume 219, November 2015, Pages 283–293 [5] Tamara Elzein,Mohamad Nasser-Eddine, ChristelleDelaite, Sophie Bistac, Philippe Dumas, “FTIR study of polycaprolactone chain organization at interfaces”, Journal of ColloidandInterfaceScienceVolume 273, Issue 2, 15 May 2004, Pages 381–387

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The 13th Asian Textile Conference Geelong, Australia, November 3 - 6, 2015

Preparation of nanoparticle fluorescent pigment dispersions by miniemulsion polymerization and its properties Jie Liu, Shaohai Fu

Key Laboratory of Eco-Textiles of the Ministry of Education, College of Textiles and Clothing, Jiangnan University

Abstract: The synthetic method of miniemulsion polymerization was used to prepare nanoparticle fluorescent pigment dispersions. Effects of emulsifier, co-emulsifier, ultrasound treatment time on particle size were investigated. The properties of fluorescent pigment dispersions were characterized by TEM, TGA, UV-visible spectrum and fluorescence intensity. The results indicated that the nanoparticle fluorescent pigment dispersions exhibited high fluorescence stability towards to temperatures, alkali and acid. Migration of fluorescent pigment dispersions showed that fluorescent dye could also transfer to the organic phase when exposed to organic solvents.

Keywords: Miniemulsion polymerization; Fluorescent pigment dispersions; Particle size; Fluorescence intensity; Stability

1. Introduction In recent years, daylight fluorescent pigments have attracted many researchers, attention owing to their bright-colored luster because they adsorb radiation in both the visible and ultraviolet range of the spectrum and make a deep impression on people at first sight compared with ordinary pigments [1, 2]. Therefore, fluorescent pigments have been used progressively in a wide range of applications such as toys, fashion, package, printing, plastics, security features, and so on [3-6]. Simultaneously, considerable efforts have been devoted to the preparation of daylight fluorescent pigments including nubby resin powder grinding, emulsion polymerization, resin separation. Among of these, the most commonly used is powder grinding method, for example, Thomas C. synthesized micron sized fluorescent pigments using a polyamide reaction product of a diamine and diacid as the resin carrier [7]. However, the obtained particle size of this method is very large, usually several microns, and the smashing cost is very high, what is worse, formaldehyde might be released in the prepared process. In order to overcome this shortcoming, a few reports about formaldehyde-free process have been reported [7-9]. Nowadays, the preparation of fluorescent pigment dispersions has attracted increasing interest in that the obtained particle size is usually very small [1, 2], powders can be also obtained as required. Miniemulsion polymerization [10-13] seems to be the perfect method to synthesize complex materials that cannot be produced otherwise [14], and the technology has been applied in many fields, such as encapsulation [15-17], highly monodisperse fluorescent polymer particles [18], composite nanoparticles [19,

E-mail address: shaohaifu@hotmail.com

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20], and so on. However, miniemulsion consisting of monomer, emulsifier, co-emulsifier, oil-dissolved fluorescent dye, water [21] about preparing fluorescent pigment dispersions has not been reported until now. In this study, nanoparticle fluorescent pigment dispersions were prepared via miniemulsion polymerization. The properties of fluorescent pigment dispersions were characterized by TEM, TGA, UV-visible spectrum.

2. Materials and methods 2.1. Materials Solvent green 5 was purchased from Guangzhou Guocai Pigment Chemical Co. Ltd., China. DNS-86 was supplied by Hanke Chemical Co. Ltd., China. Styrene (St), ammonium persulfate (APS), hexadecane (HD), hydrochloric acid (HCl), sodium hydroxide (NaOH), ethanol, were of analytical grade, all were obtained from Shanghai Reagent Co. Ltd., China.

2.2. Preparation of O/W type miniemulsion O/W type miniemulsion was prepared through two procedures, and the first one was to make coarse emulsion carried out as follows: 0.15 g solvent green 5, 15 g St, and HD were mixed together to make the organic phase, then added to the aqueous phase consisting of 30 g deionized water as well as DNS-86 in stirring state to make the coarse emulsion. The obtained coarse emulsion was emulsified at a stirring speed of 800 r/min for 30 minutes. Subsequently, the emulsion was performed by ultrasonic treatment under ice cooling in an ultrasonic homogenizer (Scientz Biotechnology Co. Ltd., Ningbo, China) set at 60% amplitude and 2 s pulse on and 2 s pulse off cycles, which was the second procedure of preparation of O/W type miniemulsion.

2.3 Miniemulsion polymerization Nanoparticle fluorescent pigment dispersions prepared by miniemulsion polymerization was carried out in a 0.1 L glass reactor containing a stirrer, a reflux condenser, a nitrogen inlet, and a sampling device. Polymerization was carried by bubbling into nitrogen in advance for 30 minutes to get rid of air including oxygen properly obstructing polymerization. APS dissolved in 5 g deionized water was added to the reactor when the temperature reached to 70 째C. Finally, the obtained pigment dispersion were filtered by 500 nm cellular filters to remove impurities, and then added to a certain amount of NaHCO 3 to adjust pH value to the neutral.

2.4. Characterization 2.4.1. Transmission electron microscopy (TEM) The morphology of the nanoparticle fluorescent pigments was determined by TEM using a JEM-2100 (Japan) instrument, the operated acceleration voltage was 200 kV. All samples were dropped onto carboncoated copper grids, dried at ambient temperature before examination.

2.4.2. Fluorescence intensity Fluorescence intensity was measured using an F-4600 (Japan) apparatus. All samples were measured at

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the excitation wavelength of 440 nm recorded at 25 °C.

2.4.3. UV-Visible spectrum A small amount of separation and purification of nanoparticle fluorescent pigment dispersion powders and solvent green 5 were dissolved in THF, and then determined its ultraviolet-visible absorption spectra using UV-2805 ultraviolet-visible spectrophotometer at 25 °C.

2.4.4. TGA Thermogravimetric analysis of samples was carried out under a nitrogen atmosphere using a SDTA851E thermogravimetric analyzer.

2.4.5. Thermal stability

2 g fluorescent pigment dispersions were put into a centrifuge tube, hermetically sealed under a certain temperature for 24 hours, the change of particle size was measured using the following formula.

d −d (1 − 0 T ) ×100% ST = d0

(2.1)

Where d 0 and d T are the particle size of fluorescent pigment dispersions before and after heating, S T is the change percentage of the particle size.

2.4.6. Acid and alkali resistance

0.25 g fluorescent pigment dispersion was diluted with 40 g deionized water, and sodium hydroxide or hydrochloric acid was added to adjust pH values. Finally different samples were tested for the change percentage of their particle sizes using the following formula.

r −r  = PC  0 1  ×100%  r0 

(2.2)

Where r o and r 1 are particle sizes before and after measurement, respectively, P C is the particle change percentage.

2.5.8. Migration of fluorescent pigment dispersions The prepared nanoparticle fluorescent pigment dispersions were filtered, and centrifuged for 30 minutes with a speed of 5000 r/min, wiped off precipitation. Afterwards, 2 g styrene, 2 g dichloromethane and 2 g MMA were added into 3 sample bottles with 2 g fluorescent pigment dispersions, respectively. Fluorescent dye would gradually migrate to the organic solvent with time going, this dye migration phenomenon was recorded by a digital camera.

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3. Results and discussion 3.1.1 Influencing facors DNS-86 is a polymerizable anionic emulsifier with long branched chains, which could not only provide electrostatic force but larger space steric hindrance, preventing particles aggregating. Therefore, DNS-86 could significantly improve the stability of dispersions compared with conventional emulsifiers and the use of it has been published in several papers [20, 22, 23]. Fig.1a shows that the particle size of fluorescent pigment dispersions and miniemulsion decreases with increasing DNS-86 concentration. It can be explained that the amount of emulsifier adsorbed on oil droplets was so little to produce repulsive force that oil droplets needed to avoid aggregating when the concentration of emulsifier is insufficient. With the increase of emulsifier, the stability of the oil droplets improves, monomers could not easily aggregate in reparation of miniemulsion or polymerization process. However, when the emulsifier concentration is more than 10%, DNS-86 molecules could polymerize into tiny particles to form a byproduct, resulting in smaller average particle size. It also shows that the particle size of fluorescent pigment dispersions and miniemulsion is proximal at 10%, so the concentration of DNS-86 is chosen at 10%. Fig.1b shows that the average particle size of miniemulsion decreases with the increase of HD, whereas average particle size of the dispersions increases. With HD increasing, oil-water interface of osmotic pressure increases, efficiently inhibiting the Ostwald ripening effect, as a result, the preparation of miniemulsion particle size decreases. Simultaneously, the chance of micellar nucleation or homogeneous nucleation in water phase decreases, thus the average particle size of latex particles has a tendency to increase. Furthermore, there is a intersection contained 77.6 nm and 77.3 nm between the curves of miniemulsion and fluorescent pigment dispersions at 8%, indicating that miniemulsion basically formed nanoparticle fluorescent pigment dispersions in 1:1. As Fig. 3c shows that average particle size of fluorescent pigment dispersions is the smallest at 0.75%, but it increases beyond the value, and the monomer conversion reaches equilibrium. The phenomenon could be explained by Eq. (3) [22].

fkd 12 12 )  I  M  Rp = K p ( k1    

(3.1)

Where R p is polymerization rate, [I] is the initiator concentration, [M] is monomer concentration, k p , k d and k 1 are constants related to monomer and initiator. It can be explained that monomer polymerization rate is so low that some monomers could not successfully polymerized under 0.75%, they might assemble with each other, thus to form bulky particles. Similar result is shown when initiator concentration is higher than 0.75%, a reason for this phenomenon is that the system is likely to be unstable at high monomer concentration, thus leading to the increasing average size. Ultrasound energy is used for overcoming the viscoelastic and surface energy of the organic phase. Oil droplets have smaller particle size and larger superficial area after ultrasound treatment, which is capable of avoiding micellar nucleation in water phase by arresting emulsifier molecules, as a result, monomer droplets are the main nucleation sites. Fig.1d demonstrates that average particle size of miniemulsion and fluorescent pigment dispersions is influenced by ultrasound treatment time, the reason is that the monomers could not been broken into droplets adequately at shorter ultrasound treatment time, leading to larger particle size of the miniemulsion. The particle size of the miniemulsion and fluorescent pigment dispersions increases because that the system becomes unstable when the treatment time is more than 10 minitues.

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240

150

160

D (nm)

D /nm

200

200 Dispersion Miniemulsion

Dispersion Miniemulsion

120

100

80 40 2

6 8 10 12 14 The mass percentage of DNS-86 to St

100

4 6 8 Mass percentage of HD to St /%

Dispersion Miniemulsion

90 80 85

Monomer conversion D

D /nm

Monomer conversion /%

D /nm

80 70

80 75 70 0.3

0.6 0.9 1.2 The mass percentage of APS to St /%

1.5

10 15 20 Ultrasound treatment time /min

Fig.1: Effect of influencing factors on fluorescent pigment dispersions and miniemulsion (a) DNS-86; (a) HD; (c) APS; (d) Ultrasound treatment time

3.2 Properties Fig.2 shows that the shape of fluorescent pigment is spherical. Fig.3 indicates that the fluorescent pigment has identical absorption wavelength in contrast with the fluorescent dye in the number range of 300-600 nm, which demonstrates that polystyrene does not affect the hue of the initial dye.

Fig. 2: The morphology of nanoparticle fluorescent pigment 1.0

Absorbance

0.8

Fluorescent dye Fluorescent pigment

0.6 0.4 0.2 0.0 300

350

400

450 500 Wavelength (nm)

550

600

Fig. 3: UV-visible spectrum of Solvent Green 5 and nanoparticle fluorescent pigment dispersion

3.4 Stability In general, some pigment dispersion particles might aggregate or subside when exposed to acid or alkali environment, as a result, particle size appears to enlarge in macro, which properly would jam ink-jet printing machine nozzle in printing process or remain color spots on fibers after dyeing procedure. Table 1 is the stability of nanoparticle fluorescent pigment dispersions, which demonstrates that temperatures (below 90 째C) barely have an impact on the particle size of fluorescent pigment dispersions and fluorescence intensity. To investigate the ability to resist acid and alkali, HCl and NaOH were applied to adjust the pH values, all were

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operated in centrifuge tubes with a volume of 50 mL using a pH meter. Just as Table 1 shows, pH values barely affect nanoparticle fluorescent pigment dispersions. Table 1: Stability of nanoparticle fluorescent pigment dispersions Temperature (째C) Stability

ST /%

Fluorescen

2.8

2.5

2.9

348

ce intensity

pH value PC /%

348

2.5

2.3

2.4

2.6

2.7

2.4

2.5

345

344

347

346

348

349

343

344

3.5 Migration performance of fluorescent dye from fluorescent pigment dispersions to solvents Apart from UV-visible spectrum and fluorescence intensity analysis, macroscopic migration of fluorescent dye between fluorescent pigment dispersions and organic solvents were also conducted to confirm whether dye could be soluble in solvents again. Fig.4 shows that the layers of styrene, MMA and dichloromethane are primitively colorless and become darker as time going, demonstrating that fluorescent dye migrates from dispersions to the organic phase. This dissolution results in the decrease of dye in dispersions when exposed to organic solvents and might play a guiding role in practical applications.

Fig. 4: Migration performance of fluorescent dye from fluorescent pigment dispersions to organic solvents: A of styrene; B of MMA; C of dichloromethane; a 0 h; b 8h; c 16h; d 24h

3.6 Thermal properties TGA and differential thermogravimetric (DTG) curves for fluorescent dye, fluorescent pigment and polystyrene are presented in Fig. 5, it shows that solvent green 5 only has one decomposition stage. Generally, the first decomposition stage of polystyrene and fluorescent pigment is the oligomer of styrene. The loss of the second decomposition stage of fluorescent pigment involved fluorescent dye and high molecular polystyrene. a

b Derivative weight (%/ min)

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60 40 20 0

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300 400 500 Temperature (째C)

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0.0 -0.5 -1.0 -1.5 Fluorescent pigment Polymer Fluorescent dye

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Fig. 5: TGA and DTG curves (a) TGA; (b) DTG

500

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4. Conclusion DNS-86 and HD are the major factors affecting particle sizes. The TEM picture exhibits the morphology of the nanoparticle pigment dispersion particles is spherical. The obtained fluorescent pigment dispersions show good thermal stability and acid and alkali stability. Fluorescent dye could migrate to the organic phase when exposed to organic solvents. TGA analysis demonstrates that both fluorescent dye and fluorescent pigment have high decomposition temperature.

References [1] J.R. Cramm, S.G. Streitel, US Patent 5215679(1993). [2] J.R. Cramm, R.G. Morrison Jr, S.G. Streitel, US Patent 5294664(1994). [3] M.Z. Gregorio, P.A. Merchak, R.J. Schwartz, US Patent 5904878(1999). [4] K.W. Hyche, US Patent 5439968(1995). [5] M.T. Nowak, Q. Chen, US Patent 6425948B1(2002). [6] P. Bischof, C. Hutter, C. Puebla, US Patent 6936078 B2(2005). [7] B. Thomas C. DiPietro, ohio, US Patent 5094777(1992). [8] A. Deckers, W. Fischer, N. Guntherberg, S. Haremza, E. Jahns, W. Ostertag, H. Schmidt, US Patent 5710197(1998). [9] J.R. Webster, US Patent 6683124(2004). [10] J. Ban, K. Kim, H. Jung, S. Choe, Homogeneously distributed magnetite in the polystyrene spherical particles using the miniemulsion polymerization, Journal of Industrial and Engineering Chemistry, 16 (2010) 1040-1049. [11] J. W. Ma, J. A. Smith, K. B. McAuley, M. F. Cunningham, B. Keoshkerian, M. K. Georges, Nitroxide-mediated radical polymerization of styrene in miniemulsion: model studies of alkoxyamine-initiated systems, Chemical Engineering Science, 58 (2003) 1163-1176. [12] G. Jia, N. Cai, Y. Xu, C. Liu, X. Tan, Miniemulsion polymerization of styrene with liquid polybutadiene as the sole co-stabilizer, Eur Polym J, 43 (2007) 4453-4459. [13] I. Capek, On inverse miniemulsion polymerization of conventional water-soluble monomers, Adv Colloid Interface, 156 (2010) 35-61. [14] J.M. Asua, Challenges for industrialization of miniemulsion polymerization, Prog Polym Sci, (2014). [15] S. Lu, J. Forcada, Preparation and characterization of magnetic polymeric composite particles by miniemulsion polymerization, Journal of Polymer Science Part A: Polymer Chemistry, 44 (2006) 4187-4203. [16] F. Tiarks, K. Landfester, M. Antonietti, Encapsulation of carbon black by miniemulsion polymerization, Macromol Chem Phys, 202 (2001) 51-60. [17] B. Erdem, E.D. Sudol, V.L. Dimonie, M.S. Elâ&#x20AC;?Aasser, Encapsulation of inorganic particles via miniemulsion polymerization. II. Preparation and characterization of styrene miniemulsion droplets containing TiO2 particles, Journal of Polymer Science Part A: Polymer Chemistry, 38 (2000) 4431-4440. [18] T. Taniguchi, N. Takeuchi, S. Kobaru, T. Nakahira, Preparation of highly monodisperse fluorescent polymer particles by miniemulsion polymerization of styrene with a polymerizable surfactant, J Colloid Interface Sci, 327 (2008) 58-62. [19] X. Zhao, Q. Meng, J. Liu, Q. Li, Hydrophobic dye/polymer composite colorants synthesized by miniemulsion solvent evaporation technique, Dyes Pigments, 100 (2014) 41-49. [20] Y. Guan, B. Tawiah, L. Zhang, C. Du, S. Fu, Preparation of UV-cured pigment/latex dispersion for textile inkjet printing, Colloids and Surfaces A: Physicochemical and Engineering Aspects, 462 (2014) 90-98. [21] N. Bechthold, K. Landfester, Kinetics of miniemulsion polymerization as revealed by calorimetry, Macromolecules, 33 (2000) 4682-4689.

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[22] S. Fu, J. Lu, X. Luo, F. Bai, Preparation of disperse dye/latex dispersion for printing of cellulose fabric, Colloids and Surfaces A: Physicochemical and Engineering Aspects, 423 (2013) 131-138. [23] S. fu, C. Du, C. Wang, A. Tian, C. Xu, Properties of lyocell spinning solution with the addition of carbon black/latex composite, Colloids and Surfaces A: Physicochemical and Engineering Aspects, 428 (2013) 1-8.

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The 13th Asian Textile Conference Geelong, Australia, November 3 - 6, 2015

Preparation of Polyvinyl Butyral/Titanium Dioxide composite used for UV blocking Zhong Zhao 1, Qiuyun Li 1, Jihong Wu 1, Lu Sun 1, 2 + 1

School of Textile Science and Engineering, Wuhan Textile University, Wuhan 430200, China 2 Institute for Frontier Materials, Deakin University, Geelong, Victoria 3216, Australia

Abstract. Polyvinyl butyral (PVB) is widely used in laminated glass and spun into nanofibres by eletrospinning methods. It possesses excellent flexibility, strength and optical clarity, while degradation caused by UV-rays during exposure to intense sunlight may shorten its service life. In this study, polyvinyl butyral/titanium dioxide composite was prepared by dispersing rutile nanoparticles, which were used as UV blocking agents, in polyvinyl alcohol (PVA) solution before the condensation reaction of PVA and butyraldehyde. The morphology, UV blocking ability and thermal stabilities of the composite were characterized by FT-IR, UV-Vis spectrophotometer and thermal gravimetric analyzer, respectively. Results show that the composite possesses excellent UV blocking ability while the thermal stabilities are not reduced.

Keywords: Polyvinyl butyral, polyvinyl alcohol, titanium dioxide, UV blocking, condensation reaction.

1. Introduction Polyvinyl butyral is synthesized from the condensation reaction of polyvinyl alcohol and n-butyl aldehyde [1]. It is widely used in laminated glass as adhesive layer because of its excellent flexibility, heat resistance and tensile strength [2]. Nanometer-scale TiO 2 is used as UV blocking agent in many industries due to its semiconducting property and scattering of UV rays [3, 4, 5]. Researches on synthesis of PVB/TiO 2 composite by blending two ingredients has been reported [6], while the UV blocking ability of this composite remains to be improved due to the accumulation of nanometer-scale TiO 2 . In this study, a new synthetic method was applied to prepare PVB/TiO 2 composite by blending PVA and modified TiO 2 nanoparticles before the condensation reaction of polyvinyl alcohol (PVA) and n-butyl aldehyde. Compared to pure PVB, the UV absorbing ability of PVB/TiO 2 composite synthesized by this method has been dramatically improved.

2. Experiments 2.1.

Materials

The polymerization degree and alcoholysis degree of PVA used in this study are 1700 and 99%. Rutile was chosen as UV blocking agent and modified by silane coupling agent KH550 to improve its surface activity while blended with PVA. N-butyl aldehyde was analytical grade, and ethanol was the dispersant for TiO 2 . The mass fraction of hydrochloric acid is 10%.

2.2.

Processes of preparation

0.1 g of TiO 2 nanoparticles were dispersed in 40ml of ethanol within a beaker, the dispersion was stirred with a glass rod while 1ml of silane coupling agent was dripped into it through a burette. After being stirred for 3 min, the dispersion was treated under sonication for 30 min. then the dispersion was filtered, the particles remained were collected and washed by unionized water before being dried in an oven at 70â&#x201E;&#x192; for 2 h. 10 g of PVA particles were weighed and added into a three-neck flask which contained 100 ml of unionized water. The flask was then heated in a thermostat water bath at 90â&#x201E;&#x192; under fierce stirring and cooled to ambient temperature after all particles were dissolved. The modified titanium dioxide particles were mixed +

Lu Sun. Tel.: + 61 3 52273247.. E-mail address: lu.sun@deakin.edu.au.

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with the PVA solution under stirring before 10ml of hydrochloric acid with a wt % of 10 were added into the mixture. 7 g of n-butyl aldehyde was dripped into the dispersion at the speed of 10 drops per minute, and the reaction took place at ambient temperature while the temperature was then gradually raised to 50℃. After reacting for 2 h, the flask was cooled to ambient temperature, again. The white particles were filtered out, washed with unionized water and collected after the redundant hydrochloric acid was neutralized by NaOH solution. 5 g of prepared white particle were weighed and placed in a three-neck flask with a condensing tube attached to one of its necks. 50 ml of ethanol were used as solvent to dissolve the white particles. The device was heated at 80℃ with condensing till all white particles were dissolved. The solution were poured into a conical flask, standing for 12 h. 10 ml of the solution was taken out from the flask and transferred to a Petri dish placed under ambient conditions. The film was peeled off after the solvent completely volatilized. All processes above were repeated to prepare pure PVB particles without TiO 2 , film of pure PVB particles was also made by repeating those procedures.

2.3.

Characterization

Dispersion of modified TiO 2 were examined by a Mastersizer 2000 machine to analyze the distribution of its particle size. Infrared spectrums of PVB/TiO 2 composite and PVB were gained by testing the films with a FTIR. Solution of PVB/TiO 2 and pure PVB at the same concentration were scanned by an UV-Vis spectrophotometer to obtain their UV-Vis absorption spectrums. Thermal properties of the two substances were examined by a thermal gravimetric analyzer.

3. Results and analysis Results were showed in figure 3.1, as (a) and (b) correspond to curves of particle size distribution of TiO 2 before and after sonication.

Fig. 1: Particle size distribution curves of TiO 2 before and after sonication

It can be seen from figure 3.1 (a) that particle size of TiO 2 mainly ranges from 50nm to 1000nm due to the accumulation of nanoparticles. Figure 3.1 (b) shows that the distribution range of particle size of TiO 2 has narrowed, from 100nm to 500nm, after sonication for 30min. By comparing (a) and (b) of figure 3.1, it could be concluded that the particle size of TiO 2 particles would be decreased by sonication to certain extent. It should also be noticed that this kind of “decrease” may not be irreversible because another essential requirement to maintain the well-dispersed state of TiO 2 dispersion, the stability to restrain accumulation, cannot be obtained by sonication. The decrease in particle size may be caused by fierce vibration during sonication, nanoparticles in the dispersion accumulated again after the vibration disappeared when no additional substance was added into the dispersion to resist gravity and produce electric repulsion on the surface of particles.

3.1.

Infrared spectrums Curve 1 and 2 relates to infrared spectrums of PVB and PVB/TiO 2 composite, respectively.

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Fig. 2: Infrared spectrums of PVB and PVB/TiO 2 composite

Most of the peaks on Curve 1 and 2 appear at the same wavenumbers. The highest peak which appeared at the wavenumber of around 1100 represents the hexatomic ring in monomer of PVB. The gentle peaks at the wavenumber of around 3370, which represents hydroxyl, shaped by moisture in the ambience. The peak on Curve 2 at the wavenumber of 609.49 which represents titanium-oxygen bond, indicates that titanium dioxide has been introduced to PVB successfully.

3.2.

UV-Vis absorption spectrums

Fig. 3: UV-Vis absorption curves of PVB and PVB/TiO 2 composite

UV-Vis absorption curves of PVB and PVB/TiO 2 composite with wavelength ranging from 200-800 nm are shown in Figure 3.3. It can be seen that the ultraviolet absorbance of PVB has been improved after the introduction of TiO 2 . From 220 to 330 nm, the ultraviolet absorbance increases gradually, while it drops rapidly from 330 to 400 nm. In the section of visible light, the absorbance intensity of PVB is much lower than that of PVB/TiO 2 composite and is close to zero. One possible reason for this result is that the accumulation of TiO 2 was not eliminated completely and the PVB/TiO 2 composite was not absolutely transparent. Thus, the solution of PVB/TiO 2 composite was also not transparent and some dose of visible light were scattered while passing through the solution. The reason why the ultraviolet absorbance of PVB/TiO 2 composite declines is that the TiO 2 nanoparticles may contain some content of anatase titanium dioxide, whose peak intensity of UV absorption normally appears at the wavelength of around 387 nm. It then caused this red-shift of UV absorption.

3.3.

Thermo Gravimetric Analysis

The tests both started from the standard ambient temperature of 25â&#x201E;&#x192; with a constant heating rate of 10â&#x201E;&#x192; /min. Both the curves of mass loss speed were recorded from 2.5 min in accord with the curves of mass loss rate.

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(a)

(b)

Figure. 3 (a) Thermogravimetric Analysis curves of PVB and PVB/TiO 2 composite (b) Differential thermal gravity curves of PVB and PVB/TiO 2 composite

Figure 3.4 (a) shows the thermo gravimetric analysis curves of PVB and PVB/TiO 2 composite. Mass loss of both PVB and PVB/TiO 2 composite begun at the temperature of 100℃ and reached first peaks at the temperature of 160℃(corresponds to the time of 16th minute since the heating rate retained at 100℃ per minute). When the heating temperature reached 450℃, both of the weight loss stopped changing. The mass loss value of PVB reached zero while that of PVB/TiO 2 composite stayed at about 9%, exactly the wt% of TiO 2 . Figure 3.4 (b) demonstrates the differential thermal gravity curves of PVB and PVB/TiO 2 composite. It was shown in figure 3.4 (b) that mass loss speed of both PVB and PVB/TiO 2 composite accelerated at the temperature of 150℃ and reached first peaks at 160℃. The mass loss speeds then slowed down from 160300℃ and accelerated again, at 300℃, all the way to 370℃. Then it went through a soft descend and rose again shortly at 420℃ before reaching zero at 450℃.

4. Conclusion Sonication could reduce the particle size of titanium dioxide to some extent, and the nanoparticles may accumulate again after sonication because it cannot provide stability to restrain accumulation for TiO 2 dispersion. After introducing of TiO 2 nanoparticles, the UV-absorbing ability of PVB was improved dramatically while its thermal stability did not deteriorate and remained unchanged. A noticeable increase in UV absorption of PVB/TiO 2 composite during the wavelength range of 200 to 330 nm was observed, while its absorbance intensity in the sector of visible light indicated that the composite was not completely transparent due to the accumulation of TiO 2 before the condensation reaction.

5. References [1] Toshihiko K, Wan NF, Yoshikage O, Preparation and characterization of several types of polyvinyl butyral hollow fiber membranes by thermally induced phase separation. Applied Polymer Science 2013; 127: 4072-4078. [2] Prikko A, Pentti K, Li S. Dynamic mechanical and mechanical properties of polypropylene/poly(vinyl butyral)/mica composites. Applied Polymer Science 1997; 65: 2003-2011 [3] Jing Z, Qian X, Zhaochi F. Importance of the Relationship between Surface Phases and Photocatalytic Activity of TiO2. Angrew. Chem. 2008; 47: 1766-1769. [4] Keqing H, Muhuo Y. Study of the Preparation and Properties of UV-Blocking Fabrics of a PET/TiO 2 Nanocomposite Prepared by In Situ Polycondensation. Applied Polymer Science 2006; 100: 1588-1593. [5] Xudong C, Zhi W. Roles of anatase and rutile TiO2 nanoparticles in photooxidation of polyurethane. Polymer Testing 2007; 26: 202-208. [6] Danjela K, Tina B, Bojan K, Marija K. Interactions between Lead–Zirconate Titanate, Polyacrylic Acid, and Polyvinyl Butyral in Ethanol and Their Influence on Electrophoretic Deposition Behavior. J. Phys. Chem. B. 2013; 117: 1651–1659.

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The 13th Asian Textile Conference Geelong, Australia, November 3 - 6, 2015

Proof-of-concept fabrication of photoactive TiO 2 -PU composite nanofibers for efficient dye degradation XiaoWen Wang1, HuaWen Hu2, ChenXi Liu3, John H. Xin4 + 1,2,3,4

Affiliation: Institute of Textile & Clothing, The Hong Kong Polytechnic University, Hung Hom, Hong Kong

Abstract. Due to its many fascinating properties, titania (TiO 2 ) nanoparticles (NPs) as the benchmark and extensively-concerned semiconductor show various potential and promising applications, such as artificial photosynthesis, environmental remediation, hydrogen production from water splitting, and fabrications of solar cells, sensors, and multifunctional biological coatings with anti-bacterial and UV-blocking performances. However, how to integrate the excellent properties of TiO 2 NPs into large-scale systems for industrial applications still remains a challenge due to the easy aggregation of the TiO 2 NPs as induced by their high surface energy. We presented here a facile electrospinning route to the TiO 2 NPs stabilized by a polyurethane (PU) nanofiber, resulting in a high-performance TiO 2 -PU composite nanofiber that could photodegrade the methylene blue (MB) dye efficiently. To fabricate the composite nanofiber, we first prepared a TiO 2 nano hydrosol through a sol-gel process without calcination, which is more energy-saving as compared to the commonlyreported TiO 2 fabrication with the need of high-temperature calcination treatment. As a result, we expect the present proof-of-concept fabrication of TiO 2 -PU composite nanofibers for efficient MB degradation could render guided information for steering toward the design and large-scale applications of TiO 2 nanomaterials in the real-world industries including wastewater purification, functional textiles with disinfection and self-cleaning properties, and others.

Keywords: polyurethane, titania, nanoparticles, electrospinning, nanofiber.

1. Introduction Metal oxide semiconductors have attracted a great deal of attention due to their special chemical and electrical properties useful for many promising applications [1]. Among them, titania (TiO 2 ) is one of the most studied semiconductors for a wide range of applications, such as photo-catalysis, solar cells, biological (anti-bacteria) coatings, and sensors [2,3]. To achieve the various applications, TiO 2 has been applied to various substrates through different deposition techniques including spin-coating, dip-coating, evaporationâ&#x20AC;&#x201C;deposition, and solâ&#x20AC;&#x201C;gel processing, etc. [4,5]. However, the existing deposition techniques normally cannot be applied to thermoplastic substrates due to their requirement Corresponding author. Tel.: + 852-27666474. E-mail address: john.xin@polyu.edu.hk.

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of high temperature sintering that is most likely to degrade the thermally-sensitive organic polymer matrices. In the present study, we developed a simple, mild hydrothermal strategy with low processing temperatures to prepare a concentrated TiO 2 nano sol containing crystalline anatase TiO 2 , of which the mass concentration is more than 10% (the size of TiO 2 particles is within nanometer scale). An interesting application was subsequently explored with respect to the incorporation of the TiO 2 nanoparticles (NPs) to a polymeric nanofiber matrix on a large scale. To this end, an electrospinning technique was employed, being capable of producing fibers with an average diameter in the range of a few microns to nanometers by applying high electric fields [6,7]. Such integration of TiO 2 NPs and polymer matrix as building blocks is expected to inherit the fascinating properties of both the inorganic and organic components for the purpose of generating a high-performance composite nanofiber. As a water-insoluble polymer, thermoplastic poly(urethane) (PU) was adopted as the organic composition in this study because of its biocompatibility and excellent mechanical properties [8,9]. As a proof-of-concept demonstration, the prepared PU-TiO 2 NPs composite nanofibers were employed to degrade the methylene blue (MB) dye. Consequently, we highly expect the present study may open a new avenue to prepare polymer nanofiber incorporating TiO 2 nanomaterials or other kinds of inorganic nanomaterials, and to promote the progress of TiO 2 photocatalysts toward commercial applications.

2. Experiment 2.1. Synthesis and fabrication of TiO 2 -PU composite nanofibers The 10 wt% TiO 2 was synthesized according to our previous approach [10]. The synthesized TiO 2 NPs were demonstrated as anatase phase. In a typical procedure, a 10 wt % PU solution (MW=330,000, medical grade, Aldrich) was prepared using DMF (analytical grade, Aldrich) as a solvent. The TiO 2 sol (10 wt%) was then mixed into the 10 wt% PU solutions, yielding bluish transparent TiO 2 /PU with a mass ratio 8:1000. The mixed solution was placed in a syringe (10mL) equipped with a cylindrical metal spinneret with an inner diameter of 0.8 mm and a wall thickness of 0.05 mm. The spinneret was connected to an electrode via an alligator clip. The electrode was connected to a high-voltage power supply and charged with positive DC voltage up to 30kV. The ES mats were collected onto a grounded rotating drum with target speed at 1.0m/min. The spinning solution was delivered at a syringe pump speed of 0.02mm/h with an applied voltage of 16kV, leakage current of 0.04ÂľA, traverse speed of 20cm/min, and a distance between the tip of the conical spinneret and the collector of 10cm.

2.2. Characterization The morphologies were investigated using field emission scanning electron microscopy (FESEM, JSMâ&#x20AC;&#x201C;6335F at 3.0kV, JEOL, Tokyo, Japan). The lattice spaces were determined employing high resolution transmission electron microscopy (HRTEM, JEOL JEM 2010 operated at 200kV). UV-Vis absorption spectra of irradiated samples were recorded on a UV-Vis spectrometer (Perkin Elmer UV-Vis spectrometer Lambda 18).

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3. Results and discussion 3.1. SEM and TEM Observations Successful formation and surface morphology of electrospun (ES) PU and TiO 2 /PU fibers were demonstrated by SEM and TEM images displayed in Figure 1 and Figure 2 respectively. In Figure 1A and 1B, it can be found that TiO 2 NPs/PU fibers are uniform with dimension of 300~500 nm.

Fig.1: FESEM observation images of ES TiO 2 NPs/PU fibers with different magnifications.

A low magnification TEM observation image of ES TiO 2 NPs/PU fibers is illustrated in Figure 2A, and TiO 2 species in PU fibers are marked using an arrow line. From the Figure 2A we can see that TiO 2 NPs were evenly dispersed on/in PU fibers. The marked area was further evidenced with a lattice fringe of 0.36 nm corresponding to the (101) plane of TiO 2 from a high resolution TEM image in Figure 2B. TiO 2 is highly crystalline with the dimension of 5-10 nm similar to that found in a previous report [10]. PU fiber alignment can also be seen as marked by an arrow line in Figure 2B, along with the carbon membrane background.

Fig.2: TEM observation images of ES TiO 2 /PU fibers. (A: low magnification image, B: high resolution TEM image)

3.2.Dye degradation with ES TiO 2 /PU under UV The dye degradation was assessed by analyzing the degradation of MB during exposure to UV irradiation. In a typical process, 100 ml (5 mg L-1) MB solution was first added into ES PU fibers plate (as control) and ES TiO 2 /PU fibers plate, followed by sealing up the reaction unit and then exposing to UV irradiation provided by Philip UV TLD 18W/08 lamps. The UV intensity on the top of the plate was 0.5~0.6 mw/cm2. The changes in the content of colorants were estimated by the change of the concentration of MB in the solution by means of tracking the max absorption peak at 660 nm in the UV/vis absorption spectra, with the results shown in shown in Figure 3.

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0.6

0.5

MB(mg)

0.4

ES PU ES TiO2 /PU

0.3

0.2

0.1

0.0 0

Time (h)

Fig. 3: Photodegradation of MB by ES TiO 2 /PU nanofibers under UV.

The concentration of MB solution in ES TiO 2 /PU fibers plate decreases gradually with UV irradiation. The colorant content was almost reduced to zero point after the photocatalytic reaction over the ES TiO 2 /PU fibers under UV irradiation for 10 h, whereas the concentration of MB solution in the control experiment (using ES PU fibers plate as a photocatalyst for 10 h reaction) remained almost the same as the starting point, with only negligible amount of MB reduced after 10 h (likely caused by a certain absorption capacity of the ES PU fibers).

4. Conclusion The concentrated TiO 2 nano hydrosol synthesized through hydrothermal reaction at low temperatures has been applied to prepare photocatalytic PU nanofibers by an electrospinning process. In this study, the photocatalytic ES TiO 2 /PU fibers have been fabricated via a sol-gel technology without any calcination. TiO 2 NPs in the fibers have been determined by HRTEM with approximately a 5 nm size and 0.36 nm fringe spacing of {101} facet. The ES TiO 2 /PU fibers and fabrics have been demonstrated to possess an excellent photocatalytic property in photodegradation of MB. The studies on the function of anti-bacteria, UV-blocking and self-cleaning of TiO 2 NPs nanofibers are underway in our laboratory. We believe that the present fabrication of TiO 2 NPs/PU nanofibers and proof-ofconcept MB degradation applications can pave the way for many multi-functional applications.

5. References [1] Drew C, Liu X, Ziegler D,Wang X, Bruno FF, et al. Nano Lett. 3 (2003) 143–147. [2] Oh SH, Finones RR, Daraio C, et al. Biomaterials 26 (2005) 4938–4943. [3] Liu SQ, Chen AC. Langmuir. 21 (2005) 8409–8413. [4] Malfatti L, Bellino MG, Innocenzi P, et al. Chem. Mater. 21 (2009) 2763–2769. [5] Chi B, Jin T. Cryst. Growth Des. 7 (2007) 815–819. [6] Bhardwaj N; Kundu SC. BIOTECHNOLOGY ADVANCES. 28(2010) 325-347. [7] Reneker D H, Yarin, A L. Polymer. 49(2008) 2387-2394. [8] Kidoaki S, Kwon IK., Matsuda TJ. Biomed Mater Res Part B: Appl Biomater. 76 (2006)219-225. [9]Yao C, Li X, Neoh KG, Shi Z, Kang ET. J Membr Sci. 15(2008) 259-266. [10] Wang RH, Wang XW, Xin JH. ACS Appl. Mater. Interfaces. 2 (2010)82–85.

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The 13th Asian Textile Conference Geelong, Australia, November 3 - 6, 2015

Re-examination of the Polymerization of Amio Acid NCAs 69. A new type topochemical polymerization of amino acid N-carboxy anhydrides. A Hitoshi Kanazawa, Aya Inada and Takuto Tanaka Department of Industrial Systems, Faculty of Symbiotic Systems Science, Fukushima University, 1 Kanayagawa, Fukushima, 960-1296, Japan; kana@sss.fukushima-u.ac.jp

Abstract. Amino acid ester NCAs were polymerized in solutions in 1,4-dioxane or N,N-dimethylformamide (DMF). Amino acid NCAs were polymerized in a heterogeneous solution in acetonitrile, in which amino acid NCAs were soluble but resulting polypeptides are not soluble. We found that when amino acid NCA crystals are put in hexane, and butylamine is added in the mixture, the NCA polymerization proceeds in the crystalline state (solid state). Both of the solid-state polymerization rate and the resulting polymer conformation were affected by the NCA crystal structures. The NCA solid state polymerization is considered as a new type topochemical polymerization, although the ring-opening of NCA molecules and the carbon dioxide generation are occurred in the course of polymerization. Keywords amino acid N-carboxy anhydrides, amino acid NCA, PBLG, topochemical polymerization, polypeptide, solid state polymerization, crystal structure

1. Introduction Polypeptides are useful materials as protein models, and are made by the effective use of amino acids. Amino acid N-carboxyanhydrides (amino acid NCAs) are extensively used for the preparation of high molecular weight polypeptides. Polymerization of amino acid NCA is a ring-opening polymerization (ROP) which gives carbon dioxide evolution. Only NCAs of γ or β esters of L-glutamic acid or L-aspartic acid are polymerized in solutions in organic solvents, because their corresponding polypeptides are soluble in the solvents. On the other hand, the preparation of simple polypeptides such as poly(L-alanine) and poly(L-leucine) are difficult in solutions, because they are not soluble in the solvents, although their corresponding amino acid NCAs are easily soluble. When amino acid crystals are put in non-polar organic liquid such as hexane and heptane, and butylamine is added in the mixture, the NCA does not dissolve and the polymeri-zation proceeds in the solid state. We have been determining the crystal structure of amino acid NCAs, and considering the solid-state polymerization with reference to the NCA crystal structures. The NCA solid state polymerization gave the characteristics typical for a topochemical polymerization.

2. Experimental Amino acid NCAs are prepared by the reaction of corresponding amino acids or amino acid esters and phosgen derivatives. NCA crystals are recrystallized in ethyl acetate and hexane about ten times until the Cl content [Cl] is decreased to about 0.01wt.%. The polymerization of NCAs are mainly carried out in acetonitrile (heteogeneous solution) or in hexane (solid state) by the initiation with butylamine. Only amino acid ester NCAs such as γ-benzyl-L-glutamate (BLG) NCA, γ-methyl-L-glutamate (MLG) NCA, β- benzyl-L-aspartate (BLA) NCA are polymerized in dioxane or N,N-demethylformamide (DMF) solutions. Molecular weights of

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polypeptides are estimated by a viscometry and a right scattering. The molecular weight distribution of PBLG is observed by GPC.

3. Results and discussion 3.1 Comparison of the reactivity of amino acid NCAs in the solid state and that in acetonitrile solution Since poly(L-alanine) and poly(L-leucine), etc. are not soluble in general organic solvents, the real solution polymerization of the corresponding NCAs is impossible. Amino acid NCAs are soluble but resulting polypeptides are not soluble in acetonitrile. Fig.1 gives the polymerization of L-alanine NCA, L-leucine NCA, L-phenylalanine NCA and L-valine NCA initiated by butylamine in acetonerile. The polymerization is considered to occur between dissolved NCAs and precipitated polymers in acetonitrile. Although it was reported that L-alanine NCAs is very reactive in acetonerile [1], we confirmed that L-alanine NCA is not so reactive in acetonitrile when the moisture contamination in the reaction system is sufficiently avoided. On the other hand, amino acid NCA crystals are not soluble in hexane. When butylamine (an initiator) is added in the mixture of NCA crystals in hexane, the polymerization takes place in the solid state. We investigated the NCA solid-state polymerization and determined the NCA crystal structures. Figure 2 gives the solid-state polymerization of five NCAs. It is remarkable that L-leucine NCA (L-leu) and L-phenylalanine NCA (L-phe) is very reactive in the solid state. These results suggest that the solid state polymerization of amino acid NCAs is largely affected by their crystal structures.

Fig. 1 Polymerization of four amino acid NCAs in the heterogeneous solution in acetonitrile initiated by butyl amine at 30 ˚C. [NCA]/[I]=200.

Fig. 2 Solid-state polymerization of four amino acid NCAs in the heterogeneous solution in acetonitrile initiated by butyl amine at 30 ˚C. [NCA]/[I]=200.

3.2 Comparison of the reactivity of amino acid ester NCAs in the solid state with that in dioxane solution The NCAs of γ-methyl-L-glutamate (MLG), γ-benzyl-L-glutamate (BLG) , β-benzyl-L-aspartate (BLA) and their corresponding polypeptides are soluble in dioxane. Thus, these solution-polymerization is possible in dioxane. Especially, as the estimation of molecular weight and molecular weight distribution (MWD) of poly(γ-benzyl-L-glutamate) (PBLG) are possible, the polymerization of BLG NCA has been extensively investigated in the world. These amino acid ester NCAs were polymerized in the dioxane solution and in the solid-state in hexane. The NCA crystals were recrystallized in ethyl acetate and hexane about ten times until the Cl content becomes about 0.01wt.%, because the purity of NCAs has a large effect on the reactivity.

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The solution polymerization was carried out in dioxane, and the solid state reaction was in hexane, by the initiation with butylamine. Molecular weights were estimated by a viscometry and a light scattering. Molecular weight distributions were observed by GPC. Table 1 gives the polymer conversion for 3 hours in the solidstate and solution polymerization of BLG NCA, MLG NCA and BLA NCA. It is remarkable that three NCAs are more reactive in the solid Table 1 Polymerization of BLG NCA, BLA NCA and MLG NCA in the solid state than in dioxane solution. state in hexane and in the solution in dioxane initiated by butyl amine. The discussion with the crystal NCA system conversion for 3 h structure is given below (3.5). solid-state 60.0 BLG

dioxane solution 26.0 solid-state 100 MLG dioxane solution 46.0 solid-state 10.5 BLA dioxane solution 3.00 Temperature: 30 ˚C, [NCA]/[I]=200, [Cl] of NCAs : 0.002-0.006wt.%. Initiator(I): butylamine..

Molecular weight

Table 2 Molecular weight and MWD of PBLG PBLG Mn Mw solid state*1 113,000 133,000 dioxane solution*2 174,200 18,600 [NCA]/[I]=200(*1), 80 (*2), temperature=30˚C, Initiator(I): butylamine.

3.3 M w /M n

Table 1 gives the molecular weight and the 1.18 molecular weight distribution 1.07 parameter, M w /M n ( a ratio of weightaverage mole-ular weight (M w ) to number-average molecular weight (M n )) of PBLG obtained in the solid state in hexane and in the solution in dioxane. The molecular weight of PBLG obtained in the solid state was much higher than that in solution. The molecular arrangement in the crystal is considered to be preferable for the polymerization.

3.4 Polymer conformation Polymer conformations of polypeptides obtained in each polymerization are summarized in Table 2. It is remarkable that poly(L-phe) and polyMLG obtained in the NCA solid-state polymerization form the β-sheet structure which is impossible in solution-polymerization. This conformation is considered to be made by the NCA crystal structure.

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3.5 Crystal structure of NCAs We have been determining the NCA crystal structures. In the crystal structure of L-leucine NCA, the fivemembered rings are in a layer, and the side chains are in another layer. These layers align alternatively and make a sandwich structure. L-Leucine NCA gave the highest reactivity in Fig.2. The molecular conformation of poly(L-leucine) obtained both in acetonitrile solution and in the solid state was the α-helix, because of he bulky isobutyl groups. It is considered that the polymerization of L-leucine NCA proceeds and forms the α helix polymer along the c axis (Fig. 3). In BLG NCA crystal, the sandwich structure is also seen in other NCA crystals. BLG NCA is more reactive in the solid state than in the dioxane solution. But, the NCA is not so reactive as compared with MLG NCA. PBLG forms the α-helix both in the solid-state and in solutions. In the crystal, the long side chains of BLG NCA have to rotate around a certain axis to form the α-helix polymer. This might be not so easy. On the other hand, MLG NCAs polymerize and the β-sheet form polymer in the crystal. The α-helix polymer is formed in solution reactions. Thus, the β-form PMLG was considered to be formed by the NCA molecular arrangement in the crystal. MLG NCA was the most reactive in the solid-state. These facts suggest that the solid-state polymerization of amino acid NCAs is a new type topochemical polymerization.

Fig.3 L-Leucine NCA crystal

3.6 SEM observantion

Fig.4 L-Leucine NCA molecular arrangement along c-axis in crystal

Table 3 Molecular conformations of polypeptides obtained in the NCA polymerization in the solid state and in the solution or heterogeneous systems

Gly L-Ala L-Val L-Leu L-Phe BLG Figure 5 gives NCA ∗ β α, p.β β α α α BLG NCA solution ∗ crystals and solid β α, p.β β α β α 200µm PBLG formed in * p.β :β− the solid-state polymerization. BLG NCA crystals are polymerized and the whole shape is maintained in the solid state. However, the polymer has not a crystal.

BLA β β

MLG α β

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4. Conclusion

Fig.5 SEM photographs of polymerized BLG NCA crystal

The NCA solid state polymerization is considered as a new type topochemical polymerization, although the ring-opening of NCA molecules and the carbon dioxide generation are occurred in the course of polymerization. The solid-state polymerization is available for each amino acid NCA.

5. References [1] Iwakura, Y., Uno, K. and Oya, M.; J.Polym. Sci., 1957, A-1, 5, 2868. [2] Kanazawa, H. and Inada, A., Acta. Cryst., 2015, E71, pp.110-112. [3] Kanazawa, H. â&#x20AC;&#x153;Encyclopedia of Polymeric Nanomaterialsâ&#x20AC;?, pp.1972-1981, Springer, 2015.

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The 13th Asian Textile Conference Geelong, Australia, November 3 - 6, 2015

Sericin removal from the silk degumming wastewater by magnetic nanoparticles: a feasible approachâ&#x20AC;? Esfandiar Pakdel* a, Jinfeng Wang a, Xungai Wang a,b a

Australian Future Fibres Research and Innovation Centre, Institute for Frontier Materials, Deakin University, Geelong, Australia b Ministry of Education Key Laboratory for Textile Fibers and Products, Wuhan Textile University, Wuhan, China

Abstract. The performance of amino-group functionalized magnetic iron oxide nanoparticles for adsorbing sericin from the silk degumming wastewater was investigated. The sericin adsorbed magnetic nanoparticle can easily be removed with the help of external magnet. The impact of influential parameters on sericin removal efficiency including pH, magnetic nanoparticles concentration and treatment time were examined. Three concentrations of magnetic nanoparticles including 0.2, 0.6 and 1 g/L were used for sericin removal. The experiments were conducted at pH=5 where sericin and magnetic nanoparticles had negative and positive surfaces charges, respectively. The sericin removal efficiency of 53% was achieved at pH=5 with a concentration of 0.6 g/L of magnetic nanoparticle after treatment for 10 min. The sericin removal mechanism is suggested to be the electrostatic interaction between positively charged nanoparticles and negatively charged sericin. The study on removing sericin with amino-group functionalized magnetic nanoparticles followed by easy separation with the help of external magnet indicate the possibilities of using magnetic nanoparticles for sericin removal from silk degumming wastewater. Keywords: Sericin, magnetic nanoparticles, wastewater, zeta potential

1. Introduction The Bombyx mori silk is composed of two main parts including fibroin and sericin [1]. Sericin constitutes around 20-30% of cocoon weight and envelops the inner fibroins gluing them together [2]. It is proven that the presence of sericin provides some properties on silk cocoons such as antimicrobial, UV protection and moisture absorption [3]. However, the presence of sericin gives rise to a rough and stiff hand feel of fibres. It also plays a role as a barrier on the outer layer of fibroins preventing the access of dyestuffs and finishing agents to inner parts of fibers. Therefore, degumming process is considered as one of the essential prerequisites of obtaining a high quality finish on silk products. The wastewater produced by the wet processing of textile industry such as silk degumming causes many environmental issues. Also, due to the presence of sericin and other types of organic compounds, the produced wastewater has a very high COD level which can endanger the aquatic life by depletion of dissolved oxygen of water [4]. It has been demonstrated that sericin has some unique features such as high moisture absorption capacity, anti-oxidant and anti-cancer features. This shows the latent potential of sericin for some applications in diverse fields such as cosmetics, biochemistry, and food industry [4]. Because of these reasons researchers have been trying to find some novel techniques to separate and recover the sericin from silk degumming wastewater prior to discharhge. Although improving the removal efficiency is critical in the sericin removal research, easy separation is very important for increasing recovery efficiency and facilitating sericin removal. One of the promising feasible recovery methods is to use magnetic nanoparticles to separate the sericin aggregates. In fact, as an important family of advanced nanomaterials, magnetic nanocomposites have gained

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much attention, due to their ability to realize the effective magnetic separation to selectively capture the objects of interest from a complex mix of substances [5]. In this study, the waste solution resulted from silk degumming process is treated with the suspension of magnetic iron oxide nanoparticles at different experimental conditions. The electrostatic interaction between magnetic nanoparticles and sericin residues plays the main role in removing the sericin from wastewater. The main objective of this investigation is understating the role of surface charge manipulation of magnetic nanoparticles in removing the proteinous compounds from the textile wastewater.

2. Experimental 2.1. Materials The silk cocoons of Bombyx mori (China) were used as sericin sources. The commercial magnetic iron oxide nanoparticles of BioMagÂŽAmine (50 g/L, Bangs Laboratories, Inc.) were employed in this study. The surface of particles was already modified with amine groups. Sodium carbonate, sodium hydroxide and hydrochloric acid (35%) were purchased from the MERCK Company.

2.2. Degumming of cocoon and waste treatment Silk cocoons were cut into 6-8 pieces and dried in an oven at 60Â°C for 8 h. The degumming process was carried out in a sodium carbonate 0.5% solution at liquid to good ratio of 100:1. The mixture of cocoons and sodium carbonate solution was mixed for 30 min at 90Â°C. Next, the solution of sericin was separated from the silk fibers and stored in the fridge. Three different concentrations of magnetic nanoparticle aqueous dispersion including 0.2, 0.6 and 1g/L were utilized. 20 ml of prepared suspensions were mixed with 20 ml the sericin solution at pH=5. The mixtures were mixed for 1 h and then the magnetic field was applied. After depositing the magnetic nanoparticles at the bottom of container, the supernatant was separated and the content of sericin was measured using a UV-vis spectrophotometer. Moreover, the mixtures of sericin and nanoparticles were mixed for 5, 10, 20, and 30 minutes to understand the impact of treatment duration in sericin removal efficiency. Figure 1 illustrates sericin removal process with magnetic nanoparticles.

Fig 1: Schematic steps of degumming wastewater treatment with magnetic nanoparticles

2.3.Characterization The zeta potentials of magnetic nanoparticles and sericin were individually measured to determine the optimum pH for wastewater treatment. The surfaces charges of sericin and magnetic nanoparticles (0.002g/L) were measured over a range of pH= 3-9 using zetasizer (Malvern instruments limited. UK). The sericin and nanoparticles were further analyzed using SEM images taken by Zeiss Supra 55 VP (Germany). The samples were prepared for SEM analysis through a gold sputter coating method. The sericin concentration change was monitored

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based on the reduction in the peak intensity of UV-visible spectrum at 280 nm [6-7] The spectrum was obtained using a Varian Carry 3000 (Australia).

3. Results and discussion 3.1. Determining the zeta potentials The mechanism attributed to protein adsorption in this research is based on the potential electrostatic interactions between magnetic nanoparticles and sericin. Therefore, the surface charges of magnetic nanoparticles and sericin play a pivotal role in the sericin removal efficiency. Figure 2 demonstrates the variation of zeta potentials of sericin and magnetic nanoparticles at different pH. The pH of solutions was adjusted by adding acid hydrochloride (HCl) and sodium hydroxide (NaOH) solutions. The greatest zeta-potential difference between sericin and magnetic nanoparticles were found at pH=5, where the surface charges of sericin and magnetic nanoparticles are -16.1 mV and 19.34 mV, respectively. Therefore, pH=5 is selected as an optimal pH to perform the sericin removal experiments.

Fig 2: Zeta potentials of sericin and magnetic nanoparticles as a function of pH

3.2. Impact of nanoparticles concentration and treatment time Three different concentrations of magnetic nanoparticles including 0.2, 0.6 and 1 g/L were used to investigate the impact of nanoparticles concentration on sericin removal. Figure 3a shows that the sericin removal efficiency increased with increasing the concentration of nanoparticles. The sericin removal efficiency was found to be 20% with a magnetic nanoparticle concentration of 0.2 g/L. This is compared with 53% sericin removal with a magnetic particle concentration of 0.6 g/L. Further increasing the concentration to 1g/L resulted in a similar sericin removal efficiency of 57%. The concentration of 0.6 g/L was chosen as the optimum one for undergoing the further experiments. Figure 3b depicts that the maximum amount of sericin adsorption in the presence of nanoparticles (0.6 g/L) can be achieved within the initial 10 minutes of treatment. Further prolonging the mixture time resulted in a similar removal efficiency. It is suggested that the saturation adsorption was reached within the first 10 min treatment.

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Fig 3: Separating the sericin from the silk degumming wastewater, impact of a) magnetic nanoparticles concentration, b) treatment duration The variation of zeta-potential further confirmed the formation of the magnetic nanoparticle and sericin aggregates. As shown in Table 1, the zeta potential of sericin at pH=5 was -20.27 eV and became -7.78 after incubation with magnetic nanoparticle. Further increasing the amount of the magnetic nanoparticle resulted in an increased zetapotential. This result indicates the existence of the electrostatic interactions between the positively charged magnetic nanoparticles and negatively charged sericin. Table 1: Variation of sericinâ&#x20AC;&#x2122;s zeta-potential before and after the treatment Solution

Zeta potential (mV)

Control sericin Sericin +NPs (0.2 g/L) Sericin +NPs (0.6 g/L) Sericin +NPs (1 g/L)

-20.27 -7.78 -2.11 -2.40

3.3. SEM images The morphology of extracted sericin and magnetic nanoparticles was observed using SEM (Figure 4). The SEM image of sericin illustrates an aggregation among sericin nanoparticles with the average size of around 500 nm (Figure 4a). Similarly, Figure 4b shows the magnetic nanoparticles in spherical shape with the approximate diameter of 20 nm. It can be seen that there is a major tendency in magnetic nanoparticles for aggregation. High aggregation among the magnetic nanoparticles can be one of the reasons of relatively low sericin removal efficiency.

Fig 4: SEM images, a) sericin, b) magnetic nanoparticles

4. Conclusion Magnetic iron oxide nanoparticles were successfully applied for removing the sericin from the silk degumming wastewater with the help of the external magnet. It was demonstrated that high sericin removal efficiency can be achieved by the surface charge manipulation of nanoparticles and sericin. The highest removal efficiency was achieved at pH=5, where the magnetic nanoparticles and sericin had positive and negative surface charges, respectively. The impacts of magnetic nanoparticles concentration, treatment duration, and zeta potentials on separation of sericin from the wastewater were investigated. The maximum sericin removal efficiency was found to be 57% after 10 minutes of treatment. The obtained results highlight the necessity of further surface modifications of nanoparticles to enhance the electrostatic separation of sericin from the silk degumming wastewater.

References

[1]. M. Lewin. Handbook of fiber chemistry, 3rd ed. Boca Raton, Florida, USA: Taylor and Francis Group, LLC; 2007. [2]. J. Lin, L. Wang, L. Wang, J Polym Environ. 20 (3) (2012) 858.

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[3]. Y.-Q. Zhang, Biotechnol. Adv. 20 (2) (2002) 91. [4]. G. Capar, S. S. Aygun, M. R. Gecit, J. Membr. Sci. 325 (2) (2008) 920. [5]. A. K. Gupta, M. Gupta, Biomater. 26 (18) (2005) 3995. [6]. D. Gupta, A. Agrawal, A. Rangi, Indian J. Fibre Text. Res. 39 (4) (2014) 364. [7]. Y. Yesol, L. S. Mi, L. H. Sol, L. K. Hoon, Int. J. Indust. Entomol. 27 (1) (2013) 203.

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The 13th Asian Textile Conference Geelong, Australia, November 3 - 6, 2015

Title: Strain sensitive cotton fabric with a graphene nanoribbon layer Lu GAN 1, Songmin Shang 1 and Shou-xiang Jiang 1 1

Institute of Textiles and Clothing The Hong Kong Polytechnic University, Hong Kong, China SAR

Abstract. In the present study, a highly conductive cotton fabric was prepared by coating the graphene nanoribbon onto the surface of the cotton fabric through a wet coating approach. The structure of the conductive cotton fabric was in terms of scanning electron microscope (SEM). The electrical properties of the conductive cotton fabric was studied specifically. It was shown from the results that the resistance of the conductive cotton fabric had a linear dependence on the strain of it when the applied strain was lower than 20%. The prepared conductive cotton fabric has great application potentials in the field of strain sensors. Keywords: graphene; cotton fabric; electrical properties; strain sensitive

1. Introduction In recent years, significant progress has been achieved in the area of technical textiles [1]. Fibers, yarns, fabrics and other structures with added-value functionality have been successfully developed for technical and high performance end-uses [2]. Among these progresses, smart textiles, especially conductive fibers have attracted tremendous interest for their wide application potentials in various smart textile fields, since they are endowed with autonomous sensing, actuation, processing, communication and energy harvesting and storage. As an extremely important member of the smart textiles, the flexible and conductive fibrous materials have attracted tremendous interest [3]. Recently, nanoparticles and nanomaterials have been established as an independent research discipline and found various applications due to their extinct structures and properties [4-6]. Graphene nanoribbon (GNR) has generated tremendous excitement recently due to its unique structure. A number of studies have been conducted to fabricate GNR filled composites for exploring the reinforcing effect of the GNR [7, 8]. In this study, the GNR was prepared and subsequently coated onto cotton fibers to fabricate conductive cotton textile through a simple wet coating process. The thermal, mechanical, especially electrical properties of the GNR coated cotton textiles were then studied systematically.

2. Experimental 2.1.

Materials

The cotton sheet with thickness of ~1.0-2.0 mm was purchased from Dalian Textile Factory (China). The multi-walled carbon nanotubes (CNTs) with diameters between 5 and 20 nm, length of 10 um, and purity over 95%, were purchased from Shenzhen Nanotech Port Co. Ltd. (China). The other solvents and chemicals were of analytical grade and used as received.

2.2.

Preparation of strain sensitive cotton fabric

The synthesis of graphene nanoribbon (GNR) follows the procedures from our previous study. The detailed steps of the preparation of strain sensitive cotton fabric are as follows. Typically, 100 mg of graphene nanoribbon, 50 mg Sodium Dodecyl Sulfonate was dissolved in 200 mL H 2 O. After the solution was sonicated for 4 h, the cotton sheet (1* 4 cm2) was dipped into the solution and removed after a short period of time. The wet cotton fabric was then dried at 60 oC for 12 h and the strain sensitive cotton fabric was finally prepared.

2.3. Characterizations Transmission electron microscopy (TEM) images of the GNR were recorded using a Jeol JEM2100F TEM instrument operated at 200 kV. Scanning electron microscopy (SEM) was conducted by the

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JEOL SEM 6490.Fourier transform infrared spectra (FT-IR) were recorded using a Perkin Elmer 100 spectrophotometer with a resolution of 4 cm-1 in 16 scans. Typical stress-strain curve was recorded using an Instron 5566 universal machine. The resistances of the textiles being dipped into the GNR solution for different times were recorded with a Keithley 2010 digital multimeter.

3. Results and discussion The structure of the CNTs and GNR is imaged by TEM shown in Figure 1. As could be seen, there was not side-wall structure of the CNTs appeared in the GNR image. Moreover, the prepared GNR had a strip appearance with the width about 40-50 nm, indicating that the CNTs had been unzipped to the GNR. FT-IR images of the CNTs and GNR were shown in Figure 2. It could be seen that after CNTs were unzipped to GNR, there was a significant increase on the intensity of the band at 1712 cm-1 (C=O stretching vibration), indicating that strong oxidants created much more carboxyl acid groups along the edge of the GNR.

Fig. 1: TEM images of (a) CNTs and (b) GNR

Besides, after the reaction, the band at around 3100 â&#x20AC;&#x201C; 3500 cm-1 became broader and stronger, which meant strong oxidants also brought about more hydroxyl groups.

Fig. 2 FT-IR spectra of CNT and GNR:

Figure 3 shows the SEM image of the GNR coated cotton fibers. It was clearly seen that the surface of the coated fiber is rougher than that of the pristine cotton fiber, indicating the GNR was coated onto the cotton fiber.

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Fig. 3 SEM image of the pristine textile (Left) and coated textile (Right)

Due to the existence of the GNR coating, the insulated cotton fabric turned electrical conductive. It was investigated by the digital multimeter that the resistance of the sensitive cotton fabric (40 Ă&#x2014; 10 mm ribbon shape) was as low as ~80 ÎŠ. The high conductivity enabled the cotton fabric with more application potentials. The resistance change of the GNR coated cotton fabric during consecutive stress-strain cycles was then conducted to investigate the conducting stability of the GNR coated cotton fabric. The fabric was stretched to 20% elongation, and released to normal state for 20 repeated cycles. The resistance values were normalized by the samples initial resistance values R 0 at zero strain. The results were shown in Figure 4. It was seen that the GNR coated cotton fabric remained conductive after 20 consecutive cycles. It was very interesting to observe that there was a linear dependence of the resistance on the strain of the cotton fabric. When the applied stress was released, the resistance of the cotton fabric returned to its initial value, indicating that the resistance of the GNR coated cotton fabric upon stretching was highly reversible when the elongation was lower than 20%.

Fig. 4 The relative resistance changes of the strain sensitive cotton fabric during 20 consecutive strain cycles between 0% and 20%.

4. Conclusion In summary, the GNR was synthesized and was then coated onto the cotton fabric surface. The GNRs were found coated on the cotton fiber surfaces, enhancing the conductivity of the cotton fabric. Moreover, the resistance of the GNR coated cotton fabric had a linear dependence on the strain when the applied strain was 20%. The results of this study indicate that the prepared GNR coated cotton fabric had great application potentials for strain sensor.

5. Acknowledgements The work was supported by the General Research Fund (Project No. 532712) of the Research Grants Council of Hong Kong.

6. References [1] L.A.A. Beex, C.W. Verberne, R.H.J. Peerlings, Experimental identification of a lattice model for woven fabrics: Application to electronic textile, Compos. Part A-Appl. S., 48 (2013) 82-92.

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[2] Z. Gao, N. Song, Y. Zhang, X. Li, Cotton textile enabled, all-solid-state flexible supercapacitors, RSC Adv., 5 (2015) 15438-15447. [3] R. Dastjerdi, M. Montazer, A review on the application of inorganic nano-structured materials in the modification of textiles: Focus on anti-microbial properties, Colloid Surf. B, 79 (2010) 5-18. [4] L.Y. Li, K.Q. Xia, L. Li, S.M. Shang, Q.Z. Guo, G.P. Yan, Fabrication and characterization of free-standing polypyrrole/graphene oxide nanocomposite paper, J. Nanopart. Res., 14 (2012). [5] L. Gan, S. Shang, C.W.M. Yuen, S.-x. Jiang, N.M. Luo, Facile preparation of graphene nanoribbon filled silicone rubber nanocomposite with improved thermal and mechanical properties, Compos. Part B-Eng., 69 (2015) 237-242. [6] T. Lu, G.R. Shan, S.M. Shang, Intermolecular Interaction in Aqueous Solution of Binary Blends of Poly(acrylamide) and Poly(ethylene glycol), J. Appl. Polym. Sci., 118 (2010) 2572-2581. [7] L. Gan, S. Shang, C.W.M. Yuen, S.-x. Jiang, Graphene nanoribbon coated flexible and conductive cotton fabric, Compos. Sci. Technol., 117 (2015) 208-214. [8] L. Gan, S. Shang, C.W.M. Yuen, S.-x. Jiang, Covalently functionalized graphene with d-glucose and its reinforcement to poly(vinyl alcohol) and poly(methyl methacrylate), RSC Adv., 5 (2015) 15954-15961.

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The 13th Asian Textile Conference Geelong, Australia, November 3 - 6, 2015

Synthesis of Ag 3 VO 4 /TiO 2 /CNT hybrids with enhanced photocatalytic

activity under visible light irradiation Chang Mou Wu*, Ching Kai Wang Department of Materials Science and Engineering, National Taiwan University of Science and Technology, Taipei 10607, Taiwan, Republic of China

Abstract. In this study, the Ag 3 VO 4 /TiO 2 /CNT hybrids was successful prepared by a facile and low cost method. The samples performed high photocatalytic activity to degradation the organic pollutant in visible light irradiation. The Ag 3 VO 4 /TiO 2 hybrids degradation of methyl blue (MB) carried out in an aqueous solution after 4 h of 27 W lamp which derived in visible light irradiation. The photocatalytic conversion ratios of MB for TiO 2 , TiO 2 /CNT, Ag 3 VO 4 , Ag 3 VO 4 /TiO 2 , Ag 3 VO 4 /TiO 2 /CNT were 4%, 17%, 62%, 94%, 80%, respectively. The improved of the degradation efficiency for the Ag 3 VO 4 /TiO 2 hybrids due to the heterogeneous photocatalysts that occurs interface of dissimilar crystalline, defect and surface area.

Keywords: silver vanadate, titanium dioxide, carbon nanotube, visible-light photocatalyst.

1. Introduction Heterogeneous photocatalysts by use of semiconductor materials has been applied as an efficient method in the field of environmental purification. Titanium dioxide (TiO 2 ) has proved to be the most suitable one because of its many desirable properties such as high activity, chemical stability, low toxicity, no secondary pollution, low cost and water insolubility under most conditions [1-3]. However, some problems in TiO 2 photocatalytic system for practical applications. Sun light radiation consists of about 5% UV light, 47% visible light and 48% infrared radiation. TiO 2 as the benchmark of UV photocatalysts is inactive under visible light due to its wide band gap (Eg = 3.2 eV for anatase) [2]. Electron–hole recombination, at the surface or in the bulk, competes with the above process and limits the efficiency of photocatalytic reactions. Several methods have been applied to improve the photocatalytic efficiency of TiO 2 . Such as doping with non-metals, metal interface modification and hybrids with mental oxides [1-3]. Carbon nanotube (CNT) hybrids with TiO 2 has been report to provide a synergistic effect which can enhance the overall efficiency of a photocatalytic process. The conductive structure of the CNTs scaffolds is believed to favour the separation of the photo-generated electron–hole pairs by formation of heterojunctions at the CNTs/TiO 2 interface. Moreover, the TiO 2 /CNT hybrids could derived TiO 2 have shown capabilities of improving visible light photocatalytic properties [4]. In this study, we mixture the Ag 3 VO 4 onto the TiO 2 /CNT to prepare the Ag 3 VO 4 /TiO 2 /CNT hybrids, which was able to absorb under visible light irradiation (λ> 400 nm) [2, 5]. The hybrids of Ag 3 VO 4 and TiO 2

Page 528 of 1108

semiconductor could enhance the charge separation by the interface of heterojunction between them and improve its wide spectral response. The expected enhanced photocatalytic activity of Ag 3 VO 4 /TiO 2 /CNT hybrids was tested by degradation of organic pollutants.

2. Experimental 2.1 Sample preparation There are five different photocatalysts, two of pure materials (TiO 2 , Ag 3 VO 4 ) and three of hybrids materials (TiO 2 /CNT, Ag 3 VO 4 /TiO 2 and Ag 3 VO 4 /TiO 2 /CNT).

2.1.1 Preparation of the TiO 2 /CNT hybrids Purified CNT (supply NC7000 by NANOCYLTM, Belgium) were dissolved by acid treatment (HNO 3 :H 2 SO 4 = 1:3, v/v) in ultrasonic bath equipped with the stirrer at 323 K from 6 h [6], followed by washing, filtrating and drying as the same conditions in purification. Acid treatment CNT was dispersed in 15 mL of absolute alcohol by stirring to obtain brown suspension which is poured into a Teflon-lined stainless autoclave. Then, 5 mL of tetrabutyl titanate (supply by ACROS organics, Belgium) was added to the autoclave and the mixture was stirred for 1 h. After that, 1 mL of concentrated hydrochloric acid was added dropwise to the above mixture. Finally, the autoclave underwent a hydrothermal process at 180 笳ｦC for 36 h, followed by cooling down to room temperature naturally. The products were harvested by centrifugation and washed several times with a mixture of ethanol and deionized water. After drying in air at 60 笳ｦC for 12 h, the TiO 2 /CNT hybrids was obtained. For the comparison pure TiO 2 were also prepared by the same method in the absence of CNT.

2.1.2 Preparation of Ag 3 VO 4 /TiO 2 /CNT hybrids 0.03 g as prepared of TiO 2 /CNT hybrids were dispersed in 20ml of 102 mg AgNO 3 (supply by ACROS organics, Belgium) solution by ultrasound and stirring for 2 h. Then, 15 mL of 24 mg NH 4 VO 3 (supply by ACROS organics, Belgium) was poured into the suspension and 2 M NaOH was used to adjust the pH value of the whole system to 9 [2]. After stirring for 2 h, the product was centrifugated and washed with distilled water for several times. The final solid product was slightly dried by cool air and then completely dried at 60 笳ｦC for 12 h to obtain Ag 3 VO 4 /TiO 2 /CNT hybrids. Ag 3 VO 4 /TiO 2 hybrids was prepared under the same procedure of Ag 3 VO 4 /TiO 2 /CNT but without adding CNT. Ag 3 VO 4 was obtained in the absence of TiO 2 /CNT by the same method.

2.2 Tests of photocatalytic degradation The photocatalytic degradation of methyl blue (MB) carried out were carry out in an aqueous solution. The light source was a 27 W lamp. A total of 20 mg of photocatalyst was added to 100 mL of simulating pollutant solution, such as MB solution (10 ppm), contained in a glass vessel with a plane side. Before irradiation, the suspension was magnetically stirred for 1 h in the dark in order to reach adsorption窶電esorption equilibrium between the catalyst and the simulating pollutant.

Page 529 of 1108

3. Result and discussion 3.1 Physicochemical properties of Ag 3 VO 4 /TiO 2 /CNT hybrids

Fig. 1. XRD patterns of TiO 2 , TiO 2 /CNT, Ag 3 VO 4 ,

Fig. 2. UV-vis patterns of TiO 2 , TiO 2 /CNT, Ag 3 VO 4 ,

Ag 3 VO 4 /TiO 2 , Ag 3 VO 4 /TiO 2 /CNT.

Ag 3 VO 4 /TiO 2 /CNT.

Fig. 1. shows the XRD patterns of the samples. Synthesized TiO 2 exhibit an anatase phase in accordance with (JCPDS 78-2486). TiO 2 /CNT nanocomposite was similar to that of as-prepared pure TiO 2 . The synthesized Ag 3 VO 4 as the comparison was in accord with monoclinic α-Ag 3 VO 4 (JCPDS 43-0542) [4]. The characteristic diffraction peaks of monoclinic α-Ag 3 VO 4 and anatase TiO 2 were obviously present of Ag 3 VO 4 /TiO 2 and Ag 3 VO 4 /TiO 2 /CNT. Notably, no typical diffraction peaks belonging to the separate CNT were observed in the TiO 2 /CNT and Ag 3 VO 4 /TiO 2 /CNT hybrids. Then, the absence of diffraction peak at 25 degree CNT can be ascribed to the fact that the main characteristic peak of CNT was shielded by the main peak of anatase TiO 2 . The UV–vis DRS patterns of TiO 2 , Ag 3 VO 4 , TiO 2 /CNT, and Ag 3 VO 4 /TiO 2 /CNT hybrids were shown in Fig. 2. Based on the analysis of DRS, there was an obvious enhancement in the visible light absorption of TiO 2 /CNT hybrids, compared to pure TiO 2 []. Moreover, the light absorption range of Ag 3 VO 4 /TiO 2 /CNT was further extended with the introduction of Ag 3 VO 4 and then the Ag 3 VO 4 /TiO 2 /CNT hybrids possessed wide spectral response including UV and visible light wavelength. So, a more efficient utilization of the solar spectrum on Ag 3 VO 4 /TiO 2 /CNT could be achieved, which contributed to the improvement in its photocatalytic activity and facilitated its use in practical environmental remediation.

3.2 Degradation pollutants of photoccatalysts As seen from Fig. 3, after 4 h of visible light irradiation, the photocatalytic conversion ratios of MB for TiO 2 , TiO 2 /CNT, Ag 3 VO 4 , Ag 3 VO 4 /TiO 2 , Ag 3 VO 4 /TiO 2 /CNT were 4%, 17%, 62%, 94%, 80%, respectively. Ag 3 VO 4 /TiO 2 composite performed the optimal visible photocatalytic activity in degradation of MB among them. Obviously, synthesis with CNT in the case of TiO 2 /CNT showed enhancement of the ability of degradation. However, compared with the case of Ag 3 VO 4 /TiO 2 /CNT, adding CNT did not raise the efficiency. And this phenomenon was incompatible with the previous results that adding CNT was contributive to improve

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the TiO 2 adsorption under visible light [3]. Here we gave a reason to explain the phenomenon. The multi-wall carbon nanotube were through to the acid treatment. The conductivity were reduced after the functionalized CNT. So that the electrons are hindered in the interface between the TiO 2 and CNT. In our measuring in UVvis spectra before, CNT has a large absorption in the visible light region. That established some defect at interface between TiO 2 and CNT to improve the photocatalyst activity in visible light irradiation. However, the heterojunction photocaatalyst was the main mechanism to improve the photocatalyst activity in the Ag 3 VO 4 /TiO 2 /CNT hybrids that were reduced the photon utilization. Accordingly, the photocatalyst activity were reduce. That is Ag 3 VO 4 /TiO 2 hybrids prepared by chemical method exhibited better photocatalytic activity than Ag 3 VO 4 /TiO 2 /CNT.

Fig. 3. Photocatalytic degradation of 10 ppm methyl blue under visible light of TiO 2 , TiO 2 /CNT, Ag 3 VO 4 , Ag 3 VO 4 /TiO 2 /CNT, Ag 3 VO 4 /TiO 2 .

4. Conclusion In this study, a series of Ag 3 VO 4 /TiO 2 /CNT hybrids photocatalysts with high photocatalytic activity were prepared. The samples exhibited excellent photocatalytic performance toward degradation of MB. The photocatalytic conversion ratios of MB for Ag 3 VO 4 /TiO 2 is 94%, which was better than pure TiO 2 and Ag 3 VO 4 . The heterojunction of Ag 3 VO 4 and TiO 2 increases the interfacial charge transfer and inhibits there combination of electronâ&#x20AC;&#x201C;hole pairs. This study demonstrated that the Ag 3 VO 4 /TiO 2 heterojunction photocatalysts are promising for environmental remediation.

5. References [1] Zhao D, Yang X, Chen C, Wang X. Journal of Colloid Interface Science, 2013, 398, 234-239. [2] Wang J., Wang P., Cao Y., Chen J., Li W., Shao Y., Zheng Y., Li D. Applied Catalysis B: Environmental, 2013, 136137, 94-102. [3] Leary R., Westwood A. Carbon, 2011, 49, 741-772 [4] Wang W., Serp P., Kalck P., Faria J. L. Journal of Molecular Catalysis A: Chemical, 2005, 235, 194-199. [5] Wu S.Z., Li K., Zhang W.D. Applied Surface Science, 2015, 324, 324-331. [6] Zhou W., Sasaki S., Kawasaki A. Carbon, 2014, 78, 121-129.

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The 13th Asian Textile Conference Geelong, Australia, November 3 - 6, 2015

Synthesis of silver nanoparticles stabilized with DOPA and their application to colorimetric sensor for heavy metal and catalyst reduction of methylene blue Ja Young Cheon, Hun Min Lee, So Yeon Jin and won Ho Park + Department of Advenced Organic Materials and Textile System Engineering, Chungnam National University, Daejeon, Korea

Abstract. Nanosized silver (Ag) and poly(DOPA) complex was prepared by facile and one-step polymerization of 3,4-dihydroxy phenylalanine (DOPA). The synthesized poly(DOPA)-Ag NPs complex was observed by transmission electron microscopy (TEM) and X-ray diffraction (XRD). And this complex was used as a sensor for the detection of heavy metals. As a result, the selectivity for the lead and copper ions was confirmed. Also, poly(vinyl alcohol) (PVA) nanofibrous web with poly(DOPA)-Ag NPs complex was prepared by electrospinning. This PVA/poly(DOPA)-Ag NPs composite was used as a catalyst for the decomposition of organic dye. The reduction reaction of dye catalyzed by Ag was monitored with a UV-VIS spectrophotometer Keywords: 3,4-dihydroxyphenyl alanine, catechol, Ag, PVA, nanofibrous, sensing, catalysis

1. Introduction Water contamination caused by dye, leather, textile, plastics and cosmetics industries has been received more and more attention, since most heavy metal and organic materials are harmful to human being and environment. Currently, much attention has been paid to the detection or removal of harmful materials from industrial wastewater. To date, lots of approaches have been reported to detection or remove them from wastewater, e.g., biological treatment, chemical technologies (e.g., ion-exchange, oxidation, and catalytic degradation), and physical methods (e.g., adsorption and membrane filtration). Among these techniques, the sensing method and a catalytic degradation were examined in this study. The recent advancements in the field of nanoscience and nanotechnology have opened up new areas for the applications of nanomaterials including the development of ultrasensitive detection and imaging methods in the analytical science. Particularly, colorimetric sensor based on silver nanoparticles (Ag NPs) is gaining increasing attention because of their strong localized surface plasmon resonance absorption and interparticles distances dependent optical properties. Colorimetric sensing methods have many advantageous such as simplicity and rapidity, high sensitivity, cost-effectiveness and ease of measurement. Electrospinning is a facile and low-cost method to fabricating continuous polymer, inorganic, and organic/inorganic hybrid fibers with a high surface area to volume ratio and a high porosity. Many synthetic and natural polymers have been electrospun to form nanofibers with a small diameter ranging from tens of nanometers to a few microns for various applications in solar cells, filtration, environmental remediation, biosensors, protective clothing, and tissue engineering scaffolds. The electrospun fibrous mats have a great advantage in terms of the recovery and easy handling of the materials. Generating NP-containing nanofibrous webs is expected to be important for the development of NP-based nanocatalyst systems. Compared with other high-surface area, high-porosity materials for catalytic applications, electrospun polymer nanofibrous materials are easy to make, and the fiber diameter can be controlled by varying the electrospinning parameters. More importantly, 3-dimensional complex organic/inorganic hybrid functional materials can be fabricated through selection and modification of the fiber components.

Corresponding author. Tel.: + 82-42-821-6613. E-mail address: parkwh@cnu.ac.kr.

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In this study, Ag NPs stabilized with the 3,4-dihydroxy phenylalanine (DOPA), which is known as musselinspired protein component, were prepared using simple and green chemistry. The synthesized Ag NPs was investigated as a colorimetric sensor for detecting copper (II) and lead (II) ions. Also, polymer nanofibrous web containing Ag NPs with DOPA was examined as a catalyst for the reduction of a model dye.

2. Experimental 2.1. Synthesis of poly(DOPA)-Ag NPs 3,4-dihydroxy-L-phenylalanine (DOPA) as reducing agent and stabilizer was purchased from Sigma Aldrich. Silver nitrate (99.9%) was used as silver precursor. The pH of the mixture was controlled by sodium hydroxide (0.01 M) for self-polymerization to poly(DOPA). Poly(DOPA)-Ag NPs complex was prepared by addition of silver nitrate solution in the poly(DOPA) solution. Briefly, AgNO 3 (1.6 x 10-4 mol) and DOPA (2.4 x 10-6 mol) were added to aqueous solution (60 ml) at pH 10.5. Synthesized poly(DOPA)-Ag NPs was confirmed by X-ray diffractometer patterns (XRD, Bruker AXS, D8 DISCOVER) at room temperature with 2 θ=10-80o, and a scan rate of 0.5 time/step and transmission electron microscopy (TEM) (Carl Zeiss EM 912 Omega). Then for metal ions test, perchlorate salt solutions of K+, Na+, Zn2+, Al3+, Cs+, Cd2+, Co2+, Cu2+, Mg2+, Li+, 2+ Ni , Fe2+, Fe3+, Hg2+ and Pb2+ were employed. The interaction of NPs complex and metal ion was confirmed by nanoparticle size analysis (Nanophox, Sympatec GmbH, Germany) and TEM.

2.2. Preparation of PVA/poly(DOPA)-Ag NPs nanofibrous web composites Poly(vinyl alcohol)(PVA) was purchased from Polyscience (Mw ~78,000, 98 mole% hydrolyzed) and distilled water was used as a solvent. The PVA solution was prepared by bath method, and the synthesized poly(DOPA)-Ag NPs powder was added to PVA solution. Then, PVA nanofibrous web containing Ag NPs with DOPA was prepared by electrospinning. The solution was delivered by a syringe pump (Model 100, KD Scientific, Incheon, Korea) at a flow rate of 1 mL/h. The distance between the needle tip and ground electrode was 10 cm, and the positive voltage applied to the polymer solutions was 20 kV. All experiments were carried out at room temperature. After electrospinning, for the stabilization of PVA nanofibers against water, the electrospun PVA nanofibrous matrix was physically crosslinked by a thermal treatment at 155 ◦C for 10 min. The morphology of PVA/poly(DOPA)-Ag NPs nanofibrous web was observed by field emission scanning electron microscopy (FE-SEM; JSM-7000F, JEOL, Japan). The catalytic activity of poly(DOPA)-Ag NPs in the PVA nanofibers web was examined, as follows: The nanofibers web containing 3 wt% poly(DOPA)-Ag NPs was placed into a MB solution in water (2.91 ml, 2.5×10-5 mol/l), followed by adding an aqueous NaBH 4 solution (0.09 ml, 0.01 mol/l), under constant stirring. The reduction reaction of MB catalysed by Ag was monitored with a UV-Vis spectrophotometer (Shimadzu UV2450, Japan).

3. Results and discussions 3.1.

Sensing ability of poly(DOPA)-Ag NPs complex for heavy metals

From TEM images, the poly(DOPA)-Ag NPs complex was spherical and its average diameter was 35 nm. Also, the crystalline phase of synthesized NPs was confirmed by XRD pattern. The selective colorimetric sensing of PDA/Ag NPs complex for series of heavy metal ion such as K+, Na+, Zn2+, Al3+, Cs+, Cd2+, Co2+, Cu2+, Mg2+, Li+, Ni2+, Fe2+, Fe3+, Hg2+ and Pb2+ was explored in aqueous solution. As a result, poly(DOPA)Ag NPs complex showed selective colorimetric changes for Pb2+ and Cu2+. This phenomenon indicated that the poly(DOPA)-Ag NPs complex was aggregated in the presence of Pb2+ and Cu2+ ion through electrostatic and metal-ligand interactions. The absorption spectra also showed selective red shift for Pb2+ and Cu2+. In comparison the absorption ratio of ΔA, no significant color change was observed for other metal ions. And Pb2+ and Cu2+ in the detection, the change in color and the form of aggregation was different. Thus, the complex synthesized in this study can be used for detection of Pb2+ and Cu2+, respectively (Fig. 1).

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Fig. 1: TEM images of poly(DOPA)-Ag NPs with heavy metal : (a) blank, (b) Cu2+, (c) Cd2+, (d) Pb2+.

3.2.

Catalyst for reduction of methylene blue

The diameter of electrospun PVA nanofibrous web with or without poly(DOPA)-Ag NPs was observed to be 400 nm from SEM images. It confirmed that the nanofiber surface is smooth and uniform. The catalytic activity of the PVA nanofibrous web with poly(DOPA)-Ag NPs was examined by a model reaction, the degradation reaction of methylene blue (MB). The catalytic activity of the poly(DOPA)-Ag NPs in the PVA nanofibers was investigated using a degradation reaction between MB dye and a reducing agent NaBH 4 . The MB has a characteristic absorption peak at 668 nm. The progression of the catalytic reduction of MB can be followed by the change in absorbance at the 位 max of 668 nm. Fig. 2 shows UV-Vis spectra of MB solution with reaction time in the presence of the PVA nanofibrous web only (control) and PVA nanofibrous web containing poly(DOPA)-Ag NPs. When the poly(DOPA)-Ag NPs are present, the absorbance at 位 max of 668 nm significantly decreased with reaction time for 30 min. The decrease in absorbance is probably due to degradation of the MB chromophore. It can also be identified by the color of the MB solution changes (insert).

Fig. 1: UV-VIS spectra of MB with reaction time: (a) only PVA nanofiber, (b) PVA nanofiber with poly(DOPA)-Ag NPs (insert : MB solution color with reaction time).

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4. Conclusions In this study, the Ag NPs were prepared by a simple method with poly(DOPA) as reducing agent and stabilizer. The poly(DOPA)-Ag NPs complex was spherical and average diameter was 35 nm. The synthesized NPs complex had the selectivity for the lead and copper ions, which can be confirmed with the naked eye and UV-Vis spectra. Also, PVA nanofibrous web containing poly(DOPA)-Ag NPs was prepared via electrospinning. The methylene blue was decomposed in a short time by the PVA/poly(DOPA)-Ag NPs nanofibrous web composite. Therefore this results suggest that the PVA/poly(DOPA)-Ag NPs nanofibrous web composite have great potential application in catalysis and wastewater treatment.

5. References [1] Lee H, Scherer NF, Messersmith PB. Proc Natl Acad Sci USA 103 (2006) 12999. [2] Lee H, Dellatore SM, Miller WM, Messersmith PB. Science 318 (2007) 426. [3] Lee BP, Dalsin JL, Messersmith PB. Biomacromolecules 3 (2002) 1038. [4] Yu M, Hwang J, Deming TJ. J Am Chem Soc 121 (1999) 5825. [5] Qi L, Shang Y, Wu F. Microchim Acta 178 (2012) 221. [6] Aksuner N. Sens Actuators B Chem 157 (2011) 162. [7] Wei Q, Zhang F, Li J, Li B, Zhao C. Polymer chemistry 1 (2010) 1430. [8] Xie Y, Yan B, Xu H, Chen J, Liu Q, et al. ACS Appl Mater Interfaces 6 (2014) 8845. [9] Vidhu VK, Philip D, Micron 56 (2014) 54. [10] Yan J, Huang Y, Miao Y, Tjiu WW, Liu T. J Hazard Mater 283 (2015) 730.

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The 13th Asian Textile Conference Geelong, Australia, November 3 - 6, 2015

The effect of Chelidonium majus var. asiaticum extract concetration on PVA nanofiber web diameter Hyeong Yeol Choi, Jung Soon Lee*, Ick Soo Kim11 Department of Clothing and Textiles, Chungnam National University, Korea Institute for Fiber Engineering Shinshu University, Japan1

Abstract. The PVA nanofibers containing celandine extracts with distilled water by electrospinning has been examined. It has been found that induces increase in celandine extracts concentration the raise in diameter and deviation. Prior to electrospinning, 12 wt% of PVA concentration and 10 kV of voltage with tip to collector distance 15cm lead to optimize the conditions of PVA nanofiber.

Keywords: Chelidonium majus var. asiaticum, Celandine, Nanofiber, PVA (polyvinyl alcohol), Voltage, tip to collector distance, diameter, SEM Image.

1. Introduction Celandine which belongs to the papaveraceae is one of the biennial plant. It blooms between May and August and can be found in any places easily because of the reason that it grows well in any sunny places. Moreover, it has got couple of characters that help recognize celandine. First, celandine is growing straightly, but it could be broken easily. Second, celandine is around 50cm in height and it is covered by the short hair. In Korean, the celandine is called aekiddongpul, meaning of baby excrement plant. The reason why this plant is called aekiddongpul is that the yellow succus which looks like a yellow excrement from babies comes out when snapping the plant. In oriental medicine, it can be used as a fork remedy that removes eczema and warts because celandine has effect of pain, diuresis and counteract the poison. The main pigment component of celandine is berberine. Also, Celandine contains a small amount of carotinoid and also kaempferol. Recently, nanofiber web made in the way of electrospinning can be manufactured in the way of combining with various types of high molecular substance. In this research, electrospinning with the condition that nanofiber web combines with PVA was examined after differentiating the concentration of celandine extract reported as pharmacologic experiment. After that, the fine structures and shape of nanofiber web made in the above way has observed.

2. Experimental Celandine was bought from medicinal herbs market and collected at Yeongcheon-si, Gyeong sangbuk-do, Korea. Also, dried stem, leaves and petals were used as sample. Celandine extract, mixed with distilled water in the ratio of 1:10, is boiled at 100â&#x201E;&#x192; for 1 hour two times. After that, celandine, mixed with distilled water in the ratio of 50:50, was examined after vacuum evaporation, using Evaporator (HV 10 Evaporator, IKA, Germany) The conditions of electrospinning are that High voltage supply unit (High voltage DC power supply unit, Matsuda Precision Inc., Japan), which can supply 0~40kv of voltage, has been used in order to produce nanofiber web with change the condition of concentration on PVA, Tip to collector distance(TCD), and voltage. The condition of electrospinning are listed in Table 1. Table 1: Conditions of electrospinning Conditions of electrospinning PVA concentration Voltage TCD(Tip to collector distance)

Range of conditions 10, 11, 12, 13 wt% 8, 10, 12, 14 kV 10, 15, 20 cm

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The optimum conditions of PVA nanofibers and added extracts of celandine with distilled water in the ratio of 50:50, various concentrations (0.5, 1, 3, 5 wt%) and the solution was stirred for 12 hour at room temperature. lastly Nanofiber with using electrospinning measured diameter and standard deviation

3. Results and discussion Table 2 shows The viscosity of the PVA of the spinning liquid changes at a various concentration (10, 11, 12, 13 wt%), with a voltage of 10 kV, tip to collector distance of 15cm. 10, 11, 12 and 13 wt% of PVA represent 360, 540, 1050 and 1560 cP of viscosity respectively. The increase of polymer concentration causes the increase of the viscosity. Table 2: Changes in viscosity of spinning solutions according to concentration of PVA solutions PVA concentration (wt%) 10 11 12 13

Viscosity (cP) 360 540 1050 1560

Table 3 shows diameter and deviation of nanofibers that changes a various concentration (10, 11, 12, 13 wt%) at a voltage of 15 kV, with a tip to collector distance of 15 cm. As observed, It shows the diameters of PVA nanofibers were 10, 11, 12 and 13 wt% represent 245, 238, 284 and 320 nm of diameters respectively. Among them, smallest deviation is 12 wt% PVA, and this, in turn, decides to use 12 wt% of optimal concentration for research. Table 3: Changes in nanofiber diameter and deviation according to PVA solution concentration PVA concentration (wt%) 10 11 12 13

Diameter(nm) 245 238 284 320

Standard deviation 50 46 43 65

Table 4 shows diameter and deviation of nanofibers that changes a various voltages (6, 8, 10, 12 kV) at a 12 wt% PVA solutions, with a tip to collector distance of 15 cm. As observed, It shows the diameters of PVA nanofibers were 6, 8, 10 and 12 kV represent 357, 308, 284 and 193 nm of diameters respectively. The increase of Voltage causes the decrease of the diameter. And the factor is found that voltage has major impacts in the PVA electrospinning. It is because of that electrospinning is not working properly with 8kv. Also, there is a fact that entanglement of nanofiber with 8 and 12 kV has observed. Moreover, smallest deviation is 10 kV, and this, in turn, decides to use 10 kV of optimal voltage for research. Table 4: Changes in nanofiber diameter and deviation according to Voltage (kV) Voltage (kV)

Diameter (nm)

6 8 10 12

357 308 284 193

Standard deviation (nm) 52 60 43 54

Table 5 shows diameter and deviation of nanofibers that changes a tip to collector distance (10, 15, 20 cm) at voltage of 15 kV by 12 wt% PVA solution. As observed, It shows the diameters of PVA nanofibers which have 10, 15, 20 cm represent 247, 284, 259 nm of diameters, respectively. Among them, smallest deviation is 15 cm and this, in turn, decides to use 15 cm of optimal tip to collect for research. In conclusion, results indicate that 12 wt% of concentration and 10 kV of voltage with tip to collector distance 15cm lead to optimize the conditions of PVA nanofiber.

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Table 5: Changes in nanofiber diameter and deviation according to Tip to collector distance (cm) Tip to collector distance (cm) 10 15 20

Diameter (nm) 247 284 259

Standard deviation (nm) 52 60 54

The above research shows that 12 wt% of concentration and 10kV of voltage with tip to collector distance 15cm lead to optimize conditions of PVA nanofiber. This conditions with various concentrations (0.5, 1, 3, 5 wt%) celandine extracts (distilled water 50:50 stock solutions) measured viscosity and has electrospinning, shown in Table 6. 0.5, 1, 3 and 5 wt% of celandine extracts (distilled water 50:50 stock solutions) concentrations represent 1230, 1170, 1140 and 990 cP of viscosity and 42, 42.4, 42 and 41.7 of surface tension respectively. The increase of celandine extracts concentration caused the decrease of the viscosity. However the increase of celandine extracts concentration did not significantly affect the surface tension. Due to the distilled water extract of celandine was diluted with distilled water and the concentration of PVA solution is lowered a little. Table 6: Changes in viscosity of spinning solutions according to concentration of celandine (distilled water 50:50 stock solutions) extracts Celandine extracts concentration (wt%) 0.5 1 3 5

Viscosity (cP) 1230 1170 1140 990

Surface tension (mN/m) 42 42.4 42 41.7

Table 7 shows the diameters of PVA nanofibers by various concentrations (0.5, 1, 3, 5 wt%) of celandine extracts. 0.5, 1, 3 and 5 wt% represent 254, 258, 279 and 314 nm of diameters respectively. The increase of celandine extracts concentration causes the increase of the diameter and deviation. Table 7: Changes in viscosity of spinning solutions according to concentration of celandine extracts (distilled water 50:50 stock solutions) Celandine extracts concentration (wt%) 0.5 1 3 5

Diameter(nm) 254 258 279 314

Standard deviation 43 56 74 72

4. Conclusions This study reported to find the optimize conditions of PVA in order to produce the PVA nanofiber containing celandine extracts. The increase in the PVA leads to raise the average diameter of nanofiber. Also, electrospinning works well with less deviation in 12wt%. Moreover, the increase in voltage induces the decrease in diameter, and also, electrospinning works well with less deviation and entanglement in 10kv of voltage. The optimize TCD would be 15cm because it makes less deviation and works well electrospinning. The above way which increase the celandine extracts concentration (0.5, 1, 3, 5 wt%) induces the raise in diameter and deviation.

5. Acknowledgments This research was supported by Basic Science Research Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Education, Science and Technology (NRF-2014R1A1 A3A0404959).

6. References [1] Young Hun Kim, Kook Bae Do, Jae Young Choi, Mohammad Mahbub Rabbani, Sang Ik Han and Jeong

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Hyun Yeum, Textile Coloration and Finishing, 2013, 25(2):118-125 [2] Youug Jin Kim, Sang Nam Kim, Oh Kyoung Kwon, Mi ran Park, Inn Kyu Kang and Se Geun Lee, Polymer

(korea), 2009, 33(4):307-312. [3] Won Pyo Chae, Zhi Cai Xing, Yong Jin Kim, Hie Sun Sang, Man Woo Huh and Inn Kyu Kang, Polymer

(korea), 2010, 33(4):210-215.

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The 13th Asian Textile Conference Geelong, Australia, November 3 - 6, 2015

The Thermal and Functional Properties of PU/CC@Ag Composite Films Chih-Ping Chin1, Kou-Bing Cheng *1,2, Jen-Yung Liu 2, Chang-Mou Wu3 1 2 3

Department of Fiber and Composite Materials, FengChia University, Taiwan

Textile and Material Industry Research Center, College of Engineering, Taiwan

Materials Science and Engineering, National Taiwan University of Science and Technology (NTUST),Taiwan

Abstract. Nano Ag particles doped with coir charcoal slurry by reduction method and after Acrylic series dispersant treatment, was added into the Polyurethane (PU), and itâ&#x20AC;&#x2122;s converted into PU/CC@Ag composite films by the sequence of actions such as stirring, coating and drying. The SEM was used to observe the morphology of PU composite films and also SEM results were utilized to determine the dispersibility of coreshell particles. The effect of thermal properties of PU composite films of different core-shell particles content was analyzed. TGA were used to measure the above properties. The infrared thermal image camera was used to measure the thermal absorption and diffusitivity properties of PU/CC@Ag composite films. Finally, the antibacterial properties of the films were tested, based on AATCC 90-1982 test method. In this study, the PU/ CC@Ag composite films were made with the integrated antimicrobial and warm retention properties. Keywords: PU/ CC@Ag composite films, Antibacterial properties, Warm retention, CC@Ag core-shell particles, TGA.

1. Introduction Polyurethane (PU) can be used to manufacture soft and hard materials for various applications because of the soft and hard segment in its molecule chain. Moreover, some functional group can also be bonded within the molecule chain of PU to fabricate multi-functional materials through mixing or synthesizing process [1]. Coir charcoal is considered as a waste reduction/minimization material which can be a good material for active carbon fabrication. The active coir charcoal powders can be produced from coconut shell through a series of drying, carbonization and activation processes. Coir charcoal has a specific surface area of 1000 m2/g which is 3 to 20 times higher than that of bamboo charcoal and wood charcoal. As well known, the adsorption property of materials is dependent upon their specific surface area, distribution of pore and the volume of the pores. Because coconut has finer tissue structure than that of bamboo and wood, and thus, higher absorption characteristic of coir charcoal is expected. In recent years, many metals, metal ions and metal oxides were found to have antiseptic effect. The pathogen disinfection and suppressing capability of metals were found in the order of Ag > >Hg > Cu > Cd > Cr >Ni> Pb > Co > Zn > Fe. Especially for Ag, it has been proved that the disinfection capability of Ag ions is several hundred times better than commercial gremicid and can disinfect more 650 different pathogens. ___________________________ +

Corresponding author. Tel.: + 86-04-2451-7250 #3400

E-mail address: kbcheng@fcu.edu.tw

In recent years, many metals, metal ions and metal oxides were found to have antiseptic effect. The pathogen disinfection and suppressing capability of metals were found in the order of Ag > >Hg > Cu > Cd > Cr >Ni> Pb > Co > Zn > Fe. Especially for Ag, it has been proved that the disinfection capability of Ag ions is several hundred times better than commercial gremicid and can disinfect more 650 different pathogens. Besides of its disinfection ability, Ag is not a hazardous matter to human body and is considered as the best natural occurred

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disinfectant. The unique characteristics of PU, such as bio compatibility, good hydrophobicity, high mechanical strength and easy processing, make it a suitable coating material for various applications. In this study, nano Ag particles doped onto coir charcoal slurry, were added into PU to prepare PU/CC@Ag multi-functional composite films by using semi-automatic coater. The mechanical and thermal properties, functionality and morphology of the PU/@Ag composite films were evaluated to determine its application in home, automobile textiles, apparel, and other products.

2. Experimental Procedures

Coir charcoal particles were prepared from waste coir shell by steam activation with help of furnace heating. Prior to coir charcoal particles preparation, waste coir shell was dried in hot oven at 120 ℃ for 24 ho enables to remove the moisture. In carbonization, the dried waste coir shell was placed into the container and heated at 900 ℃ for particles arcoal 1 hour. Coir werechmilled by ball grinding machine for 8 hours and disperse by acrylic series dispersant. Finally, the average particle size of coir charcoal particles about 820nm could be obtained [2]. Activated coir charcoal (CC) was prepared from coir shell by using chemical method [3] .for Colloidal particles with sizes of with KOH and then heated up to 100 ℃ carbon silver activation approximately 32 nm are synthesized by reduction method. These colloids nano silver covered with an CC core particle by a modified process to form mono-disperse CC@Ag particle. CC@Ag core shell particles have better dispersion, reliable and stability, and better stink absorption, anti-bacteria, and warm retention functions [4,5] . PU and MEK were first mixed in a Multipurpose Mixer with Defoaming action. During the mixing process, various ratios of nano-Ag (ppm) and coir charcoal (wt.%) were added into the PU/MEK mixture, as shown in Table 1. Nomenclature PU/CA0 PU/CA1 PU/CA2 PU/CA3 PU/CA4 PU/CA5

Table 1: Compositions of PU composite films PU/CC@Ag mixtures Solid contents PU/CC@Ag with 0 % PU/ CC@Ag with 0.5% PU/ CC@Ag with 1.0% PU/ CC@Ag with 1.5% PU/ CC@Ag with 2.0% PU/ CC@Ag with 2.5%

Nano Ag (ppm) 0 500 1000 1500 2000 2500

Coir charcoal, CC (wt.%) 0 0.5 1.0 1.5 2.0 2.5

After thorough mixing, the mixture was evenly coated on the release paper using semi-automatic coater. The film was then transferred to an oven and dried at 50℃for 24hr. The thermal conservation and warming capability of the PU/CC@Ag composite films were determined based upon the FTTS-FA-010 standard which is scale-up Taiwan Textile Research Institute (TTRI).[6] The morphology of PU/CC@Ag composite films was observed by using scanning electronic microscope to check the CC@Ag powders distribute on PU composite films. TGA was used to evaluate the thermal stability of PU/CC@Ag films which need to be dried at 70oC for 24hr under vacuum condition. Methylene blue aqueous solution was used to test the absorption capability of active coir charcoal and CC@Ag core-shell particles. The changes of methylene blue concentrations, i.e. adsorption capability of PU/CC@Ag films, were measured using a spectrophotometer. The Antibacterial test was carried out by following AATCC Test Method 90-1982 (Agar plate method) with using Staphylococcus Aureus ATCC 6538 or Klebsiella Pneumoniae ATCC 4352 [7].

3. Results and Discussions 3.1. Thermal Gravimetric analysis (TGA) The thermal characteristics and the wt.% mass change behavior of PU and PU/CC@Ag were evaluated through thermal gravimetric analysis. Table 2 shows the TGA of PU and PU/CC@Ag, and it was found that the thermal decomposition temperatures of the specimens slightly decrease as the Ag addition increases from 0 to 2,500ppm. This is probably because the higher activity of Ag that causes instability of PU during thermal decomposition, and thus, results in higher weight loss at lower temperature. As listed in Table 2, the 5% weight loss temperature (T dI ) decreases from 284.46oC to 265.28oC as the nano Ag addition increases from o to 2,500ppm. However, the residual wt.% increases from 3.76% to 6.08% as the coir charcoal addition increases from 0% to 2.5%, because higher temperature is needed for the decomposition of coir charcoal. Table 2: Thermal property of PU and PU/CC@Ag films

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Specimens

PU/Ag@CC mixtures

PU/CA0 PU/CA0.5 PU/CA1.0 PU/CA1.5 PU/CA2.0 PU/CA2.5

PU/CC@Ag with 0 % PU/CC@Ag with 0.5% PU/CC@Ag with 1.0% PU/CC@Ag with 1.5% PU/CC@Ag with 2.0% PU/CC@Ag with 2.5%

T dI (℃) (5％ weigh loss) 284.46 282.72 280.25 275.12 271.24 265.28

Residue (%) 3.76 5.26 5.56 5.77 5.89 6.08

3.2. SEM analysis During the preparation of polymer/nano particle composite material, the uniform distribution of nano particles within the polymer is considered as one of the most important factors on the specific function of the composite material. Because of its nano scale particle size, large specific surface area and high activity, nano particles may easily agglomerate into submicron particles, and thus, reduce its specific function desired. In this study, the distribution of CC@Ag within PU was analyzed through SEM images of PU/CC@Ag made with various CC@Ag additions. As shown in Fig. 1, the increase and evenly distribution of the CC@Ag addition can be observed in SEM images (B), (C) and (D), and no agglomerate was found. As the CC@Ag addition increase to 2.0% and 2.5%, agglomerates of CC@Ag addition and uneven distribution can be observed in images (E) and (F).

Fig. 1: SEM Images of PU and PU/CC@Ag Composite Films, (A)PU/AC0 (B)PU/ AC0.5 (C)PU/ AC1.0 (D)PU/ AC1.5 (E)PU/ AC2.0 (F)PU/ AC2.5

3.3. Thermal Conservation and Warming Capability In the thermal conservation and warming capability test, the differences between surface temperature of the composite films measured during testing period and before test are shown in Fig. 2. It was found that the increases of surface temperature of PU/CC@Ag composite films made with various amount of CC@Ag are generally 6°C to 7°C higher than that of pure PU after 10min of heating. It indicates that the addition of CC@Ag does improve the thermal conservation property of PU. This is because the addition of CC@Ag resulted in the darker color and much more micro-porous of the composite films, and thus improves its heat absorption property. From Fig. 2, it was found that the higher the CC@Ag powders addition, the higher the surface temperature measured after 10mim of heating. However, there is only 1oC difference between PU/CC@Ag composite films made with 0.5% and 2.5% CC@Ag addition. Fig. 3 shows the difference of surface temperature of composite films measured at the end of 20min test (after 10min of cooling) and before the test. Again, the surface temperature increases of PU/CC@Ag composite films is 0.6oC to 2.3oC higher than that of pure PU, dependent upon the amount of coir charcoal addition. These test results also show that the addition of coir charcoal can improve the warming capability of the composite film. As shown in Fig. 3, the higher the coir charcoal addition, the higher the surface temperatures of the films were measured at the end of 20min test. This can be contributed to the high specific surface area (high pore volume) of the coir charcoal that facilitate warming characteristic of the PU/CC@Ag composite films.

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Fig. 2: Increase of Surface Temperatures of PU and PU/CC@Ag Composite Films Measured during 20min Testing Period

Fig. 3: Increase of Surface Temperatures of PU and PU/CC@Ag Composite Films Measured at the end of 20min Test Period

3.4. Antibacterial test AATCC Test Method 90-1982 (Agar plate method) was followed to conduct antibacterial test. In this test, 2.8cm in diameter of PU and PU/AC composite films was cut and put in the center of bacteria growth medium. After 18hr of growing period, the color of the growth medium turned murky due to the growth of bacteria. As shown in Fig. 4, it was found that no inhibition zone can be identified for PU specimen, Fig. 12(A). For images 12(B) to 12 (F), the inhibition zone can be easily measured for PU/AC composite films. It was also found the inhibition zone of PU/AC composite films increases from 0.2mm to 0.6mm as the CC@Ag increases from 500ppm (Ag)/ 0.5% (coir charcoal) to 2,500ppm (Ag)/ 2.5% (coir charcoal). This test results indicate that the addition of CC@Ag in PU can greatly improve the bacteria inhibition characteristics of the PU composite film.

Fig. 4: Images of PU and PU/CC@Ag composite films after 18hr of bacteria growth, (A)PU/AC0 (B)PU/ AC0.5 (C)PU/ AC1.0 (D)PU/ AC1.5 (E)PU/ AC2.0 (F)PU/ AC2.5

4. Conclusion The solvent type polyurethane fabrication system is to fabricating the PU/ CC@Ag composite films with the different additions successfully. In producing PU/ CC@Ag composite films with improved performance over equivalent regular PU films. Nano Ag doped coir charcoal (CC@Ag) by using reduction method successfully. From TGA test, the thermal decomposition temperature of PU/AC film decreases as the CC@Ag addition increases from 0.5% to 2.5%. It indicates that the addition of CC@Ag may slightly reduce the thermal stability of the composite film. For thermal conservation and warming capability test, the surface temperature increase of PU/AC films are 6oC to 7oC higher than that of pure PU after 10min of heating. The surface temperature increase of PU/CC@Ag composite films is 0.6oC to 2.3oC higher than that of pure PU at the end of 20min test. The test results show that PU with CC@Ag addition can greatly improve the thermal

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conservation and warming capability of the composite film due to the high specific surface area of the coir charcoal. In antibacterial test, inhibition zone of 0.6mm for PU/AC2.5 was measured which is much better than PU that no inhibition zone can be identified. This test results indicate that the addition of CC@Ag in PU can greatly improve the bacteria inhibition characteristics of the PU composite film. Integrated the above experimental results which could obtained optimum conditions is CC@ Ag core shell structure with 1.5%.

References [1] Pablo M. Arnal, Massimiliano Comotti, and Ferdi Schuth, High-Temperature-Stable Catalysts by Hollow Sphere Encapsulation, Angew. Chem. Int. Ed. 2006, 45, 8224â&#x20AC;&#x201C;8227 [2] Jen-Yung Liu, Y.C. Ding, Kou-Bing Cheng, A Study on the Fabrication and Functional Properties of PET/ Rayon Staple Fiber Products with ACC@Ag Powders, JIT, 2013, Revised. [3] Takahata T, Toda I, Ono H, Ohshio S, Himeno S et al. Detailed Structural Analyses of KOH activated carbon from waste coffee beans. Jpn J Appl Phys 2009; 48 :117001. [4] Lill-Rodena Ma, Cazorla-Amoros D, Linares- Solano A. Understanding chemical reactions between carbons and NaOH and KOH: an insight into the chemical activation mechanism. Carbon 2003; 41 : 267275. [5] Wigmans T. Industrial aspects of production and use of activated carbon. Carbon 1989; 27: 13-22. [6] Taiwan Textile Research Institute, FTTS-FA-010 Infra Red Thermal Image Testing Standard. [7] AATCC Test Method 90-1982 (Agar plate method)

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The 13th Asian Textile Conference Geelong, Australia, November 3 - 6, 2015

Ultra-thin hierarchically structured poly(vinyl alcohol-co-ethylene) nanofirous separator for high rate lithium-ion battery Qiongzhen Liu, Jiahui Chen, Yifei Tao, Ming Xia, Mufang Li, Ke Liu, Yuedan Wang and Dong Wang 1 + 1

College of Materials Science and Engineering, Wuhan Textile University, Wuhan, 430200, China

Abstract. A hierarchically structured and highly hydrophilic nanofirous separator composed of a poly (ethylene terephthalate) (PET) nonwoven sandwiched between two interconnected PVA-co-PE nanofirous membranes has been previously reported for Lithium-ion battery. However, the thickness of the hierarchical nanofibrous membrane is fairly thicker (~50µm) relative to commercial PP separator (~25µm), greatly restricting its practical application. Thus, thinner nanofirous separator is more desirable. An ultra-thin PET nonwoven (17µm) is selected to substituting of the former PET nonwoven (38 µm) in order to reduction of the whole thickness of the separator. Therefore, surface modifications of PET nonwoven including plasma etching and alkali soaking pre-treatment before cell assembling have been attempted to improve the adhesion force between the PET and PVA-co-PE nanofirous membrane. Systematical investigations including SEM observations, porosity measurement, water/electrolyte contact angle testing and cell performance have been carried out to examine the ultra-thin nanofibrous separator. The resultant separator possesses good cell performance with a thickness of 30 µm, comparable to that of commercial PP separator. These results suggest our ultra-thin hierarchically structured PVA-co-PE nanofirous separator is a promising candidate for practical application in lithium-ion battery due to their low cost production and high performance.

Keywords: Lithium-ion batteries, nanofirous separator, hierarchical structure, surface modification, wettability, rate-capability, cycling performance.

1. Introduction Lithium-ion batteries have recently attracted increasing attention, due to their renewable and clear energy as well as high open circuit voltage, high energy density and long cycling life [1-2]. Separator is known as a critical functional component of lithium-ion battery for isolation between cathodes and anodes and facilitating lithium-ion transport. Nowadays, great attention has been paid to outstanding electrolyte-affinity separators, especially for large-sized batteries (i.e. for EV, HEV). In these applications, fast and uniform wetting of electrolyte over the entire separators is very desirable. In our previously study, hierarchically structured and highly hydrophilic NFs/PET/NFs nanofibrous separator comprising a macroscaled porous PET nonwoven sandwiched between two nanoscaled porous PVAco-PE nanofibrous membranes have been investigated [3]. Further investigations have demonstrated that inorganic Al 2 O 3 coatings can enhance the electrolyte affinity of the NFs/PET/NFs separator and thus resulting in excellent high-rate cycling performance [4]. However, the whole thickness of the nanofibrous separator is relatively thicker (~50 µm) compared to commercial polyolefin-based separators (~25µm). For batteries, separator with lower thickness is required for high energy and power densities. Our thicker separators may affect the cell capacity, thus restricting its practical application in lithium-ion batteries. Therefore, reduction of whole thickness of the separator is necessary. In present study, ultra-thin PET nonwoven (17µm) with good mechanical strength has been chosen for substitution of conventional former PET nonwoven (38 µm) to reduce the whole thickness of nanofirous separator. Considering hydrophobic nature of the ultra-thin PET nonwoven, surface activation methods including alkalis soaking and plasma etching have been attempted to improve the adhesion force between the +

Corresponding author. Tel.: + 86-02759367691 E-mail address: wangdon08@126.com

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PET and PVA-co-PE nanofirous membrane. The resulting ultrathin nanofirous separator possesses excellent cell performance with a thickness of 30 µm. The microstructure, porosity, wettability of the separators, and the cell performance including discharge capacities, discharge C-rate capability, and cycling performance have been systematically investigated.

2. Experimental 2.1．Surface treatment of PET nonwoven The as-received ultra-thin PET spun-bond nonwoven (15g/m2) is obtained from AsahiKasei Corporation with an approximate thickness of 17µm. Due to its flatness and hydrophobic nature, surface pre-treatment is necessary to improve its wettability for further application. In this study, surface treatments including NaOH soaking and plasma etch method. PET nonwoven samples with different treating conditions are referred to as PET-1, PET-2, PET-3 and PET-4, respectively. Accordingly, the corresponding separators consisting of relative PET nonwoven are referred to as NF-1, NF-2, NF-3 and NF-4 (seen as in Table 1). Table 1: Specific description of NF separators and commercial PP separator Material

Specification

Total thickness

Wettability

PET nonwoven PP separator NF-1 separator NF-2 separator NF-3 separator NF-4 separator

Commercial, AsahiKasei Commercial, Celgard PET-1: NaOH soaking- 1mol/L/2h PET-2: NaOH soaking-2mol/L/1h PET-3: Plasma etching-Air plasma PET-4: Plasma etching-Low vacuum plasma

17 µm 25 µm 28 µm 31 µm 33 µm 32 µm

Hydrophobic Hydrophobic Hydrophilic Hydrophilic Hydrophilic Hydrophilic

2.2．Fabrication of NF separator PVA-co-PE nanofibers were prepared according to previous methods reported in literature [5]. Then the nanofibers were dispersed in an aqueous solution with a high speed shear mixer to form a stable suspension. The suspension was then coated onto the surface of the aforementioned treated ultra-thin nonwoven spun-bond PET (15g/m2) substrates with a casting knife to form nanofibrous NF membranes including NF-1 to NF-4. The schematic diagram of preparation of NF separator and lithium-ion transport through the separator is shown in Scheme.1.

Scheme 1. The schematic illustrator of the NF separator consisting of ultra-thin PET nonwoven sandwiched by two PVA-co-PE nanofibers layers and lithium-ion transport through the separator.

2.3．Characterization Microstructure observation was carried out at a Scanning Electron Microscopy JSM-6510L and a FEI NanoSEM450). The wettability was measured by a contact angle analyzer (FM40 Easy Drop, KRUSS). The C-rate discharge capability, and cycling performance of cells (CR2016-type coin) were tested using a LAND battery test system (CT 2001A). Specific capacities of the cells were calculated based on the weight of active material (LiFePO 4 ) in the cathode.

3. Results and Discussion

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3.1ďź&#x17D;Morphology Fig.1 (a) shows that the surface of pristine ultra-thin spun-bond PET nonwoven is relatively flat. The nonwoven is consisted of randomly intertwined fibers with diameter ranging from 1 to 15 Îźm. Fig. 1b-e present the fiber surface morphologies of PET nonwoven modified with different methods. It is seen that surface unevenness is more pronounced for plasma treated samples (PET-3 and PET-4). For alkali treated PET-1, the fiber surface becomes rough relative to that of the native PET nonwoven. The unevenness will increase the surface energy of the PET fiber, thus improving the affinity to PAV-co-PE nanofibrous membrane. The morphology of NF-1 separator consisting of PET-1 nonwoven sandwiched between two PAV-co-PE nanofibrous membrane is shown in Fig. 1(f) with a well-tuned pore size between 50-350 nm. Therefore, this hierarchically structured separator offers interconnected nanoscaled porous structure and high porosity (56%), thus facilitating lithium ion transport and ensuring electrolyte affinity.

Fig. 1: SEM morphologies of (a) pristine spun-bond PET nonwoven (low magnification image inset), (b) PET-1, (c) PET-2, (d) PET-3, (e) PET-4 and (f) NF-1 nanofirous separator with PET-1 as supporting substrate.

3.2 wettability Water contact angle measurement is conducted to investigate the effect of pre-treatments on the wettability of ultra-thin PET nonwoven. It is seen from Fig. 2a that that the surface of ultra-thin PET nonwoven is hydrophobic with a water contact angle of 114o. When treated with alkali NaOH solution or plasma, the surface nature of the PET converts to hydrophilicity (Fig. 2a-2e). The results suggest that PET-1 has a relatively higher water affinity and surface energy. Fig2d-2e show the electrolyte contact angles of commercial PP and NF-1 nanofirous separator. It is obviously seen that our NF-1 separator exhibits very high electrolyte-wettability. It is known that high electrolyte wettability of the separators is of vital importance for large-sized battery assembly and high-rate lithium-ion batteries, thus our NF-1 separator is a promising alternative to commercial PP separator for lithium-ion battery.

Fig. 2: Photographs showing static water contact angle of (a) pristine PET nonwoven, (b) PET-1, (c) PET-2, (d) PET-3, (e) PET-4, and static electrolyte contact angle of (f) commercial PP and NF-1 separator, respectively.

3.3 Cell performance The rate capabilities of the cells with different separators at varying discharge conditions (0.2 C, 0.5 C, 1 C, 2 C) are depicted in Fig. 3. It is clearly seen that the discharge capacity of all the cells gradually decreases at higher discharge current density. Among all the separators, the cell with NF-1 separator exhibits higher capacity loss as the discharge density increases. The result implies that the separator consisting of PET-1

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nonwoven treated by NaOH alkali solution show advantage in rate capability than that of treated by plasma. Moreover, PET nonwoven treated by low vacuum plasma seems to be beneficial to nanofirous separator, comparable to that treated by air plasma. Discharge Capacity (mAh/g)

180 NF-1: NaOH (1mol/L)/2h NF-2: NaOH (2mol/L)/1h NF-3: Air plasma NF-4: Low vacuum plasma

160 140 120

0.2C

100

0.5C

2.0 C

80 1.0C

60 40

10 Cycle number

Fig. 3: The discharge capacity profiles of cells at varying discharge current density with the separators of NF-1, NF-2, NF-3 and NF-4.

The cycling performance for all the separators at a relative higher charge/discharge condition (0.5 C/0.5 C) shown in Fig. 4. The cell with NF-1 separator always exhibits higher discharge capacities during 50 cycles, compared to other nanofirous separators. This excellent cycling performance of ultra-thin NF-1 separator is comparable to that of commercial PP separator. Discharge Capacity (mAh/g)

170 Commercial PP separator NF-1: NaOH (1mol/L)/2h NF-2: NaOH (2mol/L)/1h NF-3: Air plasma NF-4: Low vacuum plasma

160 150 140 130 120 110

0.5C/0.5C

100 90 80

10 15 20 25 30 35 40 45 50 Cycle number

Fig. 4: The cycling performance of cells at 0.5C/0.5C charge/discharge current density with the separators of commercial PP, NF-1, NF-2, NF-3 and NF-4 separators.

4. Conclusion In this study, ultra-thin hierarchically structured nanofibrous separators comprising of an ultra-thin PET nonwoven sandwiched between two interconnected PVA-co-PE nanofibrous membranes have been developed for high-rate lithium-ion battery. Surface modifications of PET nonwoven including plasma etching and alkali soaking pre-treatment before cell assembling have been attempted to improve the adhesion force between the PET and PVA-co-PE nanofirous membrane. The resultant ultra-thin NF-1 separator with a thickness of 30 Âľm exhibits excellent electrolyte-affinity, rate capabilities and cycling performance comparable to that of commercial PP separator, suggesting a promising candidate for practical application in lithium-ion battery.

5. References [1] M.V. Reddy, G.V. Subba Rao, B.V. Chowdari, Chem. Rev., 113, 5364 (2013). [2] L. Ji, O. Toprakci, M. Alcoutlabi, Y. Yao, Y. Li, S. Zhang, B. Guo, Z. Lin and X. Zhang, ACS Appl. Mater. Inter., 4, 2672 (2012). [3] M. Xia, Q. Liu, Z. Zhou, Y. Tao, M. Li, K. Liu, Z. Wu and D. Wang, J. Power. Sources., 266, 29 (2014). [4] Q. Liu, M. Xia, J. Chen, Y. Tao, Y. Wang, K. Liu, M. Li, W.Wang and D. Wang, Electrochim. Acta., 176, 949 (2015). [5]

D. Wang, W. Xu, G. Sun and B.S. Chiou, ACS Appl. Mater. Inter., 3, 2838 (2011).

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The 13th Asian Textile Conference Geelong, Australia, November 3 - 6, 2015

An investigation on cellulose-based carbon composite materials fabricated by 3D printing Saeed Dadvar, Rangam Rajkhowa and Xungai Wang + Institute for Frontier Materials, Deakin University, Geelong, Victoria 3216, Australia

Abstract. This study was targeted at fabrication and characterisation of 3D printed cellulose-based carbon composite materials by 3DP process and post-printing operations. Various approaches were involved to explore the effect of printing and post-processing conditions on physical and mechanical properties of carbon composite parts. A massive linear and volume shrinkage of around 30% as well as weight loss of approximately 75% were obtained after pyrolysis of the precursor parts at 800˚C in argon atmosphere. There were no significant differences between the physical properties of the resultant as-pyrolysed parts printed according to x-, y-, and z-axis of the build chamber. Among different post-hardening solutions including poly(vinylpyrrolidone) (PVP), polycyanoacrylate (PCA), and epoxy resin for the infiltration of the aspyrolysed parts, the best performance was achieved for epoxy resin infiltrated carbon composite parts with compressive strength and compressive modulus of 20.97±0.01 MPa and 369.89±0.02 MPa, respectively. Keywords: Powder-based 3D printing, Cellulose powder, Carbon precursor, Carbon composite

1. Introduction Over the last three decades, additive manufacturing (AM) technologies have rapidly progressed to the point that they can now offer great opportunities for industrial manufacturing. In general, AM technology refers to a group of manufacturing techniques which translates computer-assisted design (CAD) models for the fabrication of parts layer-by-layer using a range of different materials. In other words, AM technology builds the components based on a CAD model through the application of material where it is required while offering great advantages of unlimited design complexity, low energy consumption, and reduced lead time [1]. AM technology was initially developed as a tool of rapid prototyping in the 1980’s, enabling the engineers and designers to fabricate their visualizations and ideas in the form of prototypes. Unlike other manufacturing methods which require multiple stages for the fabrication of parts, AM technologies can produce high precision complex parts in a single stage process. As a comparison, in other manufacturing methods, inclusion of a relatively simple change in the design dramatically increases the number of stages, and thereby, the time and cost required for the production of parts, whereas AM technologies allow not only to effectively control the whole fabrication process, but also to predict the time and cost required for the production of models, regardless of any changes that might be implemented through this influential stage of the product development [1]. AM technologies have recently attracted considerable attention towards the development of material systems for the fabrication of carbon composites. In general, “direct” or “indirect” approach has been employed for the fabrication of carbon composites by AM technologies. As far as three dimensional printing (3DP) process as one of AM technologies is concerned, the direct approach has some limitations for the fabrication of composites due to the issues associated with the incorporation of reinforcing materials such as fibres into the powder-based material system [2]. In contrast, the indirect approach allows incorporating a carbon precursor material into 3DP process for the fabrication of “precursor part” with the capability to be converted to “carbon composite part” through pyrolysis and the following resin or melt infiltration [3-6]. Cellulose is a suitable candidate as carbon precursor material [7] in terms of affordability, availability, and sustainability to be incorporated into powder-based 3DP process for the fabrication of carbon composites. It is the most abundant naturally occurring biopolymer on the earth with total annual production of approximately +

Corresponding author. Tel.: + 61-3-5227 2894. E-mail address: xungai.wang@deakin.edu.au.

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1.5 × 1012 tons [8], and can be generally produced from a broad range of inexpensive renewable natural resources such as flax fibre, kenaf fibre, cotton fibre, waste cotton fabrics, agricultural residues, and wood pulp [9-12]. In spite of few reports on the development of fibre-reinforced powder-based material systems for the fabrication of composite parts by 3DP process through the direct approach [2], the majority of studies have been conducted on the fabrication of composite parts through the indirect approach [3-5]. As regards the direct approach, Christ et al. [2] employed four different commercially available fibres including continuous PAN fibres, short PAN fibres, polyamide fibres, and short glass fibres for the reinforcement of a powder-based material system containing dental gypsum as the main powder. As far as the indirect approach for manufacturing of composite parts by 3DP process is concerned, Rambo et al. [3] fabricated a dense TiC/TiCu composite part through the production of a carbon preform from a starch-based material system followed by pyrolysis at 800˚C in nitrogen atmosphere. Cao et al. [4] employed 87 wt.% aluminium oxide, 13 wt.% urea-formaldehyde resin (in-powder adhesive), and a small amount of magnesium oxide (sintering aid) to develop a bimodal powder-based material system for the fabrication of preforms by 3DP process using a weakly acidic aqueous solution as the liquid binder. We have studied the fabrication and characterisation of 3D printed cellulose-based carbon composite materials by a powder based 3DP process and post-printing treatments. Various characterisation approaches have been involved to explore the effect of process parameters, including saturation level and layer thickness, on the physical and mechanical properties of parts with the aim of producing carbon composite parts.

2. Materials and Methods Cellulose powder with the average particle size of 50 µm was employed as the main component in this study. Dextrin as an in-powder adhesive was purchased from a local supplier, and sieved through a mesh size of 100 µm before use. The powder-based material system was prepared by mixing 60% cellulose powder with 40% dextrin using Turbula Type T2F Shaker-Mixer (Glen Mills Inc., USA) for 3 h. Once the powder mixture was developed, it was loaded into the feeder of the 3D printer (ProJet® 460Plus, 3D Systems Inc., USA). To explore the effect of process parameters including saturation level and layer thickness on the physical and mechanical properties of the printed parts, a series of cylindrical parts with the dimensions of 10 mm in diameter and 20 mm in length was designed by SolidWorks®, and then transferred to the 3D printer. The specimens with the axial direction aligned with the x, y and z-axis of the build chamber were printed at layer thicknesses of 100-175 µm and saturation levels of 25-100% using a commercial water-based liquid binder (VisiJet® PXL Clear, 3D Systems Inc., USA). Once the fabrication of parts was completed, they were left in the powder bed for 24 h to make sure that the whole part was fully consolidated. Thereafter, the as-printed parts were taken out, depowdered (removal of excessive powders from the as-printed part), and cleaned using compressed air. Subsequently, the parts were pyrolysed at 800˚C for 6 h in argon atmosphere. The as-pyrolysed parts were then infiltrated with different post-hardening solutions including 10 wt.% poly(vinylpyrrolidone) in water (PVP, M w = 2,500 g/mol Polysciences Inc., USA), poly(cyanoacrylate) (PCA, stock solution, 3D Systems Inc., USA), and epoxy resin (stock solution, Presi Ltd., UK). Thereafter, the infiltrated parts were dried/cured in the oven at 50˚C for 24 h to develop the final composites. Scanning electron microscopy (SEM, Supra 55VP, Zeiss, Germany) was employed to evaluate the morphology of cellulose parts as well as the resultant carbon composite parts infiltrated with various posthardening resins. Instron Universal Testing Machine with 1 kN load cell was employed at a constant cross head speed of 0.5 mm/min to measure the compressive strength of as-printed, as-pyrolysed, and carbon composite cylindrical parts. Compression tests were carried out for a batch size of five specimens and the engineering stress-strain curves were used to obtain different compressive mechanical parameters including compressive strength (σ c ), compressive strain (ε c ), and compressive modulus (E c ).

3. Results and Discussion 3.1.

Morphology of carbon composite parts

SEM images of the cross sections of as-printed and as-pyrolysed parts before and after infiltration with PVP, PCA, and epoxy resin are shown in Figure 1. All the samples were flash dipped in the post-hardening solutions, and then dried in the oven at 50˚C for 24 h. Fabrication of a composite part with good mechanical property requires complete filling of all pores in the structure with the post-hardening solution. It was observed that when the precursor part underwent heat treatments at high temperatures (pyrolysis process), a massive weight loss occurred leading to a highly porous structure compared to the as-printed part (compare Figure 1a with 1b). The SEM images show that flash dipping of the as-pyrolysed parts in PCA and epoxy resin is

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inadequate (compare Figure 1b with 1d) and the treatment is required to be done for longer time under vacuum to achieve a dense structure, highlighting the effect of infiltration time on the resultant mechanical strength. Further discussion on this follows in section 3.3.

(c) (d) (e) (a) (b) Fig. 1: SEM images of the cross section from (a) as-printed part, (b) as-pyrolysed part, (c) PVP infiltrated carbon composite part, (d) PCA infiltrated carbon composite part, and (e) epoxy resin infiltrated carbon composite part (scale bar = 100 µm).

Figures 2 shows a typical carbon composite 5-spoke car wheel which was printed at saturation level of 100% and layer thickness of 150 µm followed by pyrolysis at 800˚C in argon atmosphere. As can be seen, freestanding structures can be achieved through pyrolysis of the precursor parts at elevated temperatures proving the concept of this study to produce carbon composite parts by 3DP process. Further work is ongoing to achieve fully dense structures as a function of material and process parameters and the corresponding postprocessing operations.

(a) (b) (c) Fig. 2: Top view of carbon composite 5-spoke car wheel (a) before pyrolysis and (b) after pyrolysis at 800˚C in argon atmosphere followed by resin infiltration, and (c) side view of the same parts.

3.2.

Physical property of as-pyrolysed parts

Table 1 summarises the variation of physical parameters of cylindrical samples printed according to x-, y-, and z-axis of the build chamber after pyrolysis at 800˚C in argon atmosphere. It was observed that when the precursor part was pyrolysed at elevated temperatures, it showed a massive linear and volume shrinkage by around 30%. Moreover, an enormous weight loss of approximately 75% was also obtained due to heat treatments at high temperature. However, all these variations led to a reduction of 30% in apparent density (AD). We did not find any statistically significant difference between the physical properties of the resultant as-pyrolysed parts based on printing directions. Table 1. Variation of physical parameters of cylindrical samples printed according to x-, y-, and z-axis of the build chamber after pyrolysis at 800˚C in argon atmosphere (mean values ± standard deviations) Printing direction Horizontal X Horizontal Y Vertical Z

3.3.

Linear shrinkage (%) Length Diameter 31.21±0.02 28.88±0.03 28.61±0.04 29.55±0.04 31.53±0.01 28.54±0.02

Volume shrinkage (%)

Weight loss (%)

AD reduction (%)

65.21±0.04 64.57±0.01 65.04±0.03

76.19±0.04 76.19±0.03 75.81±0.01

31.56±0.02 32.80±0.01 30.80±0.01

Mechanical properties of carbon composite parts

Figure 3 depicts compressive stress-strain curves of as-printed, as-pyrolysed, and post-processed cylindrical samples printed according to y-axis of the build chamber at a saturation level of 100% and a layer thickness of 150 µm. As can be seen, infiltration with epoxy resin have had a higher impact on the compressive strength and compressive modulus of the as-pyrolysed parts than other post-hardening solutions. It was found that the use of epoxy resin as a post-hardening solution to infiltrate the as-pyrolysed parts has resulted in an increase in the compressive strength and compressive modulus from 1.85±0.02 MPa to 20.97±0.01 MPa and

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400

350

Compressive Strength (MPa)

Compressive Modulus (MPa)

from 118.04±0.09 MPa to 369.89±0.02 MPa, respectively. This indicates that epoxy resin can be a good candidate for post-hardening of the as-pyrolysed parts.

300 250 200 150 100 50 0

15 12 9 6 3 0

As-printed

As-carbonized PVP infiltrated PCA infiltrated EPO infiltrated

As-printed

As-carbonized

PVP infiltrated PCA infiltrated EPO infiltrated

(a) (b) Fig. 3: Compressive (a) modulus and (b) strength of as-printed, as-pyrolysed, and post-processed cylindrical samples printed according to y-axis of the build chamber.

Apart from the choice of an appropriate post-hardening solution to achieve a dense composite structure, other combinations of the cellulose powder mixtures with a higher dextrin content may also affect the physical and mechanical properties of the resultant carbon composite parts. Therefore, further studies are required to comprehensively understand the structure-property relationship of the as-printed cellulose-based parts and the resultant carbon composite parts fabricated by 3DP process.

4. Conclusion The current study was targeted at fabrication and characterisation of 3D printed cellulose-based carbon composite materials by 3DP process and post-printing operations. We found that cellulose-based material system has the potential to be employed for the fabrication of the precursor parts by 3DP process with the capability to be converted to carbon composite parts through post-processing operations. Among various posthardening solutions including PVP, PCA, and epoxy resin for the infiltration of the as-pyrolysed parts, epoxy performed the best based on the compressive properties of the resultant carbon composites.

References [1] I. Gibson, D. Rosen, B. Stucker, Additive manufacturing technologies, 3D printing, rapid prototyping, and direct digital manufacturing, Springer, 2015. [2] S. Christ, M. Schnabel, E. Vorndran, J. Groll, U. Gbureck, Fiber reinforcement during 3D printing, Materials Letters, 139 (2015) 165-168. [3] C.R. Rambo, N. Travitzky, K. Zimmermann, P. Greil, Synthesis of TiC/Ti–Cu composites by pressureless reactive infiltration of TiCu alloy into carbon preforms fabricated by 3D-printing, Materials Letters, 59 (2005) 1028-1031. [4] S. Cao, X.F. Wei, Z.J. Sun, H.H. Zhang, Investigation on urea-formaldehyde resin as an in-powder adhesive for the fabrication of Al 2 O 3 /borosilicate–glass composite parts by three dimensional printing (3DP), Journal of Materials Processing Technology, 217 (2015) 241-252. [5] W. Zhang, R. Melcher, N. Travitzky, R.K. Bordia, P. Greil, Three-dimensional printing of complex-shaped alumina/glass composites, Advanced Engineering Materials, 11 (2009) 1039-1043. [6] J. Moon, A.C. Caballero, L. Hozer, Y.M. Chiang, M.J. Cima, Fabrication of functionally graded reaction infiltrated SiC-Si composite by three-dimensional printing (3DP™) process, Materials Science and Engineering A, 298 (2001) 110-119. [7] A.G. Dumanlı, A.H. Windle, Carbon fibres from cellulosic precursors: a review, Journal of Materials Science, 47 (2012) 4236-4250. [8] D. Klemm, B. Heublein, H.P. Fink, A. Bohn, Cellulose: Fascinating biopolymer and sustainable raw material, Angewandte Chemie International Edition, 44 (2005) 3358-3393. [9] S. Chuayjuljit, S. Su-Uthai, C. Tunwattanaseree, S. Charuchinda, Preparation of microcrystalline cellulose from waste-cotton fabric for biodegradability enhancement of natural rubber sheets, Journal of Reinforced Plastics and Composites, 28 (2009) 1245-1254. [10] M. El-Sakhawy, M.L. Hassan, Physical and mechanical properties of microcrystalline cellulose prepared from agricultural residues, Carbohydrate Polymers, 67 (2007) 1-10. [11] D. Wang, S.B. Shang, Z.Q. Song, M.K. Lee, Evaluation of microcrystalline cellulose prepared from kenaf fibers, Journal of Industrial and Engineering Chemistry, 16 (2010) 152-156.

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[12] K. Lepp채nen, S. Andersson, M. Torkkeli, M. Knaapila, N. Kotelnikova, R. Serimaa, Structure of cellulose and microcrystalline cellulose from various wood species, cotton and flax studied by X-ray scattering, Cellulose, 16 (2009) 999-1015.

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The 13th Asian Textile Conference Geelong, Australia, November 3 - 6, 2015

Animal Fibre Diameter-Length Relationship and Its Effects on Yarn Properties Sepehr Moradi, Xin Liu, Christopher Hurren, Xungai Wang Institute for Frontier Materials, Deakin University, Geelong, Australia

Abstract. This study investigated how simultaneous changes in animal fibre diameter and length affect the properties of the resultant ring spun yarns. The relationship between single fibre diameter (MFD) and length has been evaluated for Australian superfine wool (ASFW), Inner Mongolia cashmere (IMC) and wool top. Fibre samples were separated into finer-shorter and coarser-longer groups over given lengths. Subsequently, yarn properties were predicted from varied fibre diameter and length groups using the YarnspecTM software. A strong linear correlation exists between single fibre diameter and length for unprocessed ASFW and IMC. After removing long fibres, the average diameter of the remaining fibres was reduced by about 2 to 3 μm for ASFW and IMC. The predicted yarn evenness and tenacity significantly improved for ASFW and IMC by simultaneous changes in fibre diameter and length from the coarsest-longest to finest-shortest groups. The removal of the coarser-longer fibres plays an important role in improving properties of ring spun yarns.

Keywords: Superfine Merino wool, Cashmere, Single fibre diameter, Fibre length, Yarn properties

Introduction

Wool is a highly versatile product. Processing performance, textile properties and the comfort perceptions of wearers are affected by the physical properties of wool [1]. Wool value and quality are inherently connected to its properties such as diameter and length [1, 2]. For example, raw wool fibre diameter accounts for around 70% of the total price for the fibre [2]. Finer, stronger and more even yarns can be spun from finer wools which are suited for high value garments [1]. Hence, post-processing wool value and overall wool quality are affected considerably by fibre diameter [1]. Staple length is an important determinant of wool processing performance and fibre breakage as well as the yarn tensile characteristics. For a given average fibre diameter, longer average fibre length is more desirable. Spinning of wool with long staple length is easier and can produce stronger and more even yarns compared to shorter staple length wools [1, 3]. As a result, researchers have attempted to look for a method to achieve wool with an ideal combination of fibre length and diameter. Animal breeding is one of the approaches used to produce finer fibres. Although superfine animal fibre production has increased steadily in recent decades, only small and gradual reduction in the average diameter (less than 1 µm) of Australian Merino wool over 5 to 10 years has been achieved [4]. Recently, interest has been growing in modification of wool to reduce fibre diameter. Generally physical and mechanical properties of wool fibre can be modified by oxidative/reductive treatments, however these treatments are not Ecofriendly. An alternative pre-treatment for shrink-resist treatment has been developed such as enzymatic process using protease enzymes, which can lead to a small reduction in the average diameter (1. 5 ~ 2. 0μm) [5]. Although enzymatic treatment was an Eco-friendly treatment, it can be destructive and may result in largescale damage to fibre surface. Optim™ fine fibre is the commercial name for the stretched wool product [6]. Although the stretching approach has been able to achieve the desirable fibre fineness (2-3 µm reduction), increases in length, softness and silk like lustre, the chemically treated and slenderized wool suffers from reduction in wet modulus and degradation in its cuticle scales [7, 8]. Consequently, there is a need to find an approach without chemical damage to fibres to achieve fibre fineness reduction. This project aims to understand the fibre length and diameter relationships for both raw and processed fine animal fibres, and to

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model the impact of fibre separation based on fibre length on the properties of resultant yarns using SirolanYarnspecTM software. This work is unique in that it uses a new physical approach to change the average diameter and length of animal fibres. It has the potential of adding value to luxury animal fibres and improving the quality of yarns made from the separated fibres.

Material and methods

Australian superfine Merino wool (ASFW), Inner Mongolia cashmere (IMC) and wool top were used for the study. To examine the single fibre length and diameter relationship, representative mid-side samples from ASFW and IMC were collected. The samples were cleaned and tested for single fibre length and diameter. The single fibre diameter profile tests (referred to as dry test), were carried out using SIFAN 2 [9]. The fibre diameter-length relationships were then established from the individual measurements. A simulation was conducted to selectively remove fibres over a given length, and the effect of this removal on changes in mean fibre diameter and length was examined. To further explore the impact of such fibre selection on yarn properties, a Sirolan-Yarnspec program (Yarnspec™) [10] was used to predict yarn properties when the average fibre diameter and length were changed. Group means and the correlations between the variables were analysed using the GLM procedure of SAS (1990) [11].

Results and discussion

The correlation coefficients for the relationships between single fibre diameter (µm) and length (mm) in both ASFW and IMC are shown in Fig. 1. The single fibre diameter was highly correlated with single fibre length for unprocessed ASFW (r=0.929, p<0.05) and IMC (r=0.944, p<0.05). The Mean fibre diameter in different length groups for ASFW and IMC was 15.4 (±2.0) and 16.5 (±1.4) (µm), respectively. Fig. 1 further illustrates moderate correlation between the single fibre diameter (µm) and single fibre length (mm) of processed wool (r=0.589, p<0.05). The correlation of diameter-length was lessened during wool processing due to fibre breakage. However, a slightly positive diameter-length correlation remained. The profile of fibre diameter or length is related with the size of the cortical cells during post-keratinization and the level of cell production in the follicle [12]. Fibre diameter/length ratio can be changed by factors resulting in an alternation in the cell supply [12]. In addition, the single fibre/staple length changes with the body position where the fibre is grown. Nevertheless, the fibre length-diameter co-relation for the unprocessed wool is very strong (Fig. 1).

Fig. 1: The relationship between mean fibre diameter and single fibre length.

Changes in mean theoretical values for single fibre diameter and fibre length were calculated after elimination of each length group one by one from the longest group (Table 1). The removal of longer fibres from 62-137 to 62-66 (mm) in ASFW and 33-85 to 33-44 (mm) in IMC resulted in reduced mean fibre diameter (MFD), mean fibre length (MFL), and coefficient of variation of length CVL while the coefficient of variation of diameter (CVD) was slightly increased. Shorter length groups composed finer fibres with lower variance. Predicted MFD values explained a large proportion of the changes from original fibre mass to the shortest diameter-length group for ASFW (26 %, P < 0.05) and IMC (13 %, P < 0.05), respectively. It can be seen that the maximal diameter-length group in ASFW was longer than the medium and minimal diameter-length groups by 15 % and 37%. This trend was also observed in IMC.

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Table 1. Predicted changes in fibre diameter profile after removal of coarser-longer individual fibres within staple ASFW Fibre diameter profile

Remaining diameter-length groups (mm) 62-137A

62-126

62-117

62-111

62-104

62-96

62-86

MFD (Âľm) ** 15.4 15.0 14.6 14.2 13.8 13.4 13.0 MFL (mm) ** 102.3 97.8 93.2 90.2 86.6 82.5 77.2 CVD (%) NS 12.4 12.4 12.5 12.6 12.7 12.8 12.8 CVL (%) ** 19.2 17.4 15.6 14.2 12.6 10.7 8.5 IMC Remaining diameter-length groups (mm) Fibre diameter 33-62 33-57 33-53 profile 33-85A 33-79 33-75 33-71 33-67 MFD (Âľm) **16.5 16.3 16.1 15.9 15.7 15.4 15.3 15.1 MFL (mm) **60.8 58.3 56.3 54.3 52.3 49.7 47.1 45.0 CVD (%) NS 7.9 7.9 8.0 8.0 8.0 8.1 8.0 8.1 CVL (%) **23.0 21.5 20.3 19.0 17.7 15.8 13.9 12.4 A : Original fibre mass. ** Significant at P < 0.05. NS: not significant.

62-78

62-66

12.7 72.5 12.5 7.3

11.3 64.0 13.1 4.4

% Change -26.6 -37.4 +5.4 -77.0

33-48 14.7 42.4 8.1 10.6

33-44 14.4 40.0 8.6 9.6

-13.0 -34.2 +8.9 -58.2

Table 2 shows a wide range of length groups for ASFW and IMC, respectively. Table 2. Fibre diameter-length groups Category Original fibre mass Mid-range diameter-length group Shortest diameter-length group

Longest diameter-length group Mid-range diameter-length group Shortest diameter-length group

ASFW IMC Remaining diameter-length groups (mm) 62 - 137 33 - 85 62 - 104 33 - 62 62 - 66 33 - 44 ASFW IMC Removed diameter-length groups (mm) 130 - 137 80 - 85 100 - 110 50 - 60 70 - 80 40 - 50

The predicted properties of yarn investigated are listed in Table 3. It can be seen that all predicted yarn properties were improved with decreasing percentage of coarser-longer fibre groups. Table 3. Predicted changes in properties of yarn for both remaining and removed fibre diameter-length groups Superfine wool yarn Remaining diameter-length groups Original Mid-range Shortest % fibre diameterdiameterChange mass length group length group Tenacity (cN/tex) ** 8.5 10.6 11.0 +29.0 Elongation (%) ** 24.2 34.7 37.0 +53.0 Unevenness (CV %) ** 16.0 14.8 14.2 -11.0 No of fibres in cross sec ** 59.0 73.0 82.0 +39.0 Cashmere yarn Tenacity (cN/tex) NS 7.5 7.5 7.6 +1.0 Elongation (%) NS 18.3 18.9 19.4 +6.0 Unevenness (CV %) ** 17.6 16.9 16.5 - 6.0 No of fibres in cross sec ** 51.0 58.0 60.0 +18.0 ** Significant at P < 0.05

Removed diameter-length groups Longest Mid-range Shortest diameterdiameterdiameterlength group length group length group NS 8.44 8.8 9.3 ** 22.8 25.5 28.8 ** 18.1 16.7 14.5 ** 49.0 53.0 77.0 NS 7.4 NS 17.5 ** 18.7 ** 41.0

7.6 18.8 17.5 51.0

7.7 19.6 16.5 61.0

Results given in Table 3 show that the predicted tenacity and elongation values of ASMW (+29 and +53%, P < 0.05) increased to a great extent after coarser-longer single fibre elimination, whereas in case of IMC the tenacity and elongation increased slightly (<1 and <6%, NS) in both the remaining and removed diameterlength groups. Differences between the unevenness values of the resultant predicted Merino wool and cashmere yarns from original fibre mass to the shortest diameter-length group were statistically significant at

% Change +10.7 +26.3 -20.0 +57.0 +4.0 +12.0 -12.0 +49.0

Page 556 of 1108 5%. The predicted number of fibres in yarn cross section was increased in both ASFW and IMC by 39 and 18 % in shortest diameter-length group, respectively. The coarser the fibre, the less the number of fibres in a yarn cross section, the higher the yarn irregularity. A more irregular yarn has a higher tendency to break when stress is applied [13]. Further research is required to separate fibres into different fibre diameter-length groups to produce premium quality yarns.

Conclusions

This study has confirmed the strong linear correlation between single fibre diameter and fibre length for unprocessed Australian superfine Merino wool and Inner Mongolia cashmere. After fibre processing into a top, the diameter-length correlation is weakened but remains positively correlated. When long fibres are removed from a sample, the remaining fibres become finer and shorter. The implications of these changes on yarn properties have been predicted using the Yarnspec software package. It can be inferred from the predicted results that when a fibre sample is separated into longer-coarser and shorter-finer groups, both groups will result in yarns of higher quality than the original unseparated fibre sample.

5 [1] [2] [3] [4] [5] [6] [7] [8] [9] [10] [11] [12]

[13]

References B. W. B. Holman and A. E. O. Malau-Aduli, "A Review of Sheep Wool Quality Traits," Annual Review & Research in Biology, vol. 2, pp. 1-14, 2012. C. Jones, F. Menezes, and F. Vella, "Auction price anomalies: Evidence from wool auctions in Australia," Economic Record, vol. 80, pp. 271-288, 2004. E. J. Wood, Wool processing. Nottingham, UK: Nottingham University Press, 2010. "Price maker trends for better breeding and management decision," Woolmark Business Intelligence, vol. 99 pp. 3-4, 1998. L. Ammayappan, "Eco-friendly Surface Modifications of Wool Fiber for its Improved Functionality: An Overview," Asian Journal of Textile, vol. 3, pp. 15-28, 2013. D. G. Phillips, J. Warner, and J. Juc, "PROCESS FOR STRETCHING STAPLE FIBERS AND STAPLE FIBERS PRODUCED THEREBY," USA Patent, 1995. A. J. Yao and Y. Weidong, "Study on the Properties and Application of Optimâ&#x201E;˘ Fine Fibers," Advanced Materials Research vol. 287-290, pp. 2561-2564, 2011. A. J. Zhou, H. L. Liu, W. D. Yu, and C. M. Carr, "Investigation of the structure changes and properties of stretched mohair fibre," Journal of Molecular Structure vol. 1030 pp. 40-45, 2012. A. D. Peterson, A. Brims, M. A. Brims, and S. G. Gherardi, "Measuring the diameter profile of single wool fibres by using the single fibre analyser (SIFAN)," Textile Institute, vol. 89, pp. 441-448, 1998. P. R. Lamb and S. Yang, "The prediction of spinning performance and yarn quality," in 9th Int. Wool Research Conference, Biella, Italy, 1995. SAS, "SAS/STAT User's Guide," vol. Fourth edition, Cary, N.C, 6 ed. SAS Institute, 1990. P. I. Hynd, "Follicular Determinants of the Length and Diameter of Wool Fibres. I. Comparison of Sheep Differing in Fibre Length/Diameter Ratio at Two Levels of Nutrition," Australian Journal of Agricultural Research, vol. 45, pp. 1137-47, 1994. P. R. Lamb and S. Yang, "Choosing the right top for spinning," CSIRO Division of Wool Technology and International Wool Secretariat, papers presented at Geelong, Australia1996.

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The 13th Asian Textile Conference Geelong, Australia, November 3 - 6, 2015

Back to the Nature in Future Frankie Ng and Phoebe Wang Institute of Textiles and Clothing, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong

Abstract. While fashion and textile products have been advancing with increasingly sophisticated sciences and technologies, an up and coming future direction of fashion and textiles, as well as design at large, takes a new turnabout back to the nature for inspirations and advancement. Over the last two decades or so, there have been a plethora of intrigued and exciting works subsequent to the increased multi-disciplinary research collaborations between science and art as a major future research direction, e.g., from the self-healing bioconcrete by Junkers and Schlangen (2006) to the biocuture by Lee (2010) in fashion. This paper unfolds this burgeoning future trend that is going to reshape what fashion, textile and design will be like in the coming future, illustrated with some of the most representative work in fashion, textile and design.

Keywords: biofashion, biotextile, biodesign, green materials, green technologies

1. Introduction 1.1.

Back to the Nature

The convention of fashion production relies on a complex network of large scale agricultural units, oilbased fibre production, and chemical dyeing and finishing manufacturing based on petro-chemistry (Schindler & Hauser, 2004; Kant, 2011; Fletcher, 2013). Thus, fashion industry is regarded to be responsible for causing to the problems of soil erosion, waterAb pollution, and large scale carbon dioxide emissions and waste (Correia & Judd, 1994; Slater, 2003). The global rise in oil price, animal and environmental protection has resulted in an increase in the cost of synthetic materials (Nordås, 2004; Abernathy et al., 2006; Christie, 2007). Fortunately, nature provides the ultimate model of sustainability where there is no waste and only nutrients (Kaplan, 1998; Blackburn, 2005; Davis & Song, 2006; Satyanarayana, et al., 2009; Fletcher, 2013).

1.2.

Recent Development

There have been increased studies to explore future fashion, textiles and environment when and where its materials and clothing are grown from natural renewable resources directly towards cost effectiveness, low environmental impact, labour friendliness and biodegradable materials (Biermann et al., 2000; Gross & Kalra, 2002; Klemm, et al., 2002; Kumar et al., 2002; Mohanty et al., 2002; Wu et al., 2002; Ramesh & Tharanathan, 2003; Krajewska, 2004; Woerdeman et al., 2004; Klemm et al., 2005; Krajewska, 2005; Junkers & Schlangen, 2006; Yu et al., 2006; Abdelmouleh et al., 2007; Gandini, 2008; Zhao et al., 2008; Dieffenbach, 2009; Eichhorn & Gandini, 2010; Gatenholm & Klemm, 2010; Lee, 2010; Raquez et al., 2010; Siró & Plackett, 2010; Biermann et al., 2011; Wool & Sun, 2011; Klemm et al., 2011; Zhan, 2011; Dumitriu, 2012; Gardetti, 2013; Mo & Wang, 2013; Reinders, 2013; Wang, 2013;). New material developments were inspired using natural processing to grow fashion, textiles and environment out of them towards novel creations that merged art and science.

1.3

Values and Significance

By creating fashion and textiles using self-grown materials, the conventional garment creation processes and machineries could be simplified. Likewise, the high labour costs and production processes of spinning and weaving cloth, as well as patterning, cutting and sewing could be saved too. It also expands the aesthetical and technological dimensions of fashion and textile creations that would redefine them as objects d’art through novel materials and technologies, but also would it reshape our lifestyle, environment and the cultural context in which we live.

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2. Case Study 2.1.

The System of Development

Despite the burgeoning development of biomaterials and biodesigns, a systematic review of the system of development in this area remains scare. In this paper, the authors summarises the research and development of growing materials from nature in two broad areas, namely biology and non-biology. The area of biology is further divided into vegetation (i.e., seed, moss, grass and algae), animals and insects (i.e., bee, silkworm and spider), and microorganisms (i.e., bacterium, fungus, virus and others) whereas the area of non-biology mainly refers to minerals (i.e., crystal and magnetite). The applications of these growing biological and non-biological materials are found primarily in the areas of architecture and interior, installation art and design such as fashion and textiles. Figure 1 shows the system of the areas of development of natural growing materials.

Fig. 1: The system of the areas of development of natural growing materials.

2.2

The Cases

Biology – vegetation: L’altro Lato As early as in 1990, a work by England-based artists Heather Ackroyd and Dan Harvey titled L’Altro Lato (The Other Side) depicted a long dress and hat grown out of grass (Ackroyd & Harvey, 1990). In a room where a model wore it quietly under softly lit lighting, the dress and hat exhibited a special texture like fur. The fluffy and rich layers filled the entire space with a quiet yet mysterious feeling. Figure 2 shows the work.

Fig. 2: L’Altro Lato. Bussana Vecchia,

Italy (Ackroyd & Harvey, 1999).

Biological – animals and insects: Unbearing Lightness A work named "Unbearable Lightness" was presented in 2010 by a Holland artist Tomáš Gabzdil Libertiny at the Carpenters Workshop Gallery in London during Design Miami/Basel 2010 (Libertiny, 2010; Pinto et al., 2011). Libertiny managed to gain complete control over the bees and lure them to construct their hive precisely over the figure within the vitrine that is made of a laser sintered framework. To construct Unbearable Lightness, 40,000 worker bees were released into the case to complete a wax honeycomb structure over the figure of a martyred Christ rising out of the chaos. The bees created a honeycomb skin over the figure before filling each cell with the honey they produced, Libertiny then worked to remove the honey from the

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cells and return it to the beehive, cleaning the martyred Christ back to the wax cells they

originally created. Results of the work are Figure 3.

seen in

Fig. 3: The Unbearable Lightness. Materials: beeswax, stainless steel, glass, plastic, resin. Dimension: 122 Ă&#x2014; 250 Ă&#x2014; 45cm (Studio Libertiny, 2010).9).

Figure 4 Victimless Leather - A grown in a techno-scientific 'body' (The Tissue Culture & Art Project, 2004).

prototype of stitch-less jacket

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Biological – microorganisms: Victimless Leather In 2004, Oron Catts and Ionat Zurr from the University of Western Australia ‘grew’ a small coat they titled “Victimless Leather” in a laboratory. The small coat was kept alive by laboratory means (Catts & Zurr, 2012; Miranda, 2013; Reichle, 2009; Willet & Arts, 2006). It was developed onto a polymer base covered with living cells (Catts & Zurr, 2006) It was grown out of immortalised cell lines which cultured and form a living layer of tissue supported by a biodegradable polymer matrix in a form of miniature stitch-less coat-like shape (see Figure 4). The Victimless Leather project aimed at growing living tissue into a leather-like material. By growing Victimless Leather, an actualised possibility of wearing ‘leather' without killing an animal was offered as a starting point for cultural discussion (Zurr & Catts, 2003; Catts & Cass, 2008; Stracey, 2009). Catts et al. stated that the result of their efforts should be perceived as an art form to illuminate our human conduct of exploiting other living beings. The project was to encourage thought and conversation, as well as to obtain genuine leather without affecting animals in any negative way.

Non-biological - minerals: Unsustainable As for non-biological, a project called 'Unsustainable' by Greetje van Helmond at the Royal College of Art, London seen a work consisted of a range of jewellery made by growing sugar crystals onto cords immersed in sugar solution (van Helmond, 2007) (see Figure 5). Van Helmond had created the unsustainable jewellery out of sugar which had the quality of growing further into crystals under special circumstances. By controlling the process, it allowed crystals to grow around strings to form accessories. The project dealt with issues of durability and resource consumption, deliberately using a basic material to create precious, but extremely fragile objects.

Figures 5. London (van

'Unsustainable' the Royal College of Art, Helmond, 2007)

3. Conclusion This paper presents a burgeoning approach to conceive designs grown from nature as the step forward into the future of art, design and environment. It further illustrates this trend by selected examples in each of the four areas of novel materials created from nature over the last two decades or so as a result of multidisciplinary research collaborations between science and art. This trend is believed to reshape the world in which we live. In addition to its practical values, the beauty born of coincidence seem in these work is something which a human cannot create. This creation is formed using the laws of nature, pushes the boundaries of creativity farther than our own imagination. It offers an opportunity to ponder the future of design as well as the mysterious powers of nature which transcend the limits of human imagination. It is thus left to nature to show us a beauty that exceeds our imagination. The creation so created in this way contains a strength that is sometimes thrilling since the forms of nature are unique and cannot be reproduced. This endows them with mysterious beauty and makes them fascinating to us. The success of identifying, expanding and reinventing designs via biotechnologies is of both original artistic merit and commercial value, and will enhance future research in this area.

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4. Acknowledgements The authors would like to acknowledge the financial support provided by the Research Grants Council in the form of a postgraduate award at The Hong Kong Polytechnic University for this work.

5. References [1] Abdelmouleh, M., Boufi, S., Belgacem, M. N., & Dufresne, A. (2007). Short natural-fibre reinforced polyethylene and natural rubber composites: effect of silane coupling agents and fibres loading. Composites Science and Technology, 67(7), 1627-1639. [2] Abernathy, F. H., Volpe, A., & Weil, D. (2006). The future of the apparel and textile industries: prospects and choices for public and private actors. Environment nd Planning A, 38(12), 2207. [3] Ackroyd, H. & Harvey, D. (2012). Retrieved from: http://www.ackroydandharvey.com/face-to-face/ [Accessed 25/08/2014] [4] Biermann, U., Bornscheuer, U., Meier, M. A., Metzger, J. O., & Schäfer, H. J. (2011). Oils and fats as renewable raw materials in chemistry. Angewandte Chemie International Edition, 50(17), 3854-3871. [5] Biermann, U., Friedt, W., Lang, S., Lühs, W., Machmüller, G., Metzger, J. O., & Schneider, M. P. (2000). New syntheses with oils and fats as renewable raw materials for the chemical industry. Angewandte Chemie International Edition, 39(13), 2206-2224. [6] Blackburn, R. S. (Ed.). (2005). Biodegradable and sustainable fibres. Elsevier. [7] Catts, O., & Zurr, I. (2006). Towards a new class of being-The Extended Body. Artnodes, 6(2), 1-9. [8] Catts, O., & Zurr, I. (2008). The ethics of experiential engagement with the manipulation of life. Tactical biopolitics: Art, activism, and technoscience, 125-42. [9] Catts, O., & Zurr, I. (2012). Life as a Raw Material: Illusions of Control. Somatechnics, 2(2), 250-262. [10] Christie, R. (2007). Environmental aspects of textile dyeing. Elsevier. [11] Correia, V. M., Stephenson, T., & Judd, S. J. (1994). Characterisation of textile wastewaters ‐a review. Environmental Technology, 15(10), 917-929. [12] Davis, G., & Song, J. H. (2006). Biodegradable packaging based on raw materials from crops and their impact on waste management. Industrial crops and products, 23(2), 147-161. [13] Dieffenbach, M. (2009). Green design. St. Louis, Mo.: Phoenix Learning Group. [14] Dumitriu, S. (Ed.). (2012). Polysaccharides: structural diversity and functional versatility. CRC Press. [15] Eichhorn, S. J., & Gandini, A. (2010). Materials from renewable resources. Mrs Bulletin, 35(03), 187-193. [16] Fletcher, K. (2013). Sustainable fashion and textiles: design journeys. Routledge. [17] Gandini, A. (2008). Polymers from renewable resources: a challenge for the future of macromolecular materials. Macromolecules, 41(24), 9491-9504. [18] Gardetti, M. (2013). Sustainability in fashion and textiles : Values, design, production and consumption. Sheffield [England]: Greenleaf Pub. [19] Gatenholm, P., & Klemm, D. (2010). Bacterial nanocellulose as a renewable material for biomedical applications. MRS bulletin, 35(03), 208-213. [20] Gross, R. A., & Kalra, B. (2002). Biodegradable polymers for the environment. Science, 297(5582), 803-807. [21] Junkers and Schlangen, BioConcrete. Delft University of Technology, 2006 (See, for example, https://www.youtube.com/watch?v=IJc8Xyk3w9o). [22] Kant, R. (2011). Textile dyeing industry an environmental hazard. [23] Kaplan, D. L. (1998). Introduction to biopolymers from renewable resources (pp. 1-29). Springer Berlin Heidelberg. [24] Klemm, D., Kramer, F., Moritz, S., Lindström, T., Ankerfors, M., Gray, D., & Dorris, A. (2011). Nanocelluloses: A New Family of Nature ‐Based M aterials. Angewandte -5466. [25] Klemm, D., Schmauder, H. P., & Heinze, T. (2002). Biopolymers, Vol., 6. Vandamme, S. de Beats, and A. Steinbuchel, Eds., ed Weinheim: Wiley-VCH, 290-292. [26] Krajewska, B. (2004). Application of chitin-and chitosan-based materials for enzyme immobilizations: a review. Enzyme and microbial technology, 35(2), 126-139. [27] Krajewska, B. (2005). Membrane-based processes performed with use of chitin/chitosan materials. Separation and Purification Technology, 41(3), 305-312. [28] Kumar, R., Choudhary, V., Mishra, S., Varma, I. K., & Mattiason, B. (2002). Adhesives and plastics based on soy protein products. Industrial crops and products, 16(3), 155-172. [29] Lee, S., Du Preez, W., & Thornton-Jones, N. (2005). Fashioning the future: tomorrow's wardrobe. Thames and Hudson. [30] Linbertiny, T. G.(2010). Retrieved from: http://www.studiolibertiny.com/. [Accessed 25/08/2014] [31] Miranda, C. A. (2013). Weird Science. ARTnews, 64-69. [32] Mo, X. T., & Wang, P. C. (2013). Materials Used in Sustainable Design. Advanced Materials Research, 753, 14201422. [33] Mohanty, A. K., Misra, M., & Drzal, L. T. (2002). Sustainable bio-composites from renewable resources: opportunities and challenges in the green materials world. Journal of Polymers and the Environment, 10(1-2), 19-

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26. [34] Nordås, H. K. (2004). The global textile and clothing industry post the agreement on textiles and clothing. World, 7, 1-000. [35] Pinto, R. P., Franqueira, T., Afonso, A., Mendonça, R., & Laranjeira, I. (2011). Bees: new creative agents. The Conference on Designing Pleasurable Products and Interfaces (p. 2). ACM. New York, NY, USA. [36] Ramesh, H. P., & Tharanathan, R. N. (2003). Carbohydrates-the renewable raw materials of high biotechnological value. Critical reviews in biotechnology, 23(2), 149-173. [37] Raquez, J. M., Deléglise, M., Lacrampe, M. F., & Krawczak, P. (2010). Thermosetting (bio) materials derived from renewable resources: a critical review. Progress in Polymer Science, 35(4), 487-509. [38] Ratner, B. D. (Ed.). (2004). Biomaterials science: an introduction to materials in medicine. Academic press. [39] Reichle, I. (2009). Art in the age of technoscience: genetic engineering, robotics, and artificial life in contemporary art. Springer Verlag Wien [40] Reinders, A. (2013). The power of design product innovation in sustainable energy technologies. Chichester: Wiley. [41] Satyanarayana, K. G., Arizaga, G. G., & Wypych, F. (2009). Biodegradable composites based on lignocellulosic fibers—an overview. Progress in Polymer Science, 34(9), 982-1021. [42] Schindler, W. D., & Hauser, P. J. (2004). Chemical finishing of textiles. Elsevier. [43] Siró, I., & Plackett, D. (2010). Microfibrillated cellulose and new nanocomposite materials: a review. Cellulose, 17(3), 459-494. [44] Slater, K. (2003). Environmental impact of textiles: production, processes and protection (Vol. 27). Woodhead Publishing. [45] Stracey, F. (2009). Bio-art: the ethics behind the aesthetics. Nature Reviews Molecular Cell Biology, 10(7), 496500. [46] Van Helmond, G. (2007). Unsustainable. Retrieved from: http://www.greetjevanhelmond.com/ [Accessed 25/08/2014] [47] Wang, W. (2013), Creation of Seamless Self-grown Fashion. PhD study, The Hong Kong Polytechnic University. Hong Kong. [48] Willet, J., & Arts, S. (2006). Bodies in Biotechnology: Embodied Models for Understanding Biotechnology in Contemporary Art. Leonardo Electronic Almanac, 14(08). [49] Woerdeman, D. L., Veraverbeke, W. S., Parnas, R. S., Johnson, D., Delcour, J. A., Verpoest, I., & Plummer, C. J. (2004). Designing new materials from wheat protein. Biomacromolecules, 5(4), 1262-1269. [50] Wool, R., & Sun, X. S. (2011). Bio-based polymers and composites. Academic Press. [51] Wu, L. Q., Embree, H. D., Balgley, B. M., Smith, P. J., & Payne, G. F. (2002). Utilizing renewable resources to create functional polymers: chitosan-based associative thickener. Environmental science & technology, 36(15), 3446-3454. [52] Yu, L., Dean, K., & Li, L. (2006). Polymer blends and composites from renewable resources. Progress in polymer science, 31(6), 576-602. [53] Zhan, Y. (2011). Green Design Based on the Concept of Ecological Holism. Applied Mechanics and Materials, 44, 1598-1602. [54] Zhao, R., Torley, P., & Halley, P. J. (2008). Emerging biodegradable materials: starch-and protein-based bionanocomposites. Journal of Materials Science, 43(9), 3058-3071. [55] Zurr, I., & Catts, O. (2003). The ethical claims of Bio-Art: killing the other or self-Cannibalism?. Australian and New Zealand Journal of Art, 5(1), 167-188.

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The 13th Asian Textile Conference Geelong, Australia, November 3 - 6, 2015

Brief Analysis of Uyghur Traditional Textile Technology Gulisitan Yigemu, Sainawaer Sulitan,| Munire Mubaixiaer College of Textile & Fashion, Xinjiang University, Urumqi Xinjiang , China Abstract: The Uyghur is one of ancient nations in China. During the long course of historical development, the brave and industrious Uyghurs have created a splendid culture. In particular, the traditional textiles in the Uyghur have undergone a long history with standard and systematical manufacturing techniques in wool, cotton and silk fabrics. A variety of Uyghur textiles emerged in the history satisfied not only the basic demands of Uyghur people who lived in the south and north of Tianshan Mountain for body cover and warmth, but also their sence of beauty. Moreover, many characteristic textiles were sold to central plain and Rome, and played important role in the spreading of western culture. In this paper, manufacturing techniques and process for traditional wool, cotton and silk fabrics in the Uyghur were summarized and analyzed. Keywords: Wool, cotton and silk industries are the three main industries in Uyghur traditional textile.

1. Wool Industry According to the facts that have been found by archaeologists, Uyghur people have been living in some regions near to the Tarim Basin for a very long time and engaged in agriculture and animal husbandry since then, also they have mastered varies hand crafting techniques for living. Among those techniques, the development of the wool spinning was relatively fast. Historical items such as wool hats, knitted wool skirt and wool felted blankets excavated from the cemeteries can be a proof of that. There is two main reasons why the wool textile industry has been developed so early in the Uyghur society, the first reason is that they were depending on animal husbandry for living before they upgraded to the agricultural society. The meat and milk of the livestock storage not only provided them with enough food, and also their skins and fur has provided them with clothes and raw materials. The second reason is the drawing and roving process for wool spinning is relatively easy because of the longer length of wool fiber. A wool sliver can be made with a single wooden stick, and a twisted wool spun yarn can be made out of a spindle with three wooden sticks. They understood the easiness of wool spinning long time ago, and invented a weaving loom with seven pillars, three branch and two wooden board on that basis, used it for weaving and making wool products from that. This kind of weaving loom has a very simple structure, lightweight, easy to carry and can be assembled and weave fabrics wherever there is small space to put it. Assembled weaving loom with unfinished fabric can be even closed up together and move to another place, then continued to weaving when it is necessary. Therefore, this kind of weaving loom still has been remained in some mountain areas until now. Traditional Uyghur wool products has three different types like Ghipcheďź&#x152;Shuttle-woven fabrics,

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Piltiku fabrics，because of the different manufacturing technique and different approach. Ghipche refers to those hand knitted fabric products with wool yarn such as knitted wool garments, toys and other household items. The raw materials for the traditional Ghipche fabrics are mainly fleece and camel’s hair. The combination of natural wool yarn and some dyed yarn with bright colors is the main color feature of the product. Generally, camel hair will be used for spinning without coloration process, but the fleece will be used after coloration. Ghipche fabrics and Ghipche techniques have so many advantages, the first advantage is the simplicity of the weaving tool, only few Ghipche is needed for the process rather than complicated equipments. Therefore the weaving process of Ghipche can be operated in any place. The second advantage is the time saving process. Because a very simple technique is required for the weaving of Ghipche fabrics, the whole process is easy to learn and can be carried out in any occasions like indoor or outdoor or even when one is walking or sitting. The third is its labor saving advantage. It doesn’t need too much labor for the process. The fourth advantage is the saving of raw materials. Ghipche products doesn’t need any pattern making or cutting process so that there won’t be any wastage of the raw material. The fifth advantage is it can be recycled, and can be used repeatedly. Ghipche fabrics are stretchable so that the size won’t be matter if it is slightly big or small, and it can also be revealed and fix the size when it is necessary. The sixth is a multi-functional product advantages with a great woolliness. The seventh advantage is its certain extension and contraction characteristics. Those features can reflect the body shape in a great form with a great thermal properties and light weight which suits people from any age and sex to wear. These unique advantages established its strong vitality for Ghipche items and became the reflection of Uyghur people’s wisdom from surviving and adapting the nature. Shuttle-woven fabric refers to those wool fabrics weaved by hand with weaving loom, main process included warp opening, shuttle beat up and weft insertion. Most of the weaving techniques of this product are already disappeared, and only the woolen belt weaving technique was lasted until modern times. Piltiku fabric refers tothose fabrics weaved by introducing the weft yarn into the shed with Piltiku. The main difference between Piltiku fabric and Shuttle-woven fabric is that the weft yarn of the Piltiku fabric is inserted by Piltiku, not by shuttle. Chekmen (a kind of native fabric), foot-binding cloth, carpet (rugs) are the products weaved by this technique. Although the ancestors of Uyghur not only have learned how to make woolen items by rolling and felting long ago, but also have mastered the knitting techniques of knitted items, they even have knitted long and short coats using those techniques. They not only have understood the true nature of fabric weaving, but also have mastered the coloration technique and produced wool fabrics with colour. Not only learned how to weave the plain fabric, but also mastered how to weave fabrics with animal patterns, plants and some other patterns. Unfortunately, just few types of those wool items have remained till now when most of them didn’t last long enough. Those ones remained till now are mostly kept in the remote mountain areas and pastoral areas. Although the cotton and silk products came in later than the wood products, they gradually have replaced the wool products. The main reason for the reduction of wool product and and disappearance of wool industry is the cotton and silk products have so many advantages compares to wool. First, as the main raw material of wool product, the wool fibre production can not be increased in a short term, but the cotton production can be increased much easily without any restrictions. For example, only the increase of cotton acreage can meet social needs in one or two years. Those heavy and fixed wool textile

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equipments have been subjected to certain restrictions because of the complex structure of nomadic production, Silk and cotton textile industries has been settled in agricultural areas where the emergence and using of heavy and complicated textile equipments will not be restricted any limitations, because people are tend to live longer. Third, Because of the thick and rough texture of the wool fabrics, those garments produced out of wool fabrics are not suitable for plainsman to wear, because the weather condition is not too cold in winter, and has a less rain climate. Contrast to the wool fabrics, the silk and cotton fabrics are more permeable, light and thin, suitable to wear on those mentioned weather conditions. Fourth, the wool fibre is limit by the colour selective feature. Only white wool fiber can be dyed without colour selection limits, but black, brown and any other wool fibres are difficult to dye, plus the amount of dye used to dye the wool fibre are big and cost is also high. The colour selection for silk and cotton are more free, and the amount of dye used is also less than wool. Fifth, the surface of wool fabric is rough, hard and not shiny, these characteristics of silk and cotton are just opposite to wool. Sixth, wool can be easily borer throung, other textiles donâ&#x20AC;&#x2122;t have such drawbacks. Because of these reasons mentioned above, Uyghur traditional wool textile industry continued to be degraded. This is very similar to how the products made by chemical fibre monopolized the cotton product. With the development of the agriculture, Uyghur people have been engaged in the cultivation of cotton and silkworm breeding, and that is how the silk and cotton industry emerged. Since the recent centuries,, the traditional Uyghur handmade textile production scale has been compressed and types and quantity of handcrafted textile products are decreased gradually, because of the emerged modern textile products and its increasing popularity in Uyghur peopleâ&#x20AC;&#x2122;s social life,and so many textile handcrafting techniques has been lost. Even the types and scales of some remained textile techniques are very small, Etles silk is one of them, remained until now because of its unique characteristics.

2. Cotton industry The cotton industry occupies an important position in Uyghur traditional textile industry. Especially the carded cotton textile industry, woven crash fabrics are the raw materials for clothing, bedding and other necessities of Uyghur peoples life before the liberation. That is the reason why the carded cotton industry became the widely popular, fastest growing and specialized textile industry all over the Tianshan mountain in the long historical development. Thick cotton textile products included denim (large cloth, handwoven cloth), Tully linen, and Chekmen, gauze, lining cloth, tablecloths, belts and scarves. Thick cotton products are classified into two caregories as colourless fabric and coloured fabric basid on its colour. Coarse, Tully linen and Chekmen, cotton gauze and other crude products are colourless fabric. Tablecloths, belt cloth, scarves and other products are coloured fabric. Colourless fabrics are produced in a double pedal store, belt cloth and tablecloths in coloured fabrics are produced in four pedal shops, scarves and loincloth are produced in double pedal shops. Coarse fabric belongs to the downstream products in the appearance or durability among the thick cotton extile products. Thick cotton fabric production has been mostly disappeared,and produced as rag in a veri little amount when it is needed.. Tully linen fabric has a better appearance, higher density and higher durability compares to the thick cotton.fabric. Printed fabrics, wall papers and printed cotton duvet covers can be produced use the woven Tully linen fabrics. The original white fabric can be dyed into blue, black, indigo and other colours, then can be used for sewing garments for summer and fall wear, beddings and other household items. Tully linen textile industry has now been disappeared, and only produce a small amount of

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production under special customized state. Chekmen can be regarded as the top in thick cotton products because of its durability. According to the raw material used Chekmen can be divided into white Chekmen and pale yellow Chekem. White Chekmen is made from white cotton yarn, and can be dyed into black, blue, indigo, gray and other colors for use. Pale yellow Chekmen is woven from crude yellowish cotton yarn, substantially used without any coloration. Due to the natural pale yellow color of Chekmen, it looks elegant, striking and also resistant to dirt. So it is more valuable than the white thick cotton. Rough Chekmen generally used for sewing men's robes, Chapan, short robes, sleeveless tops and other clothes and also sacks, flour bags and other daily necessities. Chekmen textile shop is also completely disappeared now. Gauze is a fine-spun cotton fabric made out of the top quality cotton. Gauza generally used to made scarves for summer, summer shirt, and also lingeries. Handmade gauze textile shop is also completely disappeared. Lining is a white cotton fabric woven from low-quality white canvas, weft and warp density of lining cloth are low, light weight, and the bad durability, in most cases, used in the preparation of a double coat linings. Lining is now producing in a very small amount, and mainly used as a rag. Tablecloth is a daily necessity for Uyghur community, especially when they are dining and that is why tablecloth is commonly used in the Uyghur families. Patterns of the tablecloth is produced by direct weaving or printing in Uyghur handcraft industry. Tablecloth has been classified into two categories such as jacquard tablecloth and printed tablecloth in order to identify the different pattern types. The traditional tablecloth production industry now has already disappeared. Coarse cotton waistband is usually weaved in a four-pedal coarse cloth weaving shop. The waist-band width is 0.5 cm and length is about 1.8 meters in general. Coarse cotton waistband has two different patterns, which are known as Sula-talang waistband and Yandurma-talang waistband. The production of coarse cotton belt is also rare nowadays. However, wearing waistband is still very common among the farmers in some rural areas. Coarse scarves weaved by the good quality cotton yarn, and the largest surface area is about one square meter. Printed with Red, earth brown, wheat, blue and green and other colours. Scarf weaving industry has been also completely disappeared. Coarse cotton towels and coarse cotton handkerchieves are weaved from carefully chosen highquality cotton yarn with good quality and long durability. Even if they cannot be compared with silk handkerchieves and silk towels, but they also have some advantages such as strong limpness, higher resistant to dirt and lower price. The colours of dyed yarn used for tablecloths, waistbands, handkerchiefs and other coarse cotton fabric weaving are tend to be intensive colours. The distinction of surface colour on entire handkerchief is very strong and bright, and it gives a lively, beautiful feeling. Colour of the tablecloths are relatively pastel. Decreased the colour difference on handkerchief surface by mixing the coloured yarn and white yarn while weaving. In the face of cross-through white cotton handkerchief with cotton suit different colours to distinguish each other further diluted. Thus, in a handkerchief colour selection, Uighur women tend to choose strong, lively, bright colours which are suitable their taste. However the colour selection for tablecloth and waistband tend to be focused on their dirt resistant features and also its real value in use. With the growing popularity of modern textile equipments in Uyghur society, coarse manual production industries gradually being out of date, and most of the coarse products varieties have disappeared.

3. Silk industry

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The silk weaving industry could be dated back to the times of Early 300 BC, Yutian(Hotan) has Sericulture industry at that time. Hotan region has crowned the title of Western Silk Center for 2,000 years. The cradle of Etles in Hotan region is the ancient Silk Road hub. And its also an important silk distribution center. Around 200 BC, Hotan silk business was already booming, from Han to the Wei dynasty silk trade begun to be more and more prosperous then Tang Dynasty entered its powerful and prosperous times. According to some records written down at Nanbei Dynasties, a caravan once transport silk over 4300 horses. Large amount of Chinese silk was transported through the southern Silk Road, and shipped to Central Asia, the Middle East even to the Mediterranean countries. "hu(foreign)businessmen keep trading outside the border everyday", "month without a break at the time." Hotanâ&#x20AC;&#x2122;s historical position in the silk trade is renowned for a long time. Most of the silk manufactured from hotan were sold to the mainland China, Etles heat spread through the Han Chinese aristocrats, Etles was a luxury item at that times. Etles is the main part of Uyghur traditional textile industry because of its uniqueness. Etles is tiedyed silk, and it has a unique weaving technique, bewildering colour with beautiful pattern .it can be dyed into various colours according to the needs of customer . The pattern is both abstract and romantic, cloud-shaped silk patterns, Etles is the best material for making high quality uyghur traditional dress. It uses old tie-dye technique, weaved with black, blue, red, green and white irregular geometric wave patterns and lines. These patterns designed are considered to be water wave, vertical lines, wood grain, almound wood patterns. The unique colour of Etles is bright and elegant, it has a sharp contrast with the Xinjiangâ&#x20AC;&#x2122;s plain colour of desert environment, it indicates the love and passion Uyghur people hold for life. Etles has four basic types, named by its colour feature which are black Etles, Red Etles, yellow Etles, and multi-coloured Etles. Base colour is fixed, and matched with the other colour in a perfect measure. Those convex line pattern, grid pattern are gorgeous without losing elegancy. Traditional Etles manufacturing methods is purely handmade, the looms is about fifty inches high, Shuttle running through the loom shed, and the loom is operated with both hands and feet, pattern is tie dyed on silk, according to the shapes of the pattern , wrapped up with the corn peelďź&#x152; a set of rigorous process is undertaken when Etles is soaked in mineral and plant pigments. Although now we have machines to weave Etles, but hand-made Etles provide more varieties of colour choice for different age groups of women, and very popular among the women from all ethnic groups in Xinjiang. Ancient Etles origins mainly in Hotan, Kashgar, Yarkend and other regions. Hotan is the most representative place for making Etles. Etles production scale, quality and techniques here are more mature than any other regions. Almost every family has one old wooden loom nowadays in some rural areas in Hoten, and almost everyone knows how to weave Etles. They make dyes for Etles by collecting pigments from the plant roots, walnut peel, tamarisk petals, and other flowers. Those Etles workshops are environmental old class. Materials are taken from nature, pigments are extracted from local walnut and flowers, silk taken from the domesticated silkworm farmers keeping by themselves . Because of natural materials and eminent technique of hand craftsmen, in addition to limited production capacity, Etles has been considered as rare as gold by outside world. Etles silk is always the most favorite clothing of Uyghur women, because it has a very soft handle, bright in color, refreshing and comfortable to wear. Handmade Etles silk dress is a must when they out on a special occasions, parties or cultural festivals. Its highly regional pattern reflects the cultural

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features by using the fruit patterns and bright colours. Etles silk patterns are mostly in large rectangular shape with patchwork arrangement, and flowing patterns which suited the passionate personality of Uyghur people perfectly. And also strongly contrasted with relatively monotonous life style of the western environment, and expressed Uyghur peopleâ&#x20AC;&#x2122;s optimistic view for the better future. However, sericulture silk technology has came to the Western Regions very long ago and dissolved into the local peopleâ&#x20AC;&#x2122;s aesthetic taste, and then turned into a complete set of atlas silk production process. Etles silk dresses are still not only popular among the local people, because it suits their taste and cultural background, but also famous among other countries because of its unique style.

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The 13th Asian Textile Conference Geelong, Australia, November 3 - 6, 2015

Control of Melt Structure of High-Molecular Weight Poly(Ethylene Terephthalate) by Hole Diameter of Spinning Nozzle in High-Speed Melt Spinning Process Do-Kun Kim, Joo-Hyung Lee, Ki-Sub Lim, And Wan-Gyu Hahm + Technical Textile & Materials R&D Group, Korea Institute of Industrial Technology,143 Hanggaulro, Sangnok-gu, Ansan-si, Gyeonggi-do, Republic of Korea

Abstract. In this study, to investigate the effect of hole diameter of spinning nozzle on melt structure of polymer in melt spinning process, high-speed melt spinning of high-molecular weight PET (HMW-PET) was conducted by using various spinning nozzles designed with different hole diameter. Characteristic relationship between the thermo-mechanical properties of obtained as-spun PET fibers and the spinning conditions such as shear rate and draft influenced by nozzle hole diameter was studied focusing on the control of melt structure of polymer in detail. As expected, fiber orientation and structure development increased with nozzle hole diameter and spinning velocity. However, in the case of as-spun fibers obtained at low spinning velocity under 2km/min, the range of strain-elongation and the elongation at break point of fibers: toughness showed a tendency to increase as nozzle hole diameter decrease. These results indicate that polymer melt structure can be improved and controlled by the capillary conditions such as hole diameter and length in the spinning nozzle Keywords: Melt spinning, shear rate, PET, draft, nozzle, hole diameter

1. Introduction Poly(ethylene terephthalate) (PET) is one of the versatile thermoplastic polymer which is used to manufacture mainly textiles and packaging materials, and more than 80 % of the annual production of synthetic fibers in the world is now occupied by PET fibers. However, for the past few decades, maximum tensile strength of PET fibers in the market remains at around 1GPa. Therefore, the study on try to improved extensibility and maximize strength of PET fibers have attracted attention, and many research group have reported for the preparation of high performance PET fibers by the control of molecular weight and the modification of process conditions, etc. Recently, Kikutani, et al. reported a study on the improvement of mechanical properties of PET fibers by using the control of polymer melt structure in the vicinity of spinning nozzle[1]. Hole diameter of spinning nozzle is one of the most effective factors to control melt polymer structure development in melt spinning process. In other words, velocity of polymer fluid in the capillary tube of spinning nozzles influences not only shear thinning behaviour of melt polymer in the capillary but also elongational stress in the spinning line. In this study, to investigate the effect of nozzle hole diameter on fiber structural development of high-molecular weight poly(ethylene terephthalate) (HMW-PET) in high-speed melt spinning, high-speed melt spinning was conducted using the various spinning nozzles with different hole diameter.

2. Experimental 2.1.

High-speed melt spinning

In this study, high-molecular weight poly(ethylene terephthalate) of I.V. 1.21 dl/g were melted using the single-screw extruder of Ă&#x2DC;40 mm, and extruded through spinning nozzle by metering gear pump. High-speed melt spinning was conducted by using spinning nozzles with Ď&#x2022; 0.4, 0.5, and 0.7 mm of L/D 4 at the various

Corresponding author. Tel.: + 82-010-7330 3042. E-mail address: wghahm@kitech.re.kr

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spinning velocities between 0.5 and 6 km/min. Spinning temperature was controlled at 295ﾂｰC and throughput rate of polymer was 4g/min.hole.

2.2.

Chracterization

The thermal properties of obtained PET as-spun fibers were investigated by a differential scanning calorimeter (DSC; TA Instruments) under a nitrogen atmosphere with a heating rate of 10 ﾂｰC/min in the 30 ~ 320 ﾂｰC temperature range. The mechanical analysis for the PET as-spun fibers was conducted with a tensile test machine (FAVIMAT; Textechno). The gauge length and the test speed were 10 mm and 10 mm/min, respectively. The orientation (birefringence (ﾎ馬)) of the PET as-spun fibers were measured through a polarization microscope (Carl-Zeiss) equipped with a Berek compensator.

3. Result and Discussion In this study, three kinds of spinning nozzles with hole diameter of 0.4, 0.5, and 0.7mm were used for melt spinning, and estimated apparent maximum shear rate and average velocity of polymer fluid in the capillary tube of each nozzle were about 8746, 4478 and 1632 s-1, and 26.2, 16.8 and 8.6 m/min under the throughput rate of 4g/min. DSC curves of obtained PET as-spun fibers shown that crystallization peak (T c ) shifts toward lower temperature as spinning velocity increases and the peak more shifts as nozzle diameter increases. T c peak disappeared after starting to shift melting peak (T m ) toward higher temperature due to stain-induced crystallization [2], and the shift of T m peak started at the relatively lower spinning velocity as nozzle diameter increased. These results indicated that fiber orientation and structural development increases with spinning stress caused by spinning velocity and nozzle hole diameter. Simulation results calculated using a Newtonian viscoelastic constitutive equations showed that spinning stress can be distinctly influenced by the nozzle hole diameter. Birefringence and tensile strength of obtained as-spun fibers also increased with spinning velocity and slope of curve risen as nozzle hole diameter increased corresponding with the results of DSC. However, in the case of as-spun fibers obtained at low spinning velocity under 1km/min, spinning stress in the spinning line is relatively very low and it can be estimated that fiber structure is more influenced by the melt behavior in the capillary of spinning nozzle than the condition of spinning line. It is worth to note that the range of strain-elongation, the elongation at break point, and toughness of as-spun fibers obtained at low spinning velocity showed a tendency to increase as nozzle hole diameter decreases. These results indicate that polymer melt structure can be controlled and modified by the capillary conditions such as hole diameter and length in the spinning nozzle.

4. References [1] M. Masuda, W. Takarada, T. Kikutani, Intern. Polymer Processing, 25, 2 (2010) [2] W.-G. Hahm, H. Ito and T. Kikutani, Intern. Polymer Processing, 21, 5 (2006)

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The 13th Asian Textile Conference Geelong, Australia, November 3 - 6, 2015

Effect of LiCl/DMAc solution treatment on solubility and mechanism of native hemp fibers Zhili Zhong 1, Min Zhu 2, Zhendong Liao 1 + and Qi Weng2+ 1

School of textile,Tianjin polytechnic university,Tianjin300387,China

Abstract. Effect of Lithium chloride / N,N-Dimethylacetamide (LiCl/DMAc) solution treatment on solubility and mechanism of native hemp fibers was evaluated. Native hemp fibers(beijiang shenyang) were immersed in 18% alkali liquor and 60,℃ bath temperature for 1, 2,3,4h. Samples were submerged in 10% LiCl/DMAc solution with a temperature of 70 ℃, 80℃ and 95℃ within 0.5h. The change of the surface morphology, crystallization structure and solubility of hemp fibers were indicated by scanning electron microscope(SEM),fourier transform infrared spectroscopy(FT-IR),x-ray diffraction(XRD) and solubility test. The research results showed that with the alkali treatment, non-cellulosic materials removed from surface,crystal form of cellulose I turned into cellulose II by the analysis of XRD. Solubility of hemp fibers increased when LiCl/DMAc treatment temperature were extended from 70 ℃ to 95℃. By fourier transform infrared spectroscopy, new characteristics peaks(1626cm-1、1508 cm-1 and 1403 cm-1) were observed. As a result, the degree of crystallinity decreased with LiCl/DMAc treatments. When treated in 10% LiCl / DMAc solution, 95℃ for 0.5h, cooled to room temperature and stirred for 2h,hemp fibers had the best dissoluvability. After alkaline activation, hemp fibers could be dissolved1.0-1.2g for 2h and 1.2-1.5g for 3h in 100ml LiCl/DMAc soluble system. The solubility and viscosity of hemp cellulose increased with increasing fibrinolytic mass and activation time .

Keywords: cellulose, hemp fibers, LiCl/DMAc,solubility.

1.Intrduction Hemp fiber is cellulose fiber, with advantages of moisture absorption, anti-bacterial and anti ultraviolet properties [1-4]. It has been widely used in papermaking,spinning,industrial application, etc. lithium/N,NDimethylacetamide chloride(LiCl/DMAc) mixture is a popular solvent system used for cellulose dissolution and analysis. However, a pre-treatment (activation) procedure is needed for most celluloses to dissolve readily in DMAc/LiCl. Alkali treatment is the most research and the most widely used method. Feng [5]observed that the effect of high temperature (100 to 180℃ alkali treatment (NaOH, 5%, 7%, 9%, 11%) on hemp fiber composition and structure, indicating that high temperature alkali treatment can effectively remove hemicellulose fibers, lignin and pectin, hemicellulose and lignin content were decreased by 79% and 83%. LiCl/DMAc system can dissolve macromolecular (Mw>106) cellulose.The degradation of cellulose in solution was not degraded. The solution viscosity at room temperature changed little with time extension and solvent was easy to be recycled. NG. Tsygankova et al[6,7,8] put forward a view that when the concentration of LiCl in LiCl/DMAc solution is 10%, the solution has the best dissolution performance. Wan hejun [9] used natural color cotton cellulose for electrospinning and Wang Yan [10] et al used LiCl/DMAc solvent system to dissolve the wood cellulose for functional materials modification. This study mainly investigated the activation and dissolution of the hemp fiber, and characterized the properties of the dissolved fiber before and after dissolution.

Corresponding author. Tel.: + 86-13821097512 E-mail address: zhongzhili@tjpu.edu.cn;minmin11012@126.com

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2.Experimental 2.1.Materials and methods Native hemp fibers used here obtained from original plants(Beijiang SP,China). Alkali (Fengchuan)was used as received.The samples of hemp celluloses were submeraged in 18% NaoH solution at 60℃ for 1-4h. The alkali-swollen materials were washed with distilled water until the pH of the distilled water was unchanged. After that, the samples were washed with DMAc for twice and dried at 60 ℃ for at least 6h until their weight were constantly. The samples were cooled to room temperature for next step. N,N-dimethylacetamide

（DMAc,Fengchuan）was used as received.Lithium chloride(Kemiou,SP) was dried at 80 ℃ in vacuum for 6h prior to use. 10% lithiumchoride/N,N-Dimethylacetamide（LiCl/DMAc）stock solution (100ml) was added into the glass reactor with a magnetic stirring and heated at a water bath temperature of 70,80,95℃. Native hemp fibers (0.2g) was added into the glass reactor stiring for 2h. Then the reaction mixture was cooled to room temperature and allowed to stir 2h. This step was to study the appropriate dissolution process. Then the finaly experimental program was as follows: Alkali activated 2 h or 3h samples of hemp fibers were used here. dried alkali-actived hemp fibers(0.2g-1.2g) was introduced into 10% LiCl/DMAc stock solution (100ml) and heated at 95℃water bath for 0.5h with a magnetic stirring. After that the mixture was cooled to temoerature and allowed to stir 2h or 3h.

2.2.Evaluation of dissolution property The samples surface morphology were examined by scanning electron microscopy (SEM) with a TM1000 microscope(rili,Japan). The samples were fixed on a conductive,double adhesive carbon tap that was cover with 4 nm platium layer by a vacunm sputter in order to limit samples damage and electron beam-caused charging.The accelerating voltage was at15-30kV. A Bruker TENSOR37 Fourier transforminfrared spectroscopy(FTIR) was used to record the FTIR spectra with a wave-number resolution of 4 cm-1. Instrument type was D8 DISCOTER with GADDA(BRUKER AXS,AMERICA). X-ray deiiraction was employed to determine crystallite size of untreated and activated native hemp celluloses. The test condition was 40 kV, 40 mA, and ì(CuKR) ) 0.154 nm.The viscosity of solution was determined with a rotary viscometer (model NDJ79) at room temperature.

3.Results and discussion 3.1.SEM analynis The surfaces of hemp fibers treated with 18%NaOH at 60℃for different time were observed by SEM .From the SEM micrographs in Fig1, it could be found that the surface of untreated hemp was smooth and complete, the defects were few and the solubility was poor. The diameter of hemp fibers was about 10-20μm by test. While the appearance of hemp fibers changed a lot after activation treatment. After alkali activation, the fiber samples swelled, the structure became loose and the surface of the fiber appeared crack, some fibers were broken, and the surface area was enlarged. As the changes of samples improved the accessibility of cellulose and the dissolution of fiber. From the SEM picture, it was found that the reactivity and solubility were improved with the extension of activation time.

Untreated

1h 2h 3h Fig. 1: SEM micrographs of untreated and alkali-activated cellulose samples

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3.2.FTIR analysis The FTIR spectra of the hemp fibers with different treatment time were illustrated in Fig.2. The absorption peak of hemp fibers had no significant change with alkali activition except several major absorption peaks. For hemp fibers, FTIR investigations mainly focused on the bands of 3000-3600 cm-1and 1330-1215 cm-1 [11]. The corresponding spectra from 3600 to 3000 cm-1 were assigned to -OH stretching region. Figure 4 shows the IR absorbance bands for -OH stretching region about 3480 cm-1.The peak of the infrared spectrum of the fiber after NaOH activation was more steep and the depth was larger. NaOH pretreatment destroyed the hydrogen bond between the molecules in the fiber, weakened the stretching vibration of the fiber and decreased

the internal bond, which facilitated the dissolution of the fiber. There appeared new feature absorption peak at 894cm-1 after alkali activation. In addition, the changes of characteristic peak was the most obvious when fibers was treated with 3h alkali treatment.It improved the dissolution of hemp fibers largely. (a)2h alkali treatment (b)3h alkali treatment Fig.2: FTIR spectra

Fig.3: X-ray diffraction pattern

Fig.4 :FTIR of mixed solution solution

3.3.X-ray Diffraction X-ray diffraction pattern from untreated and alkali activated fibers were shown in Fig.3. The peak at about 2θ=21° was from cellulose and this peak can be attributed to cellulose crystals. Hemp fibers were consist of cellulose,hemicellulose,lignin and some others. The hemicelluloses and lignin were considered to be located in the amorphous region. After the alkali treatment, the hemicelluloses and lignin were removed and the crystal degree increased. As shown in Fig.5, the untreated hemp fibers exhibited low crystallinity, while the crystallininy of hemp fibers increased after activation[12]. The X-ray diffraction pattern of the alkali treated cellulose was the mixed diffraction peak of the two crystal types of celluloseⅠand celluloseⅡ. Compared with the raw material cellulose, the crystallinity of cellulose was changed, and the crystal surface spacing became small. The cellulose I was converted to celluloseⅡ by sodium hydroxide solution. The length of the activation time had no significant effect on the crystal form of cellulose.

3.4. Cellulose dissolution in LiCl/DMAc When 0.2g native hemp fibers were used to study solubility , it was found that it was insoluble at 70℃, partially dissolved at 80℃ and completely dissolved at 95℃. it could be observed that the dissolution property of cellulose increased with the increase of temperature,the osmotic ability of [DMAcLi]+ to the cellulose feedstock was enhanced in the solvent system. The structure was destroyed faster of the cellulose. The solubility was improved with the destruction of hydrogen bond between the cellulose molecules inside and outside. The higher the degree of crystallinity of cellulose, the higher the temperature required. The reason was that the initial reaction of the entropy of activation was positive, cellulose structure changed from regular structure of high degree of crystallization to disordered amorphous type, temperature improved to accelerate the molecular motion, leading the system towards the direction of entropy increase. The solubility of hemp fibers after 2h activation was about 1.0-1.2g ,and the solubility after 3h was about 1.2-1.5g. So it can be concluded that the dissolution effciency of 3h activation was higher than that of 2h’s.Through the dissolution process, heating and stirring made hemp fibers destroyed more obviously and completely. Cooling and stirring fibers shorten the period of complete dissolution relatively. When treated with the same experiment method, Untreated samples were almost insoluble.The dissolution property of the activated cellulose was significantly better than that of the non activated cellulose. The reason was that the

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activation of hemp fiber weaken the interaction between the molecules and the microstructure of the cellulose, which increased the cellulose s olublity. From table 1, the viscosity of cellulose/DMAc/LiCl solution increased with the increase of the concentration of dissolved fiber. In the case of the same dissolution conditions and fiber concentration, the viscosity of 2h activated cellulose solution was significantly higher than that of 3h. And in the same dissolving conditions and concentration, 3h activated cellulose had an increasing trend of solution viscosity compared to 2h activated cellulose. Under the same dissolution conditions, longer activation time can improve the dissolution property of cellulose. And the cellulose was dissolved more thoroughly. After 1 weeks of static test, the viscosity of cellulose /DMAc/LiCl solution was not changed obviously, indicating that the dissolution system of LiCl/DMAc had good stability. Table 1: Viscosity test results cellulose /DMAC/LiCl solution Treatment method Alkali activation 2h Alkali activation 3h Fiber quality (g) 0.2 0.4 0.6 0.8 1.0 0.2 0.4 0.6 0.8 1.0 Viscosity value 42 55 65 80 95 55 64 77 80 85 Fig.4 showed the FTIR spectrum of cellulose /DMAC/LiCl solution. It changed slightly compared to the original Beijiang hemp. The characteristics of cellulose absorption -OH peak position changed little from 3417cm-1 to 3405 cm-1. But the absorption peak became wider, and the absorption intensity was greatly reduced. There were new absorption peak at 1626 cm-1,1508 cm-1 and 1403 cm-1, which was the characteristic peaks of amide. So it can be judged that broad absorption peak at 3405 cm-1 was no associating -NH peak actually and the -OH peak had actually been weakened. This showed that in the mixed solution of cellulose, cellulose -OH effect weakened obviously and association reduced. Namely intermolecular hydrogen bonds received damage, that is to say, the crystalline regions of cellulose in the solution were destroyed obviously.

Conclusion The morphology and molecular structure of the hemp fiber had changed a lot after alkali activation. Fiber surface was destroyed and the cellulose crystal form was changed from celluloseⅠto cellulose II. The degree of the polymerization of the hemp fiber was decreased, the hydrogen bond was destroyed and the dissolution property was increased. Activation time had effect on the morphology while no effect on cellulose crystal.When treated in 10% LiCl / DMAc solution, 95 ℃ for 0.5 h, cooled to room temperature and stirred for 2h, hemp fibers had the best dissoluvability.Hemp fibers could be dissolved1.0-1.2g for activated 2h and 1.2-1.5g for activated 3h in 100ml LiCl/DMAc soluble system. The solubility and viscosity of hemp cellulose increased with increasing activation time. The viscosity of the fiber is not changed obviously even in a week,so the LiCl/DMAc system of cellulose has good stability.

References [1] Zhang Jianchun.The structure and properties of hemp fiber. [M]2009.4:55～56. [2] Ni Yan, Ke Qinfei, Feng Yun. [J]. Textile industry and technology, 2013,01:21-23. [3] Gong Fei. [J]. Shandong Textile Science and technology, 2010,03:48-50. [4] Zhou Yongkai, Zhao Li, Zhang Jianchun. [J]. China hemp industry, 2005,05:259-264. [5] Yu Chunhua, Feng Xinxing, Jia Changlan, Chen Jianyong. [J]. Journal of textile industry, 2006,10:80-83. [6] McCormick C L, Callais P A, Hutchinson B H. [J]. Polymer Preprint, 1983, 24: 271 [7] N G Tsygankova, D D Grinshpan, A O Koren.[J]. Cellul Chem Technology, 1996(30): 357- 373. [8] Albin F, Turbak. Recent developments in cellulose solvent systems[J]. TAPPI, 1984(67): 94. [9] Wan Hejun, You Lixia, Xiong Jie, Zhou Wenlong. [J] Journal of textile industry. 2010,06:11-16. [10] Wang Yan, He Jing, Lu Ting, Pu Wen. [J]. Journal of beijing forestry university, 2006,01:114-116. [11] Hongling Liu, Lingling You, Hongbin Jin.[ J]. Fibers and polmers 2013,Vol.14,No.13.

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[12] Alfred J. Stamm Fundamental physical approach to wood and cellulose science[J] 1964,Vol.41,198.

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The 13th Asian Textile Conference Geelong, Australia, November 3 - 6, 2015

Facile manipulation of silk fibroin hydrogel property by molecular weight control Hyung Hwan Kim, Dae Woong Song, Jong Wook Kim, Chang Seok Ki, Young Hwan Park + Department of Biosystems and Biomaterials Science and Engineering, Seoul National University, Seoul, Republic of Korea

Abstract. Silk fibroin (SF) is the fibrous protein that it plays the critical role in the structural features of cocoons. This SF can be isolated by removing SS at the boiled weak alkaline solution conditions, so we called degumming. Among many natural polymers, SF has the excellent biocompatibility and biodegradability in addition to superior mechanical strength. In this reasons, many researches were progressed to use SF for applying biomaterial fields. Hydrogel has a network structure made by physical or chemical crosslinking of hydrophilic polymer chain and shows high water contents. Hydrogel has been studied in tissue engineering filed due to its pore structure which promotes exchange of small molecules, such as water, nutrients, wastes and ions, and its structural similarity to extracellular matrix. SF can form hydrogel by physical crosslinking induced by structural transition from random coil to beta-sheet. There have been many researches on the effects of gelling conditions (temperature, pH and additives) and chemical or mechanical stimuli (alcohol treatment or sheer stress like ultrasonication) on the physical properties and gelling behavior of SF hydrogel. However, until now, there is no study about the effect of molecular weight on physical properties of SF hydrogel. In this study, we fabricated the various molecular weight ranges of SF hydrogel. Also, we investigated the effect of molecular weight on the physical properties of SF hydrogel. Keywords: silk, hydrogel, molecular weight

1. Introduction Silk fibroin (SF) is a major protein, which plays a critical role in both structural feature and mechanical property of silk cocoons. To date, it has been widely reported that SF shows excellent biocompatibility as well as superior mechanical property in biomedical applications.[1-3] SF can be fabricated into various forms (e.g., film, nanofiber, sponge, hydrogel). Especially, SF hydrogel has been recently received great attention in tissue engineering field. The properties of SF hydrogel are affected by a wide variety of processing parameters, such as concentration of SF solution, incubation temperature, vortexing time, and ultra-sonic power. Although the significant few studies to manipulate SF hydrogel properties were reported, none of processing variables could elicit the change of a wide range in mechanical as well as physical properties except the concentration of the precursor SF solution. Hence, in this study, we conducted the heat-alkaline treatment (HAT) during the SF dissolution step and formed SF hydrogel by ultra-sonication, followed by physical and mechanical property analyses to investigate the effect of molecular weight of SF on the hydrogel formation. Especially, we tried to focus on the change of the hierarchical microstructure of SF hydrogel according to molecular weight variation, which allows the wide range property control of the hydrogel.

2. Materials and methods 2.1. SF hydrogel fabrication Bombyx mori cocoons were boiled to remove the sericin. Fully-dried degummed SF was dissolved in 9.3M LiBr solution. Molecular weight was controlled by using sodium hydroxide solution. Residual ions were

Corresponding author. Tel.: + 82-2-880-4622. E-mail address: nfchempf@snu.ac.kr.

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dialyzed using dialysis tube for 3 days. To initiate the gelation of SF solution, ultra-sonication was performed. The treatment was conducted in an ice chamber to prevent the heat elevation during ultra-sonication.

2.2. Molecular weight determination The molecular weight of SF was measured by gel filtration chromatography (GFC). The elution of SF was detected at 280 nm. The molecular weight of SF was determined by a calibration curve, which was obtained by a standard globular protein kit.

2.3. Swelling behavior The dried gels (W d0 ) were incubated in de-ionized water at 37°C for 24 h and washed several times. The swollen gels were then re-dried in vacuum for 24 h and its dry-weight (W d1 ) was measured. The gel fraction was obtained by following equation (1). Gel fraction (%) = W d1 /W d0 ×100 (1) The samples were incubated in pH 7.4 PBS at 37°C for 24 h. Then, the samples were weighted to obtain swollen weight of hydrogel (W s ). The swollen hydrogels were washed to remove the residual ions of PBS for 24 h using de-ionized water, followed by vacuum drying and dry weight (W d ) measurement. The equilibrium mass swelling ratio of SF hydrogel was defined as following equation (2). Swelling ratio (Q) = W s /W d (2)

3. Results and discussion 3.1. Effect of alkali hydrolysis on molecular weight of SF Fig. 1 revealed molecular weight distributions of hydrolyzed SF with different hydrolysis times. The intact SF (L0) showed a relatively narrower single peak at around 8.2 mL (~443 kDa), which is attributed to the molecular weight of SF heavy chain. As the hydrolysis time increased, the first shoulder peak at 9.5 mL (~200 kDa) appeared. With further time progression, the second shoulder peak developed at 14.0 mL (~17 kDa) while the intact SF peak at 8.2 mL gradually decreased. Hence, this hydrolysis was adequate strategy for preparing the hydrolysed SF solutions.

Fig. 1: Gel filtration chromatograms of hydrolyzed SF.

3.2. Effect of molecular weight of SF on hydrogel properties Fig. 2A and 2B presents gel fraction and equilibrium swelling ratio, respectively. The gel fraction linearly decreased with Mn of SF. On the contrary, the swelling ratio increased as Mn of SF decreased. Consequently, the lower molecular weight of SF did not efficiently form a hydrogel due to a lack of gel formation ability.

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Fig. 2: (A) Gel fraction and (B) equilibrium swelling ratio of SF hydrogels formed of different molecular weights of SF.

4. Conclusion We successfully manipulate the molecular weight of silk hydrogels with various molecular weight ranges. We found that solution properties and hydrogel properties (gel point, gel fraction, and swelling ratio) were critically affected by molecular weight variation. We expect that these results provide the novel information about the properties of SF hydrogel with different molecular weight.

5. References [1] Kundu, B et al, Prog. Polym. Sci. 2014, 39, 251-267. [2] Kundu, B et al, Adv. Drug Delivery Rev. 2013, 65, 457-470. [3] Pritchard, E. M et al, Expert Opin. Drug Delivery 2011, 8, 797-811.

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The 13th Asian Textile Conference Geelong, Australia, November 3 - 6, 2015

Functional Modification of Coir Fibre for Enhanced Oil Absorbency Prof. (Dr.) M.D. Teli1 Sanket P. Valia2 1,2

Department of Fibres and Textile Processing Technology, Institute of Chemical Technology, Matunga (E), Mumbai-400019, India

Abstract. The globalized world trade is based on fierce cost competitiveness of the high quality finished product. Most of the raw materials required for manufacturing such products are petroleum based which are obtained from crude oil. Lack of availability, limit on the production capacity and wastage caused by unintentional spills in the ocean or land has resulted in escalating the price of crude oil. In addition to the economic losses rigorous environmental problems around the world are caused due to the pollution resulting from oil spills. This paper focuses on work relating to environmental remediation by developing ecofriendly natural fibrous oil sorbent which can be used to recover the oil and also reuse the sorbent. In this paper coir which is a lignocellulosic fibre obtained as a waste from coconut fruit was modified to increase the hydrophobicity and oil sorption capacity. The product so formed was characterized by FT-IR, TGA and SEM which confirmed grafting of butyl acrylate monomer on to the coir fibres. The effects of time, temperature and monomer concentration on the grafting of coir fibre and oil absorption capacity have also been investigated. Results demonstrated that the modified coir fibre absorbed fair amount of crude oil and studies also indicate that a simple squeezing was sufficient to remove most of the oil sorbed by the fibres so that the sorbents can be reused several times for oil spill clean-up.

Keywords: Coir, grafting, oil absorption, FT-IR, TGA, SEM

1. Introduction The term â&#x20AC;&#x153;environmental damageâ&#x20AC;? includes short-term and long-term effects on the natural, physical, economic and social environment (including risks to human health) that may be attributable to the spill or from subsequent spill response activities. Oil spills pose a threat to the environment and is a potential for damage. The actual damage caused, is a major public concern. Accidents involving tankers, pipelines, refineries, drilling rigs, and storage facilities are some of the causes of oil spills into rivers, bays and the ocean. These oil spills greatly affect aquatic life as well as animals, which may in turn lead to these species getting endangered. Animals may be affected because oil spills may cause hypothermia, inducing low body temperatures. Oil may also enter the lungs or livers of animals, finding entry into the food chain and thus in turn poisoning them [1]. The use of sorbents made from organic material does not cause additional problems in the disposal of the spilled oil [2]. Previous studies have proved that natural sorbents made from ligno cellulosic waste fibres such as jute, banana have high efficiency of oil absorption and at the same time, they are most eco-friendly and cost effective due to their reusability [3, 4]. New materials can be developed by grafting natural fibres with vinyl monomers that has property of both natural and synthetic polymers. Coir is one of the lignocellulosic natural fibre which nowadays is extensively used in many applications. Coconut, the fruit of Cocos nucifera, is a tropical plant of the Arecaceae (Palmae) family and abundantly grows in coastal areas of tropical countries. The chemical composition of coir fibre is as shown in Table 1 [5]. Table 1 Chemical composition of coir fibre Cellulose (%) Hemicellulose (%) Lignin (%) Extractive (%) Ash (%)

46.2 13.1 32 6.1 2.6

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This paper reports the work done with an aim of improving the oleophilicity of the coir fibre and thus improving the oil absorption capacity. For this reason the fibres are grafted with butyl acrylate monomer in presence of crosslinker to react with hydroxyl group in the cellulose and form esters. The reaction conditions were optimised in such a way that the weight percentage gain (graft add-on) of synthetic graft polymer chain in the final product was kept optimum, both for economic reasons and to allow some swelling of individual fibres in water.

2. Materials and Methods 2.1. Materials Coir fibre was obtained from CIRCOT (Mumbai, India). The fibre was cleaned manually and washed with distilled water to remove dirt, mud and other water soluble impurities. These fibres were dried in hot air oven at 600C for 24h. Butyl acrylate monomer, Potassium per sulphate, N, N-methylene-bis-acrylamide and all other chemicals were purchased from S.D Fine Chemicals, Mumbai, India. High density oil used for the testing purpose was supplied by HPCL, India.

2.2. Methods 2.2.1 Graft copolymerization of butyl acrylate on to coir fibre The grafting reaction was carried out in a three neck round bottom flask. To control the reaction temperature, the flask was placed in a thermo stated heating mantle. The required weight of coir fibres and butyl acrylate monomer were taken in the flask and agitated for 10min. The cross linking agent N, N-methylene-bis-acrylamide and initiator potassium per sulphate were then added to the flask. The reaction was carried out under nitrogen atmosphere and the mixture was stirred continuously for the optimised time. The homopolymer formed during the graft-copolymerization reaction, was separated from the grafted copolymer by stirring for 12h in ethyl alcohol for complete removal of homopolymer and then dried in oven at 500C. Graft add-on (%) is calculated as followsW2 − W1 × 100 Graft add − on (%) = W1 Wherein, W 1 and W 2 are the weights of coir fibre and grafted coir fibre, respectively.

2.2.2. Oil absorption capacity Oil absorptivity was determined by using method reported in literature [6].

2.2.3. Recovery of sorbed oil and reusability of sorbents In order to examine the reusability of these sorbents, method described in literature [7] was followed.

3. Chemical characterization The IR spectra of original and grafted fibres were recorded using FTIR spectrophotometer using ATR sampling technique. Thermal gravimetric analysis (TGA) of the fibres was carried out by regular method. The thermograms of samples were recorded on Shimadzu 60H DTG machine using aluminum pans between temperature range 30550oC and under the inert atmosphere of N 2 at a flow rate of 50ml/min. SEM analysis of the grafted samples, to study the morphology of dried and modified sample was carried out. The samples were sputter coated with gold layers and images were recorded using scanning electron microscope.

4. Results and Discussion The effects of various parameters on the graft add-on and oil absorption of butyl acrylate monomer onto the coir fibre have been summarized in Table 2. Graft add-on increased with increase in grafting time from 2 to 4h. This may be due to the increase in the number of grafting sites in the initial stages of the reaction and also due to the higher amount of initiator participating initially in formation of reactive sites on the cellulose backbone. However, after 3h reaction time, there was no further significant increase in graft add-on. The graft add-on increased with an increase in temperature from 60°C to 70°C. On further increase in temperature the graft add-on remained more or less constant. The increase in graft add-on with temperature in the initial phase is attributed to the higher rate of initiator dissociation, as well as to the higher diffusion and mobility of the monomer from the aqueous bulk

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phase to the cellulosic fibre phase. Also at higher temperature homopolymer formation is more, therefore 70oC temperature was taken as optimised temperature. The oil absorption capacity of this grafted fibre was maximum i.e. 13.45g/g. Graft add-on increased significantly with increase in monomer concentration from 100 to 150%. This is attributed to the higher availability of the monomer in the reaction bath for grafting. As the concentration was increased to 200%, only a slight increase in graft add-on was seen indicating the exhaustion of the available sites for reaction. The oil absorption capacity increased drastically after modification to the tune of 275% because of grafted poly butyl acrylate coir fibre is oleophilic in nature and the network polymer structure formed due to crosslinking makes it more efficient for oil absorption. Table 2 Effect of different parameters on grafting of coir fibres and oil absorption Sr. No.

Time (h)

Temp 째C

Monomer concentration (%)

Effect of Time 1 2 70 150 2 3 70 150 3 4 70 150 Effect of Temperature 4 3 60 150 5 3 70 150 6 3 80 150 Effect of Monomer Concentration 7 3 70 100 8 3 70 150 9 3 70 200

Initiator (%)

Cross linker (%)

Graft addon (%)

Oil Sorption (g of oil sorbed/g of fibre)

0.1 0.1 0.1

0.05 0.05 0.05

13.86 15.53 15.15

10.68 13.45 13.31

0.1 0.1 0.1

0.05 0.05 0.05

12.75 15.50 15.31

9.39 13.45 13.12

0.1 0.1 0.1

0.05 0.05 0.05

10.28 15.54 15.58

8.22 13.45 13.31

As seen from the Fig. 1 the FTIR spectrum of the modified (grafted) fibre shows a sharp peak at 1730 cm-1 which is absent in unmodified fibre. The peak clearly indicates the introduction of ester group in the grafted fibre which makes the fibre more hydrophobic and oleophilic.

Fig.1 FT-IR spectra of unmodified and modified (grafted) coir fibre

Fig. 2 TGA of unmodified and modified (grafted) coir fibre

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It is seen from the Fig.2 that the thermal stability of modified fibres has increased as compared to that of unmodified fibre. From Fig. 3a and 3b it can be seen that there is a significant difference in the surface of the coir fibre. Heterogeneous grafting of butyl acrylate on the fibre has made the fibre more bulky and hydrophobic and this in turn makes it good material for absorbing oil.

Fig. 3a SEM of unmodified coir fibre

Fig. 3b SEM of modified coir fibre

Coir fibres on grafting with butyl acrylate gives oil absorption of 13.45g/g which is significantly higher (275% increase) than that of unmodified coir fibre (3.58g/g). The modified coir fibres oil absorption is also higher than that of polypropylene fibre (10g/g) which is mostly used in commercial products for combating oil spill. This is due to the hydrophobicity imparted as a result of modification with butyl acrylate monomer; also the crosslinker used in the reaction helps in forming the interpenetrating network which helps in holding the oil absorbed. Results from Table 3 indicate that the fibres can be reused for at least 3 times before disposing them. Table 3 Reusability of modified (grafted) coir fibre Oil sorbed, Residual oil in fibre g of oil/g of fibre g of oil/g of fibre (g/g) (g/g) First cycle

13.45

3.24

Second cycle

9.21

2.77

Third cycle

7.67

2.03

5. Conclusions Coir fibres were successfully grafted with butyl acrylate monomer using potassium persulphate as initiator and N, N-methylene-bis-acrylamide as crosslinker. Oil sorption capacity of the fibres increased with increase in weight percent gain (graft add-on) and in turn the extent of butyl acrylate grafting on the fibre increased with increase in time, temperature and monomer concentration imparting hydrophobicity to the fibre. FT-IR and SEM analysis confirmed the grafting of coir fibres with butyl acrylate monomer. Based on these results, it is undoubtedly true that the modified fibres could be used for the cleanup of oil spilled in aquatic environments.

6. References 1. https://oilsplat.wordpress.com/about/ 2. Pasila A. (2000). The effect of frost on fibre plants and their processing. Molecular Crystals and Liquid Crystals Science and Technology, Section A: Molecular Crystals and Liquid Crystals. 535, 11 â&#x20AC;&#x201C; 22. 3. Teli, M. D., & Valia, S. P. (2013). Acetylation of Jute fiber to improve oil absorbency. Fibers and Polymers, 14(6), 915919. 4. Teli, M. D., & Valia, S. P. (2013). Acetylation of banana fibre to improve oil absorbency. Carbohydrate polymers, 92(1), 328-333. 5. Khalil, H. S. A., Alwani, M. S., & Omar, A. K. M. (2007). Chemical composition, anatomy, lignin distribution, and cell wall structure of Malaysian plant waste fibers. BioResources, 1(2), 220-232.

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6. Sun, X. F., Sun, R. C., & Sun, J. X. (2004). Acetylation of sugarcane bagasse using NBS as a catalyst under mild reaction conditions for the production of oil sorption-active materials. Bioresource Technology, 95, 343â&#x20AC;&#x201C;350. 7. Choi, H. M., & Moreau, J. P. (1993). Oil sorption behaviour of various sorbents studied by sorption capacity measurement and environmental scanning electron microscopy. Microscopy Research and Technique, 25, 447â&#x20AC;&#x201C;455.

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The 13th Asian Textile Conference Geelong, Australia, November 3 - 6, 2015

In-situ analysis of fiber structure development in CO 2 laser-heated drawing of syndiotactic Polystyrene Fiber KyoungHou Kim 1, Gaku Matsuno 1, Toshifumi Ikaga 1, Yutaka Ohkoshi 1, 2 + , Takeharu Tajima 3, Hideaki Yamaguchi 3, Isao Wataoka 4 1

Faculty of Textile Science and Technology, Shinshu University, 3-15-1 Tokida, Ueda City, Nagano 3868567, Japan 2 Division of Frontier Fibers, Institute for Fiber Engineering, Shinshu University, Japan 3 Idemitsu Kosan CO., Ltd., Japan 4 Faculty of Engineering and Design, Kyoto Institute of Technology, Japan

Abstract. Syndiotactic polystyrene (sPS) which is known as a crystalline polymer was melt-spun and laserheated drawn to various draw ratios. Initial process of the fiber structure development was characterized by the in-situ WAXD/SAXS measurements using an ultrahigh luminance X-ray beam of SPring-8 during the laserheated drawing. By the WAXD patterns, it was revealed that a low oriented amorphous phase of as-spun fiber was oriented to the fiber axis by necking. The oriented amorphous phase was transformed into a mesomorphic form just after necking, and transformed again into Îą-crystal. By the SAXS result, two-point SAXS pattern corresponding the long-period structure appeared after neck-drawing, and disappeared with the cooling of fiber because the small difference of molecular density between amorphous and crystal phases at room temperature. The maximum SAXS intensity showed at the shorter elapsed time with increasing draw ratio. The obtained long-period also increased with the draw ratio, and also increase with the elapsed time.

Keywords: fiber structure formation, syndiotactic polystyrene fiber, laser drawing

1. Introduction Syndiotactic polystyrene (sPS) is an ordered structure with the phenyl group positioned on alternating sided of the hydrocarbon backbone. Our research group has produced a sPS fiber by melt spinning and drew to high draw ratio (draw ratio 5) by laser-heated drawing. The laser-heated drawn sPS fiber attained 400 MPa in tensile strength, which was much higher than the highest one reported previously, 200 MPa [1]. But the mechanism for high strength sPS fiber has not been known yet. Our research group has succeeded in an in-situ measurement of structure development around the location where the necking occurs during a laser-heated drawing. The location is fixed within almost 0.2 mm because the laser irradiation enables rapid and homogeneous heating of the running fiber without contact. We have reported on the in-situ measurement of neck-drawing behavior, fiber temperature, and WAXD/SAXS as a function of elapsed time after necking occurrence. In particular, by utilizing the ultra-high luminance synchrotron radiation of SPring-8, we have analyzed the structure development of poly(ethylene terephthalate) (PET) [2~4], poly(trimethylene terephthalate) (PTT) [5], poly(ethylene naphthalate) (PEN) [6, 7], poly(butylene terephthalate) (PBT) [8], polypropylene (PP) [9], poly(vinylidene fluoride) (PVDF) [10], and polyphenylene sulfide (PPS) [11] monofilaments. In this study, by wide-angle and small-angle X-ray scatterings (WAXD/SAXS) using synchrotron radiation of SPring-8, the initial stage of fiber structure development is studied and in particular the fiber +

Corresponding author. Tel.: +81-268-21-5364 . E-mail address: yokoshi@shinshu-u.ac.jp

Page 585 of 1108

structure development and the mechanism of high strength fiber production with changing draw ratio are analyzed.

2. Experimental sPS resin (XAREC 90ZC, Mw=200,000) provided by Idemitsu Kosan Co., Ltd. was melt-spun through a nozzle of single hole (1.0 ϕ) with a mass flow rate 2.0 g/min and a take-up speed 120 m/min at spinning temperature 310°C. An as-spun sPS fiber was 148±3 µm in diameter. The fiber was drawn using a laser-heated drawing system, and WAXD and SAXS were on-line measured during the drawing, as shown in Fig.1. The running sPS fiber was heated through three-directional irradiation that is minimized the cross-sectional distribution of temperature in the fiber, and was drawn by means of a speed differential between the feed and take-up rollers. WAXD and SAXS images were obtained as a function of elapsed time (t) after necking, which was calculated from distance (D) between measurement and necking point. The applied wavelengths were 0.08 nm and 0.15 nm and the sample-to-detector distances were 318 mm and 1158 mm for WAXD and SAXS measurements, respectively. Time resolution, which was obtained by dividing position resolution of necking by fiber running speed, was 0.27~0.32 ms. For the drawn sPS fibers, tensile tests and birefringence measurements were conducted.

Fig. 1: Schematic diagram of in-situ measurement system.

3. Results and Discussion WAXD intensity profiles along equatorial direction, which were from WAXD images taken at various elapsed times, are shown in Fig.2. The origin of the elapsed time was defined as the time of necking. Amorphous halos were observed around 2θ=5° and 10°, broad peak of hexagonal mesomorphic form appeared after necking around 2θ=6°. The (110) diffraction of α-crystal appeared at 0.77 ms, and its (220) and (300) diffractions were separated from the mesomorphic peak after 2.1 ms. As a result, it was revealed that the low oriented amorphous phase of as-spun sPS fiber was oriented by the neck-drawing, and the oriented amorphous phase transformed into α-crystal by way of mesomorphic form. Fig. 3 showed SAXS images obtained for draw ratios of 4.3, 4.5, and 4.6. For all drawn ratios, although the intensity was very weak, meridian two-pointed scattering pattern of long-period structure appeared after 2.0 ms. This scattering pattern was able to be observed until 16 ms after neck drawing, but it almost disappeared for drawn fibers. By the increase of draw ratio, SAXS intensity took the higher maximum at the shorter elapsed time. The higher drawing stress would promote the formation of long-period structure. The disappearance of the two-point scattering seems to be caused by the decrease of density difference by cooling. Because the density of crystal and amorphous phases at room temperature is 1.033 and 1.045 g/cm3, respectively, the scattering hardly observed at the lower temperature, while it could be observed at the higher temperature over 200°C. By treated meridian SAXS intensity profiles with Debye-Bueche model and applied Lorentz correction [12~14], a corrected long-period was obtained and shown in Fig. 4. It is interesting that the long-period structure was formed during the drawing and increased with the increase of elapsed time, which is the totally opposite tendency with PET [2], PTT [5], PP [9], and PPS[11]. For PET, PPS and PP, the long-period

Page 586 of 1108

decreased with increasing elapsed time. It seems because these crystal structures were developed from the metastable fibrillar structure, the long-period decreases with the growth of additional crystallites. While the case of sPS, the long-period structure seemed to be formed by the axial shift of molecular triplets including crystallites. That is, the long-period seems to be increased with the lined up of crystallites to the lateral direction. Along with the structure development, the amount of taut tie-chains would be increased by the rearrangement of crystallites. The higher draw ratio leads the longer long-period, which indicated the more amount of rearrangement occurring under the higher drawing stress. Accordingly the fiber strength increased with the draw ratio due to an increase in the amount of taut tie-chains.

Fig. 2:WAXD intensity profiles obtained for sPS fibers of draw ratio 4.5. Elapsed times after necking are noted in the

Page 587 of 1108

Fig. 4: Long-period of sPS fibers obtained by the meridional profile of SAXS image.

4. References [1] T. Himeno, T. Ikaga, Y. Ohkoshi, K. H. Kim, T. Tajima, and H. Yamaguchi, Sen’i Gakkaishi, Accepted 11 August, 2015. [2] T. Yamaguchi, K. Kim, T Murata, M. Koide, S. Hitoosa, H. Urakawa, Y. Ohkoshi, Y. Gotoh, M Nagura, M. Kotera and K. Kajiwara, Journal of Polymer Science: Part B: Polymer Physics, 46, 2126 (2008). [3] K. H. Kim, T. Yamaguchi, Y. Ohkoshi, Y. Gotoh, M. Nagura, H. Urakawa, M. Kotera, T. Kikutani, Journal of Polymer Science Part B: Polymer Physics, 47, 1653, (2009). [4] K. H. Kim, T. Murata, Y. Kang, Y. Ohkoshi, Y. Gotoh, M. Nagura, and H. Urakawa, Macromolecules, 44, 7378, (2011). [5] K. H. Kim, Y. A. Kang, T. Murata, S. Ikehata, Y. Ohkoshi, Y. Gotoh, M. Nagura, M. Koide, H. Urakawa, and M. Kotera, Polymer, 49, 5705, (2008). [6] K. H. Kim, R. Aida, Y. A. Kang, Y. Ohkoshi, Y. Gotoh, M. Nagura, and H. Urakawa, Polymer, 50, 4429, (2009). [7] K. H. Kim, R. Aida, Y. A. Kang, T. Ikaga, Y. Ohkoshi, I. Wataoka, and H. Urakawa, Polymer, 53, 4272, (2012). [8] K. H. Kim, Y. A. Kang, A. Yokoyama, T. Ikaga, Y. Ohkoshi, I. Wataoka and H. Urakawa, Polymer Journal, 44, 1030, (2012). [9] Y. A. Kang, K. H. Kim, S. Ikehata, Y. Ohkoshi, Y. Gotoh, M. Nagura, and H. Urakawa, Polymer, 52, 2044 (2011). [10] Y. A. Kang, K. H. Kim, S. Ikehata, Y. Ohkoshi, Y. Gotoh, M. Nagura, M. Koide and H. Urakawa, Polymer Journal, 42, 657, (2010). [11] K. Ide, T. Ikaga, Y. Ohkoshi, I. Wataoka, M. Masuda, and Y. Maeda, Sen’i Gakkaishi, 70, 76, (2014). [12] C. Wang, Y. W. Cheng, Y. C. Hsu, and T. L. Lin, Journal of Polymer Science: Part B: Polymer Physics, 40, 1626 (2002). [13] W. P. Liao, T. L. Lin, E. M. Woo, and C. Wang, Journal of Polymer Research, 9, 91 (2002). [14] C. Wang, W. P. Liao, and Y. W. Cheng, Journal of Polymer Science: Part B: Polymer Physics, 41, 2457 (2003).

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The 13th Asian Textile Conference Geelong, Australia, November 3 - 6, 2015

Investigating drug delivery properties of silk fibres and particles Mehdi Kazemimostaghim1, Rangam Rajkhowa1, Xungai Wang1,2 + 1

Australian Future Fibres Research and Innovation Centre, Institute for Frontier Materials, Deakin University, Geelong, VIC 3217, Australia. 2 School of Textile Science and Engineering, Wuhan Textile University, Wuhan, China.

Abstract. Silk is the only natural textile fibre that has FDA approval for biomedical applications. Particles from silk fibres have been investigated in the areas of drug delivery, tissue engineering and cosmetic medicine. However, there are major challenges in controlling particle size and size distribution, ensuring safety of the process and products, and in achieving structural stability of ultrafine silk particles. Almost all attempts so far to make fine silk particles have used the regeneration approach, which uses chemicals to dissolve silk fibres first and then generate silk particles from the silk solution. The silk fibroin is usually degraded during the process and the chemicals used are also harmful to the environment. We have achieved, for the first time, submicron particles that have a narrow size distribution, and are stable and free from harmful chemical residues with milling method. In this study, milled silk particles with volume median particle size (d(0.5)) of 7 µm and 281 nm as well as silk fibres were used for loading of model drugs Orange G, Azophloxine, Rhodamine B, and Crystal Violet. Loading and release of these chemicals depended on the size of silk particles, pH, and the structure and properties of model drugs. Both fibres and particles could slowly release the drugs over many days at pH 7.4 and 37°C without a significant initial burst release. As particle size decreased, the amount of model drug release also decreased. The release of drugs by the silk fibres was quicker than the silk particles. This process is expected to open exciting opportunities for use of milled silk materials in the biomedical applications.

Keywords: silk particles, drug delivery, silk drug adsorption.

1. Introduction Silk is a biologically derived material which does not produce toxic by-products during decomposition, and have high cellular uptake properties which enhance its efficiency for drug delivery systems [1]. Nanospheres (1-1000 nm) are usually used for short-acting drug delivery systems via intramuscular, intravenous, etc. either as a solid powder or with a liquid carrier [2-4] . Microspheres are generally used as a depot drugs for long lasting delivery and usually administered subcutaneously or intramuscularly [2-4]. Chemical and milling methods can be used to fabricate silk particles from silk fibroin with various properties. In chemical methods, fibroin is dissolved in an aqueous solution of chemicals such as LiBr. After dissolving, it can be converted to silk particles [5]. In milling method, fibroin is processed through different kinds of milling machines to achieve a desirable particle size after cutting to small snippets [6]. Recently, we have reported production of micron and submicron silk particles with volume median particle size from 1000 µm down to 200 nm in aqueous media by a milling method [7, 8]. Submicron silk particles with d(0.5) of 200 nm had almost similar β structure, thermal properties, and crystallinity with silk fibres [9]. Comparison of milling and solution method indicated that particles in solution methods were aggregates with d(0.5) bigger than 40 µm whereas particles prepared by milling were separated with a specific size from d(0.5)= 300 nm and above [10]. Here we present our investigation on loading of model drugs with positive and negative charges on particles prepared by milling. The drug loading kinetics of silk fibres and particles are investigated. In addition, release of model drugs loaded on the milled silk particle is evaluated.

Corresponding author. Tel.: + 61-03-5227 2894. E-mail address: xungai.wang@deakin.edu.au.

Page 589 of 1108

2. Materials and methods 2.1. Materials Model drugs Orange G, Azophloxine, Rhodamine B, Crystal Violet were used in this study. Eri silk was selected as the raw material and sourced from northeast India.

2.2. Silk particle fabrication by milling Fibres, snippets (d(0.5)= 71.11), and particles with d(0.5) of 7.05Âľm and 281 nm were used in these experiments. Cutter mill, attritor mill, and bead mill were used to produce snippets and particles. Details of the powdering processes were reported in our previous work [7]. Mastersizer 2000 (Malvern, UK) was used for determining particle sizes using deionised water as a dispersion media. Fig. 1 indicates the image of silk materials used in this study.

Fig. 1 SEM image of a) fibre, b) snippets, c) 7 Âľm, and d) 281 nm particles.

2.3. Drug loading 50 mL model drug solution was added to reaction tubes containing 50 mg silk fibres, snippets, 7 Âľm powders, or 281 nm silk particles. pH was 2.1, 3.4, 7, and 10. The sample solutions were analysed for their drug concentration using a UV-Vis spectrophotometer by measuring their absorption, after determining Îť max for each model drug. Drug loading (adsorption) and loading (adsorption) efficiency were calculated from the following formulas: %đ??żđ??żđ??żđ??żđ??żđ??żđ??żđ??żđ??żđ??żđ??żđ??żđ??żđ??ż =

đ??´đ??´0 â&#x2C6;&#x2019; đ??´đ??´đ?&#x2018;Ąđ?&#x2018;Ą đ?&#x2018; đ?&#x2018; đ?&#x2018; đ?&#x2018; đ?&#x2018; đ?&#x2018; đ?&#x2018; đ?&#x2018; đ?&#x2018;&#x161;đ?&#x2018;&#x161;đ?&#x2018;&#x161;đ?&#x2018;&#x161;đ?&#x2018;&#x161;đ?&#x2018;&#x161;đ?&#x2018;&#x161;đ?&#x2018;&#x161;đ?&#x2018;&#x161;đ?&#x2018;&#x161;đ?&#x2018;&#x161;đ?&#x2018;&#x161;đ?&#x2018;&#x161;đ?&#x2018;&#x161;đ?&#x2018;&#x161;đ?&#x2018;&#x161;đ?&#x2018;&#x161;đ?&#x2018;&#x161; đ?&#x2018;¤đ?&#x2018;¤đ?&#x2018;¤đ?&#x2018;¤đ?&#x2018;¤đ?&#x2018;¤đ?&#x2018;¤đ?&#x2018;¤â&#x201E;&#x17D;đ?&#x2018;Ąđ?&#x2018;Ą

Ă&#x2014; 100

%đ??żđ??żđ??żđ??żđ??żđ??żđ??żđ??żđ??żđ??żđ??żđ??żđ??żđ??ż đ?&#x2018;&#x2019;đ?&#x2018;&#x2019;đ?&#x2018;&#x2019;đ?&#x2018;&#x2019;đ?&#x2018;&#x2019;đ?&#x2018;&#x2019;đ?&#x2018;&#x2019;đ?&#x2018;&#x2019;đ?&#x2018;&#x2019;đ?&#x2018;&#x2019;đ?&#x2018;&#x2019;đ?&#x2018;&#x2019;đ?&#x2018;&#x2019;đ?&#x2018;&#x2019;đ?&#x2018;&#x2019;đ?&#x2018;&#x2019;đ?&#x2018;&#x2019;đ?&#x2018;&#x2019;đ?&#x2018;&#x2019;đ?&#x2018;&#x2019; =

đ??´đ??´0 â&#x2C6;&#x2019; đ??´đ??´đ?&#x2018;Ąđ?&#x2018;Ą đ??´đ??´0

Ă&#x2014; 100

Where A 0 is the initial model drug concentration on the weight of material (owm) in the reaction solution and A t is the model drug concentration (owm) in the reaction solution at time t after exposure to the silk materials.

2.4. Drug release 5 mg model drug loaded silk materials placed in a vial containing 1 mL PBS solution (pH 7.4). As separation of 5 mg drug loaded fibres was difficult, 50 mg fibres was placed in a tube containing 10 mL PBS solutions. Vail and tubes were constantly shaken in a shaking water bath (Ratek) at 37 Â°C. Supernatants were used for calculating concentration of model drug release after centrifuging vials at 25000 rpm for 10 minutes, and separating fibres from released solutions. Removed supernatants were replaced daily with a fresh solutions. Drug release was calculated from the following formula: đ?&#x2018;&#x2026;đ?&#x2018;&#x2026;0 â&#x2C6;&#x2019; đ?&#x2018;&#x2026;đ?&#x2018;&#x2026;đ?&#x2018;Ąđ?&#x2018;Ą % đ?&#x2018;&#x2026;đ?&#x2018;&#x2026;đ?&#x2018;&#x2026;đ?&#x2018;&#x2026;đ?&#x2018;&#x2026;đ?&#x2018;&#x2026;đ?&#x2018;&#x2026;đ?&#x2018;&#x2026;đ?&#x2018;&#x2026;đ?&#x2018;&#x2026;đ?&#x2018;&#x2026;đ?&#x2018;&#x2026;đ?&#x2018;&#x2026;đ?&#x2018;&#x2026; = Ă&#x2014; 100 đ?&#x2018;&#x2026;đ?&#x2018;&#x2026;0 Where R t was the amount (mg) of drug at time t in the solution, and R 0 was amount of drug (mg) in the silk materials.

3. Results and discussion

Page 590 of 1108

3.1. Equilibrium and binding rate at ambient temperature After finding the appropriate pH for maximum loading of particles, the relative loading of the model drugs on silk materials was compared at room temperature in the appropriate pHs as shown in Fig.2. As seen in Fig. 2, for all model drugs, loading of 281 nm and 7 µm particles completed in 1 h. The loading amount of 281 nm particles and 7 µm particles was not similar for all model drugs. The loading of 281 nm particles was lower than 7 µm particles for Orange G, and the difference in loading declined for Azophloxine. Then it became almost similar for Rhodamine B, and the correlation reversed for Crystal Violet where the adsorption was higher for 281 nm particles compared to 7 µm particles. The reaction rate of snippets is higher than fibres (Fig. 2) indicating easier access of model drug molecules to reaction sites of snippets due to cutting of fibres to small sizes (d(0.5)= 71.11 µm).

Fig. 2 Loading of silk 281 nm particles, 7 µm particles, snippets, and fibres with a) Orange G and b) Axophlexine at pH 2.1; c) Rhodamine B and d) Crystal Violet at pH 7 at ambient temperature as a function of time

Except for Orange G, loading of fibres was lower than powders and snippets even after 72 h at room temperature. To increase drug loading in fibres, higher temperatures were used. Higher temperatures can increase the vibration of model drugs and bring them in the field of short range forces as well as swollen the fibres for better penetration of drug molecules [11]. Maximum adsorption was observed at 40 °C with Orange G (data were not shown). The maximum loading temperature for Azophloxine, and Rhodamine B, and Crystal Violet was 60 °C, and no further adsorption was observed by increasing reaction times beyond 1 hour. The results showed that the increasing of the temperature could increase the loading of fibres significantly to the equilibrium level of the silk 7 µm particles. It also showed that for investigation of the drug loading of a model drug that can tolerate high temperatures, fibres can be used to predict the loading of the silk particles.

3.2. Release of model drugs The in vitro releases of model drugs are shown at Fig. 3. The release of Orange G and Azophloxine are shown at pH 2.1 as the release of these model drugs was very fast at pH 7 and almost all the model drugs were released from fibres in 1 day s. The release study in acidic pH may be useful for some applications. For instance, delivery of the therapeutic to some tumour sites in acidic pH is a key issue [1]. As seen in Fig.3, release of drugs from fibres are the highest among the silk materials, and release from 7 µm particles are higher than 281 nm particles for all model drugs. This trend may be explained due to easier and better availability of reaction sites for drugs when the size of silk materials is smaller. As a result, they produce more stable interactions with silk materials, and the required energy for breaking such interactions is higher. Comparison of Orange G and Axophlexine reveals that at similar period of times the release of Orange G

Fig. 3 Release of a) Orange G and b) Azophloxine at pH 2.1, and c) Rhodamine B and d) Crystal Violet at pH 7 and 37 °C as a function of time.

is higher than Azophloxine. Comparison of the structure of these molecules indicates that Azophloxine have CH 3 CONH- group more than Orange G in its structure thereby allowing stronger hydrogen or Van der Waals bonds with silk materials. Similar trend was also observed for Rhodamine B and Cryastal Violet molecules.

Page 591 of 1108

The chemical structure of Crystal Violet allows better chemical bonds with silk materials, therefor; its release is slower than Rhodamine B molecules. We comapred the release of Rhodamine B and Crystal Violet with the report of Lammel et al.[12] who studied the loading and release of these model drugs on silk particles prepared by solution method. We found no burst release in our experiments for Rhodamine B, and Crystal Violet whereas Lammel et al found that the release of these model drugs was 83% and 17 % for Rhodamine B and Crystal Violet, respectively. In addition, the overall release of Crystal violet was less than their experiments. For example, the release of Crystal Violet in their experiment was ~ 40% after 14 days whereas in the same amount of time the release from milled particles in our experiments was less than 20%. It can be concluded that particles in top-down approach have better release properties due to no burst of model drugs, and lower amount of release compared to particles produced by bottom-up approach. As a constant release was observed with fibres and particles, the results suggest that the silk fibres can be used not only for drug delivery systems but also for predicting the release behaviour of milled silk particles if the real drug could tolerate the high temperature which is needed for loading on silk fibres.

4. Conclusion The loading of 281 nm and 7 Âľm particles was completed at 1 h for all model drugs at ambient temperature while by increasing the size of silk materials the equilibrium time increased considerably. Increasing loading temperature was a successful approach for reducing the equilibrium loading time in the case of fibres. Silk 281 nm, and 7 Âľm particles loaded at ambient temperature as well as fibres loaded at high temperatures indicated a sustained release. Release of silk materials dropped by decreasing particle size, and it was highest for silk fibre. Silk fibre can be used for prediction of the release of model drug behaviour of micron and submicron particles prepared with milling method.

5. References [1] A.B. Mathur, V. Gupta, Silk fibroin-derived nanoparticles for biomedical applications, Nanomedicine, 5 (2010) 807-820. [2] X. Wang, T. Yucel, Q. Lu, X. Hu, D.L. Kaplan, Silk nanospheres and microspheres from silk/pva blend films for drug delivery, Biomaterials, 31 (2010) 1025-1035. [3] R.C. Mundargi, V.R. Babu, V. Rangaswamy, P. Patel, T.M. Aminabhavi, Nano/micro technologies for delivering macromolecular therapeutics using poly(d,l-lactide-co-glycolide) and its derivatives, Journal of Controlled Release, 125 (2008) 193-209. [4] P. Hoet, B. Hohlfeld, O. Salata, J. Nanotoxicol., 2 (2004) 1. [5] J.G. Hardy, T.R. Scheibel, Composite materials based on silk proteins, Progress in Polymer Science, 35 (2010) 1093-1115. [6] R. Rajkhowa, L. Wang, X. Wang, Ultra-fine silk powder preparation through rotary and ball milling, Powder Technology, 185 (2008) 87-95. [7] M. Kazemimostaghim, R. Rajkhowa, T. Tsuzuki, X. Wang, Production of submicron silk particles by milling, Powder Technology, 241 (2013) 230-235. [8] M. Kazemimostaghim, R. Rajkhowa, T. Tsuzuki, X. Wang, Ultrafine silk powder from biocompatible surfactantassisted milling, Powder Technology, 249 (2013) 253-257. [9] M. Kazemimostaghim, R. Rajkhowa, K. Patil, T. Tsuzuki, X. Wang, Structure and characteristics of milled silk particles, Powder Technology, 254 (2014) 488-493. [10] M. Kazemimostaghim, R. Rajkhowa, X. Wang, Comparison of milling and solution approach for production of silk particles, Powder Technology, 262 (2014) 156-161. [11] E.R. Trotman, Dyeing and chemical technology of textile fibres, E. Arnold1984. A.S. Lammel, X. Hu, S.-H. Park, D.L. Kaplan, T.R. Scheibel, Controlling silk fibroin particle features for drug delivery, Biomaterials, 31 (2010) 4583-4591.

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The 13th Asian Textile Conference Geelong, Australia, November 3 - 6, 2015

Modification of chemically stable polymeric materials 62. Improvement of the hydrophilic property of wool fibers and preparation of water-wettable polypropylene and silicone rubber Hitoshi Kanazawa* and Aya Inada Department of Industrial Systems, Faculty of Symbiotic Systems Science, Fukushima University, 1 Kanayagawa, Fukushima, 960-1296, Japan; kana@sss.fukushima-u.ac.jp

Abstract. Polymeric materials such as polyethylene, ultrahigh molecular weight polyethylene and polypropylene, polyethylene terephthalate, silicone resin and fluorocarbon resin, etc. were modified by a new combination method of physical and chemical processes. The modified polypropylene and silicone rubber sheets were wet with water. The present technique was useful for the modification of wool and other chemical fibers. The modified materials could be adhered well to each other or to other materials.

Keywords: modification, hydrophilic property, polyethylene, polypropylene, silicone rubber, adhesion

1. Introduction Polyolefins such as polypropylene (PP), polyethylene (PE), ultrahigh molecular weight PE (UHMWPE) and poly(methyl pentene) (PMP), etc. are chemically stable and hydrophobic. Many techniques were carried out to modify the surface property of polyolefins [1,2]. However, their durable improvement is not obtained. For instance, when PE or PP materials are treated by a plasma or a corona discharge treatments, these materials become wet with water. But the modified property is lost with time. We tried to combine two or three methods, and found that the combination of some techniques was effective for the modification of chemically stable polymeric materials [3,4]. The obtained hydrophilic property was not lost for several years. In addition, a water-based paint coating on the modified materials and a solvent-bonding of silicone rubber tubes to PP tubes are examined.

2. Experimental 2.1 Materials Polymeric materials (forms: film, sheets, boards, rods and tubes), fabrics and fibers were used after washing with methanol. Commercial chemical reagents and hydrophilic reagents were used after a simple purification.

2.2 Treatment Polymeric materials were activated by chemical oxidations, UV irradiation or electrical discharges. The activated polymeric materials were treated with chemical reagents in the presence of catalysts or initiators. These techniques were named as “KANA methods”.

2.3 Water absorption Contact angles of water drops were observed by a Kyowa CA-X apparatus. Modified fabrics or fibers were dipped in water, and the water contents were weighed after a given time.

2.4 Adhesion strength and analysis Adhesives such as polyvinylpyrrolidone (PVP) glue, starch glue, polyvinylacetate (PVAC)-polyvinyl alcohol (PVA) mixture, polycyanoacrylate (PCA), epoxy resin bonds were used to examine the adhesive property of modified polymeric materials. Adhesion shear strengths of polymeric materials bonded to other materials were measured by a tensile tester, Shimadzu AGS-H5KN. +

Corresponding author. Tel.: + 81-24-548-8184.

E-mail address：kana@sss.fukushima-u.ac.jp

Page 593 of 1108

IR spectra were observed by a Shimadzu IRPrestige-21 equipped with a Smiths DuraSampl IR II (ATR accessory). XPS of materials were measured by a Ulvack-Phi, PHI 5000 VersaProbe II.

3. Results and Discussion 3.1 Water Absorption Property PP nonwoven fabrics modified by the present method gave a high water-absorption property (Figure 1). The obtained property has a durability to aqueous alkaline or acid solutions, which is suitable for a battery separator use.

Fig.1 PP non-woven fabrics, left: unmodified PP and right : modified PP. Silicone (Si) rubber has a high water-repellency and its modification is very difficult. We investigated the technique. A part of silicone rubber sheet modified by the KANA method gave a durable water wettability (Figure 2). Poly(methylpentene) (PMP) is one of the most difficult materials to be modified. PMP-made containers were modified by the present method; the inner wall of the modified one is wetted with water (Figure 3).

Fig. 2 Modified silicone rubber sheet wetted with water.

Fig.3 Water-wettability of unmodified (left) and modified (right) PMP resin containers.

The hydrophilicity of wool and chemical fibers were increased well by the present method.

3.2 Water-based paint coating Modification conditions suitable for giving a durable water-based paint coating to hydrophobic polymeric materials were investigated. Figure 4 gives a comparison of the present method and a usual plasma treatment at atmospheric pressure. Silicone rubber sheets treated by a plasma discharge lose the hydrophilic property with time; the modified specimen was not coated with water-based paint at five hours after the plasma treatment. On the other hand, silicone rubber sheets modified by the KANA method were coated well at 110 days after the modification. Such a durable modification might be impossible by usual methods. PMP materials are known to be highly hydrophobic, and they are used as remover materials for adhesive materials. The modification is very difficult by usual methods. Fig. 4 gives the water-based paint coating on an unmodified PMP sheet and a PMP sheet modified by the present method. The modified PMP sheet obtained a full mark, 100/100 in the JIS cross-cut test (peeling test).

Page 594 of 1108

Fig.5 Water-based paint coated unmodified PMP sheet (left) and modified PMP (right).

Fig. 4 Comparison of the water-based paint coating of the silicone rubber sheets modified by the present treatmentFig.6 (bottom row) andused plasma-treated silicone Specimens in the adhesion tensile rubber sheets (upper rows). Numbers indicatesheet the strength test;two upper: modified Si rubber elapsed time aftertoeach treatment. adhered wooden board , under: unmodified Si rubber sheet adhered to wooden board. Adhesive: wood-use glue.

3.3

Adhesion property

It is possible to adhere hydrophilic silicone resins to other materials using any kinds of adhesives. Figure 6 gives the specimens used in the adhesion tensile strength test; upper: a modified silicone rubber sheet adhered to wooden plate with wood-use glue, and lower: modified silicone rubber sheet adhered to wooden plate with wood-use glue. The unmodified silicone rubber sheet gave no adhesion property, but modified one gave a material failure in the shear strength test.

3.4 Solvent bonding Materials modified by the KANA method are bonded to other materials without adhesives; a solvent bonding is possible. Figure 7 gives a connection of poly(butadiene) tube to PP intravenous drip tube by a solvent bonding. This technique is preferable for the production of harmless medical devices.

3.5 Improvement of syringes When silicone rubber tubes are used as syringe parts, they cannot be connected by medical adhesive tapes. But, we modified silicone rubber surface. An adhesive tube can be bonded to only the modified silicone rubber tubes (under syringe in Fig.8).

Fig.7 Solvent-bonding of poly(butadiene) tube to PP intravenous drip tube.

4. Conclusion Polymeric materials modified by the present techniques are useful in many fields. Especially, they are useful for medical articles and devices. Other applications are expected.

5. References [1] Young, R. H. Sr., et. al., United State Patent, No.5432000 (1995). [2] Kinoshita, M., Japanese Patent Application, No.09012752 (1997). [3] Kanazawa, H., USA Patents No.7294673 and No. 6830782B2, [4] Kanazawa, H., Japanese Patent No.4229421, etc.

Fig.8 Improvement of silicone rubbermade syringe. Unmodified (upper) syringe and modified syringe (lower).

Page 595 of 1108

The 13th Asian Textile Conference Geelong, Australia, November 3 - 6, 2015

Plasma Assisted Finishing of Cotton Fabric with Chitosan Maryam Naebe 1, Aysu Onur 1, and Xungai Wang 1 1

Australia Future Fibres Research &Innovation Centre, Institute for Frontier Materials, Deakin University, Geelong, Australia

Abstract. In this study, we investigated the effect of helium atmospheric pressure plasma treatment on adsorption of chitosan onto the cotton fabric. The purpose of the study was to investigate to which extent adsorption of chitosan on cotton can be improved by helium plasma treatment. Fibre surface and adsorption of chitosan were characterized by X-ray Photoelectron Spectroscopy (XPS) and Fourier Transform Infrared (FTIR) spectroscopy. Changes in hydrophobicity of fabric`s surface and fibre morphology were evaluated using contact angle method and scanning electron microscopy (SEM), respectively. The results from XPS showed an increase in nitrogen concentration of fabrics treated with plasma and coated with chitosan, compared with fabric only treated with chitosan. The characteristic absorbance band of chitosan, amide II (N-H bending vibration) showed a slight enlargement for all fabrics treated with helium and chitosan, as assessed by FTIR. While the plasma only treated fabric surface was very hydrophilic, the surface became hydrophobic after chitosan coating. Further investigation is required to verify if the enhanced chitosan adsorption on the surface of plasma treated fabric is pure physical adsorption or the result of chemical binding between two polysaccharides. Keywords: helium plasma, chitosan, cotton, adsorption.

1. Introduction Chitosan is a natural and non-toxic polymer which can be used as a multifunctional, e.g. antimicrobial or anti-wrinkle, agent on cotton fabrics where it offers many advantages over traditional treatments because of its nontoxicity and biodegradability [1]. However, due to the lack of strong bonding forces between two polysaccharides, chitosan coating on cotton has poor durability. To provide efficient and irreversible chitosan adsorption on cotton substrate, it is required to build appropriate binding sites and to activate the substrate material properly. For this purpose, different chemical processes have been used which often require toxic chemicals to form ester crosslinking and uniform adsorption between cotton and chitosan [1]. Using these chemicals is ecologically undesirable and there is a chance for deterioration of fibre mechanical properties. Therefore, more environmentally friendly methods are still needed to reduce or eliminate the use of toxic chemicals without adversely affecting the structure of fibres. An environmentally friendly option involves the application of plasma treatments, which can be used harmless surface activation procedures to enhance the adsorption of chitosan towards cotton fabrics without the need for harmful chemicals [2,3]. Previous studies showed that plasma treatment modifies the surface and introduces new functional groups on the surface by surface functionalization, etching, chain scission and crosslinking [4,5]. In this study, helium atmospheric pressure plasma treatment was used as a technique to modify the surface properties of cotton fabrics. Surface changes and the chitosan adsorption onto the cotton were investigated while chitosan coating was applied on the surface of cotton fabric in different sequences.

2. Experimental 2.1. Fabrics A plain weave pure cotton fabric was used (140 g/m2 and 2/40 Ne). Fabric samples were scoured by nonionic detergent at 60Ë&#x161;C (60 minutes) and then were bleached with 1% hydrogen peroxide solution at 85Ë&#x161;C (pH=10, 40 minutes) and kept as a control fabric in the conditioning room for further treatment. +

Corresponding author. Tel.: + 61 3 5227 2783. E-mail address: maryam.naebe@deakin.edu.au

Page 596 of 1108

2.2. Plasma Treatment An Atmospheric Plasma Treatment System APC 2000 (Sigma Technologies, USA) was used. The operating frequency and roller speed were 90 KHz and 25 rpm, respectively. Helium was used as the plasma gas, with a flow rate of 14 L/min. Fabrics were treated with 30 second helium plasma exposure time at different stages prior to and after chitosan coating as described in section 2.3.

2.3. Chitosan Treatment Chitosan solution of 2% (w/v) was prepared by dissolving chitosan in 0.1M acetic acid (in glacial acetic acid and deionized water). Control fabric samples were impregnated in chitosan solution for 1 hour (80˚C). Coating was then carried out with pad dry cure methods. Different sequences of helium plasma treatment and chitosan coating were applied: (CHT/Cure); control fabric was impregnated with chitosan and immediately after impregnation, fabric was padded (100% pick up), dried (100˚C, 5 min) and cured (160˚C, 2 min), (PTHe/CHT/cure); plasma treatment was applied prior to chitosan coating and cure, (CHT/PTHe/Cure); impregnation and pad dry steps were applied at the beginning, then plasma treatment and cure steps were carried out respectively. (PTHe/CHT); plasma treatment and chitosan coating were carried out without further curing. As a reference, a chitosan film was also casted from 2% chitosan finishing solution as explained.

3. Testing and analysis 3.1. Scanning electron microscopy (SEM) Morphological changes on the surface of the fabrics were observed on a Zeiss Supra 55VP SEM.

3.2. Contact Angle Measurement

KSV CAM 200 contact angle meter (KSV Instruments Ltd, Finland) was used to observe changes in wetting properties of the fabrics. Liquid drops of 1.91 mm were placed on each fabric sample. To measure contact angle the image of each drop was captured as quickly as possible after drops were deposited onto the surface. The absorption time when the water drop was completely absorbed was recorded. The average of 5 measurements was reported.

3.3. Fourier transform infrared spectroscopy (FTIR) Infrared spectra were recorded with a Bruker LUMOS FTIR Microscope (USA) in ATR mode, with accumulation of 64 scans at 4 cm−1 resolution. FTIR spectra of control fabric were subtracted from the spectra of fabric coated with chitosan (CHT/Cure). Similarly, spectra of fabric treated with helium plasma and chitosan coated were subtracted from spectra of fabric pre-treated with helium plasma. The average of 3 measurements was reported.

3.4. X-ray photoelectron spectroscopy (XPS) Fabric samples were analysed using an AXIS Nova spectrometer (Kratos Analytical Ltd., UK) equipped with a monochromatic X-ray source (Al Kα, hν = 1486.6 eV), operating at 150 W.

4. Results and Discussion 4.1. Surface Morphology SEM images (Fig. 1) showed that the untreated control fabric (a) had a smooth surface, while only plasma treated fabric (c) showed some sign of cracks on the surface. Cracks on the surface makes the coating of materials easier [3] as the higher chitosan adsorption was observed on the surface of plasma treated fabrics regardless of the sequence of plasma treatment. All plasma treated and chitosan coated fabrics had a similar surface morphology with more even chitosan coating on the plasma treated surface than the untreated fabric (b).

a a

Page 597 of 1108

Fig. 1: SEM images of: a) Control fabric, b) cotton fabric coated with chitosan (CHT/Cure), c) cotton fabric treated with helium plasma (PTHe), d) cotton fabric treated with helium plasma, coated with chitosan and then cured (PTHe/CHT/Cure), e) cotton fabric coated with chitosan then treated with helium plasma and cured (CHT/PTHe/Cure), f) cotton fabric treated with helium plasma, and then coated with chitosan with no further cure (PTHe/CHT)

4.2. Wetting Properties All chitosan coated fabrics showed an increase in the contact angles and absorption times (Table 1), whereas the control and PTHe fabrics were quite hydrophilic. Among all plasma treated and chitosan coated fabrics, the PTHe/CHT had the lowest contact angle and absorption time, confirming the significant effect of curing on chitosan adsorption, consistent with the XPS results. Furthermore, the PTHe/CHT/Cure and CHT/PTHe/Cure did not show significant differences in wettability, and, compared to CHT/cure fabric, illustrated uniform wetting properties on the surface of the fabrics as shown by lower standard deviation at different measurements. It can be concluded that the main impact of the plasma pre-treatment was to enhance the even distribution of chitosan on the substrate surface. Table 1: Contact angle and absorption time Sample

Control

CHT/Cure

PTHe

PTHe/CHT/Cure

CHT/PTHe/Cure

PTHe/CHT

131 (±4)

122 (±3)

126 (± 3)

107 (± 3)

154 (±17)

127 (± 8)

131 (± 9)

55 (±11)

Contact Angle (◦± s.d*) Absorption time (sec± s.d*)

* Standard deviation of 5 measurements.

4.3.

FTIR-ATR Analysis

The subtracted FTIR spectra are illustrated in Fig 2. The absorbance peaks of OH groups at 3325.2 cm-1, 3330.9 cm-1 and 3263.4 cm-1are shown on all plasma treated fabrics (b, c and d). The peaks around 2896.9 cm1 and 2922.0 cm-1 correspond to CH 2 stretching vibrations and the absorbance peaks in the region of 1620.1 cm-1 and 1639.4 cm-1 reveal the C = O in amide group (amide I band) [6]. Furthermore, the peaks at 1325.0 cm-1 and 1338.5 cm-1 are assigned to the C-N stretching (amide III). The absorbance peak of amide II (N-H bending vibration) was also observed at 1589.3 cm-1. The plasma treated fabrics regardless of chitosan coating before or after, showed slightly greater peaks in comparison with the only chitosan coated fabric.

Page 598 of 1108

Fig. 2: FTIR spectra of: a) cotton fabric coated with chitosan (CHT/Cure) – control fabric , b) cotton fabric treated with f helium plasma, and then coated with chitosan then cured (PTHe/CHT/Cure) – PTHe, c) cotton fabric coated with chitosan then treated with helium plasma and cured (CHT/PTHe/Cure) – PTHe, (d) cotton fabric treated with helium plasma, and then coated with chitosan with no further cure (PTHe/CHT) – PTHe, e) chitosan film

4.4. XPS Analysis Table 2 shows the relative atomic percentage concentrations of carbon, oxygen and nitrogen on the surface of the treated and untreated cotton fabrics and chitosan film. An increase in oxygen and a decrease in the carbon concentration were observed for plasma treated and chitosan coated fabrics. The O/C ratio of control fabric was enhanced from 0.23 to 0.25 after plasma treatment confirming that plasma treatment oxidised the surface of the fabric [5, 6]. An increase in nitrogen content was observed for all fabrics treated with chitosan. Higher concentration of nitrogen was reported for fabrics treated with plasma compared with the untreated, though there was not a significant difference between PTHe/CHT/Cure and CHT/PTHe/Cure. Lower N/C concentration of PTHe/CHT compared with other plasma treated fabrics confirmed the effect of curing on chitosan adsorption. Table 2: Chemical composition of untreated and treated cotton fabric and chitosan film Sample O 1s (531.7 eV) C 1s (284.8 eV) N 1s (398.8 eV) O/C N/C Control 18.47 79.32 0.76 0.23 0.01 CHT Film 22.91 69.2 4.34 0.33 0.06 CHT/cure

24.99

71.78

3.22

0.35

0.05

PTHe

19.74

77.9

0.46

0.25

0.01

PTHe/CHT/Cure

25.2

70.63

4.18

0.36

0.06

CHT/PTHe/Cure

24.64

71.14

4.22

0.35

0.06

PTHe/CHT

23.37

72.84

3.79

0.32

0.05

5. Conclusion Helium plasma treatment leads to more uniform spread of chitosan regardless of the sequence of plasma treatment. While plasma treatment slightly enhanced the adsorption of chitosan on the surface of the cotton fabric, plasma treatment before or after chitosan treatment did not show any significant differences on chitosan adsorption. Though the results confirmed the enhanced adsorption of chitosan on the surface of plasma treated fabrics, further investigation is needed to elucidate if this adsorption is physical adsorption or the result of chemical binding between two polysaccharides.

6. Acknowledgment Funding for this study was provided by the Central Research Grants Scheme, Deakin University. The authors express their gratitude to Dr Rob Jones (Centre for Materials and Surface Science, La Trobe University) for running XPS experiments and to Mr Peter Herwig (CSIRO Manufacturing Flagship) for providing the cotton fabric.

7. References [1] [2] [3] [4]

[5] [6]

D. Enescu, "Use of Chitosan in Surface Modification of Textile Materials," Romanian Biotechnological Letters, vol. 13, pp. 4037-4048, 2008. L. Fras Zemljič, Z. Peršin, and P. Stenius, "Improvement of Chitosan Adsorption onto Cellulosic Fabrics by Plasma Treatment," Biomacromolecules, vol. 10, pp. 1181-1187, 2009/05/11 2009. C.-E. Zhou and C.-w. Kan, "Plasma-assisted regenerable chitosan antimicrobial finishing for cotton," Cellulose, vol. 21, pp. 2951-2962, 2014/08/01 2014. Y. J. Hwang, M. G. Mccord, J. S. An, B. C. Kang, and S. W. Park, "Effects of Helium Atmospheric Pressure Plasma Treatment on Low-Stress Mechanical Properties of Polypropylene Nonwoven Fabrics," Textile Research Journal, vol. 75, pp. 771-778, November 1, 2005 2005. H. A. Karahan and E. Özdoğan, "Improvements of surface functionality of cotton fibers by atmospheric plasma treatment," Fibers and Polymers, vol. 9, pp. 21-26, 2008/02/01 2008. C. M. P. a. P. Kiekens, Surface Characteristics of Fibers and Textiles: Inc, 2001.

Page 599 of 1108

The 13th Asian Textile Conference Geelong, Australia, November 3 - 6, 2015

Preparation and Characterization of Islands-in-the-Sea Bicomponent Fibers (Polyarylate/PA6) by Melt Spinning Process Joo-Hyung Lee1, In-Woo Nam1, Do-Kum Kim1, Ki-Sub Lim1 and Wan-Gyu Hahm1 ď&#x20AC;Ť 1

Technical Textile & Materials R&D Group, Korea Institute of Industrial Technology, 143 Hanggaulro, Sangnok-gu, Ansan-si, Gyeonggi-do, Korea

Abstract. The aim of this study was to investigate fiber formation behavior of islands-in-the-sea type bicomponent fibers of polyarylate thermotropic liquid crystal polymer (TLCP) and Polyamide6 (PA6) in melt spinning process. The bicomponent as-spun fibers were prepared by incorporating 60 wt% of the TLCP as islands component into the sea component of PA6 with increasing take-up velocity. The fiber structure formation of the individual components and the physical properties of the bicomponent fibers were investigated with the measurements on optical microscope, scanning electron microscope (SEM), X-ray diffraction, differential scanning calorimetry (DSC), thermogravimetric analysis (TGA) and tensile test. As a result of morphology analysis, the bicomponent fiber with sub-micro scaled islands could be obtained. Obtained bicomponent as-spun fibers also showed high mechanical properties indicating the sub-micro scaled island fibers of polyarylate have highly oriented fiber structure.

Keywords: Thermotropic Liquid Crystalline polymer, Polyamide6, Islands-sea type fiber, melt spinning

1. Introduction Recently, with increasing of demand for the high performance fiber material, the melt spinning of thermotropic liquid crystal polymer (TLCP) has attracted great attentions, because of their high mechanical properties, excellent thermal stability, and good processability. In general, the scale of the fibers effects on the mechanical properties because a smaller diameter leads to larger surface area. However, because it is difficult to produce nano fiber by melt spinning process, electrospinning is the most popular method in preparation of nanofibers, including solution and melt electrospinning. But this method has several drawback such as low production efficiency and low crystallinity and orientation. In recent years, the islands-sea type bi-component melt spinning technique has studied to fabricate polymer nanofibers. The principle is to choose two kinds of partially miscible or immiscible polymers, and melt spinning by conventional spinning system. After dissolving sea component, polymer nanofiber can be obtained. Based on many researches, polypropylene (PP), poly(butyleneterephthalate) (PBT), poly(trimethylene terephthalate) (PTT) nanofiber have already been fabricated by using this process, successfully. However, islands-in-the-sea bicomponent fiber made with TLCP as island component has been rarely reported. Meanwhile, in general, introducing of nano-scaled reinforcement such as carbon nanotube (CNT), nano-cellulose, and etc. into the polymer matrix can improve the mechanical properties, thermal properties of the composites. And the orientation of the reinforcement has affected on the performance of the composites films or fibers. Moreover, according to several researches, the enhancing effect of highly oriented long fibers in polymer matrix along the spinline has been reported. Therefore, in this study, islands-sea type bicomponent fibers consisting of TLCP as islands and PA6 as sea component were manufactured by melt spinning process and analysis of morphology, mechanical properties, thermal properties, and crystalline development were carried out.

2. Experimental ď&#x20AC;Ť

Corresponding author. Tel.: + 86-010-7330-3042. E-mail address: wghahm@kitech.re.kr

Page 600 of 1108

2.1. Materials Polyarylate TLCP (Vectra) and PA6 used in this work is supplied by Celanese co. and Hyosung co., respectively. All the materials were dried before being used to minimize the effect of any internal moisture and then melt spun on a pilot-scale melt spinning system with a single-screw extruder. The spinneret used in this study was specially designed to extrude islands-in-the-sea type bi-component fibers with a 12 holes, each of 0.25 mm diameter and each hole contains 74 islands component orifice, uniformly. The predetermined Islands (Polyarylate)/Sea (PA6) composition was 60 : 40 (w/w). The spinning temperature was 280 oC and the Polyarylate/PA6 islands-in-the-sea bicomponent as-spun fiber was obtained at take-up 500, 1,000, 1,500 and 2,000 m/min, respectively.

2.2. Characterization To confirm the formation of the islands-in-the-sea type bicomponent fiber, the morphology of the products was studied by using optical microscope and scanning electron microscopy (SEM, Hitachi SU8000). The mechanical properties of bicomponent fibers were measured at room temperature with an Textechno Favimat tensile testing machine. The gauge length and crosshead speed were set to 20 mm/min equally. The thermal behavior of bicomponent fibers were investigated with DSC (TA Instrument) under nitrogen gas purge over the temperature range of 30 to 330oC employing a scanning rate of 10oC/min. Thermogravimetric analysis (TGA, TA Instrument) was performed over the temperature range of 30 to 800oC under the nitrogen atmosphere.

3. Result and Discussion The morphology of fractured surfaces of polyarylate/PA6 bicomponent fibers were characterized by optical microscope. As shown in optical microscope images of bicomponent fiber obtained from spinning speed of 500m/min, the structure of islands shape was formed well. This observation suggests that the bicomponent fibers consisting of TLCP and PA6 for islands and sea component respectively was good melt-spinnability. To evaluate the morphology of bicomponent fibers, the scanning electron microscope (SEM) analysis was performed. As shown in the SEM images of fractured surface, the bicomponent fibers with sub-micro scaled islands component could be obtained at a take-up speed of 2,000m/min, successfully. Regardless of melt spinning speed, it can be seen that the TLCP as islands was separated from each other and arranged homogeneously in the PA6 matrix. Moreover, an aggregation of island component was not found in the fractured surface. These morphological observations can be considered as the possibility for leading to better mechanical properties of bicomponent fiber consisting of immiscible polymers. To estimate the reinforcing effect of the spinning speed for the islands-in-the-sea fiber structure, the mechanical properties were investigated. The tenacity of the islands-in-the-sea fiber was increased from 7.8 to 8.3 g/den with the spinning speed increasing from 1,000 to 1,500 m/min, respectively. However, the elongation at break did not exceed 2.5% for all the bicomponent fiber obtained from various spinning speed. In general, the PA6 fibers obtained from take-up velocity of 1,000 m/min shows elongation at break much higher than 2.5%, this result suggests that PA6 as sea component did not affect the mechanical property of the bicomponent fibers. The estimated mechanical property excluding sea component by weight composition, the tenacity can be expected to show that of general polyarylate fibers approximately. On the other hand, the mechanical properties was decreased at take-up velocity of 2,000 m/min, this can be attributed to reduction of formation stability in higher spinning speed.

4. Conclusion In this study, the islands-in-the-sea type bicomponent fibers consisting of polyarylate TLCP and PA6 were prepared at various take-up velocity and the structure development was investigated. As shown in the optical microscope and SEM images, the structure of the bicomponent fiber including 74 islands component was formed successfully. Due to the mutual interaction between islands component and sea component melts along the spinline, the processability of TLCP/PA6 bicomponent spinning was improved. The mechanical property of the bicomponent fiber was enhanced with increasing take-up velocity. This results means that suitable combination of polymers with different inherent properties can also lead to structure development of individual component and the enhanced mechanical properties can be obtained with increasing take-up speed.

5. Reference

Page 601 of 1108

[1] W.-G. Hahm, H. Ito and T. Kikutani, Intern. Polymer Processing, 21, 5 (2006)

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The 13th Asian Textile Conference Geelong, Australia, November 3 - 6, 2015

Preparation and flame retardancy of 3-(hydroxyphenylphosphinyl)propanoic acid esters of cellulose and their fibers Yunbo Zheng1 Jun Song1,2 Bowen Cheng1,2 Xiaolin Fang1 Ya Yuan1 1 Key Laboratory of Tianjin city modification and functional fiber, Department of Materials Science and Engineering, Tianjin Polytechnic University, Tianjin 300387,China 2 State Key Laboratory of hollow Fiber Membrane Materials and Processes, Department of Materials Science and Engineering，Tianjin Polytechnic University，Tianjin 300387,China

Abstract. New 3-(hydroxyphenylphosphinyl)-propanoic acid (3-HPP) esters of cellulose were synthesized in N, N-dimethylacetamide/LiCl (DMAc/LiCl) homogeneously by the method of in situ activation with ptoluenesulfonyl chloride (Tos-Cl). Chemical structure and thermal properties of the cellulose esters were investigated by FTIR, 13C-NMR and their flame retardancy was studied by limiting oxygen index (LOI) test and vertical flammability test. It was found that the degree of substitution (DS) of cellulose esters, in the range from 0.62 to 1.42, had an obvious effect on solubility of cellulose esters. Besides, ESEM observation also confirmed that flame retardant cellulose (FRC) fibers with 3wt% cellulose acetate prepared by dry-wet spinning technique possessed good flame resistance.

Keywords :Cellulose, Homogeneous modification, Fire-retardant fiber

1.Introduction Cellulose is an abundant and renewable resource, and gar ments made from it are usually comfort and breathable. As a result, cellulose fiber has become one of the most commonly employed fibers in the textile field. However, cellulose is generally easy flammability (with limiting oxygen index (LOI) of 18.4%), which has restricted its wide application [1]. In the past few years, there have been many successes in improving flame retardancy of textile [2-4]. Several strategies, including pad−dry−cure, graft polymerization, multistep sol−gel and layer-by-layer assembly, have been used to confer flame retardancy properties of cotton cellulose [5]. Chemical homogeneous modification is the most important tool to obtain cellulose with functional groups [6,7]. Among all solvents of cellulose, DMAc/LiCl is a non-derivatizing and non-aqueous solvent system, and has been widely employed for analysis of cellulose and for preparation of a wide variety of derivatives without significant degradation under homogenous reaction conditions [8,9]. By contrast, esterification of cellulose with carboxylic acids through in situ activation by sulfonic acid chlorides is a relatively new modification route, in which the introduction of a wide range of carboxyl-functionalized substitutents can be controlled effectively [10]. As a kind of flame retardant, halogen-free phosphorus compounds are likely to be the promising flame retardant candidates for cotton cellulose, since these environmentally friendly compounds can catalyze the dehydration of cellulose as the char former under acid condition, thus reducing the formation of flammable volatiles and smoke [11]. In this paper, 3-(hydroxyphenylphosphinyl)-propanoic acid esters of cellulose were prepared using in suit activation with Tos-Cl in DMAc/LiCl, and then flame retardancy of the cellulose esters were studied. Afterwards, the cellulose esters were dissolved in conventional organic solvents to spin flame retardant fibers, and the mechanical property and flame resistance of the fibers were discussed. Corresponding author: Bowen Cheng E-mail: bowen15@tjpu.edu.cn

Tel: (086) 022-83955588

Page 603 of 1108

2.Experimental 2.1 Materials Cellulose (DP=630), supplied by Jilin Chemical fiber CO. LTD., China, was treated in a vacuum oven at 95℃ for 12 h to remove any moisture before use. DMAc, anhydrous LiCl and Tos-Cl were purchased from Kermel Chemical CO. LTD., China. 3-HPP was acquired from kaixin Chemical CO. LTD., China. DMAc was dried and distilled before use according to conventional methods. Anhydrous LiCl was dried at 130℃ for 10 h under vacuum. Other reagent grade chemicals were used without further purification.

2.2 Methods Esterification reaction of cellulose with 3-HPP / Tos-Cl 3.96 g 3-HPP (18.6 mmol) and 3.53 g (18.6 mmol) Tos-Cl were dissolved in two copies of 10 mL DMAc, respectively. Then, the obtained two solutions were added to the cellulose solution containing 1 g (6.2 mmol) cellulose. After homogeneous reaction at 40°C for 24 h, the product was precipitated in 300 mL ice water, filtered off, washed with water and ethanol, and dried in vacuum at room temperature. Preparation of 3-HPP ester of cellulose (FRC) fibers A certain amount of FRC (17wt%) and cellulose acetate (3wt%) were added into dimethyl sulfoxide (DMSO) to form 20wt% homogeneous spinning solution at 80℃ under mechanical stirring. After degassing and filtering, the solution was extruded under a pressure of 0.2 MPa by dry–wet spinning procedure, and the process could last until the solution was exhausted. Here, the coagulation was distilled water, the spinning speed was 1.5 m/min, and the extruded speed for the solution was 2 ml/min. Measurements Fourier transform infrared spectroscopy (FT-IR) was performed on a Bruker TENSOR37 instrument with the KBr-technique. 13 C NMR spectra were acquired on a Bruker AMX 400 MHz spectrometer. The content of phosphorus (%P) in the FRC was determined by ICP-9000(N+M) to calculate the degree of substitution (DS) . The LOI was measured according to GB/T2403-1993 by using JF-3 LOI instrument. The vertical flammability was measured according to GB/T 5455-1997 by using CZF-3 instrument. Environmental scanning electron microscope (ESEM) (CzechQuan ta200) was used to observe the morphology of FRC fibers. Tensile strength of the fibers was performed on XQ-1fiber tensile tester (LaiZhou Electron Instrument Co. Ltd., Shandong, China).

3. Results and discussion 3.1 Synthesis and characterization of FRCs

Scheme 1 Esterification of cellulose with 3-HPP

Scheme 1 shows the esterification of cellulose with 3-HPP at 40℃for 24h. From Table 1, it is noted that the DS of all FRCs increases with the ratio of AGU/3-HPP/Tos-Cl increasing and that the highest DS is 1.42 when the molar ratio reaches 1:5:5. Notably, different distribution of the functional groups may lead to different solubility. The products obtained with cellulose are well soluble in DMSO when DS≥0.67, so that DMSO is an important solvent for cellulose esters from a technical point of view, especially for fiber spinning. Table 1 Conditions for and results of the preparation of FRCs with 3-HPP in DMAc/LiCl Partial DS at Position 6 3 2

NO.

Molar ratioa

DSb

1#FRC

1:1:1

0.62

0.25

0.20

0.17

2#FRC

1:2:2

0.67

0.27

0.22

0.18

3#FRC

1:3:3

0.96

0.39

0.30

0.27

Solubilityc DMSO DMAc ⊕ + ⊕ +

⊕

THF -

Page 604 of 1108

4#FRC

1:4:4

1.33

0.53

0.44

0.36

⊕

5#FRC

1:5:5

1.42

0.54

0.48

0.40

⊕

Mole AGU/mole 3-HPP/mole Tos-Cl Degree of substitution

b c

Soluble(+), swelling(⊕), insoluble(-)

FTIR spectra (Fig. 1) of FRCs present the typical absorptions of the cellulose backbone as well as signals of aromatics at 1600, 1530 and 1421cm-1. Furthermore, the band at 1731cm-1 confirms the presence of the ester carbonyl group (C=O). It is obvious that the intensity of the C=O stretching band (1731 cm-1) increases with the increase of substitution degree[12]. Fig. 2 shows the structure of the cellulose esters analyzed by 13C-NMR spectroscopy in DMSO-d6. Besides the carbon signals of modified AGU in the region of δ= 59.1 to 104.8 ppm, the resonances assigned to the carbon atoms of the 3-HPP moieties are visible at δ=126-136 ppm (C-10~C-15), 24-26 ppm (C-9) and 26-28 ppm (C-8). Furthermore, the signal at 173–174.2 ppm which originates from the carbonyl carbon of the ester (C-7) linkage confirms the formation of ester. In addition, the signal at δ= 98.8 ppm can be assigned to C-1' (C-1 atom influenced by O-2)[13].Unfortunately, the spectrum is lack of resolution for exactly assigning signals of the carbons influenced by the esterification at C-2 and C-6 (C-2s and C-6s respectively).

Fig. 2 13C-NMR spectra of 3#FRC (DS=0.96)

Fig. 1 FTIR spectra of cellulose and FRCs

3.2 Flame retardant properties of the FRCs Vertical flammability and LOI were employed to evaluate flame retardant properties of the FRCs (Table 2). The results show that esterification reaction with 3-HPP can decrease the flammability of cellulose. On the one hand, char length, afterflame and afterglow time are all changed significantly, so that the flame spread rate of the FRCs is also much lower than that of cellulose. On the other hand, with the increase of DS, the LOI values of the FRCs are improved gradually and the highest LOI value can reach 38.7, which confirms that phosphorus-based compounds can enhance flame retardancy of cellulose effectively[14]. Table 2 Vertical flammability and LOI test for different FRCs and cellulose

Fabric

Afterflame time

（sec） Cellulose 30 2#FRC 0 3#FRC 0 5#FRC 0 a 17%FRC+3%CA

Vertical flammability Afterglow Char time length （sec） 6 0 0 0

（cm） 30 2.5 1.8 0.7

LOI Rate of flame spread

Average of LOI

（mm/s） 7.1 2.1 1.5 0.58

（vol%） 18.6 27.1 32.0 38.7

Average of LOI

（vol%） 18.6 26.2 30.3 36.0

3.3 Morphology and mechanical characterization of FRC fibers Spinning property of the FRCs will be deteriorated due to the bulky moieties, whereas adding 3wt% cellulose acetate can improve the spinnability of the solution. As shown in Fig. 3, FRC fibers show a smooth surface and rounded cross section, and the breaking strength of the nascent FRC fibers can reach about 1.2cN/dtex. High breaking elongation can make a contribution to stretching and orientation, thus further increasing breaking strength of the fibers (Table 3). Moreover, it can be found from Table 2 that the LOI values of the blend fibers with 3wt% cellulose acetate are still high.

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Fig.3 ESEM images of the FRC fibers

NO. Breaking strength (cN/dtex) Breaking elongation (%)

Table 3 Mechanical properties of the FRC fibers 2#FRC fiber 3#FRC fiber 1.19 1.21 85.51

83.12

5#FRC fiber 1.28 70.75

4. Conclusions In the present work, homogeneous esterification reactions of cellulose were carried out via in situ activation with Tos-Cl in DMAc/LiCl. The results of FTIR, 13C-NMR and ICP analysis showed that 3-HPP was grafted onto the backbone of cellulose, and that the highest DS could reach 1.42 when mole ratio of AGU/3-HPP/TosCl was 1:5:5. After reacting with 3-HPP, flame retardancy of cellulose ester was increased. Meanwhile, the LOI values of cellulose esters were improved gradually with increasing DS, and the highest LOI value could reach 38.7. The results of vertical flame test showed that cellulose treated with 3-HPP had less char length, lower flame spread rate and no afterflame or afterglow time.The FRC fibers with 3wt% cellulose acetate prepared by dry-wet spinning technique were confirmed to possess superior flame resistance.

5. References [1] Lewin M (2010) Handbook of fiber chemistry. CRC Press. [2] Hong KH, Liu N, Sun G (2009) Eur Polym J 45:2443-2449 [3] Horrocks AR (2011) Polym Degrad Stabil 96:377-392 [4] Liang SY, Neisius NM, Gaan S (2013) Prog Org Coat 76:1642-1665 [5] Alongi J, Carosio F, Malucelli G (2013b) Current emerging techniques to impart flame retardancy to fabrics: An overview. Polym Degrad Stabil 106:138-149 [6] Gr채bner D, Liebert T, Heinze T (2002) Cellulose 9:193-201 [7] Liebert TF, Heinze T (2005) Biomacromolecules 6:333-340 [8] Liebert T 2010. Oxford University Press, pp 3-54 [9] Raus V et al. (2012) Cellulose 19:1893-1906 [10] Hasani MM, Westman G (2007) Cellulose 14:347-356 [11] Rupper P, Gaan S, Salimova V, Heuberger M (2010) J Anal Appl Pyro 87:93-98 [12] Sui X et al. (2008) Biomacromolecules 9:2615-2620 [13] Hussain MA, Liebert T, Heinze T (2004) Macromolecular rapid communications 25:916-920

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[14] Liu W, Chen L, Wang Y-Z (2012) Polym Degrad Stabil 97:2487-2491

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The 13th Asian Textile Conference Geelong, Australia, November 3 - 6, 2015, pp. xxx-xxx

Preparation of kapok/TiO 2 UV-blocking fiber by in-situ deposition Ruixue Li1, Xiaolin Shen1*, Weilin Xu1, 2 1 2

School of Textile Science and Engineering, Wuhan Textile University, Wuhan, China

State Key Laboratory of New Textile Materials and Advanced Technology, Wuhan Textile University, Wuhan, China

Abstract. In this study, in-situ deposition method was adopted to deposit the TiO 2 , used as UV-blocking agent here, onto kapok fiber to prepare functional fiber with UV-blocking ability. The properties of the fiber were examined by X-ray diffraction (XRD) and scanning electron microscope (SEM). The influences of precursor, precipitator, temperature and process time of reaction on the effect of in-situ polymerization were also studied. The effectiveness of UV-blocking was characterized by the ultraviolet protection factor (UPF). Results showed that, the optimal process parameters of the concentration of precursor, the time of this process and handling temperature were 8 g/L, 20 min and 30

.â&#x201E;&#x192;, respectively. The UPF value could rise up t

Keywords: kapok fiber; TiO 2 ; UV-blocking; in-situ

1. Introduction As a natural environmental cellulose fiber, kapok fiber has been widely used for fill material, heat insulation and sound absorption material, buoyancy and lightweight fabric for its particular vacuum structure and excellent properties which including natural antibacterial, water-repellency, oil-absorbent and so on[1-5]. In this experiment, kapok/TiO 2 UV-blocking fiber is a thin nanoscale TiO 2 layer in-situ deposited on the surface of kapok fiber. This treatment ensured kapok/TiO 2 fiber has excellent anti-ultraviolet property and enhanced the surface roughness of kapok fiber without affect its specific property. It would benefit broadening the application of kapok fiber in textile field.

2. Experimental 2.1. Materials Kapok fiber; deionized water; tertrabutyl titanate and absolute ethanol were of analytical reagent and without any purification.

2.2. Preparation of kapok/TiO 2 UV-blocking fiber In this experiment, kapok fiber was used as the basic material of in-situ deposition, tertrabutyl titanate was dissolved in the ethanol and was used as the precursor solution, and the deionized water was used as the precipitator solution. Kapok fibers were immersed into the precursor solution and set aside for several minutes, then rolled the kapok fiber to ensure the liquid rate is 130%~140%. The treated kapok fibers impregnated with *

Xiaolin Shen. Tel.: + 86-027-5936 7572. E-mail address: xiaolin_shen 527@126.com.

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the precipitator solution and set aside for a while, and rolled subsequently. And after rinsing and lowtemperature drying, kapok/TiO 2 UV-blocking fiber was generated. For TiO 2 could give kapok fiber excellent anti-ultraviolet property, the UPF value of kapok/TiO 2 UV-blocking fiber was measured to evaluate the sound effects of in-situ deposition.

2.3. Characterization of structure and performance A Philips X’Pert Pro diffractometer (XRD) was used to characterize the deposited products (TiO 2 ). The surface morphology of simples was observed by the Scanning Electron Microscope (SEM, JEOLISM-5610LV) and Scanning Desktop Electron Microscope (SEM, PHENOM PRO). The UPF value of simples was measured with the Ultraviolet Transmission Analyzer HB902 according to GB/T Test Method 18830-2009.

3. Result and discuss 3.1. XRD of kapok/TiO2 fibers In order to prove the deposition of TiO 2 , proportion sample were placed in a crucible and calcined by the Muffle Furnace at 600℃ for 30min. The calcination residues of the samples were determined using XRD. Fig.1 shows the XRD patterns of the fiber samples using this method. As shown in the figure, no peak is found in pattern a, which is the original kapok fibers. While in the pattern b, all diffraction peaks are indexed as typical tetragonal crystal structure of nano-TiO 2 . And the diffraction peak at 2θ = 27.45°, and 36.08° corresponding to the (110), and (101) planes of rutile TiO 2 , while the peaks at 2θ = 25.23°, and 54.74° are attributed to the (101), and (105) planes of anatase TiO 2 , respectively. The characteristic diffraction peak of the rutile nano-TiO2 at 2θ = 27.43° was stronger than other peaks; this is due to the (110) planes of rutile TiO 2 has lower surface energy and is the steadier structure phase in the mixed crystal structure. All the deposited TiO 2 were composed as crystal structure instead of amorphous structure, which with high UV-blocking performance.

Fig.1. XRD patterns for fibers samples: (a) original kapok fibers; (b) kapok/TiO 2 fibers

3.2. SEM of kapok/TiO 2 fibers Kapok fiber was composed by cellulose and xylogen, after calcination the residues of original kapok fibers showed as random powder (Fig.2.a.); however, the residues of kapok/TiO 2 fibers showed in fibrous (Fig.2.b.). That is, during the calcination process, the TiO 2 particles which generated during the in-situ deposition process adhered the irregular powder into fibrous.

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Fig.2. SEM images for calcination residues of fibers samples: (a) original kapok fibers; (b)kapok/TiO 2 fibers

The SEM images of the fiber samples were showed in the Fig.3. It could be easily observed that the natural kapok fiber has a smoothness surface without any convolution and looks as a cylinder (Fig.3.a.). Whereas, the continue TiO 2 particles coated on the outer surface of the kapok/TiO 2 fiber (Fig.3.b.), which provide excellent UV-blocking properties for the treated kapok fiber and increases the cohesive force among fibers during the spinning process. Fig.3.c. shows that the TiO 2 particles deposited on the inner surface of kapok/TiO 2 fiber, which further increases anti-ultraviolet ability of the kapok fiber.

Fig.3. SEM images for fibers samples: (a) original kapok fibers; (b) ,(c) kapok/TiO 2 fibers

3.3. Influence of the process time on the UPF of kapok/TiO 2 fibers Fig.4 presents the UPF value curve of kapok fibers treated with different process time. When the process time increased from 10min to 20min, the UPF value went up and then decreased with the increase of process time from 20min to 50min. The results show that the process time influence significantly the UV-blocking performance of kapok/TiO 2 fibers. This is due to that when the process time increases, the TiO 2 in-situ deposited on the surface of kapok fiber added, thus introducing the kapok fibers better UV-blocking performance. When the process time increases further, the TiO 2 film generated on the surface of kapok fiber cracked and finally fell off after rinsing, so the TiO 2 in-situ deposited on the surface of kapok fibers decrease, therefore UV-blocking performance of kapok/TiO 2 fibers is worse.

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Fig.4. UV-blocking performance of kapok fibers treated with different process time

3.4. Influence of the process temperature on the UPF of kapok/TiO 2 fibers Fig.5 is the UPF value curve of kapok fibers treated with different process temperature. Obviously, the UVblocking performance increases with the increase of process temperature due to that as the process temperature increases, the in-situ deposition reacted more fully; but under higher temperate, the TiO 2 layer deposited on the surface of kapok fibers increases thickness and fell off finally. Therefore the UPF value of the fiber sample distinctly showed the lower degree at 60 ℃.

Fig.5. UV-blocking performance of kapok fibers treated with different process temperature

3.5. Influence of the precursor on the effect of polymerization The UPF value curve of kapok fibers treated with different concentration of precursor is showed in the Fig.6. It can be seen that the UPF value of the kapok/TiO 2 fibers increases with the increase of precursor solution’s concentration and showed a turning point at precursor solution’s concentration of 8g/L, further, the kapok/TiO 2 UV-blocking fibers were well polymerized. The reason may be that when the concentration increased to 8g/L, the TiO 2 in-situ deposition has achieved optimum levels, and went on increasing the concentration the layer of TiO 2 cannot adhere on the surface of kapok fiber well.

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Fig.6. UV-blocking performance of kapok fibers treated with different concentration of precursor

4. Conclusions This study introduced an effective in-situ deposition in order to produce an ideal UV-blocking kapok fiber. The TiO 2 particles were successfully in-situ deposited on the kapok fiber surface. SEM images confirm the presence of TiO 2 particles on the surface of the kapok fiber. UPF value analysis illustrated that optimal process are the precursor solutionâ&#x20AC;&#x2122;s concentration of 8g/L, the precursor process time of 20min, and the processing temperature of 30 eâ&#x201E;&#x192;,UPF respectively. value of kapok/TiO At this point th fiber has achieved 2 UV-blocking 107.7, which shows excellent UV-blocking performance.

References: [1] SHI Meiwu, XIAO Hong, YU Weidong. The Fine Structure of the Kapok Fiber[J]. Journal of Textile Research, 2005, 26(4):4-6. [2] XIAO Hong, YU Weidong, SHI Meiwu. Structures and performance of the kapok fiber[J]. Journal of Textile Research, 2005, 26(4):4-6. [3] DING Ying, LOU Xuejun, HU Zhenyin, et al. The performance and application of kapok fiber [J]. Industrial Textile, 2008, 11: 1-3. [4] WU Shuangquan, ZHANG Peihua. Kapok fiber and its application in textiles [J]. Melliand China, 2009,1:11-16. [5] YAN Jinjiang, WANG Fumei, XU Bugao. Compressional resilience of the kapok fibrous assembly[J]. Journal of Textile Reasearch, 2014, 84(13):1441-1450.

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The 13th Asian Textile Conference Geelong, Australia, November 3 - 6, 2015

Shrink Proofing of Wool Fibers: Effect of Pretreatments with Shellac and Keratinase Naoko Nagashima 1+, Yuichi Hirata 2 , Kunihiro Hamada2 and Toru Takagishi 3 1

University

Faculty of Human Ecology, Wayo Women’s University 2 Faculty of Textile Science and Technology, Shinshu 3 Former Osaka Prefecture University

Abstract. The reduction of adsorbable organic halogens, AOX in textile waste water is strongly requested in the textile processing from the eco-friendly point of view. The purpose of this work is to gain an insight into the information about shrink proofing of wool fibers using an enzyme and Shellac. The enzyme employed in this experiment was a new type of keratinase obtained from Nocardiopsis sp. Shellac is a naturally-occurring and thermosetting resin of fatty acids which has been certified by Food and Drug Administration, FDA in USA and is applied to food additives. After the treatment of the fibers with Shellac alone or Shellac/enzyme, shrink resistance, tensile strength, and surface morphology were measured. The shrinkage was evaluated according to the Aachen felting test using wool slivers. When wool fibers were treated with the enzyme alone, shrink proofing was observed. However tensile strength was decreased as the keratinase content in the crude enzyme was decreased because the enzyme used in this experiment involves the other proteases which might penetrate into cortex regions through cell membrane complex, CMC and attack them. As a result the strength of the fibers seems to decrease. Although the SEM pictures of fibers treated with the enzyme alone showed fibrillation and damage, morphological changes were not observed by the treatment with Shellac alone or the dual treatment with Shellac and then keratinase. It was found that the satisfactory shrink resistance was attained with slight lowering of strength by the treatment with Shellac alone or Shellac/keratinase. Shellac is soluble in methanol but insoluble in water. From the eco-friendly point of view the use of methanol as a solvent for Shellac is not preferable. Shellac was found to be soluble in 1% aq. ammonia solution. The SEM observation showed to unite scales with the resin and inhibit the penetration of enzyme into cortex regions through CMC after the fibers were treated with Shellac in 1% aq. ammonia solution. Shellac is expected to penetrate into the CMC regions and prevent the enzyme, in particular impure proteases from diffusing into the cortex regions. The dimensional stability for washing was also investigated.

Keywords: wool, shrink proofing, keratinase, Shellac.

1. Introduction Recently in the textile industries various kinds of synthetic fibers with a variety of functions, in particular comfort, have been extensively produced as “Shingosen”. However wool fibers which have been used from ancient times as textile materials are the most excellent and functional for apparel end use among the natural and synthetic ones. The only defect of wool fibers which must be made improvements is to show shrinking behaviors when mechanical washing is carried out in water. The chlorine/Hercosett or DCCA finishing process is widely employed for shrink resistant finish of wool. Most of the chemicals used for oxidation involve halogen derivatives and are environmentally harmful as adsorbable organic halogens, AOX. Therefore intensive research has been made to develop more environmentally friendly processes. In previous papers it was found that proteases usually tried for shrink proofing cause to decrease tensile strength although the shrink resistance is improved [1,2]. Thus wool fibers were modified by pulse corona discharge and keratinases to improve the shrink resistance and tensile strength. The pulse corona treatment alone did not greatly affect the shrink resistance. After the discharge treatment the fibers were subjected to +

Corresponding author. Tel.: + 81-47-371- 2486. E-mail address: n-nagashima@wayo.ac.jp

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the treatment with the keratinases, in particular a single component of keratinase and a monomeric protein. The dual treatment with the pulse corona discharge and the pure keratinase improved both the shrink resistance and tensile strength. When a crude keratinase, Biosoak K, which has been used in this study, was employed, t h e t ensi l e st r en gt h was decr e as e d appr eci abl y du e t o t he ot her pr ot ea s es i n vol ved i n the crude keratinase as impurities. However the pure keratinase is difficult to use practically because of high cost. The purpose of this investigation is to gain an insight into the information about shrink proofing of wool fibers using Shellac and the crude keratinase, Biosoak K. Sorption behaviour of Shellac, which is a natural and thermosetting resin containing no halogen, on wool fibers and also enzymatic degradation of Shellac-modified wool fibers have been studied by Okabe et al. [3]. In this investigation after the treatment of the fibers with Shellac alone or Shellac/Biosoak K, shrink resistance, tensile strength, surface morphology, ESCA analysis, handle, and dimensional stability for washing have been studied.

2. Experimental Wool fabrics and merino wool slivers (JIS L0803) were used. The enzyme employed was a keratinase, Biosoak K, which is obtained from Nocardiopsis sp. (Amano Enzymes Inc) [1]. Biosoak K was the crude keratinase containing the other proteases. The molecular weight of the single component of keratinase was 20,000. Shellac (Gifu Shellac Manufacturing Co., Ltd) is a naturally-occuring and thermosetting resine of fatty acids which has been certified by Food and Drug Administration, FDA in USA and is widely applied to food additives. The enzyme treatment was carried out in 0.1M Tris-acetate buffer at pH 9 and 50°C in the bath ratio of 1:50 for 0.5-2 hrs. The enzyme concentration was 1 g・dm-3. The treatment with Shellac was done once or twice in methanol at 25 or 50°C in the bath ratio of 1:100 for 24 hrs. The Shellac concentration was 100 g・dm-3. Shellac was soluble in methanol but insoluble in water. The use of methanol as a solvent for Shellac is not preferable from the eco-friendly point of view. It was found that Shellac is soluble in 1% aq. ammonia solution. Thus the treatment with Shellac in 1% aq. ammonia solution was done at the concentration of 5-50 g・dm-3 also. After the treatment the fibers were neutralized and washed. The shrinkage was evaluated according to the Aachen felting test (IWTO-20-69E) using wool slivers. After the treatment the diameter of felt ball was measured to estimate the density of the ball. After the treatments with Shellac or Shellac/keratinase the tensile strength, SEM observation, handle, and dimensional stability for washing were measured by the usual way. At least three samples were measured in each experiment.

3. Results and discussion Figure 1 shows the relation between the degree of shrinkage and the treatment time of Biosoak K. In A : Untreated B : Biosoak (0.5hr) C : Biosoak (2hr) D : Shellac (once) E : Shellac (once)/ Biosoak (0.5hr) F : Shellac (once)/ Biosoak (2hr) G : Shellac (twice) H : Shellac (twice)/ Biosoak (0.5hr) I : Shellac (twice)/ Biosoak (2hr)

Felt-ball density / g・10-3 dm-3

0.10

0.08

0.06

0.04

Shellac conc. : 100 g・dm-3 in methanol

0.02

0.00

D E Samples

Fig. 1: Relation between density of felt ball of wool slivers and treatment time of Biosoak K.

Page 614 of 1108

this case the shrinkage was evaluated according to the Aachen felting test using wool slivers. The density of felt ball of the untreated slivers showed to be 0.09g・10-3 dm-3 whereas that of Shellac/Biosoak K-treated slivers was ca. 0.04g・10-3 dm-3. The density of felt ball tends to decrease as the shrink resistance of slivers appears. As is apparent in Fig. 1, the density of felt ball decreases when the slivers are treated with Shellac alone or Shellac/Biosoak K suggesting that Shellac alone exhibits shrink resistance and Shellac/Biosoak K is also effective. As mentioned before the use of methanol as a solvent for Shellac is not recommended because of the ecological and economical reasons. Thus we checked solvents for Shellac and found that 1% aq. ammonia solution is the best and Shellac can be dissolved in a concentration of 50 g・dm-3. Figure 2 exhibits the relation between the degree of shrinkage and the Shellac concentrations in 1% aq. ammonia solution. It was found that excellent shrink resistance can be achieved in dilute Shellac solution, 5 g ・dm-3.

Felt-ball density / g・10-3 dm-3

0.10

A : Untreated B : Shellac (5g・dm-3) C : Shellac (10g・dm-3) D : Shellac (25g・dm-3) E : Shellac (50g・dm-3)

0.08

0.06

0.04

0.02

0.00

C Samples

Fig. 2: Relation between density of felt ball of wool slivers treated with Shellac in 1% aq. ammonia solution and concentration of Shellac. Figure 3 illustrares the relative strength of wool fabrics treated with Biosoak K , Shellac, and Shellac/Biosoak K compared to that of the original ones. In this case the fabrics were used instead of the slivers. It is clear that the treatment with Biosoak K alone tends to lower appreciably the strength. The treatment with Shellac does not change the strength compared to the untreated. The decrease of strength using the enzyme alone is suppressed by the dual treatment with Shellac/Biosoak K. In addition the decrease of strength was not observed for the samples treated with Shellac alone in 1% aq. ammonia solution. A : Untreated B : Biosoak (1g・dm-3) 2hr C : Shellac (100g・dm-3) once D : Shellac (100g・dm-3) once / Biosoak (1g・dm-3) 0.5hr E : Shellac (100g・dm-3) once/ Biosoak (1g・dm-3) 1hr F : Shellac (100g・dm-3) once/ Biosoak (1g・dm-3) 2hr

Relative tensile strength / %

100

Samples

Fig. 3: Relative intensity of wool fabrics treated with Biosoak K, Shellac, and Shellac/Biosoak K.

Page 615 of 1108

In order to observe the surface morphology of wool fibers treated with Shellac alone and Shellac/Biosoak K, the SEM photographs were taken. The results are shown in Fig. 4. The SEM pictures of fibers treated with Biosoak K alone showed slight damage whereas those treated with Shellac alone or Shellac/Biosoak K did not.

(a)Untreated

(b)Biosoak K

(d) Shellac (methanol) / Biosoak K

Fig. 4: SEM photographs of wool fibers treated with Shellac, Biosoak K, and Shellac/Biosoak K. Also as can be seen in Fig. 5, the treatment with Shellac in 1% aq. ammonia solution does not show damage. In addition from the ESCA spectra it was not observed that Shellac covers the surface of fibers.

（a）1% aq. NH 3

（b）Shellac in 1% aq. NH 3 (50g・dm-3)

Fig.5: SEM photographs of wool fibers treated with Shellac in 1% aq. ammonia solution. Finally the dimensional stability of the treated fabrics for repeated washings of five times was measured at room temperature in water in the presence of detergents (A) and (B) (JIS L1096-8.39). The detergent (A) contains sodium salt of fatty acids and enzymes, and (B) does an anionic surfactant and enzymes. The trends of minus dimensional change for the untreated sample and plus for the Shellac or Shellac/Biosoak K-treated ones were observed. The dimensional stability of the fabrics treated with Shellac and Shellac/Biosoak K was maintained after the five times of washing. Although the treatment with Shellac alone was effective to improve the shrink resistance and tensile strength, the handle which was measured by KES-FB after the treatment became stiff slightly. However the handle was restored after the repeated washing. Okabe assumed from the results of SEM observation of surface morphology of Shellac-modified wool fibers and differential scanning calorimetric curves for Shellac-treated fibers that Shellac sorbes selectively into the curticle intercellular regions, exists within the cell membrane complex, and penetrates gradually into the cortex cell [3]. Although ESCA analysis in this study did not show clear evidence that Shellac is located in the CMC regions, from the results obtained it is likely that Shellac exists in the CMC and inhibits the penetration of crude proteases involved in Biosoak K into cortex regions through the CMC. This might result in the satisfactory strength. The treatment with Shellac alone improved both the shrink resistance and tensile strength. The slightly stiff handle was observed after the treatment with Shellac but recovered by the subsequent treatment with Biosoak K. However at the present stage further study is necessary for the practical application of Shellac to the shrink proofing.

4. References [1] N. Nagashima et al., Sen’i Gakkaishi, 68, 225 (2012). [2] N. Nagashima et al., Proc. of the Internat. Symp. on Fiber Sci. and Tech., Tokyo, Japan (2014). [3] T. Okabe et al., Sen’i Gakkaishi, 62, 123(2006), 63, 60 (2007).

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The 13th Asian Textile Conference Geelong, Australia, November 3 - 6, 2015

Silk modification through crosslink and in-situ polymerization under visible light Ka I LEE, Pui Fai NG, Bin FEI* 1

Institute of Textiles and Clothing, Hong Kong Polytechnic University, Hong Kong (* tcfeib@polyu.edu.hk)

Abstract. Natural silk was modified by simultaneous crosslinking and in-situ polymerization of sodium acrylate, with a novel initiator system under visible light. The silk was firstly swollen in aqueous solutions, where two different media were compared (DI water vs. formic acid solution). This fiber swelling allowed monomer penetration into the fiber and further polymerization inside. The modified silks were characterized by optical microscope, Fourier transform infrared spectroscope, and also evaluated in surface morphology and water absorption. Worse results were obtained for the formic acid solution, which is ascribed to the low pH effect on silk and catalyst. The successful modification may improve silk applications in biomedical textiles, such as wound dressings and dermal sealants. Keywords: silk, photocatalyst, crosslink, polymerization, water absorption

1. Introduction Modification of silk fibers by polymers was commonly achieved by graft polymerization of vinyl monomers, like acrylamide [1], methylmethacrylate [2], acrylonitrile [3] vinyltrimethoxysilane [4], and phosphoamide [5]. Extensive studies were conducted to modify the silk fibers to improve their textile performance such as thermal stability, crease recovery and anti-bacterial property. However, their water absorption performance was poor. For example, graft polymerization of methyl methacrylate on silk fiber decreased its water retention value from 3.80 g/g (ungrafted) to 1.82 g/g (grafted) [2]. In order to enhance the water absorption performance of silk fibers, sodium acrylate monomer would be selected. Sodium acrylate is well-known for preparation of superabsorbent polymers. Improvement in silk fiber or fabric’s water absorbency can improve its applications in biomedical textiles, such as wound dressings and sutures. Abundant and renewable light source enables to perform “green chemical reactions” under mild and environmental friendly conditions [6]. A photocatalyst, organometallic ruthenium (II) polypyridine complexes, like Ru(bpy) 3 2+, has been extensively studied due to their chemical stability at room temperature and long excited state lifetimes [7]. Among these complexes, tris(2,2’-bipyridyl)ruthenium(II) chloride (Ru(bpy)3Cl2) is commercially available and widely used as photocatalyst. It has been reported as an initiator for crosslinking of several proteins including silk fibroin. However, it has not been studied as an initiator for polymerization of vinyl monomers. In this research, we use Ru(bpy)3Cl2 as a photocatalyst for both silk crosslinking and acrylate polymerization. Two media are tried to modify silks with this novel initiator.

2. Experimental Bombyx Mori silk cocoon was purchased from Aurora Silk. Sodium acrylate (NaA), N, N’-methylene bisacrylamide (MBAAm), tris(2,2′-bipyridyl)ruthenium(II) chloride hexahydrate (Ru(bpy)3Cl2), and ammonium persulfate (APS) were all purchased from Sigma-Aldrich Co. and used without further purification. Silk fibers were drawn out of boiled cocoons and dried. Then they were immersed into DI water or formic acid solution (pH 1.9), in which 0.5 mM Ru(bpy)3Cl2, 10 mM APS, 10 wt% NaA and 2 wt% (of NaA) MBAAm were added. The immersion continued for 60 min in darkness at room temperature. The wet silks were taken out and irradiated under office light for 60 min at room temperature. Then, the resultant silk fibers were rinsed by DI water to remove unreacted residues and dried at 65 °C in the oven till constant weight. The silks treated in DI water and formic acid were denoted as S-DI and S-FA respectively. A controlled silk was treated by the same procedure but with pure DI water only, which is recorded as CS.

Page 617 of 1108

Silks were sandwiched between cover slide and glass slide. 9.3M LiBr was added to the samples for 60 min at room temperature, then sealed and heated in the oven for 60 min at 65 Â°C. The silks were observed under optical microscope (OM, Nikon OPTIPHOT-POL) to check their solubility. FTIR spectra were collected by attenuated total reflection Fourier transform infrared spectroscope (PerkinElmer Spectrum 100) in reflectance mode in a spectral region of 4000-650 cm-1 with 16 scans at 4 cm1 resolution. To examine their morphology, the wet silks were freeze-dried (Christ Alpha 1-4LD), then observed under a field emission scanning electron microscope (FE-SEM, JEOL JSM-6490) operating at 20 kV after gold sputtering. To measure the water absorption, the silks were immersed in DI water till equilibrium weight. The swollen silks were then centrifuged at 500 rpm for 1 min to remove free water. The water absorption was calculated by Q (g/g) = (Wf - Wi) / Wi, where Wi = weight of dry silk (g), Wf = weight of wet silk (g).

3. Results and discussion 3.1 Dissolution behavior The stability of obtained S-DI and S-FA in 9.3 M LiBr was observed under optical microscope (Figure 1). At beginning, both these fibers swelled irregularly. They gradually swelled into a confined fiber shape during immersion for 60 min. After heating, S-DI and S-FA showed fully swollen twin fibers without dissolution. The S-FA produced some additional dirties beside fibers. It was possibly caused by the degradation of silk during formic acid treatment [8]. While the CS swelled faster than those modified silks at room temperature, and finally dissolved upon heating.

Figure 1. Optical images of silks in 9.3 M LiBr after immersion for 1 min (1) and 60 min (2) and heating for 60 min (3): (a) S-DI, (b) S-FA, (c) CS.

3.2 FTIR analysis Figure 2 shows the FTIR spectra of various silk samples. The silk absorption peaks at 1515, 1440 and 1410 cm-1 are ascribed to N-H deformation and C-N stretching, CH2 bending and CÎąH2 wagging of silk proteins [9]. However, the increment in peak intensity at 1404 cm-1 was clearly seen in modified silks. After modification, the peak at 1410 cm-1 shifted to 1404 cm-1 and increased in intensity. It approves the incorporation of poly(sodium acrylate) (PANa) into silk fibers, since 1404 cm-1 is characteristic absorption peak of PANa due to CH2 bending [10]. While the other two characteristic peaks at 1554 and 1453 cm-1

Page 618 of 1108

(corresponding to asymmetric and symmetric stretching of carboxylate ion COO-) overlapped with the silk peaks at 1515 and 1453 cm-1. The S-FA gives a relative weak peak at 1404 cm-1 in comparison to that of SDI. This difference may be caused by the low pH of formic acid solution, which decreases the stability of Ru(bpy) 3 2+ and affects the silk crosslinking and acrylate polymerization.

Figure 2. FTIR spectra of silk fibers samples, where all curves were normalized at 3275 cm-1.

3.3 Surface morphology SEM images of various silks are shown in Figure 3. The raw silk presents very smooth and flat surface and twin fibers adhering together. The CS remains smooth and even while its twin fibers become separated due to loss of sericin. After the modification with additional crosslinked polymers, silks appeared differently. S-DI and S-FA showed some unevenness on surfaces. Their twin fibers are still fixed together with additional synthetic gels.

Figure 3. SEM images of freeze-dried (a) Raw silk, (b) CS, (c) S-DI, (d) S-FA.

3.4 Water absorption performance

Page 619 of 1108

The water absorption of a bundle of silks was measured by the gravitational method - monitoring the mass change during immersion in DI water. The polymerization enhanced the water absorption ability of silks, as was evident from the results of CS and modified silks (Table 1). At least 4 times higher water absorption was achieved through the incorporation of crosslinked PANa into silk fibers. Table 1. Bulk water absorption ratio of samples at equilibrium absorption.

Samples

Water absorption ratio (g/g)

1.8

S-DI

8.9

S-FA

8.6

4. Conclusion Silk fibers were modified with Ru(bpy)3Cl2 / APS initiator in two different media. The modified silks were successfully crosslinked and retained as integral twin fibers against dissolution in 9.3 M LiBr. FTIR results confirmed the incorporation of PANa network in silks. The water absorption performance of silks was significantly improved by this modification. These successfully modified silk fibers would be useful in biomedical textiles.

5. References [1] Das, A. M.; Chowdhury, P. K.; Saikia, C. N.; Rao, P. G. Silk fibre modification through graft copolymerization using vinyl monomer. Indian Journal of Fibre & Textile Research, 2010, 35, 107-114. [2] Das, A. M.; Saikia, C. N.; Hussain, S. Grafting of methyl methacrylate (MMA) onto Antheraea assama silk fiber. J. Appl. Polym. Sci. 2001, 81, 2633-2641. [3] Bajpai, S. K.; Chand, N.; Mary G. Preparation of poly(acrylonitrile)-grafted silk fibers with antibacterial properties. Fiber. Polym. 2010, 11, 338-345. [4] Tsukada, M; Arai, T.; Winkler, S.; Freddi, G. Physical properties of silk fibers grafted with vinyltrimethoxysilane. J. Appl. Polym. Sci. 2001, 79, 1764-1770. [5] Guan, J.; Chen, G. Performance of flame retardancy silk modified with water-soluble vinyl phosphoamide. J. Appl. Polym. Sci. 2013, 129, 2335-2341. [6] Schultz, D. M.; Yoon, T. P. Solar synthesis: prospects in visible light photocatalysis. Science 2014, 343, 343. [7] Narayanam, J. M. R.; Stephenson, C. R. J. Visible light photoredox catalysis- applications in organic synthesis. Chem. Soc. Rev. 2011, 40, 102-113. [8] Zhang, F.; Lu, Q.; Ming, J.; Dou, H.; Liu, Z.; Zuo, B.; Qin, M.; Li, F.; Kaplan, D. L.; Zhang, X. Silk dissolution and regeneration at the nanofibril scale. J. Mater. Chem. B. 2014, 2, 3879-3885. [9] Boulet-Audet M.; LefĂ¨vre, T.; Buffeteau, T.; PĂŠzolet. M. Attenuated total reflection infrared spectroscopy-an efficient technique to quantitatively determine the orientation and conformation of proteins in single silk fibers. Appl. Spectrosc. 2008, 62, 956-962. [10] Kirwan, L. J.; Fawell, P. D.; van Bronswijk, W. In situ FTIR-ATR examination of poly(acrylic acid) adsorbed onto hematite at low pH. Langmuir 2003, 19, 5802-5807.

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The 13th Asian Textile Conference Geelong, Australia, November 3 - 6, 2015

The effect of copper and iron on wool photostability Alison King 1+, Keith Millington 1 1

CSIRO Manufacturing, Deakin University, Pigdons Road, Waurn Ponds 3216,

Abstract. Photoyellowing of wool occurs via a free-radical oxidation reaction when absorbing chromophores within the fibre are excited by UV wavelengths. Oxidation can be catalysed by metal ions, particularly iron and copper. Wool fabric was doped with aqueous iron or copper and exposed to UVB, and cotton and nylon were treated similarly for comparison. All fibres exhibited a colour change after exposure. Copper-doped wool yellowed to the greatest extent, after treatment with oxalic acid to remove free metal ions and complexes. Contrary to its effect on colour, copper did not increase hydroxyl radical production in wool, whereas iron increased production by up to 50%. The tryptophan and visible fluorescence of unirradiated wool were reduced by the presence of metal ions that was dependant on concentration. Keywords: wool, photostability, photo oxidation

1. Introduction Wool and all other natural fibres degrade and oxidise when chromophores present in their structure absorb UV and react with atmospheric oxygen [1]. In the case of wool, the absorbing chromophores are the amino acids tyrosine, tryptophan and phenylalanine, which in the presence of atmospheric oxygen initiate the production of hydrogen peroxide, superoxide and hydroxyl radicals [1]. These reactive oxygen species are associated with chain scission and the generation of sulphur- and carbon-centred radicals [2] which results in crosslinking and oxidation of the wool proteins. The yellow oxidation products of tryptophan are considered to be the major cause of yellowing in photoirradiated wool [3] and there is a strong correlation between photoyellowing and the degradation of tryptophan residues after exposure to UV [4]. Metals that are capable of single-electron transfer, in particular copper and iron, catalyse the production of hydroxyl radicals in aqueous hydrogen peroxide solution via the Fenton reaction. The reaction occurs in living cells, where reactive oxygen species interact with protein-bound copper and iron to catalyse hydroxyl radical production [5]. It is likely that copper and iron have the same effect on wool proteins, since these metals increase the photosensitivity of wool [3] and hydroxyl radical production decreases in photoirradiated wool when metal ions, including copper and iron, are removed by chelation [1, 5]. In this study, the effect of copper and iron on the photostability of wool was determined by exposing metaldoped wool to UV light and measuring the change in colour. The samples were moist during irradiation to accelerate yellowing [6] and allow metal-catalysed oxidation reactions to occur. Cotton and nylon were also doped and irradiated under the same conditions for comparison, as these fibres have non-aromatic monomers and only one type of functional group. The colour of irradiated metal-treated fabric was measured after treatment with oxalic acid to chelate and remove all free and loosely bound metal ions. By removing these coloured complexes, the residual colour of irradiated fibres is due to the natural wool chromophores and those induced by exposure to UV. Hydroxyl radical production in doped photoirradiated wool was determined using a fluorescent probe [1] to evaluate the contribution of copper and iron. The proximity of copper and iron to tryptophan residues may affect the rate of degradation of tryptophan, since hydroxyl radicals are highly reactive and interact close to where they are generated. Fluorescence measurements of tryptophan (290 nm excitation (ex) and 340 nm emission wavelength (em)) and the oxidation products (370ex, 450em) in wool were used to determine if copper and iron affected tryptophan + Corresponding author. Tel.: + 61-352 464804 E-mail address: Lee.King@csiro.au

degradation after exposure to UV. Severely yellowed wool has a significantly weaker tryptophan signal than whiter wool [6]. The visible fluorescence peak is stronger in yellowed wool, and in the tips of the fibre exposed

Page 621 of 1108

to the maximum dose of UV radiation which have the highest metal content [6].

2. Materials and methods 2.1.

Preparation of fabrics

Iron (II) and copper (II) sulphates were obtained from BDH Chemicals, Australia and Ajax Laboratory Chemicals, Australia, respectively. Pure wool, plain weave fabric (142 g/m2) was produced at CSIRO Manufacturing. Copper and iron solutions (5 and 50 ppm) were prepared with ultra-pure water. The pH of the iron solution was adjusted to pH 2 with sulphuric acid to prevent rapid oxidation of Fe2+ to Fe3+ and the copper solution was prepared without pH control (pH< 4). Fabrics were wet out and shaken in the metal solutions for 30 minutes at a liquor ratio of 3:1. Wool was treated with both 5 and 50 ppm solutions and cotton and nylon were treated with the 50 ppm solution. Excess liquid was removed and the samples were rinsed in 100 ml ultra-pure water, drained and shaken in a fresh bath of 100 ml of ultra-pure water for 15 minutes, centrifuged and air dried. The copper and iron contents of the wool samples (Table 1) were determined using ICP-AES as previously described [7]. Table 1. Iron and copper content (mg/kg) of doped wool doping solution â&#x20AC;&#x2022;

2.2.

Sample

Copper

Iron

untreated

4.1

Copper 5 ppm

Cu 5

Copper 50 ppm

Cu 50

283

Iron 5 ppm

Fe 5

3.9

Iron 50 ppm

Fe 50

4.1

Measurement of colour, fluorescence and hydroxyl radical production

Samples were wet out with a surfactant solution and excess liquid was removed. The wet samples were sealed in plastic bags, placed in contact with a broadband UVB lamp (Philips TL20 W/12RS, major peaks 280320 nm) and irradiated for four hours before being removed from the bags and air dried. Fabric was folded into four layers for colour measurement using a Gretag Macbeth Color-Eye 7000A reflectance spectrophotometer (Munich, Germany) using the small area view aperture (7.5x10 mm), a D65 light source and a 10Â° collection angle with the spectral component included. The CIE L*a*b* colour values were measured by averaging three readings. The colour was measured again after soaking the samples overnight in a 0.5% solution of oxalic acid and thoroughly rinsing and drying. L* indicates brightness; 100 is the lightest and 0 is the blackest. Samples with positive a* are redder and those with negative a* are greener. Positive b* indicates that samples are yellower and negative b* indicates they tend to be blue. The fluorescence of wool samples was measured using a Hitachi F4500 fluorescence spectrophotometer fitted with a solid sampling accessory oriented to eliminate specular reflectance. Hydroxyl radical production in photoirradiated wool was determined using terephthalic acid which reacts specifically with hydroxyl radicals to form hydroxyterephthalic acid (HTA) that is detectable using fluorescence spectroscopy [1]

3. Results and discussion 3.1.

The effect of iron and copper on colour and hydroxyl radical production

Treatment with a copper solution caused all fibres to become greener (Table 2) due to the formation of copper complexes, while treatment with iron had very little effect on colour. The differences between doped and untreated wool, and between treated wool and nylon and cotton, became more apparent after UVB irradiation. Copper-doped cotton and nylon, and undoped wool remained green while copper-treated wool became significantly redder and yellower. Iron-doped wool became greener after irradiation compared to undoped wool and iron-doped and irradiated cotton was redder. Treatment with oxalic acid stripped or destroyed the chromophores from metal-doped nylon to the extent that their colour was similar to undoped nylon, whilst copper-doped cotton remained yellower. A similar result was observed for iron-doped wool, where the colour became yellower after oxalic acid treatment. Although oxalic acid extracted chromophores

Page 622 of 1108

from copper-doped wool, the fibres were significantly redder and yellower than undoped wool that was treated under similar conditions. These observations demonstrate that coloured metal species contributed to the colour of all photoirradiated fibres. They also show that copper and iron can affect the photosensitivity of wool and cotton, but not nylon. The UV absorbing chromophores in cotton and nylon are from additives and contaminants and not the fibres themselves [1]. The amide species in nylon are not sites on which copper and iron bind and catalyse the reactions that cause oxidation. However, these metals seem to have an affinity for the carboxyl and hydroxyl groups in cotton and a small influence its photosensitivity. On the other hand, copper had a strong effect on wool and increased the rate of photoyellowing to a greater extent than iron. The yellow coloration has been identified as oxidation products of wool proteins [3] although it is possible that some protein-bound copper remained in the wool after oxalic acid treatment and contributed to the overall colour. Copper (II)-protein complexes, with amines, amides and amino sulfones, are violet coloured and copper (II)-protein complexes absorb UV which may have increased the photosensitisation of wool. Alternatively, copper may be bound close to the aromatic amino acid residues and catalyse oxidation reactions that cause yellowing. Table 2 L*, a*and b* CIE values of undoped (und) and wool, cotton and nylon doped with a 50 ppm solution of copper and iron before and after irradiation with UVB for 4 hours and after irradiation and treatment with oxalic acid. L*

wool

cotton

nylon

wool

cotton

nylon

wool

cotton

nylon

undoped

84.5

90.2

94.5

0.84

-0.01

-1.08

12.2

4.4

3.71

undoped UVB

83.2

91.1

94.0

-0.02

-0.23

-1.04

16.3

3.45

5.1

undoped UVB OA

86.2

91.4

93.4

-0.41

-0.18

-1.46

15.8

3.0

6.41

copper doped

83.1

90.2

93.7

-0.79

-1.18

-1.92

11.4

4.19

3.15

copper doped UVB

78.0

88.7

93.1

1.82

-1.29

-1.69

21.6

7.32

5.41

copper doped UVB OA

82.2

90.5

93.2

0.61

-0.27

-1.33

20.4

5.78

6.28

iron doped

83.2

89.9

94.0

0.76

0.00

-1.05

11.9

4.62

3.72

iron doped UVB

79.0

89.1

93.2

-0.65

0.38

-1.04

14.3

5.68

5.32

iron doped UVB OA

86.0

91.4

93.6

-0.38

-0.28

-1.35

17.5

3.94

6.22

Fluorescence intensity

Hydroxyl radicals are produced when wool is exposed to UV [1]. The production of hydroxyl radicals was measured in copper- and iron-treated wool during exposure to UV to assess their ability to act as catalysts. Contrary to its effect on colour, the presence of copper had no effect on the amount of hydroxyl radicals detected (Fig. 1). Iron, which was present at a lower concentration than copper, increased hydroxyl radical production by as much as 50%, and this increased with iron content of the wool. Iron and copper either initiate different reactions when wool is exposed to UV, or they are bound to different sites on the wool proteins. Copper may be bound to histidine [8] residues which has antioxidant properties. Hydroxyl radicals produced by metal-catalysed reactions may not contribute significantly to photoyellowing in copper-doped wool. 8 6 4 2 0 blank un-doped

Cu 5

Cu 50

Fe 5

Fe 50

ppm ppm ppm Fig. 1 Fluorescence intensity of HTA (位 ex =315 nm, 位ppm em =425 nm) indicating hydroxyl radical concentration after irradiation with UVA for 1 hour in TA (blank), undoped and copper and iron treated wool (5 and 50 ppm solutions).

Both metals reduced the fluorescence of tryptophan in unirradiated wool (Table 3), copper having the strongest effect. Metals that are bound in close proximity to the fluorophores can quench the fluorescence of proteins [9]. While copper may be bound closer to tryptophan than iron, the effect is more likely due to the metal content of the wool. The copper content of wool treated with the 50 ppm copper solution was 283 mg/kg (4.5 mmol/kg; Cu 50) whereas the content of iron in wool treated with a similar concentration iron solution

Page 623 of 1108

was 78 mg/kg (1.4 mmol/kg (Fe 50). In addition, the cumulative iron and copper content for each fabric was negatively and linearly correlated to both the tryptophan (r2=0.9) and the visible (r2=0.95) fluorescence in unirradiated wool. The tryptophan fluorescence was reduced in all irradiated fabrics, and the differences in the visible fluorescence were small. Table 3 Tryptophan fluorescence (290ex 340em) and visible fluorescence (370ex 450em) of untreated and copper and iron treated wool 290ex 340em unirradiated

370ex 450em

4hrs UVB

unirradiated

4hrs UVB

untreated

822

25.3

468

309

Cu5

687

25.6

408

347

Cu50

414

28.6

229

232

Fe5

835

22.7

465

311

Fe50

684

30.6

391

361

4. Conclusions Doping wool with copper increased its rate of photoyellowing to the greatest extent, whereas hydroxyl radical production increased only in iron-doped photoirradiated wool. This suggests that copper and iron may be involved in different mechanisms, possibly due to different sites they bind to on the wool proteins. The proximity of bound copper and iron to tryptophan residues, and their effect on the oxidation of wool could not be determined using fluorescence spectroscopy.

5. References [1] Millington, K.R. and L.J. Kirschenbaum, Detection of hydroxyl radicals in photoirradiated wool, cotton, nylon and polyester fabrics using a fluorescent probe. Coloration Technology, 2002. 118: p. 6-14. [2] Smith, G.J., The effect of light at different wavelengths on the electron spin resonances in wool. Textile Research Journal, 1976. 46: p. 510-513. [3] Dyer, J.M., S.D. Bringans and W.G. Bryson, Characterisation of photo-oxidation products within photoyellowed wool proteins: tryptophan and tyrosine derived chromophores. Photochemical and Photobiological Sciences, 2006. 5: p. 698-706. [4] Lennox, F.G. and R.J. Rowlands, Photochemical degradation of keratins. Photochemistry and Photobiology, 1969. 9(4): p. 359-367. [5] Smith, G.J., Effect of bound metal ions on photosensitivity of wool. New Zealand Journal of Science, 1974. 17: p. 349-350. [6] Millington, K.R., Photoyellowing of wool. Part 1: Factors affecting photoyellowing and experimental techniques. Coloration Technology, 2006. 122: p. 169-186. [7] King, A.L. and K.R. Millington, Trace metals in fleece wool and correlations with yellowness. Biological Trace Element Research, 2013. 151(3): p. 365-72. [8] Marsh, J.M., et al., Advanced hair damage model from ultra-violet radiation in the presence of copper. International Journal of Cosmetic Science, 2015: p. 1-10. [9] Rahimi, Y., A. Goulding, S. Shrestha, S. Mirpuri and S.K. Deo, Mechanism of copper induced fluorescence quenching of red fluorescent protein, DsRed. Biochemical and Biophysical Research Communications, 2008. 370(1): p. 57-61.

Page 624 of 1108

The 13th Asian Textile Conference Geelong, Australia, November 3 - 6, 2015

The Glass Transition Temperature of Cotton C.M. Denham+ 1, 2, M.G. Huson 1, S.G. Gordon 1 and X. Wang 2 1

CSIRO Manufacturing Deakin University, Institute for Frontier Materials

Abstract. Single fibre samples of cotton, Tencel and viscose were studied using dynamic mechanical analysis (DMA) under changing humidity conditions. This enabled the softening of these cellulosic fibres to be detected by measurement of the storage modulus as a function of water addition at set temperatures. At high temperature and humidity, a significant drop in storage modulus was observed for all three fibre types, allowing the glass transition to be determined. Keywords: Cotton, cellulose, glass transition, relative humidity, DMA

1. Introduction Cotton lint fibre is produced by the epidermal cells of the cotton seed and is made up primarily of cellulose, which accounts for over 90% of the entire cell mass1. Cellulose is a polymer made up of glucose residues in a straight chain (non-branching) configuration, and is the world’s most abundant biopolymer. While it is widely studied, researchers remain divided as to whether cellulose, and therefore cotton fibre, goes through a glass transition. Among those who accept that a transition exists, there is no definitive result. The glass transition (Tg) of a polymer occurs as the polymer molecules, within the amorphous regions, reach a temperature sufficient to allow free rotation around the polymer backbone. At low temperatures, below Tg, molecules only have enough energy for small vibrational movements, making the material stiff and glasslike. As the temperature increases beyond Tg, there is sufficient energy to allow greater molecular movement and the material softens to become more rubbery. Many polymer properties change during this transition, such as heat capacity, elasticity, refractive index, conductivity and permiability2, and these may be used as a means of measuring the transition. The transition from a glassy to rubbery state can also occur as the moisture content of a sample is increased3. Water within the polymer structure acts as a plasticizer and reduces the temperature at which the glassy transition occurs. This means that by holding the sample at a constant temperature, the glass transition may be determined via the addition of moisture, to give the water volume fraction at glass transition (Wg), which can then be converted to Tg via water sorption isotherms. There have been several studies published aimed at determining the Tg of cellulose. Of these, most have focused on microcrystalline cellulose (MCC)4,5,6,7 as used in the pharmaceutical industry and to a lesser extent as wood pulp for paper production8,9,10,11. Kargin in 196012 first reported a dry Tg of cellulose of 220°C. This was done using a thermomechanical method to investigate solvent doped regenerated cellulose. Since then, the Tg of cellulose has been studied using predominantly differential scanning calorimetry (DSC)6,7,10,11 or mechanical methods8,9,11 with mixed success. There have been many reported Tg values for cellulose under moist conditions, however these have been shown to vary by up to 100°C between authors4,11. Some of this variation may be accounted for by differences in cellulose origin and measurement technique. Nevertheless, it is clear that although several authors have measured transitions, there is a great deal of variation in the measured temperatures. ___________________________________________ +

Corresponding author. Tel.: + 61-352-464 037 E-mail address: Chantal.Denham@CSIRO.au

Page 625 of 1108

Further work is therefore needed to find a reliable and reproducible method of measuring the Tg of cellulose. This investigation aims to do this by utilizing the plasticisation effect caused by the addition of water to cellulose, to study the glass to rubber transition.

2. Experimental Dynamic mechanical analysis was used to determine the Wg of three cellulose samples. A single cotton, Tencel or viscose fibre was mounted in the film/fibre tension clamp of a TA Instruments Q800 dynamic mechanical analyser, fitted with the TA DMA-RH accessory. Preliminary stress-strain curves were conducted at 35°C, under dry nitrogen at a rate of 0.1 N/min-1 (data not shown), and used as the basis for programming instrument strain and static force for each sample, as shown in Table 1. A minimum dynamic force of 0.001 N was applied to each sample. Samples were equilibrated at each set temperature, (from 10 to 90°C) for 20 mins. At each temperature, the relative humidity was taken to 50% and equilibrated for a further hour before increasing the humidity in 1% steps every 8 mins, up to a maximum of 90% relative humidity. The onset of Wg was defined as the initial downward inflexion in storage modulus, measured using tangential lines before and after the inflection. The storage modulus is relative only, due to the difficulty of accurately defining the fibre cross-sectional area. Table 1: DMA strain and force parameters set for each sample. Cotton

Tencel

Viscose

Oscillating Strain (%)

0.0375

0.1000

0.1016

Static Force (N)

0.0011

0.0110

0.0019

3. Results and Discussion The storage modulus results for each temperature were plotted together, as a function of relative humidity (RH), for comparison. The curves obtained for cotton are typical of the three fibre types and are presented in Figure 1. Fibres showed a clear lowering of modulus as the humidity increased. Of chief interest is the rapid decrease in modulus at high humidity, most prominent in the 70°C and 80°C cycles. This drop and leveling off is consistent with the behaviour of a polymer being plasticised by moisture and going through its glass transition. Furthermore, the transition is shown to shift to lower humidity as temperature increases. This pattern was consistent across all cellulosic three sample types. It is also worth noting that the change in modulus is reasonably small in comparison to those seen in synthetic polymers, most likely due to the diluting effects of a highly crystalline polymer. Relative Storage Modulus (%)

10°C 20°C 30°C 40°C 50°C 60°C 70°C 80°C Relative Humidity (%)

90°C

Figure 1: Change in storage modulus of a single cotton fibre as humidity is increased under different temperature conditions.

The glass transition results for all fibres measured as a function of humidity, Wg, are summarised in Table 2. Moisture sorption isotherms for each fibre type14,15 allow for the determination of their moisture content (MC) at each humidity. Ideally, the moisture sorption isotherms used to translate RH to MC would be collected at the same temperature as the experimental data, because sorption decreases at elevated temperature. However, very few isotherms collected at elevated temperatures are available in the literature. For this reason all results

Page 626 of 1108

were initially converted using isotherms collected at 25°C, and then the 40°C, 70°C and 90°C cycles of cotton and viscose were also corrected using literature isotherms available at 35.5°C, 70°C and 100°C13. Table 2: Glass transition expressed as the RH and MC at which softening occurs for a given temperature. Cycle

Cotton Wg

Tencel Wg

Viscose Wg

Temp (°C)

RH (%)

MC (%)

MCcor (%)

RH (%)

MC (%)

RH (%)

MC (%)

MCcor (%)

79.2

10.3

8.9

77.4

16.6

80.5

16.4

15.3

77.6

9.7

---

15.9

78.5

15.5

---

9.2

---

74.6

15.4

77.6

15.2

---

75.1

9.1

7.1

14.8

76.4

14.7

8.3

---

70.5

13.9

72.3

13.2

---

71.1

8.1

5.3

---

71.3

12.8

9.3

These experimental results are shown in Figure 2, along with the results expected when calculated using the Fox equation3: 1 = w1 + w2 Tg Tg1 Tg2

Glass Transition Temperature (°C)

Crystallinity (%)

The Fox equation calculates the Tg of a ‘mixture’ by accounting for the Tg of the individual components, Tg1 (cellulose Tg = 220°C12) and Tg2 (water Tg = -137°C16), with reference to the weight fraction of each (w1 and w2). It is necessary to take polymer crystallinity into account using this equation, as it is assumed that water can only enter the amorphous fraction of the polymer. Without doing so, a crystalline polymer such as cellulose would have a significantly higher weight fraction of water within the amorphous regions than the calculated weight fraction of water for the whole sample. Figure 2 shows the glass transition temperatures calculated using the Fox equation at varying fibre crystallinities. 0 25 50 75 90 Cotton

Water Content (%) Figure 2: Experimental glass transition results for cellulose both raw (•) and corrected for temperature (×)13, overlaid on the predicted results calculated using the Fox equation (―).

While the raw data does not conform well to the Tg predicted using the Fox equation, correcting for temperature when converting to moisture content improves the correlation. For cotton, the raw data is best described by the Fox equation at 50% crystallinity, this is somewhat lower than the expected crystallinity of around 75%1. After correction, the data conforms better to the Fox equation curves and shows crystallinity approximately 60%. As expected, the regenerated cellulose samples conform to the Fox equation curves, at a lower crystallinity than cotton. The results found in this study show similar trends in cotton as those shown by Ogiwara9, and between regenerated cellulose and ball milled wood cellulose as studied by Paes11. That said, there are differences in Tg for given humidities of up to 25°C in cotton, which may be accounted for by difference in method. Method of examination is important to consider. For example comparing the Tg as measured by the loss of modulus,

Page 627 of 1108

to the temperature dependence of water binding using NMR9, may show different results due to varying sensitivity to the transition or shifting of the measured temperature due the rate dependent nature of the transition. In contrast, these findings are not consistent with results reported by Batzer10 and Hancock4 who claim sub-ambient temperatures for Tg of cellulose conditioned at high relative humidity. Similarly low Tg measurements were also reported by Szczesniak7 using DSC. It is worth noting that the moisture contents reported by Batzer10 and Hancock4 at high humidity are somewhat greater than the generally accepted literature values of 15-30% for untreated cellulose.

4. Conclusion The glass transition of cotton, Tencel and viscose was studied with respect to moisture content using dynamic mechanical analysis. A clear transition was observed in cotton at 70°C and a relative humidity of 75%, lowering to 72% RH at 80°C, consistent with the behavior of a polymer going through its glass transition. Regenerated celluloses also showed clear transitions at similar humidities for each temperature. Further work is underway to confirm these results using alternative techniques.

5. References [1] Basra, A. S. (1999). Cotton fibers : Developmental Biology, Quality Improvement, and Textile Processing. New York ;London, Food Products Press. [2] Collins , E. A., J. Bares and F. W. Billmeyer (1973). "Experiments in polymer science”. [3] Cowie , J. M. G. and V. Arrighi (2007). Polymers: chemistry and physics of modern materials, CRC press. [4] Hancock, B. C. and G. Zografi (1994). "The Relationship Between the Glass Transition Temperature and the Water Content of Amorphous Pharmaceutical Solids." Pharmaceutical Research 11(4): 471-477. [5] Ford , J. L. (1999). "Thermal Analysis of Hydroxypropylmethylcellulose and Methylcellulose: Powders, Gels and Matrix Tablets." International Journal of Pharmaceutics 179(2): 209-228 [6] Picker, K. M. & S. W. Hoag (2002). "Characterization of the Thermal Properties of Microcrystalline Cellulose by Modulated Temperature Differential Scanning Calorimetry." Journal of Pharmaceutical Sciences 91(2): 342-349. [7] Szcześniak, L., A. Rachocki and J. Tritt-Goc (2008). "Glass Transition Temperature and Thermal Decomposition of Cellulose Powder." Cellulose 15(3): 445-451. [8] Goring , D. A. I. (1963). "Thermal Softening of Lignan, Hemicellulose and Cellulose." Pulp and Paper Magazine of Canada 64(12): T517-T527. [9] Ogiwara, Y., H. Kubota, S. Hayashi and N. Mitomo (1970). "Temperature Dependency of Bound Water of Cellulose Studied by a High-Resolution NMR Spectrometer." Journal of Applied Polymer Science 14(2): 303-309 [10] Batzer, H. and U. T. Kreibich (1981). "Influence of Water on Thermal Transitions in Natural Polymers and Synthetic Polyamides." Polymer Bulletin 5(11): 585-590. [11] Paes , S. S., S. Sun, W. MacNaughtan, R. Ibbett, J. Ganster, T. J. Foster and J. R. Mitchell (2010). "The Glass Transition and Crystallization of Ball Milled Cellulose." Cellulose 17(4): 693-709 [12] Kargin, V. A., P. V. Kozlov and N. Wang (1960). "The Glass Transition Temperature of Cellulose." Dokl Akad Nauk SSSR 130: 356-358 [13] Wiegerink, J. G. (1940). "The moisture relations of textile fibres at elevated temperatures." Textile Research Journal 10(9): 357-371. [14] Wertz, J.-L., O. Bédué and J.-P. Mercier (2010). Cellulose Science and Technology. Lausanne, EPFL Press. [15] Okubayashi, S., U. J. Griesser and T. Bechtold (2005). "Moisture Sorption/Desorption Behavior of Various Manmade Cellulosic Fibers." Journal of Applied Polymer Science 97(4): 1621-1625. [16] Capaccioli, S. and K. Ngai (2011). "Resolving the Controversy on the Glass Transition Temperature of Water?" The Journal of chemical physics 135: 104504.

Page 628 of 1108

The 13th Asian Textile Conference Geelong, Australia, November 3 - 6, 2015

The Role of Various Fabric Parameters on the FAST Results of Wool and Wool Blend Worsted Fabrics Sweta Das1 +, L. Hunter1,2 and A. F. Botha2 1

Department of Textile Science, Faculty of Science, Nelson Mandela Metropolitan University P.O. Box 77000, Port Elizabeth 6031, South Africa 2 CSIR Materials Science and Manufacturing, Polymers and Composites Competence Area, P.O. Box 1124, Port Elizabeth 6000, South Africa

Abstract. The objective of this study was to develop a better understanding of the fabric parameters which affect the quality related properties of wool and wool blend worsted type fabrics. The main focus was on Fabric Objective Measurement (FOM), a highly developed technology which provides a more complete picture of fabric quality, tailorability and clothing performance. A range of mostly locally sourced commercial and pilot plant wool and wool blend fabrics were measured on the FAST (Fabric Assurance by Simple Testing) system for this purpose. The range of fabrics covered different weave structures and blends (100% wool, wool and polyester and wool and mohair. Composite FAST fingerprint charts were generated and results statistically analysed, tabulated and plotted so as to illustrate the main trends and effects.

Keywords: FOM, fabric quality, FAST

1. Introduction Fabric quality, especially handle, colour and lustre, has been traditionally, and often still is, subjectively evaluated by individuals belonging to the textile and clothing industries as well as people from other backgrounds, including consumers. Handle, in particular, has been considered and used as a subjective measure of quality, and has been the basis of fabric selection. By handling a fabric an expert can form a considered opinion of the quality of the fabric and the ease with which it can be made up into the required garment. Nevertheless, there are inconsistencies in the results, even of such experts, the subjective assessments often varying due to various factors, such as culture and religion. As mentioned by Kawabata et al. [1], it has been found that the fabric mechanical properties are of the utmost importance in determining fabric and garment quality and performance, including handle. This, together with limitations in subjective evaluations, have resulted in a considerable amount of research on the objective measurement of fabrics; firstly as a scientific means to quantify certain fabric quality and performance characteristics and secondly, as a basis for fabric specification, product and process development, process control and quality assurance. With increasing demands for new styles and patterns and large scale production, the need for a systematic, accurate, efficient and reliable system of fabric quality assessment became imperative. It is probably true to say that Peirce [2] was one of the first researchers to investigate the relationship between fabric handle and the fabric mechanical properties, and can be called â&#x20AC;&#x153;the father of Fabric Objective Measurementâ&#x20AC;?. After him, many other researchers, notably Postle, Kawabata and Niwa [3-5] made major contributions towards the science and technology of the objective measurement and characterization of fabric quality related properties, such as handle, making up and wear performance. This eventually culminated in the revolutionary KES-F technology and communication system of fabric objective measurement (FOM), popularly known as the Kawabata system, developed by Prof. Kawabata and his team in Japan. This system certainly represented a quantum leap as far as fabric objective measurement is concerned. Nevertheless, the system, though ideal for research laboratories and large and advanced fabric and clothing manufacturers, was +

Corresponding author. Tel.: + 27-041-585 0385. E-mail address: sweta.patnaik2010@gmail.com

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considered too sophisticated and expensive for wider use. This lead to the development of the Fabric Assurance by Simple Testing (FAST) system, which was more user friendly and less expensive than the Kawabata system. It was developed to provide the industry with a single, robust and relatively inexpensive system for the objective measurement of fabric properties important in tailoring. Although both the Kawabata and FAST system were initially developed for, and applied to, worsted type fabrics, mainly wool and wool blends, and for providing a measure of fabric handle and tailorability, both systems have found many other applications. A considerable amount of research, focused on specific aspects of FOM, has been carried out and published, much of which has been captured in review or book form. Except for the initial development of the KES-F and FAST database, charts (fingerprints) and control limits, little further work appears to have been carried out, or published at least, on creating more recent databases and also ones specific to a particular country or region. Furthermore, there can be no doubt that, in this highly competitive and technology driven global environment, no manufacturer of high quality fabric or clothing will continue to be globally competitive without resorting to FOM. In the light of the above, and the fact that FOM is still in its infancy in South Africa, and attracts little interest from fabric and clothing manufacturers, it was decided to build a FAST database of worsted type fabrics either produced in South Africa or imported and converted locally into garments. This could be used by local fabric and clothing manufacturers as a basis of reference, or benchmark, in future, and could stimulate the interest of local fabric and clothing manufacturers in applying FOM (FAST in this case) on a routine basis for fabric and garment quality control and assurance, product development, etc. To this end, a wide selection of worsted type fabrics was sourced from different local fabric and clothing manufacturers and tested on the FAST system.

2. Research Methodology 2.1 FAST tests The various FAST related properties were studied using different wool and wool blend fabrics of various weights ranging from 200-250 g/m2. Three different fabrics of different weave types (plain and twill) and different blends (wool/mohair, wool/polyester and 100% wool) were sourced in South Africa. The data obtained by carrying out the FAST tests were analyzed, interpreted, and appropriate conclusions and recommendations made. Wherever relevant, individual FAST properties of various fabrics were combined and subjected to statistical analysis, using ANOVA, for assessing the statistical significance of the properties and any differences in this respect.

2.2 FOM application and distribution The global manufacturers and suppliers of FAST and Kawabata FOM systems [6-8], with headquarters in Australia and Japan, respectively, were contacted for information on the global application, sales and distribution of their respective systems in order to assess the extent to which these systems have found application, as well as in which institutions and countries, thereby providing background and motivation for local companies to adopt FOM system for improved quality control and assurance.

3. Results and Discussions On the basis of the testing carried out on the FAST set of instruments, control charts have been prepared(few of which are shown) and compared with other similar weight fabrics within a particular group categorized on the basis of area weight (g/m2). In addition to this, a statistical analysis of the selected FAST properties was carried out by grouping similar weight fabrics. A particular group of fabrics, ranging in weight from 200 to 250 gm/m2 have been selected for analyzing the FAST properties. The results were captured, tabulated and analyzed, where they collectively reflect on related aspects. The ANOVA method was used to compare a group of fabrics in terms of certain fabric properties such as bending length and extensibility.

3.1 Data analysis: bending length In the statistical analysis on warp bending length, as measured on the FAST, three different types of fabrics, varying in weave structure (plain and twill weave) and with weight within the range of 200 to 250 g/m2, have been compared.

Page 630 of 1108

Table 1: Bending length (mm) of fabrics Wool/Mohair (200 g/m2) 16.5 16 17 17 16.5 16 16.5

Wool/Polyester (255 g/m2) 6.3 6 7 7.5 6.5 5 5.5

100% Wool (250 g/m2) 5 4 5 8 2 5 4.8

Table 2: Statistical analysis of warp bending length Îą

ANOVA: Single factor

0.05

SUMMARY Groups

Count

Sum

Average

Variance

Wool/Mohair

115.5

16.5

0.17

Wool/Polyester

43.8

6.3

0.73

Wool

33.8

4.8

3.14

ANOVA Source of Variation

P-Value

F crit

Between Groups

567.4181

283.709

211

0.000

3.554557

Within Groups

24.21143

1.345079

Total

591.6295 20 Reject null hypothesis because p < 0.05 (Means are Different)

Table 1 shows the bending length results obtained on the FAST, the bending length varying significantly for the different fabric types and blends. As can be seen from Table 1, the wool/mohair fabrics generally had the highest bending length, which generally makes it easier to carry out the cutting operation, whereas the wool/polyester and 100% wool fabrics could cause problems during cutting. According to Table 2, since F< F crit i.e. 211 < 3.554557, it can be concluded that the null hypothesis is rejected, i.e. the differences are statistically highly significant, the wool/mohair fabrics being significantly stiffer.

3.2 Extensibility of different fabrics Table 3: Warp extensibility (E100-1) of fabrics Wool/Mohair 1.6 1.5 1.7 1.5

Wool/Polyester 2.2 1.6 2.8 2.2

100% Wool 2.1 1.9 2.3 2.1

Table 3 shows, the fabric extensibility, in the warp direction as measured on the FAST, the extensibility varying for the different fabric types and blends. The wool and wool/polyester fabrics had significantly higher extensibility (Table 4), which would make it easier to carry out the laying up operation before cutting, while the wool/mohair fabrics had a lower extensibility, which might cause overfeed and moulding issues. Table 4: Statistical analysis of extensibility of fabrics Îą

ANOVA: Single factor

0.05

SUMMARY Groups

Count

Sum

Average

Variance

Wool/Mohair

6.3

1.575

0.009167

Page 631 of 1108

Wool/Polyester

8.8

2.2

0.24

Wool

8.4

2.1

0.026667

ANOVA Source of Variation

P-Value

F crit

Between Groups

0.901667

0.450833

4.903323

0.036

4.256495

Within Groups

0.8275

0.091944

Total

1.729167 11 Reject Null Hypothesis because p < 0.05 (Means are Different)

3.3 Control Charts On completion of the FAST tests, the data collected was formulated into control charts. Three control charts were created on the basis of the data obtained from the respective fabric types. From the FAST data and control charts certain conclusions could be drawn. For example, the relaxation shrinkage of the 100% wool fabric was greater than that of the wool/polyester fabric, which could result in sizing issues, possibly causing difficulty in pleating and fusing of panels. Also, the hygral expansion of the 100% wool fabrics was greater than that of the wool/polyester fabric which could lead to problems with puckering. Formability is basically the difference between extensions at E20 and E5, which was very similar for the different types of fabric. The extensibility and bending properties of the fabrics have already been discussed. It was apparent that, although the fabric weights fell within the same range, of 200 – 250 g/m2, their FAST properties differed in many respects due to different weave types and blends.

3. FOM installations worldwide According to the Kawabata manufacturers and suppliers around 2012 there were, 78 Kawabata systems being in place in 16 countries, with most systems being in Asia (45), followed by Europe (20), most systems being in place in research and educational institutions, as opposed to commercial firms. According to the FAST manufacturers and suppliers, around 2012 there were some 121 FAST systems in place in 31 countries, most (47) being in Europe, followed by Asia (43). Most of the systems, 70 in all, were used in companies, which contrasts with the Kawabata system. Only two companies in South Africa own FAST instruments, one of which is no longer using their system, as they have changed their area of operation from manufacturing to retailing, the other firm using the FAST system for quality control purposes. There is therefore clearly a need and huge opportunity for local companies to adopt FOM in order to improve their apparel fabric as well as garment quality, particularly when they are involved in formal type of wear, such as worsted type jackets and suitings.

4. Conclusions South Africa, as a country, lags behind most other countries in terms of the use of FOM. This indicates that there is considerable scope for introducing this highly advanced technology into the textile and clothing manufacturing and retail pipeline in South Africa, with the associated benefits of improved quality control and assurance, particularly in the field of formal wear. It was demonstrated that even if fabric weight fell within a similar range, fabrics could perform quite differently, with the wool/mohair fabric being best in terms of bending stiffness and wool and wool/polyester in terms of extensibility.

5. References [1] S. Kawabata, R. Postle and M. Niwa, in Proc. 1st Japan-Australia Joint Symposium, Kyoto, Text. Mach. Soc. Japan, Osaka, 1982. [2] F. T. Peirce, J. Text. Int. Vol 2, T377, 1930. [3] S. Kawabata, in Proc. 1st Japan-Australia Joint Symposium, Kyoto, Text. Mach. Society Japan, Osaka, 1982. [4] S.Kawabata, R.Postle and M.Niwa (Editors), ‘Proc. 2nd Australia- Japan Symposium on Objective Evaluation of Apparel Fabrics, Melbourne, 1983’, Text. Mach. Soc. Japan, Osaka, 1984.

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[5] S. Kawabata, R. Postle and M. Niwa (Editors), in Proc. 3rd Japan-Australia Symposium on Objective Measurement: Applications to product design and process control, Kyoto, 1985â&#x20AC;&#x2122; Text. Mach. Soc. Japan, Osaka, 1986. [6] CSIRO 1989, SiroFAST Instruction Manual. [7] http://english.keskato.co.jp/products. [8] SiroFAST System 2012, Available at: www.itec-innovation.com/productDetails.php

Page 633 of 1108

The 13th Asian Textile Conference Geelong, Australia, November 3 - 6, 2015

Understanding how the processing conditions influence the properties of ionic liquid regenerated cellulose fibres De Silva. R1â&#x20AC; , Vongsanga. K1, Wang. X1 and Byrne. N1 1

Institute for Frontier Materials, Deakin University, Pigdons Road, Waurn Ponds, Victoria, Australia, 3216.

Abstract. The degree of polymerisation (DP), is an important polymer property which has a direct influence on the mechanical properties. Here we measure the DP of regenerated cellulose dissolved in the ionic liquids 1-butyl-3-methylimidazolium acetate (BMIMOAc) and 1-allyl-3-methylimidazolium chloride (AMIMCl), at different dissolution temperatures, times and coagulants. We show that dissolution temperature has a dramatic impact on the DP of the regenerated cellulose. We also find that ionic liquid remains trapped in the regenerated cellulose, and over a period of two years a significant reduction in DP is measured likely to continue interaction between the cellulose and the trapped ionic liquid.

Keywords: Regenerated cellulose; Ionic liquids; Degree of polymerisation

1. Introduction Cotton is the most popular cellulosic fibre used in textiles. However, cotton crops consume large amounts of land, and water. As such regenerated cellulose fibres have become increasingly more popular. Regenerated cellulose fibres are produced by dissolving wood pulp in a solvent[1, 2]. To date, there are only two classes of regenerated cellulose fibres commercially available; with viscose currently being the most commonly used. In the viscose process, the cellulose is converted into sodium cellulose xanthate using carbon disulfide, which makes the cellulose soluble in NaOH, the fibre is then wet spun from the NaOH solution[1, 3, 4]. A major disadvantage of this process is the use of carbon disulfide (CS 2 ), a volatile and toxic gas, which is harmful to both the environment and human health [5-7]. In the lyocell process, cellulose is directly dissolved in Nmethylmorpholine-N-oxide (NMMO) and dry-jet spun from the NMMO solution [1, 2, 8]. This method suffers from long processing times and the formation of by-products due to the degradation of both NMMO and cellulose[1, 2]. Due to such limitations in current cellulose regeneration methods, new solvents for cellulose processing are constantly being sought. One relatively new and growing class of cellulose solvents is ionic liquids (ILs). The dissolution of cellulose, in ILs was first reported by , Swatloski et al.,[9] in 2002. Since then, many researchers have focused on IL design to increase the amount of cellulose which can be dissolved by the IL[6, 10-14]. It has been reported by others and us that cellulose regenerated from ILs suffers from poor mechanical

â&#x20AC;

Corresponding author: De Silva. R E-mail: rdesil@deakin.edu.au

Page 634 of 1108

properties[15-19]. The degree of polymerisation (DP) is an important polymer property which can impact the mechanical properties of the resulting polymer.

2. Results and discussion In this work, we have investigated how the processing conditions including dissolution time and temperature as well as coagulant impacts the degree of polymerisation. We have selected three cellulose dissolving ionic liquids: 1-butyl-3-methylimidazolium acetate (BMIMOAc), 1-allyl-3-methylimidazolium chloride (AMIMCl). The dissolved cellulose were regenerated using water, methanol and iso-propanol as coagulants. The DP was determined using the intrinsic average viscosity method [20]. Next we measured the DP of regenerated cellulose dissolved in BMIMOAc and AMIMCI. Figure 1 (a-b) shows the DP of regenerated cellulose as a function of dissolution temperature and the dissolution time respectively for cotton dissolved in BMIMOAc and AMIMCI. It can be seen from Figure 1a, that the temperature of dissolution has a dramatic effect on the DP. When dissolution of raw cotton was performed at 80Ë&#x161;C, a DP of 650 is measured, this compares to a DP of 280 when the temperature is increased to 130Ë&#x161;C. Interestingly, the choice of IL did not alter the DP significantly. Figure 1b shows the influence of dissolution time on the DP. Over a period of 8 hours, a decrease in the DP from 550 to 430 was measured. It has been proposed that the IL aids in the hydrolysis reaction occurring at the glycoside bond which promotes dissolution, from our results its clear that the hydrolysis reaction is driven by temperature.

1(a)

1(b)

Figure 1(a-b): (a): The change in the DP of 8 wt% regenerated cellulose A in AMIMCl (black curve) and BMIMOAc (red curve) at different temperatures. (b): The effect of reaction time on the DP of 8 wt% regenerated cellulose (A) in AMIMCl dissolving at 100Ë&#x161;C

The DP can directly impact the mechanical properties of the polymer. Therefore we measured the tensile properties of the regenerated cellulose as a function of dissolution time at different dissolution temperatures The mechanical properties of the samples is given in Table 1. The regenerated cellulose dissolved at the higher temperature had the poorest tensile properties which correlates well with the DP data. AS the dissolution temperature is reduced the tensile properties increase in line with the DP trend, a higher DP equates to

Page 635 of 1108

improved mechanical properties. By reducing the dissolution temperature from 130˚C to 80˚C, the stress at break was improved by 33.33%.

Sample

Measured DP

Stress at breakage (Mpa)

Strain at breakage (%)

Cellulose regenerated from 80 ˚C Cellulose regenerated from 100 ˚C Cellulose regenerated from 130 ˚C

640

59.41 ± 5.41

4.13 ± 0.83

Young’s modulus (Gpa) 1.89 ± 0.22

550

57.98 ± 6.73

4.48 ± 0.95

1.88 ± 0.26

280

45.86 ± 6.20

3.42 ± 0.88

1.84 ± 0.23

Table 1: Mechanical properties of 8 wt% regenerated cellulose in AMIMCl at various temperatures

Figure 2 shows the change in DP for the regenerated cellulose as a function of the time after regeneration. Notably, after two years, the DP of the regenerated cellulose was found to have reduced quiet significantly from 550 to 310. The probability of trapped ionic liquid in the fibre is a possible explanation for the reduction in the DP over time. It is likely that trapped IL continuously hydrolysis the glycoside bond to reduce the DP over the time. The mechanical properties would also decrease as a function of time. Therefore the complete removal of the ionic liquid is critical to maintain the long term mechanical properties of the regenerated cellulose fibres.

Figure 2: Effect of time on the DP of 8 wt% regenerated cellulose in AMIMCl dissolved at 100˚C

3. Conclusion We have shown that the higher dissolution temperature and prolonged dissolution time reduced the DP of the regenerated cellulose leading to inferior material properties as measured. The implications of this trapped ionic liquid on the DP was shown with a significant lowering of the DP as a function of time. Further studies on diffusion equilibrium in cellulose-ionic liquid system is carried out to explain this possible phenomena.

Page 636 of 1108

4. References [1] [2] [3] [4] [5] [6] [7]

[8] [9] [10] [11] [12] [13] [14] [15]

[16] [17] [18] [19] [20]

R. Kotek, "Regenerated Cellulose Fibers," in Handbook of fiber chemistry. vol. 16, M. Lewin, Ed., 3rd ed Boca Raton: CRC Press, 2007. C. Woodings, "Fibers, Regenerated Cellulose," in Kirk-Othmer Encyclopedia of Chemical Technology, ed: John Wiley & Sons, Inc., 2000. M. E. Gibril and Z. Yue, "Current status of applications of ionic liquids for cellulose dissolution and modifications: review," Int J Eng Sci Technol, vol. 4, pp. 3556-3571, 2012. D. Klemm, B. Heublein, H. P. Fink, and A. Bohn, "Cellulose: fascinating biopolymer and sustainable raw material," Angewandte Chemie International Edition, vol. 44, pp. 3358-3393, 2005. T. Heinze and T. Liebert, "Unconventional methods in cellulose functionalization," Progress in Polymer Science, vol. 26, pp. 1689-1762, 2001. S. Zhu, Y. Wu, Q. Chen, Z. Yu, C. Wang, S. Jin, et al., "Dissolution of cellulose with ionic liquids and its application: a mini-review," Green Chemistry, vol. 8, pp. 325-327, 2006. SIGMA-ALDRICH. (2013, 19.09.2013). Material Safty Data Sheet (Carbon disulfide) (5.1 ed.). Available: http://www.sigmaaldrich.com/MSDS/MSDS/DisplayMSDSPage.do?country=AU&language=en&p roductNumber=335266&brand=SIAL&PageToGoToURL=http%3A%2F%2Fwww.sigmaaldrich.com%2Fcata log%2Fproduct%2Fsial%2F335266%3Flang%3Den H. P. Fink, P. Weigel, H. J. Purz, and J. Ganster, "Structure formation of regenerated cellulose materials from NMMO-solutions," Progress in Polymer Science, vol. 26, pp. 1473-1524, 2001. R. P. Swatloski, S. K. Spear, J. D. Holbrey, and R. D. Rogers, "Dissolution of Cellose with Ionic Liquids," Journal of the American Chemical Society, vol. 124, pp. 4974-4975, 2002/05/01 2002. B. Kosan, C. Michels, and F. Meister, "Dissolution and forming of cellulose with ionic liquids," Cellulose, vol. 15, pp. 59-66, 2008/02/01 2008. A. Pinkert, K. N. Marsh, S. Pang, and M. P. Staiger, "Ionic liquids and their interaction with cellulose," Chemical reviews, vol. 109, p. 6712, 2009. H. Xie, S. Li, and S. Zhang, "Ionic liquids as novel solvents for the dissolution and blending of wool keratin fibers," Green Chemistry, vol. 7, p. 606, 2005. M. E. Zakrzewska, E. Bogel-ﾅ「kasik, and R. Bogel-ﾅ「kasik, "Solubility of Carbohydrates in Ionic Liquids," Energy & Fuels, vol. 24, pp. 737-745, 2010/02/18 2010. M. Zavrel, D. Bross, M. Funke, J. Bﾃｼchs, and A. C. Spiess, "High-throughput screening for ionic liquids dissolving (ligno-)cellulose," Bioresource technology, vol. 100, pp. 2580-2587, 2009. Y. Cao, H. Li, Y. Zhang, J. Zhang, and J. He, "Structure and properties of novel regenerated cellulose films prepared from cornhusk cellulose in room temperature ionic liquids," Journal of Applied Polymer Science, vol. 116, pp. 547-554, 2010. N. Hameed and Q. Guo, "Natural wool/cellulose acetate blends regenerated from the ionic liquid 1-butyl-3methylimidazolium chloride," Carbohydrate Polymers, vol. 78, pp. 999-1004, 2009. N. Hameed and Q. Guo, "Blend films of natural wool and cellulose prepared from an ionic liquid," Cellulose, vol. 17, pp. 803-813, 2010. R. De Silva, X. Wang, and N. Byrne, "Tri-component bio-composite materials prepared using an eco-friendly processing route," Cellulose, vol. 20, pp. 2461-2468, 2013/10/01 2013. R. De Silva, K. Vongsanga, X. Wang, and N. Byrne, "Development of a novel regenerated cellulose composite material," Carbohydrate Polymers, vol. 121, pp. 382-387, 5/5/ 2015. "Standard Test Method for Intrinsic Viscosity of Cellulose," in ASTM D1795-13, ed. West Conshohocken, PA: ASTM International.

Page 637 of 1108

The 13th Asian Textile Conference Geelong, Australia, November 3 - 6, 2015

Use of Bamboo Fibre in Textile Varinder Kaur1* and D.P.Chattopadhyay2 1

Department of Chemistry, Guru Nanak Dev University, Amritsar, 143005, India Department of Textile Chemistry, Faculty of Technology & Engineering, The M. S. University of Baroda, Vadodara, 390001, India

Abstract: In recent years a great zeal for natural textile fibres has increased throughout the world. Bamboo fibre being natural has recently attracted environment concerned researchers. The chemical composition of bamboo is similar to other bast materials. The Bamboo Culm is aligned with cellulose fibers along its length, carrying nutrients between the leaves and roots. Its chemical constituents are primary cellulose, hemicellulose and lignin, accounting to more than 85% of the total mass. The lignin content in bamboo is much higher than that in bast fibres. In general, an increase in lignin leads to a reduction in cellulose content. Since cellulose is a primary component of bamboo textiles, younger culms may be better suited to textile applications as lignification continues beyond the first growth season. Bamboo textiles are usually source from bamboo aged from three to five years. Textile fibre extraction generally consumes massive amounts of energy, water and chemicals, producing lethal wastewater, which contains miscellaneous range of contaminants, and results in serious environmental problems. Therefore, it is necessary to develop sustainable technologies for textile fibre extraction leading to minimization of the adverse effect of discharge on the environment. This review addresses the potential application of different technologies of bamboo fibre extraction and delignification methods to enhance its acceptability as textile fibre.

Keywords: Bamboo fibres; Fibre extraction; Lignin content;

1 Introduction Ecological or environmental problems have become global in character and there is an urgent need worldwide to tackle these problems. Environmental protection and production of quality textiles of international standards are two serious challenges before textile processors. Along with the ecofriendly approach of choosing natural dyes, the consideration to other natural materials has also been enhanced. In textiles, market of bamboo clothing has suddenly raised due to the facts that it is ecofriendly, 100% biodegradable and can be completely decomposed in soil by micro organisms. Some studies convey that bamboo, jute, ramie etc. fibres/fabrics can be manufactured or produced with use of ecofriendly chemical or additive. The present study is therefore aimed at pretreating the bamboo fibre/fabric in environmentally friendly ways and investigating the effect of pretreatments on the properties and dyeing behavior of the fibre particularly with natural dyes like turmeric, tea [1].

1.1 Use of Bamboo in textiles Bamboo has antibacterial properties which bamboo fabric is apparently able to retain, even through multiple washings. This helps to reduce bacteria that thrive on clothing and cause unpleasant odors. It can also kill odor causing bacteria that live on human skin, making the wearer and his or her clothing smell better. In addition, bamboo fabric has insulating properties and will keep the wearer cooler in summer and warmer in winter. The versatility of bamboo fabric makes it an excellent choice for clothing designers exploring alternative textiles, and in addition, the fabric is able to take bright dye colors well. Natural bamboo fibers have excellent properties suggesting that there is a good potential for them to be used in textiles; however, they have not received the attention that they deserve owing to their coarse and stiff quality. The high lignin content of the fibre is the major cause of its stiffness. ď&#x20AC;Ť

Varinder Kaur, Tel.: 09888504121. *varinder_gndu@yahoo.com

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There are two ways to process bamboo to make the plant into a fabric: mechanically or chemically [2]. The mechanical way is by crushing the woody parts of the bamboo plant and then use natural enzymes to break the bamboo walls into a mushy mass so that the natural fibres can be mechanically combed out, spun into yarn and then into fabric. Bamboo fabric made from this process is sometimes called bamboo linen. Chemically manufactured bamboo fibre is a regenerated cellulose fibre similar to rayon or modal. The bamboo fibre which is the current eco-fashion range is chemically manufactured by â&#x20AC;&#x153;cookingâ&#x20AC;? the bamboo leaves and woody shoots in strong chemical solvents such as sodium hydroxide and carbon disulfide in a process known as hydrolysis alkalization combined with multi-phase bleaching. Bamboo is a lignocelluloses fibre i.e. its main components are cellulose (61%) and lignin (32%). Bamboo fibre in comparison to other natural fibres has fibre bundles which are more brittle due to their thicker diameter. These composition and physical parameters play an important role to finalize single fibre strength, fibre bundle strength and mixing of fibre bundle. In addition to this, moisture regain, fibre swelling and fibre rigidity are also affected by these compositions.

1.2 Delignification of Bamboo Significant delignification of bamboo is conservatively based on techniques similar to those generally applied to wood pulping [3]. On the other hand, hemicellulose and lignin can be regenerated to fabricate preparatory materials for phenolic resin, epoxy, and furan resin production. A serious drawback in utilizing lignocellulosic biomass for biofuel manufacture has been the restraint in its pretreatment process due to the presence of covalent cross-linkages between lignin and carbohydrates in the plant cell wall and the crystallinity of the cellulose [4]. Further processing on the lignocellulosic biomass may overcome this problem to some extent, a number of methods have been used but each has its own negative aspect. Chemical treatments using acid or alkali are expensive and not ecofriendly [5]. Physiochemical treatments viz., steam explosion require high temperatures, pressures and make use of boosters, although, are measured as very capable methods, [6]. On the other hand, natural methods require long treatment time [7] while mechanical methods viz., milling, involve considerable energy and high capital deal. The effectiveness of the mechanical methods is also doubtful for complete removal of lignin. Removal of lignin during treatment with reducing agent after hydrogen peroxide bleaching of lignocelluloses material prebleached with sodium hypochlorite was found to be dependent on the nature of reducing agents used [8].

2 Materials and Experiments 2.1 Materials Raw culm of Bambosa vulgasis was harvested from Botanical Garden of Guru Nanak Dev University, Amritsar. All the chemicals used in this investigation were of AR grade and were purchased from Merck Ltd., Hi-media Labs, Bombay (India).

2.2 Methods The retted fibre bundles were treated with different concentrations of sodium hydroxide. After removal from the sodium hydroxide solution, the fibres were washed, neutralized and semidrying for 1 hour; the fibres were further subjected to bleaching processes for maximum separation of the fibres.

2.3 Optimization of NaOH concentration The retted bamboo fibres were soaked into NaOH solution with different concentration (0.05 N, 0.1 N, 0.2 N & 0.3 N) with a fibre to liquor 1:40 at 35 oC for 72 hour followed by washing at 40 oC for 15 minutes, neutralization and drying.

2.4 Bleaching with Peracetic Acid (PAA): The in-house prepared peracetic acid was used to bleach the pretreated bamboo fibres using 10 g/L of stock solution at 70 oC for 90 minute using pH 7 in the presence of 5//L sodium meta silicate as stabilizer. After bleaching samples were thoroughly washed and dried.

2.5 Bleaching with hydrogen peroxide (H2O2): The pretreated bamboo fibres were bleached using 10 g/L of hydrogen peroxide solution (30%/) at 90 oC for 60 minute using 2 g/L Ultavon EL and 3 g/L caustic soda in the presence of 1g/L Clarite G as stabilizer. After that the bleaching samples were thoroughly washed and dried.

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3 Determinations of Fibre Characteristics 3.1 Tensile Testing Breaking strength and breaking extension of bamboo were tested using an Instron series IX fiber breaking strength machine in a constant 27oC temperature and 65% relative humidity using ASTM Method D-5035.

3.2 Weight loss Fiber weight loss was calculated using Eq. 1:

Where fiber.

, is the initial weight of the raw bamboo fiber and

is the final weight of treated bamboo

3.3 Scanning electron microscopy observations The deformation behavior of a single elementary retted bamboo fibre bundle was investigated by scanning electron microscopy (SEM) using Quorum Q150RES (Supra 55- CARLZEISS) equipment.

3.4 Chemical analysis The chemical composition of the original bamboo culm (without outmost layer) and retted bamboo fibre bundles was analyzed for lignin contents by using TAPPI standard T250-um-85.

3.5 Whiteness and Yellowness Indices

The colorimetric properties [9] of the retted fibers (D65 illumination, 10o observer) were determined using a Spectraflash 600 colorimeter (Datacolor International).

4 Results and Discussion 4.1 Effect of NaOH concentration on lignin content of CAN retted, sequential sodium hydroxide & peracetic treated and sequential sodium hydroxide & hydrogen peroxide treated bamboo fiber Figure 4.1 shows the changes in lignin content with the increase in concentrations of sodium hydroxide (with & without subsequent bleaching process). The maximum loss in lignin was caused by NaOH→H2O2 process with no acceptable weight loss in pretreated fibres with higher concentration of sodium hydroxide i.e., 0.3 N. NaOH→PAA process produced reasonable reduction in lignin content and weight loss.

Fig. 4.1: Effect of NaOH concentration on lignin content of retted, NaOH→ PAA treated & NaOH→H2O2 treated bamboo fiber

4.2 Surface morphology of bamboo fibres Surface pictures of treated bamboo fibre with different concentrations of sodium hydroxide and further differently (individually) treated with PAA & H2O2 bleaching agents are shown in Figure 4.2 (b & c). A huge amount of gum in the alkali treated bamboo fibres can be seen in Figures 4.2 (a). After treatment with PAA & H2O2, the bamboo fibres were fiberized, but it can be seen that the bamboo fibre were joined with large amount of gum on surface in case of PAA bleaching (Figures 4.2 (b)). With the bleaching with H2O2, the bamboo fibres were receiving smoother and finer surfaces (Figures

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4.2 (c)). These pictures show that the fibres treated with PAA & H2O2 have a more uniform geometry of fibrils arrangement than the fibres treated with different concentrations of alkali (without subsequent bleaching).

Fig. 4.2 (a): 0.3 N NaOH

Fig. 4.2 (b): 0.3 N NaOH →PAA

Fig. 4.2 (b): 0.3 N NaOH →H2O2

5 Conclusions This two-stage delignification of bamboo fibres with alkali and different bleaching agents could obtain fibres with good physical appearance & properties. Alkali pretreatment prior to bleaching could significantly reduce H2O2 & PAA loading in subsequent stage by partially removing the lignin and swelling the fibres.The maximum loss in lignin was found in case of NaOH→H2O2 process along with no acceptable weight loss. On the other hand, the pretreated fibres with higher concentration of sodium hydroxide i.e., 0.3 N followed by PAA bleaching step (NaOH→PAA) produced reasonable reduction in lignin content and weight loss with acceptable whiteness and tensile strength.

Reference [1] S. Kaur, D.P. Chattopadhyay, V. Kaur. Dyeing of Bamboo with Tea as a natural Dye. Research Journal of Engineering Sciences, 2012, 1(4), 21-26. [2] Bamboo fibre and its manufacture; US Patent Application No: 2007/0267, 159. [3] J. Zakzeski, P. C. A. Bruijnincx, A. L. Jongerius, B.M. Weckhuysen. The Catalytic Valorization of Lignin for the Production of Renewable Chemicals. Chemical Reviews, 2010, 110: 3552-3599. [4] L. D. Gomez, C. G. Steele-King,, S. J. McQueen-Mason. Sustainable liquid biofuels from biomass: the writing's on the walls. New Phytologist, 2008, 178: 473–485. [5] C.E. Wyman, B.E. Dale, R. T. Elander, M. Holtzapple, M. R. Ladisch, Y. Y. Lee. Comparative sugar recovery data from laboratory scale application of leading pretreatment technologies to corn stover. Bioresour Techno. 2005, 96(18):2026. [6] R. P. Chandra, R. Bura, W. E. Mabee, A. Berlin, X. Pan, J. N. Saddler. Substrate pretreatment: the key to effective enzymatic hydrolysis of lignocellulosics? Adv Biochem Eng Biotechnol. 2007, 108, 67-93. [7] M. Galbe, G. Zacchi, Pretreatment of lignocellulosic materials for efficient bioethanol production. Adv Biochem Eng Biotechnol. 2007, 108, 41-65. [8] A. P. James, I. S. MacKirdy, The chemistry of peroxygen bleaching. Chem Ind, 1990, 641-645. [9] Standard Methods for the Determination of Color Fastness of Textiles and Leather, (5th edition), Society of Dyers and Colorists, Bradford, UK, 1990.

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The 13th Asian Textile Conference Geelong, Australia, November 3 - 6, 2015

Using Micro-Electron Spin Resonance to Study Free Radicals in Protein Fibres Keith R Millington CSIRO Manufacturing, Geelong Technology Precinct, 75 Pigdons Road, Waurn Ponds, VIC 3216 +

Abstract. Micro-electron spin resonance instruments can effectively determine the presence of free radicals in fibrous proteins. They can be used to study the intrinsic free radicals present in the melanin granules of pigmented fibres, and can also be applied to radicals photogenerated in the protein during exposure to ultraviolet light. The spectra obtained are of similar quality to those previously reported using conventional ESR instruments. The low cost of micro-ESR instruments (~US$50k) will improve the accessibility and application of the ESR technique in the textile and hair care industries.

Keywords: Fibrous proteins, electron spin resonance, free radicals

1. Introduction When fibrous proteins such as wool, silk and unpigmented human hair are exposed to the ultraviolet (UV) wavelengths present in sunlight, they become photoyellowed [1-3]. In natural sunlight, where the intensity of the visible and infrared components are significantly higher than the UV intensity, photoyellowing and photobleaching processes occur concurrently in protein fibres. Thus photoyellowing occurs more rapidly after bleaching, since the benefit of concurrent photobleaching in slowing down the rate of yellowing is smaller for bleached fibres, and also for keratin fibres bleaching with hydrogen peroxide oxidises high numbers of cystine residues present in the cuticle that confer some photoprotection both as an antioxidant and as a UV absorber [4]. The photostability of unpigmented protein fibres is poor compared to cotton and synthetic fibres, and much research has been undertaken to understand their photochemistry and to improve their performance. The chemistry of both photoyellowing and photobleaching processes in fibrous proteins involves the formation of free radicals as the first stage. This was first demonstrated by electron spin resonance (ESR) studies carried out on wool exposed to UV radiation in the early 1960s and later by studies on wool exposed to blue light (400â&#x2C6;&#x2019;450 nm) leading to photobleaching [5-7]. Photoyellowing occurs via reaction of free radicals with oxygen according to the autoxidation mechanism established by Bolland and Gee in the late 1940s [8, 9]. Photo-induced chemiluminescence (PICL) is also produced via the reaction of free radicals in irradiated fibrous proteins with oxygen [10]. The yellow chromophores formed in heavily irradiated wool fabric have been separated using proteomic techniques and identified as oxidation products of the aromatic amino acid residues tryptophan, tyrosine and phenylalanine [11, 12]. Pigmented animal fibres contain melanin granules that are responsible for their black (eumelanin) and red (pheomelanin) coloration and various combinations, as normally observed in human hair for example. Melanins are highly conjugated biopolymers comprised mainly of o-quinone and o-hydroquinone units that contain large numbers of intrinsic free radicals in their structure. When melanins are exposed to sunlight, higher numbers of radicals are formed [13]. Electron spin resonance (ESR) the only technique capable of directly measuring free radicals in materials. Free radicals always contain unpaired electrons and therefore have a magnetic moment which is split into two energy levels when placed in a magnetic field. Transitions between the two levels can occur when microwave radiation is absorbed. ESR is a powerful tool for studying free radicals in both unpigmented and pigmented fibrous proteins. In addition to the multiple studies carried out on wool and pigmented fibres cited above, ESR

Corresponding author. Tel.: + 61-352-464792 E-mail address: keith.millington@csiro.au

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studies have also been conducted on silk [14-16], unpigmented human hair [17, 18] and also on human skin [19, 20], which contains both keratin and collagen. Until recently, the high cost, large size and technical complexity of ESR spectrometers has tended to limit their use to specialised research centres, which in turn has limited the use of the technique. However the recent rapid growth in miniaturised sensing technologies has led to the development of a number of micro-ESR instruments that are now available. These instruments use small, strong rare earth permanent magnet assemblies, a low-power microwave sensor and miniaturised wireless components adapted from mobile phone technology [21]. This paper explores the application of Micro-ESR to study the intrinsic free radicals in pigmented protein fibres, and photogenerated free radicals in unpigmented fibres exposed to UV radiation. Results of these studies are compared to previous data from the literature obtained using conventional ESR instrumentation.

2. Experimental Scoured undyed 100% Merino wool fabric was sourced from the fabric archive at CSIRO Manufacturing. Human hair of various colours was sourced through India Hair International, New Delhi. Samples were placed into 5 mm quartz tubes and dried at 100oC for 4 hours before cooling in a dessicator and running in the ESR instrument. Previous work has shown that ESR signals in fibrous proteins are sensitive to moisture content [22]. UV irradiation of samples was carried out by attaching the quartz ESR tubes to a fluorescent UV tube using rubber bands. Three UV tubes were used emitting different wavelengths, as shown in Table 1. Table 1

UV band UVC UVB UVA

Details of UV sources used to irradiate samples

Wavelength (nm) 254 305 366

Tube Philips TUV Philips TL20W/12RS Philips TL

A benchtop micro-ESR instrument (Active Spectrum, Foster City, California) was used to obtain room temperature ESR spectra from various fibrous proteins. The instrument was calibrated using a standard DPPH (2,2-diphenyl-1-picrylhydrazyl) solid sample dispersed in arabinose and held in a capillary tube, for which a single sharp peak appears at g = 2.0036. The optimum instrument settings for fibrous protein samples were found to be 10 mW microwave power and 100% modulation coil amplitude. Spectra were measured in the range 3309â&#x20AC;&#x201C;3641 G using 2656 data points per spectrum, and to maximise the signal to noise ratio (S/N) for weaker ESR signals the mean of 50 spectra was obtained over a period of ~13 minutes. To allow for baseline drift, the spectrum of a clean empty quartz tube was also recorded and this data subtracted from the sample data before reporting the final spectrum.

3. Results 3.1.

Intrinsic ESR studies on human hair of various colours

The corrected intrinsic ESR spectra for human hair samples measured on the Micro-ESR spectrometer at room temperature is shown in Figure 1. In all cases the signal is a single peak centred around g = 2.004. The signal from Asian black hair is very strong, since this contains the highest level of eumelanin, and the intensity decreases with the level of pigment. The spectra obtained are very similar to those obtained previously on hair samples using a conventional ESR spectrometer at room temperature [23].

3.2.

Wool exposed to UV radiation

Corrected ESR spectra of dry Merino wool fabric exposed to UV radiation of different wavelengths at room temperature are shown in Figure 2A. Higher energy UV exposure results in a more complex spectrum comprised of two features. The asymmetric low-field signal observed after exposure to UVC and UVB is due

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to sulphur radicals derived from cystine residues. The sharp single line at g = 2.003 is characteristic of carbon free radicals. Previous studies using conventional ESR spectrometers have given very similar results [24, 25]. Applications to look at the effects of additives on the photoprotection of protein fibres are currently in progress. In future research, studies looking at free radicals produced in fibres by mechanical damage and ionizing radiation are planned.

Fig. 1: The intrinsic ESR spectra of human hair of different colours A. Dried for 4h at 100oC and measured using the Active Spectrum Micro-ESR instrument at room temperature B. Hair samples measured similarly using a conventional ESR instrument (from ref. [23], Fig. 1).

Fig. 2A: ESR spectra of Merino wool fabric dried for 4h at 100oC irradiated with UV of different wavelengths and measured using the Active Spectrum Micro-ESR instrument at room temperature 2B. Lincoln wool irradiated at 310 nm at room temperature and measured on conventional ESR instrument (from ref. [25], Fig. 7).

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4. Conclusions Micro-ESR is a powerful technique for studying free radicals in protein fibres at room temperature, including wool, hair and silk, and gives similar spectra to those reported previously using conventional ESR instruments. The low cost of micro-ESR instruments (~US$50k) will improve the accessibility and application of the ESR technique, which has clear potential for looking at the effects of various additives, such as antioxidants and UV absorbers, on the photoprotection of protein fibres for the hair care and textile industries.

5. References [1] Millington KR. Photoyellowing of wool. Part 1: Factors affecting photoyellowing. and experimental techniques. Color Technol. 2006;122(4):169-86. [2] Millington KR. Photoyellowing of wool. Part 2: Photoyellowing mechanisms and methods of prevention. Color Technol. 2006;122(6):301-16. [3] Millington KR. Bleaching and Whitening of Wool: Photostability of Whites. In: Lewis DM, Rippon JA, editors. The Coloration of Wool and other Keratin Fibres. Chichester UK: Wiley; 2013. p. 131-55. [4] Millington KR. Diffuse reflectance spectroscopy of fibrous proteins. Amino Acids. 2012;43(3):1277-85. [5] Shatkay A, Michaeli I. Electron Paramagnetic Resonance Study of Wool Irradiated by Ultraviolet and Visible Light. Radiat Res. 1970;43(3):485-98. [6] Shatkay A, Michaeli I. Free Radicals in Irradiated Wool. Text Res J. 1971;41(3):269-70. [7] Shatkay A, Michaeli I. EPR Study of Wool Irradiated with Blue Light. Photochem Photobiol. 1972;15(2):11938. [8] Bolland JL. Kinetics of Olefin Oxidation. Q Rev Chem Soc. 1949;3(1):1-21. [9] Bolland JL, Gee G. Kinetic studies in the chemistry of rubber and related materials 2. The kinetics of oxidation of unconjugated olefins. T Faraday Soc. 1946;42(3-4):236-43. [10] Millington KR, Deledicque C, Jones MJ, Maurdev G. Photo-induced chemiluminescence from fibrous polymers and proteins. Polym Degrad Stab. 2008;93(3):640-7. [11] Dyer JM, Bringans SD, Bryson WG. Characterisation of photo-oxidation products within photoyellowed wool proteins: tryptophan and tyrosine derived chromophores. Photoch Photobio Sci. 2006;5:698-706. [12] Dyer JM, Bringans SD, Bryson WG. Determination of photo-oxidation products within photoyellowed bleached wool proteins. Photochem Photobiol. 2006;82(2):551-7. [13] Arnaud R, Perbet G, Deflandre A, Lang G. Electron-Spin Resonance of Melanin from Hair - Effects of Temperature, Ph and Light Irradiation. Photochem Photobiol. 1983;38(2):161-8. [14] Liu RQ, Xie LD, Sheng KL. ESR signals from silk fabrics irradiated by UV-rays. Nucl Sci Tech. 2007;18(5):268-71. [15] Mamedov SV, Aktas B, Canturk M, Aksakal B, Alekperov V, Bulbul F, et al. The ESR signals in silk fibroin and wool keratin under both the effect of UV-irradiation and without any external effects and the formation of free radicals. Biomaterials. 2002;23(16):3405-12. [16] Shao J, Carr CM, Rowlands CP, Walton J. XPS, SIMS, and ESR studies of UV/ozone-irradiated silk and wool. J Text I. 1999;90(4):459-68. [17] Yanagi N, Niwa M, Sakurai Y, Nakajima A, Kanaori K, Tajima K. ESR Study of Disulfide Neutral Radical of alpha-Keratin Present in Dried White Human Hair Exposed to Near-UV Radiation. Chem Lett. 2010;39(4):340-1. [18] Yanagi N, Niwa M, Sakurai Y, Nakajima A, Kanaori K, Tajima K. ESR Spectrum Attributed to Trisulfide Neutral Radical [RSS(R)(SR).R] of Protein Observed for Îą-Keratin Present in White Human Hair. Chem Lett. 2010;39(7):756-7. [19] Jurkiewicz BA, Buettner GR. Ultraviolet Light-Induced Free-Radical Formation in Skin - an ElectronParamagnetic-Resonance Study. Photochem Photobiol. 1994;59(1):1-4. [20] Jurkiewicz BA, Buettner GR. EPR detection of free radicals in UV-irradiated skin: Mouse versus human. Photochem Photobiol. 1996;64(6):918-22. [21] White CJ, Elliott CT, White JR. Micro-Electron Spin Resonance (ESR/EPR) Spectroscopy. In: Druy M, Brown C, Crocombe R, editors. Next-Generation Spectroscopic Technologies III. 7680: SPIE; 2010. [22] Stratton K, Pathak MA. Photoehancement of Electron Spin Resonance Signal from Melanins. Arch Biochem Biophys. 1968;123(3):477-83. [23] Kirschenbaum LJ, Qu X, Borish ET. Oxygen radicals from photoirradiated human hair: An ESR and fluorescence study. J Cosmet Sci. 2000;51:169-82. [24] Leaver IH. Studies in Wool Yellowing. XXII. ESR Investigations of Action of UV Radiation. Text Res J. 1968;38(7):729-34. [25] Pailthorpe MT, Nicholls CH. ESR Studies of the Low Temperature Irradiation of Keratin and Its Component Amino Acids. Photochem Photobiol. 1972;15(5):465-77.

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The 13th Asian Textile Conference Geelong, Australia, November 3 - 6,2015

Water-free Chemical Treatment and Enzymatic Treatment of Wool to Change the Fiber Surface Morphology and Mechanical Properties Chendi Tu1, Satoko Okubayashi1, Fusako Kawai 2, Kunihiko Watanabe 3 and Sachiko Sukigara1 + 1

Department of Advanced Fibro-Science, Kyoto Institute of Technology, Japan 2 Center for Fiber and Textile Science, Kyoto Institute of Technology, Japan 3 Division of Applied Life Sciences, Kyoto Prefectural University, Japan

Abstract. Many users are unsatisfied with the skin comfort of some woolen fabrics. Current chlorine-based treatments not only decrease strength and worsen the appearance of wool, but also release adsorbable organic halogens, which are harmful to humans and pollute the environment. This experiment was aimed at reducing the discomfort of woolen products by modifying wool fiber scales using eco-friendly treatments. Two treatments for wool fiber surfaces were examined, a water-free chemical oxidation treatment using acetic acid as the oxidizing agent and hexane as the solvent and one using a protease of Meiothermus ruber H328 to corrode wool scale by hydrolyzing peptide linkages of wool keratin. Results show successful wool scale modification by the protease treatment (10% protease concentration, 3 days) with a degradation rate of approximately 1.9%.

Keywords: wool, scale, skin comfort, CH 3 COOH, H328 protease

1. Introduction Wool is one of the most widely used natural fibers in the world, and is popular for its high thermal insulation properties. However, woolen products are often perceived as uncomfortable due to the stiffness, prickle, and itch associated with fabrics made from coarse fibers. To solve these problems, we approached to modify the scale on wool fiber surface. The modified wool surface can increase hygroscopicity of the wool fiber and decrease fiber diameter. Conventional chlorine-based treatments decrease the strength of wool and worsen its appearance. Furthermore, they release adsorbable organic halogens, which are harmful to humans and the environment [1]. This study was aimed toward reducing the discomfort of woolen products by modifying the wool fiber scale using eco-friendly treatments.

2. Experimental 2.1.

Water-free chemical treatment on wool 2.1.1. Materials Merino wool sliver and 25 tex yarn were used. Mean fiber diameter was 24.5μm.

2.1.2. Process Wool sliver (0.2 ± 0.005 g) and a 60-cm length of wool yarn were immersed in a 15 mL mixture of 10% or 20% acetic acid solution (v/v, hexane solvent), then the mixture was fed to an ultrasonic processor (VCX750, Sonics & Materials Inc.) operating at a frequency of 10 kHz. As the reaction progressed, the system temperature would increase and evaporate the hexane, because the boiling point of hexane is 68.7°C. The ultrasonic processor was paused for 1 min after every 2 min of treatment for cooling to limit evaporation and the solvent was replenished to replace evaporated solvent. The ultrasonic treatment was expected to affect the wool scale structure, so the ultrasonic processing times were precisely recorded and used as reaction times in this experiment: 5, 10, 15, and 20 min. After treatment, samples were scoured in 15 mL pure hexane for 1 min + Corresponding author. Tel.: +81-075-724-7365. E-mail address: sukigara@kit.ac.jp.

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under ultrasonication (10 kHz). The scouring process was repeated three times. In the control experiment, hexane was used instead of acetic acid solution. The experiment was performed in triplicate under each condition.

2.1.3. Characterization Felting density. A felt ball test was performed to evaluate the degree of felt after treatment. The mean felt ball diameter was the mean value of 9 measurements. Then, the felt density was calculated by using Eq. (2.1) to reveal the degree of felting. (2.1)

Here, δ is the mean felt density (g/cm ), d is the mean felt ball diameter (cm) from 9 measurements, and G is the ball weight (g). SEM. The wool surface morphology was observed by analytical scanning electron microscopy (JSM6010LA, JEOL Ltd.) at an acceleration voltage of 10.0 kV after gold sputter coating. Tensile test. A high-sensitivity tensile strength tester (KES-G1S, Kato Tech Co., Ltd.) was used to measure the tensile properties of the yarn samples. The samples were equilibrated in a constant temperature and humidity chamber (20 °C, 65% RH) for 12 h before measurement. Cyclic force extension tests were carried out at a maximum tensile load of 0.8 N/yarn at a speed of 0.1 mm/s. Loading and unloading cycles were performed in the tensile strength test. The gauge length was 5 cm and 10 specimens were used for a sample. 3

2.2.

Enzyme H328 treatment on wool fiber 2.2.1. Materials

Merino wool slivers with mean fiber diameters of 18.5, 21.5, and 24.5 μm were used for the treatment. A partially purified protease of Meiothermus ruber H328 (8.6 U/ml) was used for the enzymatic treatment. The organism was isolated from a soil sample collected at the Arima Hot Spring in northern Kobe, Japan [2].

2.2.2. Process The reaction mixture (10 mL) contained 10% (v/v) protease H328, 500 mM Tris-HCl buffer (pH 8.5), 100 mM CaCl 2 , and deionized water. Wool sliver (0.2 ± 0.005 g) of each sample was immersed in the solution and incubated at 60 ºC for 3 days. As a control, deionized water was used instead of protease.

2.2.3. Characterization Amino acid measurement.The ninhydrin colorimetric method was applied to determine the amino acid content in the supernatant, which was obtained by removing wool sliver from the reaction mixture as soon as the incubation ended. The amino acid content in the supernatant was obtained by subtracting the control value. The degradation rate was calculated, using leucine as a standard amino acid. Moisture regain. The moisture regain of wool sliver samples was measured at two humidity levels (60% and 80% RH). The sample was oven-dried at 70 ºC for 1 h and then weighed. The sample was suspended in a chamber at 25 °C, 60% RH for 3 h to achieve adsorption equilibrium, then the sample was taken out and immediately weighed. The sample was then replaced into the chamber and the humidity was increased to 80% RH. The weight under each humidity condition was recorded. Finally, the moisture regain (MR) was calculated according to following equation: (2.2)

Here, MR (x) is the moisture regain for x = 60% or 80% RH, W x is the weight of the wool sample after adsorption equilibrium at humidity x, and W d is the weight of the wool sample after oven drying.

3. Results and discussion 3.1.

Effect of water-free chemical treatment on wool

After treatment in the acetic acid-hexane-ultrasonic system, the wool slivers took on a felt ball shape (Fig.1(a)). Figure 1(b) shows the felt density. No notable felt formation was seen after 5 min treatment with

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the 10% acetic acid reagent, but was more pronounced at longer reaction times. Felt formation was clearer at the 20% acetic acid concentration. The control samples retained their initial shape. The increase of felt density was probably due to the additional acetic acid, which may have opened the wool scale and increased scale entanglement. (b)

(a)

5min

10min 15min 20min 20min-control

Fig. 1(a) Felt phenomenon of wool sliver after chemical treatment by different time, and (b)felt density change in 10% and 20% CH 3 COOH mixture

Figure 2 shows the fiber surface morphology. The surface morphology of undamaged wool fiber (Fig. 2(a)) shows clear, approximately circular, well-organized scales. The control sample (Fig. 2(b)) had a mass of lifting cuticle layers caused by the ultrasonication, which would peel rather than dissolve the scale [3]. There was some scale damage such as reduced scale height or extended scale width in the sample treated by 10% acetic acid for 20 min (Fig. 2(c)). However, homologous scale damage was observed in the untreated wool sliver sample. The effect of acetic acid on wool descaling thus remains ambiguous. (a)

(b)

(c)

Fig. 2 Surface morphology of (a) untreated, (b) 20 min hexane control, and (c) 20 min 10% CH 3 COOH treated samples

The results of tensile strength measurement (Fig. 3) suggest that extension at the maximum tension force (EM) of 10% acetic acid-treated wool yarn gradually increased with reaction time. The higher EM value as compared with the control indicates structural change, but the tensile resilience (RT) of the acetic acid-treated samples decreased, while the hexane control samples retained their initial levels. This suggests that acetic acid played a role in lowering the elasticity. However, the wool yarn samples shrank by an average of 6% in length in the 10% acetic acid-treated sample after a 15 min reaction time, while no shrinkage was observed in the hexane control sample. This might result in the different tensile properties seen between the acetic acid-treated samples and the hexane controls.

Fig. 3 Tensile results of 10% CH 3 COOH treated wool yarn with different reaction time.

3.2.

Effect of H328 protease treatment on wool fiber

The primary amino acid was detected in the reaction supernatant by the ninhydrin method. The sample with a mean fiber diameter (MFD) of 18.5 μm degraded by 1.81% by weight. The MFD 21.5 μm sample degraded by 1.98%, while the MFD 24.5 μm sample degraded by 1.92%. Some traces of degradation were observed at the scale edges of the protease-treated samples (Fig. 4(a)), but the degree of scale degradation was not uniformly distributed.

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(a)

(b)

Fig. 4 Surface morphology of (a) enzyme treated (10%, 3days) and (b) water control wool sliver (average mean fiber diameter of 24.5μm)

Figure 5 shows that the moisture regains were larger in the protease-treated and water-control samples than in the untreated sample. This indicates that the wool fiber was spontaneously hydrolyzed, which was presumed to be basic hydrolysis of cell membrane complex (CMC) and the cortex in the wool interior. At 60% RH, no difference between the protease-treated sample and the control sample was observed. At the 80% humidity condition, moisture regain of the protease-treated sample is lower than that of the water control.

Fig. 5 Moisture property changes of wool sliver samples caused by enzyme treatment (10%, 3days)

4. Conclusions Two eco-friendly treatments for reducing the discomfort of woolen products were applied to wool samples to modify the wool fiber scale. A water-free chemical oxidation treatment was applied to wool sliver and wool yarn samples by an acetic acid-hexane-ultrasonication system. The acetic acid treatment resulted in a felting phenomenon, where the hexane control sample did not form felt. Surface observations indicated characteristic ultrasonic-caused scale peeling damage, but the effect of acetic acid on descaling was ambiguous due to interference of the initial scale damage in the untreated samples. In addition, there was increased extensibility in the acetic acid-treated wool yarn, but this might have been caused by wool shrinkage rather than by oxidation with acetic acid. A protease treatment was used to modify wool scale. The results showed that the protease effectively catalyzed the hydrolysis of peptide linkage, resulting in light degradation of scale edges. The detection of free amino acid in the reaction supernatant suggested an approximately 1.9% degradation of wool fiber after 3 days’ treatment with 10% protease. The aqueous solution system led to basic hydrolysis of the wool so that the moisture regain ability of both the protease-treated and water-control samples increased. The chemical treatment didn’t present prominent modification on wool scale, while protease treatment showed more effective modification.

5. References [1] Q. Wang, P. Wang, X. Fan et al. A comparative study on wool bio-antifelting based on different chemical pretreatments. Fiber and polymers, 10(5): 724-730, 2009. [2] T. Matsui, Y. Yamada, K. Watanabe. Sustainable and practical degradation of intact chicken feathers by cultivating a newly isolated thermophilicMeiothermusruber H328. Applied Microbiology and Biotechnology, 82(5): 941-950, 2009 [3] C. Bae and I. Um, The effect of ultrasonication on the micro-splitting of wool fiber. Fibers and Polymers, 13(7): 943-947, 2012

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The 13th Asian Textile Conference Geelong, Australia, November 3 - 6, 2015

A theoretical model for thermal resistance of Single Layer Cotton/Nylon-Kermel Blended Fabrics A. Kakvan 1 and S. Shaikhzadeh Najar 1 1

Department of Textile Engineering, Amirkabir University of Technology, Tehran, 15875-4413, Iran;

Abstract. In this research a theoretical model of a single cell woven fabric has been developed to predict the thermal resistance of cotton/nylon-Kermel blended fabrics in a non-convective environment. The obtained values from the developed model have been compared with experimental results indicated that there is a good correlation between them. The average error percentage between the experimental and theoretical values for cotton/nylon-Kermal blended fabrics also confirmed the good relation between actual and predicted values by the model. It can be seen from the results that with increasing the ratio of Kermel fibers in blended fabrics, predicted thermal resistance values of fabric samples increased almost similar trend compared with experimental values.

Keywords: Heat Transfer, Conduction, Radiation, Thermal Resistance, Kermel Fiber.

1. Introduction Heat can be defined as the form of energy that is transferred between a system and its surrounding as a result of temperature difference. There are three modes of heat transfer: (a) convection, (b) conduction and (c) radiation [1-3]. Thermal resistance is defined as the resistance to heat transfer by the way of conduction, convection and radiation [4, 5]. The most important thermo-physical properties of a material, which are needed for calculating heat transfer, are: thermal conductivity, thermal diffusivity and specific heat [6]. Fibrous materials are used as thermal insulation to reduce the radiation heat transfer. Under atmospheric conditions fibers suppress convection; therefore radiation and conduction heat transfer are both important even at the moderate temperature [7]. Thermal comfort implies many parameters which include body heat generation or metabolic heat, heat and moisture transfer from the body to the clothing micro-environment which is the area between the clothing and skin, and then heat and moisture transfer from clothing to the environment [8-10]. The thermal comfort properties of clothing are affected by heat and mass transfer through textiles [11, 12]. Fabric properties such as structure, porosity, surface treatment, air permeability, surrounding temperature, material and properties of fibers are effect on thermal properties of textiles such as thermal resistance, thermal absorptivity and thermal conductivity [13]. The thermal conductivity, determined by measuring temperature potential, heat flux and thickness, is therefore an effective thermal conductivity, describing the effect of fabric materials and combined process of energy transfer [11, 12, 14]. To make a mathematical model, the fabric is supposed as a porous structure. A theoretical model based on combined series and parallel conduction for the effective thermal conductivity of fluid-saturated screen has developed by Chang [15]. To predict the effective thermal conductivity a unit cell model was utilized to simulate the wire mesh. A method was developed by Luikov et al. [16] to predict the effective conductivity of the porous system by using the comparison of electrical system. They have considered an elementary cell to be a system of resistance. Bhattacharjee and Kothari [11, 12] built a mathematical model to predict the thermal resistance of woven fabrics in a non-convective environment. Conduction and radiation were considered to be the most important modes of dry heat transfer through textiles in their model. It may be considered that few studies have been carried out on the influence of fiber blend ratio and yarn porosity on effective thermal conductivity of fabrics. In particular, previous study by the authors investigated the effect of blend ratio on thermal comfort properties of cotton/nylon-Kermel blended fabrics. The results of that study indicated that with increase of Kermel fiber blend ratio, the fabric porosity, air permeability and thermal resistance are increased [17]. The objective of this study is to consider the effect of fiber blend ratio

Page 650 of 1108

and yarn packing density on thermal resistance of blended woven fabrics and hence develop a theoretical model based on Bhattacharjee and Kothari [11, 12] model to predict the thermal resistance of blended cotton/nylonKermel woven fabrics and compare the predicted values with experimental results. In this study, a general equation is proposed to calculate the effective thermal conductivity of homogenous and blended yarns in terms of fiber blend ratio, yarn packing density and thermal conductivity of fibers. This equation in essence is different from that of appeared in other research studies [11, 12]. Finally, these calculated values replaced with the thermal conductivity values of warp and weft yarns to calculate the total thermal resistance of blended fabric samples.

2. Theoretical Model The model which is used and developed in our study is based on first principle of heat transfer through porous materials [11]. The pronounced attributes of model are as follow: • It is assumed that the woven fabric has a cellular geometry through which conductive heat transfer takes place from the air pores as well as the yarns. • All the basic weaves can be modified into a simple geometry of air pores, modular length of yarns and intersections. • Yarns are considered as porous materials comprising infinite cylindrical fibers and air. • Heat transfer through convection is not accounted for in this model. • Heat transfer by radiation takes place in two ways: through the yarns and through the air pores. Heat transfer from body to environment through the fabric take place by conduction, convection and radiation. The sum of the values of heat transfer through each of these modes is total heat transfer, which is givens as follow [11, 12]: (1.1) Qtotal = Qconduction + Qconvection + Qradiation The effect of forced convection can be neglected if the fabric is kept in a restricted environment under a constant pressure. Therefore, only the heat transfer through conduction and radiation modes is considered. There are mainly three areas from which conduction takes place in a single cell of the plain woven fabric: (i) through warp and weft yarn; (ii) through interlacements; and (iii) through air pores. The basic equation of conductive heat transfer is given by Fourier’s law, i.e.: dQ

= − kA

∂T

(2.1)

dτ ∂x where dQ is the quantity of heat conducted in time dτ; T, the temperature; x, the thickness of the wall perpendicular to the direction of heat; A, the area of the heated surface; and k, the coefficient of thermal conduction. Under the steady state conditions when Eq. (2.1) is integrated over a time τ :

T −T (3.1) Qconduction = kA( 1 2 ) t where T 1 and T 2 are the hot and cold temperature respectively; and t, the thickness of the material. Q conduction is the total heat transfer due to conduction. Fig. 1 shown the interlacement areas consist of warp and weft yarns as well as air. They characterized in term of series resistances. According to Fig. 2 a single plain woven cell can be assumed to have a warp, a weft, an interlacement and an air pore. Based on Eq. (3.1), the conductive heat loss through modular lengths of warp and weft are given by the following equations: Qcond .warp =

[ a1 ( p2 − a2 )](T1 − T2 ) a sec θ1 t − a1 sec θ1 ( 1 ) + keff .warp k air

(4.1)

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[ a2 ( p1 − a1 )](T1 − T2 ) Qcond .weft = a sec θ 2 t − a2 sec θ 2 ( 2 ) + keff .weft k air

(5.1)

where a 1 and a 2 are the warp and weft yarns diameter; p 1 and p 2 are the warp and weft yarn spacing; θ 1 and θ 2 are the weaving angle, respectively. Also k eff.warp , k eff.weft and k air values are the effective coefficient of thermal conduction of warp yarn, weft yarn and air respectively. Conduction through interlacement (Q cond.in ) and through air pore (Q cond.air ) are given by:

Qcond .in =

Qcond .air =

a1a2 (T1 − T2 ) a1 a2 + ( ) keff .warp keff .weft

( p1 − a1 )( p2 − a2 )(T1 − T2 ) a1 + a2

(6.1)

(7.1)

k air

Fig. 1: Cross section view of the fabric as a system of resistances between warp and weft yarns and air (1warp/weft+air, 2- warp+weft)

Fig. 2: Top view of the elementary cell of the fabric

Therefore the total heat transfer due to conduction is given by:

Qcond .total = Qcond .warp + Qcond .weft + Qcond .in + Qcond .air The conduction per unit area as follow:

(8.1)

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Q Qconduction = cond .total p1 p2 Hence, the resistance of the fabric due to conduction as following equation:

(9.1)

(T1 − T2 ) (10.1) Rconduction = Qconduction Whereas in this study we used cotton/nylon blended with Kermel fibers to make yarns and fabrics, for calculating thermal resistance and thermal conductivity of fabrics it is necessary to calculate effective thermal conductivity of yarns and then use them in above equations. It can be assumed that the solid-fluid matrix in the yarn complies with the system of parallel resistances arrangement [3, 11, 12]. In this study, by considering to the blends law [18], and also trapped air between the pore spaces of yarns, the effective conductivity is given by follow equations. Finally, these calculated values should be replaced with k eff.warp and k eff.weft in above equations. Hence, the general equation for calculating the effective thermal conductivity of blended fabric as follow: n (11.1) keff = ∑ φ y × k fi × p fi + (1 −φ y ) × k air i=1 where p fi is percent of fiber in blended yarn; Ф y is yarn packing density of yarn; and k fi is thermal conductivity of fiber. If it is assumed that the produced blended yarn completely solid without any pore and trapped air (Ф y = 1), then the effective thermal conductivity of yarn equals to the thermal conductivity of fiber according to percentage of the fiber in blended yarn; and also if it is assumed that the produced blended yarn completely fluid (Ф y = 0), then the effective thermal conductivity of yarn equals to the thermal conductivity of air. In the cell model of fabric there are three ways that heat transfer due to radiation tales place: (a) from skin to environment through air pores; (b) from yarns to environment; and (c) between yarns and skin [11, 12]. The basic equation of heat transfer due to radiation as follow [19, 20]:

4 4 σ (Ti − T j ) Qradiation = Rij

(12.1)

where T is temperature; б Stefan Boltzmann’s constant (5.66×10-8 W/m2K4); R ij is the total resistance encountered during radiation heat transfer through two surfaces (i and j). Finally the equation of radiation heat transfer becomes:

4 4 σ (Ti − T j ) Qradiation = 1 − ε 1− ε j  i + 1 +    Aiε i Ai Fij A j ε j 

(13.1)

where ε is emissivity of the surface; A the area of the surface; and F ij the view factor between two surfaces (i and j). Therefore, the heat transfers due to radiation through the plain woven cell are given as: • Through air pore:

Qrad .air =

• Between yarn and environment:

σ [( p1 − a1 ) × ( p2 − a2 )](T14 − T24 )

1 − ε air     ε air 

(14.1)

Page 653 of 1108

σ [ a1 ( p2 − a2 ) + p1a2 ](T14 − T24 ) Qrad . yarn = 1 − ε yarn     ε yarn 

(15.1)

• Between skin and yarns:

σ [ a1 ( p2 − a2 ) + p1a2 ](T14 − T24 ) Qrad . yarn.skin =  1 − ε yarn   1 − ε skin     +1+    ε yarn     ε skin   

(16.1)

In this study, by considering to the blends law the emissivity of blend yarn calculated as follow:

ε yarn = (ε f 1 × p f 1 ) + (ε f 2 × p f 2 ) + (ε f 3 × p f 3 )

(17.1)

Total heat transfer due to radiation and total heat transfer due to radiation per unit area as following equations:

Qrad .total = Qrad .air + Qrad . yarn + Qrad . yarn.skin Qradiation =

Qrad .total p1 p2

(18.1)

(19.1)

Therefore, the resistance of the fabric due to radiation is given by the following equation:

(T − T ) (20.1) Rradiation = 1 2 Qradiation If the modes of heat transfer are made analogous to a parallel circuit system, then the overall resistance of fabric is given by the following relationship: (21.1) Rtotal = [( Rconduction ) −1 + ( Rradiation ) −1 ]−1 This value gives the total thermal resistance of the cotton/nylon blended with Kermel fabrics in the absence of any convection heat flux.

3. Experimental 3.1.

Materials and Methods

In our previous study, six plain woven blended fabrics were used for evaluation. The blend ratio of cotton, nylon and Kermel was designed systematically as shown in Table 1 and two reference fabrics made of cottonnylon blend and pure Kermel yarns were used. All of the fabric samples have the same number of ends of 26 cm-1and picks of 19 cm-1. The fabrics were kept 24h in standard ambient conditions at temperature of 20±2 °C and relative humidity of 65±2 % for conditioning and relaxation [17]. According to ISO 11092 the sweating guarded hot plate was used to determine thermal resistance and water vapor resistance of blended fabrics under steady-state conditions. The temperature of the measuring plate was kept constant at 35 °C, the wind velocity at 1 m/s and the ambient conditions at 20 °C and 65% of relative humidity for measuring thermal resistance and at 35 °C and 40% of relative humidity for measuring water vapor resistance of fabrics. The thicknesses of woven fabrics were measured using the Frank thickness tester (Karl Frank GmbH, Germany) at a pressure of 2kPa according to ISO 5084:1997. Fourteen tests were conducted for each fabric sample [17]. Table 1: Specifications of cotton/nylon-Kermel blended woven fabrics

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S. No.

Fiber Blend Ratio [%]

Thickness [mm]

1 2 3 4 5 6

50:50 Cotton/Nylon 50:40:10 Cotton/Nylon-Kermel 50:30:20 Cotton/Nylon-Kermel 50:20:30 Cotton/Nylon-Kermel 50:10:40 Cotton/Nylon-Kermel 100 Kermel

0.63±0.01 0.65±0.01 0.64±0.01 0.64±0.01 0.64±0.01 0.71±0.02

Thermal Resistance [m2.K/W] Experimental Predicted 0.0071 0.0066 0.0072 0.0069 0.0074 0.0074 0.0074 0.0079 0.0076 0.0085 0.0084 0.0086 Average Error (%) = 5.24

Error (%) 7.69 4.81 0.87 6.17 9.78 2.11

4. Results and Discussion 4.1.

Comparison of experimental and theoretical values

The values obtained from the model were compared with the thermal resistance values of blended fabrics obtained from experimental results (Table 1). It can be seen from Figure 3 that the R2 value (0.7) is high which indicates a strong correlation between the experimental (actual) and theoretical (predicted) values. The average error percentage between the experimental and theoretical values is 5.24% for cotton/nylon-Kermel blended fabrics that also confirmed the good relation between actual and predicted values by the model. In this model, heat transfer though convection mode is not taken into consideration as there was no air gap (space) between hot and cold plates on sweating guarded hot plate. It can be seen from Table 1 and also Fig. 3 that the thermal resistance values of some samples obtained by the experimental data are higher than those obtained from the prediction data by the model, and also some values are lower. This result can be attributed to the yarn packing density as well as to yarn flattening in sweating guarded hot plate instrument which are explained as follow: It was shown that with increase of Kermel fiber blend ratio, the fabric porosity and consequently the thermal resistance are increased [17], the increase in fabric porosity is mainly related to yarn packing density and fabric thickness, however, in theoretical section it was assumed that the yarn packing density of all the blended yarns is constant; on the other hand, the pressure applied by the top plate of measuring instrument leads to flatten the yarns and increase in the conductive heat loss of fabric samples, but we assumed that the yarn cross section shape is circular and thus yarn flattening effect is ignored. Fig. 4 shows that with increasing the ratio of Kermel fibers in blended fabrics, thermal resistance values of fabric samples increase. It is shown that the general trend variation of predicted values against Kermel fiber blend ratio is similar to experimental values. It is interesting to note that the theoretical and experimental values of thermal resistance for 100% Kermel fabric are almost identical.

Fig. 3: Correlation between actual and predicted thermal resistance values of cotton/nylon-Kermel blended fabrics

Page 655 of 1108

Fig. 4: Effect of Kermel fibers blend ratio on experimental and predicted thermal resistance values of cotton/nylonKermel blended fabrics

5. Conclusions In this study, the thermal resistance of cotton/nylon-Kermel blended fabrics modeled by using a system of series resistances. The single cell woven theoretical model gives a good prediction of thermal resistance of plain woven fabrics. The obtained correlation between actual and predicted values is high. The average error percentage between the experimental and theoretical values for cotton/nylon-Kermal blended fabrics also confirmed the good relation between actual and predicted values by the model. It can be seen from the results that with increasing the ratio of Kermel fibers in blended fabrics, predicted thermal resistance values of fabric samples increased almost similar trend compared with experimental values. Further, research works can be done in this area to improve the validity of this theoretical model by considering the actual values of yarn packing density with different fiber blend ratio, and also yarn flattening effect.

6. References [1] Lienhard, J.H. and J. Lienhard, A heat transfer textbook. 2000: Phlogiston Press Cambridge, Massachusetts. [2] Mohammadi, M., P. Banks-Lee, and P. Ghadimi, Determining effective thermal conductivity of multilayered nonwoven fabrics. Textile research journal, 2003. 73(9): p. 802-808. [3] Kaviany, M., Principles of heat transfer. 2002: John Wiley & Sons. [4] Gagge, A.P., A.C. Burton, and H.C. Bazett, A practical system of units for the description of the heat exchange of man with his environment. Science, 1941. 94(2445): p. 428-430. [5] Huang, J., Theoretical analysis of three methods for calculating thermal insulation of clothing from thermal manikin. Annals of occupational hygiene, 2012. 56(6): p. 728-735. [6] Wr贸bel, G., S. Pawlak, and G. Muzia, Thermal diffusivity measurements of selected fiber reinforced polymer composites using heat pulse method. Archives of Materials Science and Engineering, 2011. 48(1): p. 25-32. [7] Lee, S., Effect of fiber orientation on thermal radiation in fibrous media. International journal of heat and mass transfer, 1989. 32(2): p. 311-319. [8] Prakash, C. and G. Ramakrishnan, Effect of Blend Ratio, Loop Length, and Yarn Linear Density on Thermal Comfort Properties of Single Jersey Knitted Fabrics. International Journal of Thermophysics, 2013. 34(1): p. 113121. [9] Wu, H.Y., W.Y. Zhang, and J. Li, Study on Improving the Thermal-Wet Comfort of Clothing during Exercise with an Assembly of Fabrics. Fibres & Textiles in Eastern Europe, 2009. 17(4): p. 46-51. [10] Williams, J.T., Textiles for cold weather apparel. 2009: Elsevier. [11] Bhattacharjee, D. and V. Kothari, A theoretical model to predict the thermal resistance of plain woven fabrics. INDIAN JOURNAL OF FIBRE AND TEXTILE RESEARCH, 2005. 30(3): p. 252. [12] Kothari, V. and D. Bhattacharjee, Prediction of thermal resistance of woven fabrics. Part I: Mathematical model. Journal of the Textile Institute, 2008. 99(5): p. 421-432.

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[13] Hes, L. and C. Loghin, Heat, moisture and air transfer properties of selected woven fabrics in wet state. Journal of Fiber Bioengineering and Informatics, 2009. 2(3): p. 141-1499. [14] Ismail, M., A. Ammar, and M. El-Okeily, Heat transfer through textile fabrics: mathematical model. Applied mathematical modelling, 1988. 12(4): p. 434-440. [15] Chang, W.S., Porosity and effective thermal conductivity of wire screens. Journal of heat transfer, 1990. 112(1): p. 5-9. [16] Luikov, A., et al., Thermal conductivity of porous systems. International Journal of Heat and Mass Transfer, 1968. 11(2): p. 117-140. [17] Study on effect of blend ratio on thermal comfort properties of cotton/nylon-blended fabrics with highperformance Kermel fibre. The Journal of The Textile Institute, 2014(ahead-of-print): p. 1-9. [18] Yoon, H.N. and A. Buckley, Improved comfort polyester: Part 1: Transport propeties and thermal comfort of polyester/cotton blend fabrics. Textile Research Journal, 1984. 54(5): p. 289-298. [19] Tong, T. and C. Tien, Radiative heat transfer in fibrous insulationsâ&#x20AC;&#x201D;Part I: analytical study. Journal of Heat Transfer, 1983. 105(1): p. 70-75. [20] Tong, T., Q. Yang, and C. Tien, Radiative heat transfer in fibrous insulationsâ&#x20AC;&#x201D;Part II: experimental study. Journal of Heat Transfer, 1983. 105(1): p. 76-81.

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The 13th Asian Textile Conference Geelong, Australia, November 3 - 6, 2015

Application of regenerated animal fibers for scaffold preparation Kazuya Sawada 1 +, Tomoaki Aoyama2, Yojiro Saka2, Hiroki Goto2, Toshiya Fujisato2 1

Department of Integrated Life, Osaka Seikei Collage Department of Biomedical Engineering, Osaka Institute of Technology

Abstract. Extraction of keratin from wool fibers was examined using oxidative and reductive isolation methods. Keratin was effectively extracted from the cortex region at an approximately 40% yield. Molecular mass analysis showed that extracts, consisting of an α and γ fraction, had average masses of 40–60 kDa and 10–30 kDa, respectively. The biodegradability of extracted keratin was evaluated in vitro by enzymatic hydrolysis using several types of proteases. Keratin was found to be completely hydrolyzed by proteases within a short time. The rate of enzymatic hydrolysis could be controlled by moderate crosslinking. In order to evaluate the potential of keratin as a scaffold material, extracted keratin was processed into several structures such as thin film, porous sponge, and nanofiber sheet. The physical properties of each of the keratin structures were evaluated for hydrophilicity, mechanical strength, and surface structure. The results of these evaluations showed keratin to have suitable properties for a scaffold. The keratin materials were evaluated for their biocompatibility by culturing the structures with fibroblasts. Cells attached well and grew steadily on all of the keratin scaffold structures. The rate of cell growth on keratin was equivalent to that of the control. Keratin materials were then subcutaneously implanted in rats. Recipient cells were found to infiltrate into keratin scaffolds without eliciting a major inflammatory response.

Keywords: keratin, wool, nanofiber, scaffold

1. Introductions A variety of scaffolds made from synthetic polymers and tissue-derived materials have been investigated. Synthetic polymers such as polylactic acid and polyglycolic acid are advantageous as their shape and mechanical properties are easily controlled. In addition, these polymers are biodegradable and do not elicit an immune response. However, synthetic polymers generally have low cell affinity. Conversely, tissuederived natural materials generally have properties opposite to synthetic polymers. To address the problems of each scaffold material, hybrid materials of synthetic and natural polymers have been investigated in recent years and are still under the development. Currently, collagen is the most commonly used scaffold material. Collagen is a structural protein with good biocompatibility. In addition, the durability and strength of collagen are suitable for scaffold materials. However, there is a concern pertaining to the safety of collagen, as it has been linked with an incidence of bovine spongiform encephalopathy (BSE). Considering this issue, we chose to focus on keratin protein as an alternative material to collagen. Keratin is a fibrous protein that constitutes the intermediate filaments in epithelial cells of vertebrate animals and is a chief constituent of hair, nail, horn, and beak [1]. A key characteristic of keratin is its amino acid composition and high cysteine content that permits the formation of many disulfide bonds. These bonds maintain a firm steric structure and make the protein water-insoluble. Keratin also contains amino acid sequences such as RGD and LDV that are involved in cell adhesion and have similarities to fibronectin, which is a known cell-adhesive protein [2]. Thus, much like fibronectin, high cell affinity is expected for keratin if it is used as a biomaterial. In this study, keratin protein extracted from wool fibers was formulated into various structures including thin films, porous sponges, and nanofiber sheets. Further, its potential to be used as a scaffold material was evaluated. +

Corresponding author. Tel.: + 81-6-6829 2561. E-mail address: sawada-k@osaka-seikei.ac.jp

Page 658 of 1108

2. Experimental 2.1 Materials and sample preparation Wool fibers were kindly supplied from the Toyobo Co., Ltd and were washed three times with a mixture of chloroform/methanol (5:1) before the extraction procedure. All chemicals used were reagent grade and were obtained from Wako Pure Chemicals Industries, Ltd. Oxidative extraction: Keratose, which is categorized as an oxidative derivative of keratin, was obtained from wool fibers. Wool fibers were oxidized for 2 h in peracetic acid at 323 K, and then filtered and completely washed using distilled water. Oxidized fibers were submerged in Tris-base solution to extract the keratose. The Tris-base solution was vigorously stirred overnight and then filtered to remove insoluble contents. The keratose fraction of the filtrate was precipitated by pH adjustment using acetic acid. The precipitates were lyophilized and stored in a desiccator until needed. Reductive extraction: Keratein, a reductive derivative of keratin, was obtained from wool fibers. Wool fibers were immersed in a Tris (3-hydroxypropyl) phosphine/guanidinium hydrochloride solution for 3 days at 323 K. After filtration, filtrates containing reduced keratin (keratein) were dialyzed in distilled water using a 14kDa molecular weight cutoff cellulose membrane. The obtained samples were lyophilized and stored in a desiccator until needed. Films were prepared by a simple cast method using keratin solution containing either keratose or keratein. Porous sponges with different pore sizes were prepared by lyophilization of the keratin solution. The pore size of the sponge was controlled by changing the preliminary freezing temperature. Nanofiber sheets were prepared by electrospinning using a keratin/formic acid solution. PEG (Polyethylene glycol, M.W. 500000) was also added to the dope solution to increase viscosity.

2.2 Evaluation of materials Keratin biodegradability was evaluated in vitro by enzymatic hydrolysis using several different proteases. The proteases used in this study included trypsin, chymotrypsin, papain, thermolysin, orientase, and bromelain. Enzymatic hydrolysis was followed by quantitative analysis of the hydrolyzed proteins using the bicinchoninic acid assay. The physical properties of the keratin materials were evaluated for hydrophilicity, mechanical strength, and surface structure. The hydrophilicity of keratin films and nanofiber sheets was analyzed by measuring the water contact angle. The mechanical strength of each structure was measured by tensile strength test and the elastic modulus was evaluated. The surface structure of the films, sponges, and nanofiber sheets was assessed using scanning electron microscopy (SEM). To evaluate the biocompatibility of the keratin structures in vitro, keratin films, porous sponges, and nanofiber sheets were cultured with L929 mouse fibroblast cells. In addition, sponges were subcutaneously implanted into rats to evaluate its biodegradability and biocompatibility in vivo.

3. Results and Discussion Both keratein and keratose were effectively extracted from wool fibers without reduction in their molecular weight during the extraction process. The distribution of molecular weights of the Îą and Îł fractions of the keratin molecule were in agreement with published values [3]. The biodegradability of keratin was evaluated by enzymatic hydrolysis with a variety of proteases. In a homogeneous system, enzymes quickly and completely hydrolyzed extracted keratose. In a heterogeneous system, the reaction rate of enzymatic hydrolysis of keratose could be controlled by moderate crosslinking with glutaraldehyde. Keratein was also hydrolyzed by enzymes; however the reaction was lower than that of keratose. The hydrophilicity of the keratin material was greatly dependent on the surface structure. Films were found to have hydrophilic surfaces comparable to collagen, whereas the surface of nanofiber sheets showed hydrophobicity at the initial stage due to its nanostructure. The initial hydrophobicity of the nanofiber sheets was gradually improved with the dissolution of PEG and finally reached an equivalent level to that of the films. Similar results were observed with both keratein and keratose. The surface characteristics of the keratin materials were evaluated by SEM. Both keratein and keratose films had smooth, nonporous surfaces. This result suggests that infiltration of cells into films may be difficult even if the surface of films has a high cell affinity. In the living body, keratin films may be useful as a

Page 659 of 1108

membrane for blocking mass transfers rather than as a cell scaffold. In contrast, keratose sponges prepared by freeze-drying were porous. In addition, the pore size in the sponge was controlled by changing the prefreezing temperature. As the temperature of the pre-freezing was lowered, the pore size in the sponge was reduced. These results suggest that the pore size of the sponges could be altered to suit different cell culture environments. Keratin nanofibers prepared by electrospinning were found to have different fiber diameters depending on the keratose content of the spun solution. Figure 1 shows the relationships between nanofiber diameter and keratose concentration.

Keratose : 0%

Keratose : 50%

Keratose : 100%

Fig. 1: The relationship between nanofiber diameter and keratose concentration As shown in Figure 1, the nanofiber diameter can be changed by controlling the ratio of keratose/PEG. The porosity of the nanofiber sheets also changed with the variation of fiber diameter and it markedly increased after immersion in an aqueous solution of PEG, which contained high concentration of water soluble PEG. When PEG was added to a keratose 100% dope solution, small beads of mixed polymers (keratin/PEG) were formed and nanofibers did not successfully form. Two-dimensional cell culture on keratin films and nanofiber sheets was performed using the L929 mouse fibroblast cell line. In both keratose and keratein films, seeded cells attached well to the substrates and successfully proliferated over time. The growth rate of cells seeded on keratin films was nearly equivalent to that of cells seeded on collagen. Similar results were also obtained using nanofiber sheets, even though growth rate of cells seeded on keratein and keratose was slightly different. Day1

Day3

Day5

Keratein Nanofiber

Control commercial culture dish

Fig. 2: Live/Dead stain of cultured cells on the keratein nanofiber sheet Figure 2 shows representative photographs of cultured cells stained using Calcein AM and Ethidium homodimer-1. Living cells and dead cells stained with correspondent fluorochrome emit fluorescence in green and red, respectively. As shown in Figure 2, dead cells were scarcely observed in each photograph.

Page 660 of 1108

The cell numbers increased with time in the culture. However, the growth rate of cells on keratein nanofiber sheets was lower than that of the control. In contrast, the growth rate of cells on keratose nanofiber sheets was the same as that of the control. The difference in the surface charge of each fiber may have affected the growth rate of the cells. These results suggest that keratose and keratin have good cytophilic properties, although their characteristics are slightly different. To evaluate the adhesion and invasion of recipient cells in vivo, keratose films and sponges were then subcutaneously implanted in rats. One week after implantation, recipient cells were found adherent on the surface of films. However, cells were not found to infiltrate films even after 4 weeks of growth. Keratose films may have a role as a membrane for tissue isolation. In contrast, cells were found to infiltrate the entire volume of sponges. After 4 weeks, vascularization was also observed in sponges. In contrast to the enzymatic hydrolysis results observed in vitro, keratose films and sponges were scarcely hydrolyzed in vivo until 4 weeks. In both films and sponges, no major inflammatory reaction was observed after subcutaneous implantation. Keratin is a biologically derived polymer that can be obtained from human hair. Therefore, if these materials are derived from human hair in future studies, they could be derived from non-vascular, homogenous sources, which is quite advantageous. In conclusion, the results of this study show that keratin is a comparable material to collagen but further examination of its mechanical properties and biocompatibility is warranted.

4. References [1] F. M. Keratin, Encyclopedia of Polymer Science and Engineering, 2nd Edition, Wiley. 2nd ed. New York: Wiley, 566, (1985). [2] A.Tachibana, Y. Furuta, H. Takeshima, J Biotechnol., 93(2), 165 (2002). [3] P. Hill, H. Brantley, M.V.Dyke, Biomaterilas, 31(4), 585 (2010)

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The 13th Asian Textile Conference Geelong, Australia, November 3 - 6, 2015

Coated Fabric Geomembranes Mike Sadlier, Geosynthetic Consultants Australia Steve Aggenbach, Infrastructure Technologies ( Australia ) Pty Ltd

Abstract. Geomembranes are low permeability materials used in civil engineering to provide barriers to liquid migration. They may be used for containment of valuable fluids or for environmental protection. This paper will discuss the numerous application and performance advantages of a geomembrane produced by applying a flexible polymer cementitious coating to a technical fabric substrate. Provided that the coating has suitable properties of flexibility and durability then the underlying substrate can be used to engineer behaviour and performance characteristics that are desirable for particular applications. When high flexibility and elongation is a required a non-woven may be chosen or when tensile strength and low elongation are desired a woven may be chosen or a composite may be chosen to provide a little of both worlds. The paper will discuss the properties that can be achieved by this technology and discuss them in comparison to conventional polymeric geomembranes.

1. Background Coated fabric geomembranes have been around for some years a seeking to provide more versatile and cost effective alternatives to polymeric geomembranes. Field spraying has been problematic due to inconsistency of coating (both too little and too much) and factory coating can yield better results but still depends on the consistency and texture of the substrate fabric. With a proper marriage of the coating and the substrate fabric is it possible to use slight differences in the materials to provide a finished geomembrane suited to particular purposes. We have seen unsuccessful attempts to develop field coated fabric geomembranes using coating materials ranging from bitumen based materials to acrylics to two part polyurethanes. Most of these suffered from difficulties with control thickness that had both quality and cost implications. The two part polyurethanes have enjoyed some success in smaller complex applications such as decorative ponds but larger engineering applications such as water storages, channels and the like continue to be dominated by preformed geomembranes which usually require some sort of welding process at the seams. This paper will discuss a preformed coated fabric geomembrane developed by Infrastructure Technologies (Australia) called ITL Aqualiner where the coating is a specially developed proprietary polymer cement compound and the coating is applied in a controlled factory environment. Consistent application and takeup of the coating is as much dependent on the consistent surface and texture of the fabric as it is on the consistent application of the coating. ITL Aqualiner has either been patented or is patent pending in key international markets.

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2. Properties Typical properties are set out in Table 1 and for comparison similar properties of the common HDPE and LLDPE materials are provided as well. The coated fabric geomembrane is not subject to the Environmental Stress Cracking that afflicts polyethylene materials and it does not contain additives whose depletion can be measured by Standard and High Pressure Oxidation Induction Time testing. Table 1 - Comparison of Typical Properties

Property

ITL Aqualiner

HDPE

LLDPE

Thickness (AS 2001.2.15A, ASTM D 5199) Unit Mass (AS 2001.2.13), Grab Tensile

2.25 mm

1.5 mm

1070 g/sqm

940 g/sqm

939 g/sqm

MD 1230 N TD 1800 N

Strip Tensile (ASTM D751 25 mm strip or ASTM D6693 - 6 mm wide dumbbell) CBR Burst (AS 3706.4) Rod Puncture (ASTM D4833) Trapezoidal tear (AS 3706.3) Graves tear (ASTM D1004 Multiaxial Burst (ASTM D5617

MD 488 N/25 mm (20 N/mm) TD 547 N/25 mm (22 N/mm) Yield elongation 24.88% 3.76 kN

Test used on fabric materials not used on polymer sheets 40 N/mm Yield elongation 12%

Test used on fabric materials not used on polymer sheets 40 N/mm No yield point on curve

480 N

370 N

187 N

150 N

Rupture elongation 20%

Rupture elongation 80%

715 N 350 N

Rupture pressure 15 psi Rupture elongation 34%

Accelerated QUV exposure testing for 1600 hrs (simulated outdoor exposure of about 15 years) has not found any visible or material signs of degradation. Some of the useful and different properties of this coated fabric geomembrane include: • • • •

ITL Aqualiner is a polymer - cementitious coating bonded to a woven/non-woven geofabric, and is intended to perform as anlow permeability liner or barrier. Flexible properties allow liner to conform and move with the substrate without cracking. These properties can be configured by different geotextile selection. Structure incorporates a cushioning geotextile for lining over potentially damaging subgrades. Resists mechanical, human and fauna traffic.

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• • • •

AS4020 certified (for potable water applications). Non-flammable - passes UL94 which requires that the membrane must not sustain combustion and must be self extinguishing after the removal of flame. Integrates easily into existing headwalls, pipe penetrations and containment structures. Easily repaired and maintained in the field

3. Installation The coated fabric geomembrane requires limited subgrade preparation with anchor trenches, slopes rarely steeper than 1:1 and the geotextile base provides a built in cushion that protects against small rocks etc.

Figure 1. Trangi Nevertire Channel Project Figure 1. shows a typical installation where panels have been deployed from a spreader bar or similar device and are being seamed. A worker is using a small machine to dig anchor trenches in advance and will return to backfill anchor trenches after seaming.

4. Seaming and Quality Control Set out below are the procedures for seaming and field testing. • • • • •

Site to be cleared (with nominal compaction), shaped and anchor trenches formed. On steep inclines, joints can be secured with suitable geotextile anchor pins or staples Lay coated liner and lap join (150 mm minimum overlap) using specified Moisture Curing Urethane adhesive in 3 beads. Spray apply coating over joint ensuring good coverage of the exposed edges. Coating will skin in 2-3 hours; allow curing for 5 to 7 days in normal weather prior to use. Secure the fabric into anchor trenches or fix to concrete structures.

Seam integrity can be assured by physical inspection and probing as well as vacuum box testing. Destructive testing can be carried on cured seams taken from the work or from seam overruns.

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Table 2. Seam properties compared to HDPE and VLDPE. Seam Property ITL Aqualiner HDPE (1.5 mm) wedge welded Shear strength 502 M/25 mm 525 N/25 mm (ASTM D 6392) Peel strength 1550 N/25 mm 398 N/25 mm (ASTM D 6392)

LLDPE (1.5 mm) wedge welded 394 N/25 mm 328 N/25 mm

5. Areas of Application The coated fabric geomembrane has been successfully used in a number of example projects associated with channel lining and remediation. These include the Newcastle Coal drainage spillway and a water channel at Maffra.

Figure 3. Maffra Channel

6. Summary and Conclusions ITL Aqualiner is an innovative combination of geotextile fabric with a proprietary polymer cement coating that can be engineered to provide performance properties to suit a range of applications . Installation is straight forward without any special skills or equipment and it can be installed over less than perfect subgrades to give a cost effective and durable low permeability barrier

References • • •

•

Aseervatham E, and Sadlier M.A “Earthen Channel Lining Trials” Eighth International Conference on Geosynthetics, September 2006, Yokohama Excelplas Testing Report on Accelerated Weathering by QUV dated 11th March, 2010 GRI Test Method GM13 for HDPE , Geosynthetic Institute Philadelphia Revision 12, November 14, 2014 GRI Test Method GM17 for LLDPE Geosynthetic Institute Philadelphia Revision 11, April 13, 2015

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The 13th Asian Textile Conference Geelong, Australia, November 3 - 6, 2015

Development of 3-Dimensional Fibrous Scaffolds using draw texturing and tubular knitting Jaehoon Ko 1,Young Hwan Park 1, Changwoo Nam 1, Chong Soo Cho 2, and Tae-Hee Kim 1 1

Korea Institute of Industrial Technology, Korea 2 Seoul National University, Korea

Abstract. Conventional biodegradable fiber have limitations regarding application to the tissue engineering because of their characteristic compact structure. To address this problem, PLGA fibers were designed with pore size 10-100 ㎛ to allow the micro-environment for cell attachment, migration, proliferation, as well as to provide a matrix for delivery of biological factors. Firstly, PLGA multifilament was fabricated by meltspinning process. To modulate the pore characteristics of PLGA fibers, DTY (draw textured yarn) process and repeated elongation-relaxation were performed in the second step, resulting in the bulky, looping and crimping structures. The fibers showed a mean fineness of 17 ㎛ and heterogeneous pore size distribution. In the third step, PLGA biodegradable multifilament draw-textured yarn (DTY, 200 denier, 64 filaments) was inserted inside a tubular knitted fabric made of PLGA. Then, the PLGA DTY yarn was drawn at a ratio of 15% and cut into a size of 10mm to prepare 3D porous scaffolds. To provide hydrophilic surface for efficient cell attachment and growth, the scaffolds were treated with plasma in the presence of oxygen for 5 min. Finally, the cell was seeded and cultured on scaffolds to apply on tissue therapy. The scaffold was designed to have high flexibility and porosity with aligned microfibrous bulky structure inside the tube having advanced biomimetic structure for cell growth.

Keywords: PLGA, DTY, tubular knit, scaffold

1. Introduction Tissue engineering is an interdisciplinary field that applies the principles and innovation of engineering and life sciences to develop biological substitutes, which restore, maintain, or improve tissue/organ functions[1]. The major challenges in tissue engineering are to design and fabricate a suitable scaffold[2, 3] to provide a three dimensional support for cell attachment, migration, proliferation, as well as to provide a matrix for delivery of biological factors. To design functional substitutes for damaged tissues and organs, we have developed new concept of scaffolds by modifying existing textile manufacturing process. We have developed novel threedimensional porous poly(lactic–co-glycolic acid) (PLGA) scaffolds by using draw texturing and tubular knitting process. The scaffold is designed to have high flexibility and porosity with aligned microfibrous bulky structure inside the tube having advanced biomimetic structure for cell growth.

2. Experimental 2.1.

Preparation of bulky structured PLGA filament

Draw textured PLGA yarn was fabricated by adopting three-step procedure. Firstly, We span PLGA(10:90) into filament using multi nozzle by conventional melt-spinning process at 240℃. Secondly, bulky yarn(DTY) was made from POY by draw-false twisting process(texturing process). The POY delivered to a main heater between the 1st roller and the 2nd roller was adjusted to maintain temperature not less than 145℃ during Ztwisting. And then, the Z-twisted POY was delivered to sub heater between the 2nd and the 3rd heater off during S-twisting. The numbers of Z and S twists were exactly the same. Additional drawing (Draw ration 1.07) was conducted to enlarge the bulky structure.

Page 666 of 1108

Fig. 1: DTY (drawn textured yarn) process of melt-spinning to produce PLGA filament.

2.2.

Preparation of 3D scaffolds

The PLGA (1:9) biodegradable multifilament draw-textured yarn (DTY, 200 denier, 64 filaments) was inserted inside a tubular knitted fabric made of PLGA. Then, the PLGA DTY yarn was drawn at a ratio of 15% and cut into a size of 10mm to prepare 3D porous scaffolds. To provide hydrophilic surface for efficient cell attachment and growth, the scaffolds were treated with plasma in the presence of oxygen for 5 min.

Fig. 2: Preparation of cylinder shaped 3D scaffold.

2.3.

Cell seeding

NIH 3T3 Fibroblast cell from mouse embryo tissue was seeded and cultured on 3D porous scaffolds at seeding density of 1×104 cells/cm2. The density and morphology of cells were analyzed by SEM and fluorescent microscope.

3. Results and Discussion The developed PLGA filament showed a unique configuration compared to those of other biodegradable fibers in Fig. 3. PLGA filament consisted of 2 parts; bulky area and compact area. The width of bulky part was about 5 times larger than that of compact area of 3D scaffold after elongation. In the architecture of this fiber, the fibers can hold the cells and the pore between the fibers can offer the sufficient space for cell proliferation. The average diameter of individual fiber was 17 µm and the mean pore diameter in bulky area was 38.5 µm. Their distribution is disclosed in Fig. 3, By analyzing the pore size and distribution, we could observe that developed filament presented a heterogeneous pore structure fitting for cell culture(Fig. 4).

Page 667 of 1108

Fig. 3: Configuration of PLGA multi filament. Optical micrograph (A); SEM micrographs of bulky area (B); SEM micrographs of compact area(C).

0 0

100

Pore diameter(Âľm)

Fig. 4: Pore size distribution of PLGA multi filament; melt spinning 240â&#x201E;&#x192;, DR 2.9, 800d/256f.

The cell proliferation was measured after 1, 3, 5, and 7 days by using a fluorescent microscope. Fig. 5 showed that NIH 3T3 Fibroblast cell was well attached to the 3D scaffold, covering the pores between fibers. Also, the density of cells attached to the 3D scaffold increased significantly during incubation and the number of cells increased about 12 times during 7 days incubation in this study(Fig. 5).

After 7 days

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Fig. 5: Proliferation and adhesion images of NIH3T3 fibroblasts cell on cylinder shaped 3D scaffolds as ply.

4. Conclusion The results of cell seeding showed that pore size, pore distribution, and fiber fineness of prepared scaffolds were suitable as a biocompatible scaffold in vitro for NIH 3T3 Fibroblast cell. Also, we expect that prepared scaffolds will provide numerous benefits as a noninvasive alternative for tissue engineering applications.

5. Acknowledgement This work was supported by Industrial Source Technology Development Programs (No.10047811) funded by the Ministry of Trade, Industry and Energy (MOTIE, Korea)

6. References [1] Langer R, Vacanti JP, Tissue engineering, Science 260, 920-926 (1993). [2] F. G. Giancotti and E. Ruoslahti, "Integrin Signaling", Science, 13, 1028-1032 (1999). [3] K. E. Gonsalves, C. R. Halberstadt, C. T. Laurencin, and L. S. Nair, "ECM Interactions with Cells from

the Macro- to Nano Scale", pp.225-260, John Wiley and Sons, New York (2008).

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The 13th Asian Textile Conference Geelong, Australia, November 3 - 6, 2015

Effect of tensile properties of layers on the performance of geocells made from woven fabrics in bearing capacity of reinforced soil Hadi dabiryan 1, Mohammad maroufi 2 and Ghazal ghamkhar 3 + 1 2

Assistant professor of textile department of amirkabir university of technology Assistant professor of textile department of amirkabir university of technology 3 Graduate student of textile department of amirkabir university of technology

Abstract. The aim of this study is to investigate the effect of tensile properties of layers on the performance of geocells formed by woven fabrics in bearing capacity of reinforced soil. For this purpose, geocells were provided using different woven layers. Series of laboratory-model tests were carried out to determine the bearing capacity of footing supported by geocell reinforced soil. The results showed that the tensile strength of fabrics has a key role in bearing capacity of reinforced soil so that the goecells formed by high tensile strength layers showed less settlement than those of low tensile strength layers. In the other word, gecells made from high tensile strength layers improve the bearing capacity of reinforced soil than those of low tensile strength layers.

Keywords: Tensile properties, geocell, bearimg capacity, reinforced soil.

1. Introduction A geocell is a geosynthetic product with a three-dimensional cellular network constructed from thin polymeric strips. Many investigators have reported the beneficial use of geocell layer at the base of embankment: as an immediate working platform for the construction, more uniform settlements, reduced construction time and eliminated excavation and replacement costs, increased bearing capacity and decreased settlements. Despite the large amount of research and successful field applications, geocell reinforcement is still not widely used at the same level as conventional methods such as piling, soil replacement, or traditional planar (geogrid or geotextile) basal reinforcement, due to the lack of design procedures for the use of geocells as basal reinforcement in many countries[1]. Including research this area in recent decades, can be noted to the research Madhavi Latha[2] about that the embankments supported with geocells. The influence on the behavior of the embankment of various parameters was studied. Geocell reinforcement was found to be advantageous in increasing the load-bearing capacity and reducing the deformations of the embankments. The experimental results were validated using a general purpose slope-stability program and a design procedure useful for the preliminary design of geocellsupported embankments is illustrated.She also presented the finite-element simulations of the behavior of strip footings resting on sand beds, with different density of soil, reinforced with geocells of different dimensions. The strength and stiffness of sand confined with geocells is represented by an equivalent composite model developed from triaxial compression tests. The additional confining pressure due to geocells, calculated using hoop tension theory, is used to obtain the apparent cohesive strength imparted to sand due to geocells. The elastic modulus of the geocell encased sand is related to the elastic modulus of the unreinforced sand and the tensile modulus of the geocell material using an empirical equation. Load-settlement response of strip footings on geocell reinforced sand beds obtained from the numerical simulations are compared with the corresponding experimental results and the match is found to be good. In addition, numerical results showed that with the provision of a geocell layer, the mobilized shear stress contours become horizontal and shift downwards, indicating that the geocell mattress transmits the footing load to a deeper depth, thereby bringing about a higher load carrying capacity[3]. In another study that conducted by Sujit kumar dash, a series of model tests has carried out to develop an understanding of the influence of the geocell material on the load-carrying mechanism of the geocell-reinforced sand foundations under strip loading. Geocells of different types were prepared using +

E-mail address:ghazal.ghamkhar@yahoo.com

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geogrids of different types. The parameters studied are as follows: the footing load-settlement response, deformation on the fill surface, strain in the geocell, pressure transmitted to the subgrade soil underlying the geocell mattress, and load dispersion in the geocell mattress. The test results indicate that the strength, stiffness, aperture opening size, and orientation of the rib of the geocell material influence the performance of the reinforced-sand foundation bed. Geocells made of geogrids of higher strength, relatively smaller size aperture opening, and ribs of orthogonal orientation give better performance improvement [4]. Based on the result of S.N. Moghaddas Tafreshi studies on bearing capacity of a strip footing on sand with geocell and with planar forms of geotextile reinforcement the following conclusions can be extracted[5]: (1) Provision of the geocell reinforcement in reinforcing the sand layer significantly increases the load carrying capacity, reduces the footing settlement and decreases the surface heave of the footing bed more than the planar reinforcement with the same characteristics and the same mass used. (2) Overall, with increase in the number of planar reinforcement layers, the height of geocell reinforcement and the reinforcement width, the bearing pressure of the foundation bed increases and the footing settlement decreases. The efficiency of reinforcement was decreased by increasing the above parameters. (3) The optimum depth of the topmost layer of planar reinforcement is approximately 0.35 times of the footing width while the depth to the top of the geocell should be approximately 0.1 times of the footing width. (4) The tests performed with different reinforcement widths (short, medium and long reinforcement width) indicate that increasing the reinforcement width more than 4.2 and 5.5 (approximately) times of footing width for the geocell and planar reinforcement, respectively, would not provide much additional improvement in bearing pressure nor additional reduction in footing settlement. (5) For amounts of settlement that are tolerated in practical applications, improvements in bearing capacity greater than 200% and reductions in settlement by 75% can be achieved with the application of geocell reinforcement, whereas planar reinforcement arrangements can only deliver 150 and 64% for these two quantities, respectively. (6) The comparative investigations imply that in order to achieve a specified improvement in bearing pressure and footing settlement, less mass of material would be used in a geocell implementation compared to a planar one. In the example given in this paper, a geocell reinforcement achieved a similar performance to a planar reinforcement arrangement that contained three times as much mass of geotextile material. With investigated the influence of relative density of soil on performance of geocell-reinforced sand foundations by Sujit Kumar Dash, found that the deformation pattern on fill surface and in sand subgrade indicates that the relative size of test tank and footing, used in the present study, is adequate enough to overcome the boundary effect. It is observed that the beneficial effect of geocell reinforcement, in terms of increase in stiffness, bearing capacity, and load dispersion angle of the foundation bed, is present over a wide range of relative density (ID=30–70%); however, it is higher for dense condition of foundation soil. The value of subgrade modulus at 3% settlement has increased from about 10 MN/m3 with ID=30% to about 40 MN/m3 with ID=70%, indicating that the stiffness of the geocell-reinforced foundation bed has increased by fourfold with increase in relative density of soil from 30 to 70%. At relatively lower settlement of footing, the value of If does not change much with change in relative density of soil, while, at higher settlement range, the rate of increase of bearing capacity factor with increase in relative density is relatively rapid with dense soil compared to that with loose soil. With geocell reinforcement offering three-dimensional confinement the dilation induced benefit is substantially high for dense soil fill. Therefore, for effective utilization of geocell reinforcement, the foundation soil should be compacted to higher density. In field, to achieve dense soil fill within geocells, it is suggested that light rolling compaction with some amount of overfilling should be adopted. With repeated passage of rolling and filling, a dense and compact geocell structure can be achieved[6]. According to research, It has been suggested that the main geocell layer functions in three aspects [1]: (a) lateral resistance effect: A geocell consists of three-dimensional cells that contain, confine and reinforce a variety of filled materials within its cells that completely arrest the lateral spreading and increase the shear strength of filled materials. Moreover, interfacial resistances, which result from the interaction between the geocell reinforcement and the soils below and above the reinforcement, as shown in Fig.1, increase the lateral confinement and lower lateral strain, that result in an increase in the modulus of the cushion layer and improving vertical stress distribution on the subgrade which is called ‘‘vertical stress dispersion effect’’ below, and reducing the vertical pressure on the top of the subgrade correspondingly.

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Fig. 1: Lateral resistance effect of geocell reinforcement.

(b) vertical stress dispersion effect: As mentioned above, the horizontal geocell-reinforced cushion behaves as an immediate working platform that redistributes the footing load per unit area over a wider area, as shown in Fig.2. This refers to herein as ‘‘stress dispersion effect’’. As a result, the soilpressure onto the soft subgrade soil surface is smaller than that onto the subgrade soil in the absence of geocell.

Fig. 2: Vertical stress dispersion effect of geocell reinforcement.

(c) membrane effect: The loads from the embankment deflect the geocell reinforcement thus generate a further tension force, as shown in Fig.3. The vertical component of the tension force in the reinforcement is helpful to reduce the pressure on the subgrade soil. Then the vertical deformation of the soft subgrade is reduced and the bearing capacity of the subgrade soil is enhanced as well. As the depth of the ruts increases the deformed shape of the geocell reinforcement, the reinforcement can provide a further tension force duo to this membrane effect.

Fig. 3: Membrance effect of geocell reinforcement.

So the bearing capacity of the geocell-reinforced embankment foundation p rs can be evaluated by putting the bearing capacity of the untreated foundation soil p s and the bearing capacity increment ∆p on the foundation soil due to the placement of the geocell-reinforced cushion at the base of the embankment together:

2h tan θ c + 2T sin α =  2 sin α T +  2hc tan θ c + 1 prs = p s + ∆p = p s + ∆pr + ∆pt = p s + c  p s    ps bn bn bn    bn  (0.1) Where h c and θ c are the height and the dispersion angle of geocell reinforcement, respectively. b n is the width of the uniform load p s , T is the tensile force and α is the horizontal angle of the tensional force T.

2. Materials and methods 2.1.

Materials

We used layers made from polyester woven fabrics with different tensile properties have been prepared in accordance with the specifications listed in Table 1, for reinforced silica sandy soil. Table 1: properties of tested geocells.

2.2.

Shape

height (cm)

number of layers

width of a cell (cm)

length of a cell (cm)

width of geocell (cm)

length of geocell (cm)

Square

Methods

In this work, the thickness of layer was measured using of DSL thickness gauge. After then we used Instron tensile tester 5566 for determine tensile properties of textile layers. Finally, after making geocells and reinforced soil with them, static loading test was conducted on loading machine at the laboratory scale which

Page 672 of 1108

records changes of force and movement to breaking point. To study more accurate the effect of tensile properties of layers on the bearing capacity of reinforced soil, photos were taken before and after loading test from layers. All tests were performed under standard conditions (temperature: 25±2 oc and relative humidity 65±2 %).

3. Results and discussion Result of the static loading to investigate whether there was any significant effect of different tensile properties of layers on the bearing capacity of reinforced soil with geocells, are shown in Fig.4. According to this figure, said to be the tensile strength of the woven layer geocell building is less, geocell not much resistance against force and reinforced soil is failurt earlier. As well as, by applying force give more deformation. Also, careful observation of samples showed that in general,interaction of higher modulus and lower tensile strength causes more damage in layers of geocell. On the contrary, geocells with higher tensile strength increase the bearing capacity of reinforced soil, decreases the settlement of soil and soil will endure more settlement until the soil failure.

Fig. 4: Bearing capacity of reinforced soil with geocells and tensile strength woven layers geocells manufacturer.

4. Conclusion The results showed that the tensile strength of fabrics has a key role in bearing capacity of reinforced soil so that the goecells formed by high tensile strength layers showed less settlement than those of low tensile strength layers. In the other word, gecells made from high tensile strength layers improve the bearing capacity of reinforced soil than those of low tensile strength layers.

5. References [1] Ling Zhang; Minghua Zhao; Caijun Shi; Heng Zhao; “Bearing capacity of geocell reinforcement in embankment engineering ” , Geotextiles and Geomembranes, p.p. 475-482, Vol.28. 2010. [2] G. Madhavi Latha; K. Rajagopal; N. R. Krishnaswamy; “Experimental and theoretical investigations on geocellsupported embankments”, Internatiomal Journal of Geomechanics, p.p. 30-35, Jan/Feb. 2006. [3] G. Madhavi Latha; Sujit Kumar Dash; K. Rajagopal; “Numerical simulation of the behavior of geocell reinforced sand in foundations”, Internatiomal Journal of Geomechanics, p.p. 143-152, Aug. 2009. [4] Sujit Kumar Dash; “Effect of geocell type on load-carrying mechanisms of geocell-reinforced sand foundations”, Internatiomal Journal of Geomechanics, p.p. 537-548, Sep/Oct. 2012. [5] S.N. Moghaddas Tafreshi; A.R. Dawson; “Comparison of bearing capacity of a strip footing on sand with geocell and with planar forms of geotextile reinforcement”, , Geotextiles and Geomembranes, p.p. 72-84, Vol.28. 2010. [6] Sujit Kumar Dash; “Influence of relative density of soil on performance of geocell-reinforced sand foundations”, Journal of Materials in Civil Engineering, p.p. 533-538, May. 2010.

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The 13th Asian Textile Conference Geelong, Australia, November 3 - 6, 2015

Effects of Different Extraction Conditions on the Efficacy of Shatterstone Ching-Wen Lou 1, Chien-Lin Huang 2, Chiung-Yun Chang 3, Po-Ching Lu 4, Tzu-Hsuan Chao 4 and Jia-Horng Lin 4, 5, 6 + 1

Institute of Biomedical Engineering and Materials Science, Central Taiwan University of Science and Technology, Taichung City 40601, Taiwan, R.O.C. 2 Department of Fiber and Composite Materials, Feng Chia University, Taichung City 40724, Taiwan, R.O.C. 3 Department of Dental Technology and Materials Science, Central Taiwan University of Science and Technology, Taichung City 40601, Taiwan, R.O.C. 4 Laboratory of Fiber Application and Manufacturing, Department of Fiber and Composite Materials, Feng Chia University, Taichung City 40724, Taiwan, R.O.C. 5 School of Chinese Medicine, China Medical University, Taichung City 40402, Taiwan, R.O.C. 6 Department of Fashion Design, Asia University, Taichung City 41354, Taiwan, R.O.C.

Abstract. Shatterstone is a chinese medicine, and is used for the treatment of tetanus and choleplania. This study uses different extraction conditions to prepare the chamomile extracts, and examines the influences of the conditions on the concentrations of the extracts. Different combinations of alcohol concentrations, solidto-liquid ratios, temperatures, and durations are incorporated with the extraction process of Shatterstone. The extracts are filtered in order to remove the undissolvable substances. Next, the concentrations of the extracts are evaluated by using an UV-vis spectrophotometer. The anti-bacterial efficacy of the extracts is finally tested. The test results indicate that the extract concentrations are proportional to the concentration of the alcohol or the extraction temperature. The anti-bacterial test results show that the Shatterstone extracts have anti-bacterial efficacy against both Staphylococcus aureus and Escherichia coli.

Keywords: Shatterstone, anti-bacterial, Staphylococcus aureus.

1. Introduction When human skin tissue is damaged in a large area by burning and cutting, the wounds require a longer time for healing while suffering from a high moisture loss and infection possibility. Therefore, an ideal dressing should be anti-bacterial and have moisture retention and resistance to adhesion in order to shorten the recovery of wounds and prevent infections and secondary injuries. Phyllanthus urinaria Linnea (P. urinariais) is a commonly used traditional Chinese medicine that contains diverse constituents, including acid, alkanol, benzenoid, coumarins, ester, flavonoids, lignans, phytallate, sterols, tannins and triterpenes. It is used to reduce heat, calm the livers, relieve inflammation, and remove food stagnancy. In addition, it is also used for the treatments for stomatitis, enteritis, and nephritis [1-7] due to its antibacterial properties and biocompability. In this study, how the concentrations of chamomile extract are in relation to the extraction solvents, the extraction temperatures, the solid/liquid ratio of P. urinariais to the solvent, and the extraction durations are examined. The influences of the extraction concentrations on the anti-bacterial properties against Escherichia coli and Staphylococcus aureus are then examined in order to evaluate the efficacy of Phyllanthus urinaria Linnea when using in wound dressings.

2. Experimental +

Corresponding author. Tel.: + 886-4-2451-8672. E-mail address: jhlin@fcu.edu.tw

Page 674 of 1108

2.1.

Materials

Phyllanthus urinaria Linnea (P. urinaria) purchased from Fountain, Taiwan, ROC. Alcohol (Murong Technology Co., Ltd., Tawain, ROC) has a concentration of 95 %.

2.2.

Procedures

2.3.

Measurements

First, P. urinaria at a weight of 15 g are extracted for 24 hours at 40 ˚C by using three solvents that are composed of the 300 ml water/alcohol mixtures with blending ratios of 100/0, 50/50, and 0/100. The extracts that are diluted 20 times are then measured for their Abs-wavelength by using a UV-vis spectrophotometer, which is to determine the optimal solvent. Secondly, the only variable of extraction is extraction temperature (i.e., 20, 40, 60, and 80 ˚C) with the specified solvent and specified extraction conditions. The same extraction process and measurement are incorporated in order to obtain the optimal extraction temperature. Thirdly, the only variable of the extraction is the solid/liquid ratio of P. urinaria to the solvent, which are 3 g/100 ml, 4 g/100 ml, 5 g/100 ml, and 6g/100 ml. The extraction conditions are specified. The same extraction and measurement cycle is repeated to determine the optimal solid/liquid ratio. Finally, the only variable of extraction is extraction duration that is 3, 6, 12, 24, 36, and 24 hours, while the extraction conditions are specified. The same extraction and measurement cycle is carried out again in order to yield the optimal extraction duration.

UV-VIS Spectrophotometer P. urinaria is extracted with different extraction conditons. The extracts are diluted 20 times, followed by being measured in a scan frequency range of 190-1000 nm by using a UV-vis spectrophotometer (Suntex Instruments Co., Ltd., Taiwan, ROC). The characteristic absorption peaks of P. urinaria between 240-285 nm indicate its absorbance that are then computed to yield the linear regression equations and related coefficients.

Anti-Bacterial Test The antibacterial test uses a qualitative antibacterial analysis, and follows JIS1902-2002. P. urinaria is extracted by using alcohol as a solvent, and is then purified by using a rotary evaporator. The extract is then dried in an oven 45 ˚C in order to evaporate the alcohol and get the extract powders. The powder is then diluted with deionized water and alcohol in order to form P. urinaria extracts with concentrations of 0.1, 0.5, 1.0, 5.0, and 10.0 mg/ml. The experimental subject bacteria are Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli). The liquid medium containing S. aureus or E. coli is is smeared evenly over the solid agar, and all materials are cultured in an incubator for 24 hours. A disk containing P. urinaria extract is attached to the agar, followed by being cultured for 18-24 hours. The diameter of inhibition zones is finally measured.

3. Results and Discussion Figure 1 (a) indicates that the absorbance of P. urinaria solutions by using a UV-vis spectrophotometer. The solutions consist of P. urinaria and water/alcohol solvents (100/0, 50/50, and 0/100). There are two major characteristic absorption peaks of two Flavonoid compounds observed between 240-285 nm, which are band I between 300 and 400 nm that is caused by Cinnamomum cassia, as well as band II between 240-285 nm that is caused by Benzoyl. These two compounds have absorbance that differ in their levels. The solution that is made by using an alcohol solvent has the highest absorbance, followed by using a 50:50 water/alcohol solvent, and then by using a water solvent. A high absorbance within a specified frequency indicates a high content of its corresponding ingredient. Namely, in this case, it means the greatest amount of the effective elements of P. urinaria has been extracted. Figure 1(b) indicates the absorbance of P. urinaria solutions that are extracted with different extraction temperatures. The absorbance between 240-285 nm, where the characteristic absorption peaks of Flavonoid fall, is ranked according to the extraction tempertures as 80 ˚C, 40 ˚C, 60 ˚C, and 20 ˚C. An extraction temperature of 80 ˚C results in the highest extraction yield, because the solvent is pure alcohol that has a boiling point of 78.4 ˚C, and a greater temperature helps to evaporate the alcohol, but also damages the effective elements of P. urinaria. Therefore, the extraction temperature is set to be 40 ˚C. Figure 2 indicates the absorbance of P. urinaria solutions that are extracted by using different solid/liquid ratios of P. urinaria a to a pure alcohol solvent. The absorbance between 240-285 nm is ranked according to the solid/liquid ratios of 5 g/100 ml, 4 g/100 ml, 6 g/100 ml, and 3 g/100 ml. The optimal ratio is 5 g/100 ml that obtains the most effective elements of P. urinaria. Figure 3 indicates the absorbance of P. urinaria extraction solutions that are extracted with different extraction durations. The absorbance for Flavonoid in

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240-285 nm can be ranked according to the extraction durations as 24 hours, 36 hours, 48 hours, 12 hours, 6 hours, and 3 hours. Namely, the extraction duration of 24 hours is optimal, which contributes to the highest yield of effective elements. In sum, the extraction of P. urinaria is highly dependent on the solvent types, the extraction temperatures, the solid/liquid ratio, and the extraction durations. The optimal extraction parameters are as follows: a pure alcohol solvent, a solid/liquid ratio of 5 g/100ml, an extraction temperature of 40 ˚C, and an extraction duration of 24 hours.

Fig. 1: Abs-wavelength of P. urinary extraction solution as related to the (a) solvents that are composed of water/alcohol ratios of 0/100, 50/50, and 100/0 (b) extraction temperatures of 20 ˚C, 40 ˚C, 60 ˚C, and 80 ˚C, The solvent has a water/alcohol ratio of 0/100. The extraction temperature is 40 ˚C , the extraction duration is 24 hours, and the extraction solution has a solid/liquid ratio of 5g/100 ml.

Fig. 2: Abs-wavelength of P. urinary extraction solution that are composed of solid/liquid ratios of solid extract to alcohol (i.e., 3 g/100 ml, 4 g/100 ml, 5 g/100 ml, and 6g/100 ml).The solvent has a water/alcohol ratio of 0/100. The extraction temperature is 40 ˚C, and the extraction extraction duration is 24 hours.

Fig. 3: Abs-wavelength of P. urinary extraction solution as related to the extraction durations of 3, 6, 12, 24, 36, and 48 hours. The solvent has a water/alcohol ratio of 0/100. The extraction temperature is 40 ˚C, and the extraction solution has a solid/liquid ratio of 5 g/100 ml.

The anti-bacterial efficacy of P. urinaria against S. aureus and E. coli respectively is indicated in Figures 4 (a) and (b). The diameter of the disk is 7 mm. The increase in diameter of inhibition zone is 1mm for both

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experimental subjects (S. aureus and E. coli), regardless of the P. urinaria extract ratios being 3 mg/100 ml, 4 mg/ml, 5 mg/ml, and 6mg/ml. These results indicate the poor antibacterial efficacy of P. urinaria against S. aureus and E. coli. It is surmised that the amount of extract that is added to the disk is too low, which in turn causes a poor antibacterial efficacy.

Fig. 4: Antibacterial efficacy of P. urinaria extracts against (a) S. aureus (b) E. coli, as related to the P. urinaria extract ratios of 3 mg/100ml, 4 g/100ml, 5 mg/100ml, and 6 mg/100ml.

4. Conclusions This study successfully examines the antibacterial efficacy of P. urinaria extracts against S. aureus and E. coli. The UV-vis spectrophotometer results indicate that using a solvent with a water/alcohol ratio of 100/0 (i.e., a pure alcohol solvent) can have a 69.92 % and 200.01 % greater P. urinaria extract yield than 50/50 and 0/100, respectively. The extract yield with a corresonding extraction temperature of 40 ˚C is 73.04 % and 495.68 % greater than the 60 ˚C and 20 ˚C. The optimal parameters for the optimal P. urinaria extracts include a pure alcohol solvent, a solid/liquid ratio of 5g/100ml, an extraction temperature of 40 ˚C, and an extraction duration of 24 hours. The extract results in a smaller inhibition zone when it is cultured with S. aureus and E. coli.

5. Acknowledgements The authors would like to thank Ministry of Science and Technology of Taiwan, for financially supporting this research under Contract MOST-2622-E-166-001-CC2.

6. References [1] C.M. Yang, H.Y. Cheng, T.C. Lin, L.C. Chiang and C.C. Lin, Antivir. Res., 67(1), 24, 2005. [2] L.Z. Zhang, Y.J. Guo, G.Z. Tu, F. Miao and W.B. Guo, Zhongguo Zhong Yao Za Zhi, 25(12), 725, 2000. [3] L.Z. Zhang, Y.J. Guo, G.Z. Tu, W.B. Guo and F. Miao, Acta Pharmaceutica Sinica., 39, 119, 2004. [4] K.C. Liu, M.T. Lin, S.S. Lee, J.F. Chiou, S. Ren and E.J. Lien, Planta. Med., 65(1), 43, 1999. [5] S.H. Fang, Y. K. Rao and Y.M. Tzeng, J. Ethnopharmacol., 116(2), 333, 2008. [6] C.M. Yang, H.Y. Cheng, T.C. Lin, L.C. Chiang and C.C. Lin, J. Ethnopharmacol., 110(3), 555, 2007. [7] C.C. Chang, Y.C. Lien, K.C. Liu and S.S. Lee, Phytochemistry, 63(7), 825, 2003.

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The 13th Asian Textile Conference Geelong, Australia, November 3 - 6, 2015

Effects of Recycled Kevlar Fibers on Physical Properties of Nonwoven Geotextiles Jia-Hsun Li 1, Jing-Chzi Hsieh 2, Ching-Wen Lou 3, Wen-Hao Hsing 4 and Jia-Horng Lin 5, 6, 7 + 1

Department of Ph. D Program in Civil and Hydraulic Engineering, Feng Chia University, Taichung City 40724, Taiwan, R.O.C. 2 Department of Land Management, Feng Chia University, Taichung City 40724, Taiwan, R.O.C. 3 Institute of Biomedical Engineering and Materials Science, Central Taiwan University of Science and Technology, Taichung City 40601, Taiwan, R.O.C. 4 The Department of Textile Engineering, Chinese Culture University, Taipei City 11114, Taiwan, R.O.C. 5 Laboratory of Fiber Application and Manufacturing, Department of Fiber and Composite Materials, Feng Chia University, Taichung City 40724, Taiwan, R.O.C. 6 School of Chinese Medicine, China Medical University, Taichung City 40402, Taiwan, R.O.C. 7 Department of Fashion Design, Asia University, Taichung City 41354, Taiwan, R.O.C.

Abstract. Having features of high modulus and high strength, Kevlar fibers have been commonly used in many fields. This study recycles and reclaims Kevlar selvages for applications in civil engineering, after which Kevlar/PET/LPET nonwoven geotextile are made by using nonwoven manufacturing techniques. In this study, the fiber mixing ratios are varied in order to examine the influences of Kevlar fibers on the physical properties, as well as to simulate the nonwoven geotextiles to encounter the environments. The nonwoven geotextiles are then tested for bursting strength, static puncture resistance, and tensile strength at various temperatures. The test results indicate that 20wt% of Kevlar fibers augments the mechanical properties of the nonwoven geotextiles by 50% to 60%. Such a manufacturing process can effectively reduce textile waste, and at the same time, reinforce the mechanical properties of the nonwoven fabrics.

1. Introduction Geotextiles are composed of polymeric or synthetic materials, and can be divided into woven geotextiles, knitted geotextiles, and nonwoven geotextiles. The nonwoven geotextiles are made by fibers that are isotropically distributed and randomly oriented via needle punching, thermal bonding or adhesives. Tensile strength of the geotextiles that are made out of polymers is thus a significant index referring to their properties when applied to civil engineering. Andrejack et al. (2010) and Rawal et al. (2013) indicated that geotextiles were widely used under tensile load conditions in landfills, slopes, retaining walls, road subgrades and foundations in which they were subjected to tensile stresses as well as ambient temperature variations throughout their service life [1, 2]. Temperatures distinctly influenced the physical and mechanical properties of the geotextiles that are composed of polymer and fibers, as indicated in the test results by Henry et al. (2007) [3]. In addition, when the geotextiles are exerted with an external force under an increasing ambient temperature, they succumb to a loss of tensile strength [4, 5]. Nevertheless, different types of geotextiles possess different functions as a result of their different designs, including separation, filtration, drainage, reinforcement, protection, barrier, and surficial erosion control. There are sharp objects of stones or woods on the slopes and road subgrades where the geotextiles are used. Koerner et al. (2010) thus highlighted the importance to evaluate the puncture resistance of geotextiles [6].

Corresponding author. Tel.: + 886-4-2451-8672. E-mail address: jhlin@fcu.edu.tw.

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Nonwoven geotextiles are porous, and can be used for filtration and drainage. However, they are subjected to low mechanical properties. To compensate for this shortcoming, different materials can thus be synthesized for the preparation of composite geotextiles. According to the study by Lou et al., the incorporation of Kevlar fibers improve the tensile strength, tearing strength, bursting strength, and static puncture resistance of the nonwoven composites [7]. Similarly, the study by Li et al. also indicated that the conjunction of Kevlar fibers promotes the static puncture and dynamic puncture resistance of nonwoven composites [8, 9]. In this study, recycled Kevlar fibers that are obtained from selvages are used to reinforce the geotextiles. The Kevlar/PET/LPET nonwoven geotextiles are made by using nonwoven manufacturing techniques, after which they are tested by administering a bursting strength test, a static puncture resistance test, and a tensile strength under various ambient temperatures, in order to determine the amounts of Kevlar fibers on the physical properties of the geotextiles. Such manufacturing processes can effectively reduce textile waste, reinforce the environmental protection projects.

2. Experimental 2.1. Materials Crimped polyester (PET) fiber (Far Eastern New Century, Taiwan, R.O.C.) has a fineness of 7D and length of 64 mm. Recycled Kevlar unidirectional selvage fiber (Dupont company, U.S.) has a fineness of 2820D K129 and 1000D K29, and length of 50-60 mm. Low-melting-point PET (LPET) fiber (Far Eastern New Century, Taiwan, R.O.C.) has a fineness of 4D and length of 51 mm.

2.2. Sample Preparation Kevlar fibers, PET fibers, and LPET fibers at blending ratios of 0/80/20, 5/75/20, 10/70/20, 15/65/20, and 20/60/20 are processed with opening, blending, carding, lapping, and needle-punching to form PET/Kevlar/LPET nonwoven geotextiles. All process parameters are kept constant except the blending rate, which is varied to obtain desired nonwoven geotextiles with a mass per unit area of 200±10 g/m2.

2.3. Tests Bursting Strength Test Bursting strength test was performed by Instron 5566 Universal Tester (Instron, USA) according to ASTM F2054. The size of samples was 130 mm × 130 mm. A hemispherical-nose impactor moved down at a constant speed of 100mm/min and the maximum value during the impact was recorded. Static Puncture Resistance Test Static puncture test is conducted by using an Instron 5566 (Instron, US), according to ASTM F1342-05. Specimens measuring 100×100 mm2 are located between the fixtures and then are punctured via a 4-mmdiameter probe with a penetrating speed of 508 mm/min through a 20 mm-diameter aperture. Effects of Temperature on Tensile Strength Tensile strength test is conducted by using an Instron 5566 (Instron, US), according to ASTM D5035-11. The tensile speed is 305±13 mm/min. Temperature conditions are set to at 25℃ and 50℃. The strength values along the cross machine direction (CD) and machine direction (MD) are both measured.

3. Results and Discussion 3.1. Influence of Fiber Blending Ratio on Bursting Strength This study examines the influence of the conjunction of Kevlar fiber on the physical properties of the nonwoven geotextiles. Figure 1 indicates that the bursting strength of PET/Kevlar/LPET nonwoven geotextiles has an increasing trend with the amount of Kevlar fibers increasing from 0wt% to 20wt%. Such a result is ascribed to Kevlar fibers that have a high modulus and strength. Therefore, the friction of the geotextile against the bursting force increases as a result of the increasing amount of Kevlar fibers, and thereby prevent fiber gliding, and eventually augments the mechanical property of the geotextiles.

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Fig. 1: Bursting strength of the PET/Kevlar/LPET nonwoven geotextiles, as related to various fiber blending ratios.

3.2. Influence of Fiber Blending on Static Puncture Resistance Figure 2 depicts the static puncture resistance of PET/Kevlar/LPET nonwoven geotextiles with various fiber blending ratio. The static puncture resistance of PET/Kevlar/LPET nonwoven geotextiles is augmented by the increasing amount of Kevlar fibers. As Kevlar fibers have a greater denier, namely a greater thickness, a greater amount of Kevlar fibers results in a higher density of PET/Kevlar/LPET nonwoven geotextiles. As a result, when the puncture probe impacts the nonwoven geotextiles with a greater density, the geotextiles exhibit a greater shearing resistance to their corresponding puncture force, and at the same time results in a greater puncture resistance.

Fig. 2: Static puncture resistance of the PET/Kevlar/LPET nonwoven geotextiles, as related to various fiber blending ratio.

3.3. Fiber Blending Ratio and Ambient Temperatures on Tensile Strength of Nonwoven Geotextiles The Kevlar/PET/LPET nonwoven geotextiles are subjected to the tensile strength test, in order to examine their withstanding stress-strain ability under various ambient temperatures (i.e., 25℃ and 50℃). Figure 4 indicates that the tensile strength of the nonwoven geotextiles is marginally lower when they are tested under 50℃, rather than 25℃. Because LPET fibers have a glass transition temperature (Tg) of 60℃ and PET fibers have a Tg of 70~80℃, the molecular chains are softened at an ambient temperature of 50~60 ℃, which in turn leads to a lower tensile strength. Moreover, the tensile strength of nonwoven geotextiles increases as a result of the increasing amount of Kevlar fibers, as indicated in Figure 3. Such a result is ascribed to the benzene structure that Kevlar fibers have. Kevlar fibers have high modulus and high strength, and an incorporation of 20wt% Kevlar fibers results in an optimal tensile strength of Kevlar/PET/LPET nonwoven geotextiles. In addition, as the majority of fibers are arranged along the cross machine direction (CD), the tensile strength along the CD is thus greater than along the machine direction (MD).

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Fig. 3: Tensile strength of Kevlar/ PET/ LPET nonwoven geotextile, as related to various fiber blending ratios as well as various ambient temperatures.

4. Conclusions This study successfully reclaims Kevlar selvages to be applied to civil engineering. The nonwoven geotextiles are made out of recycled Kevlar fibers, PET fibers, and LPET fibers. The test results show that increasing Kevlar fibers from 0wt% to 20wt% provides the geotextiles with a 60% greater bursting strength, 58% greater puncture resistance, and 48% greater tensile strength. The ambient temperature also exerts influences on the tensile strength of the nonwoven geotextiles, which is exemplified by a greater tensile strength of the geotextile under a test temperature 25â&#x201E;&#x192;, in comparison to that under 50â&#x201E;&#x192;. Such a result is ascribed to the thermo-physical properties and molecular bonding strength of Kevlar/PET/ LPET nonwoven geotextiles under the varied temperature conditions. Finally, the results of this study can offer a concrete solution for feasible applications, while also offering a significant protective aspect for the eco-environment.

5. Acknowledgements The authors would like to thank Ministry of Science and Technology of Taiwan, for financially supporting this research under Contract MOST 103-2622-E-035-025-CC2.

6. References [1]

T. L. Andrejack and J. Wartman, Geotext Geomembranes, 28, 559 (2010).

[2]

A. Rawal, M. M. Alamgir Sayeed, H. Saraswat, and T. Shah, Geotext Geomembranes, 36, 66 (2013).

[3]

K. S. Henry and G. R. Durell, Geosynth Int, 14, 320 (2007).

[4]

J. M. Southen and R. K. Rowe, Geosynth Int, 18, 289 (2011).

[5]

F. M. Azad, R. K. Rowe, A. El-Zein, and D. W. Airey, Geotext Geomembranes, 29, 534 (2011).

[6]

G. R. Koerner and R. M. Koerner, Geotext Geomembranes, 29, 360 (2011).

[7]

C. W. Lou, A. P. Chen, Y. Y. Chuang, J. Y. Lin, M. C. Lin, and J. H. Lin, Advanced Materials Research, 627, 831 (2013).

[8]

T. T. Li, R. Wang, C. W. Lou, and J. H. Lin, Compos Part B-Eng, 59, 60 (2014).

[9]

T. T. Li, R. Wang, C. W. Lou, and J. H. Lin, J Ind Text, 43, 247 (2013).

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The 13th Asian Textile Conference Geelong, Australia, November 3 - 6, 2015

Geotextiles Made by Different Nonwoven Fabric Manufacturing Conditions: Manufacturing Techniques and Property Evaluations Wen-Hao Hsing 1, Ching-Wen Lou 2, Po-Ching Lu 3, Wen-Cheng Tsai 3 and Jia-Horng Lin 3,4,5 + 1

The Department of Textile Engineering, Chinese Culture University, Taipei City 11114, Taiwan, R.O.C. Institute of Biomedical Engineering and Materials Science, Central Taiwan University of Science and Technology, Taichung City 40601, Taiwan, R.O.C. 3 Laboratory of Fiber Application and Manufacturing, Department of Fiber and Composite Materials, Feng Chia University, Taichung City 40724, Taiwan, R.O.C. 4 School of Chinese Medicine, China Medical University, Taichung City 40402, Taiwan, R.O.C. 5 Department of Fashion Design, Asia University, Taichung City 41354, Taiwan, R.O.C. 2

Abstract. Ideal geotextiles are featured by having a lightweight, a high tensile strength, good water penetrability, a high temperature resistance, fatigue-resistance, and erosion-resistance. As a result, geotextiles can be created based on their applications in terms of positions and functions, including filtration, drainage, barrier, reinforcement, anti-seepage, and protection. This study aims to examine the influences of the processing condition on the properties of the geotextiles, as well as the applications of geotextiles made of different parameters. Polypropylene fibers and low-melting-point polyester fibers are blended, and made into geotextiles by using a nonwoven manufacturing technique. During the process, the parameters are verified, in order to provide the geotextiles with different structures and properties. Finally, the geotextiles are thermally treated at 130 째C for 30 minutes. The tensile strength, tear strength, and bursting strength of the geotextiles are then evaluated in order to determine the influences of different parameters. The test results show that all mechanical properties are proportional to the depth of needle-punching. Keywords: geotextiles, Polypropylene fibers, low-melting-point polyester fibers.

1. Introduction Being featured by having filtration, drainage, isolation, reinforcement, seepage prevention, protection, lightweight, tensile strength, water permeability, heat resistance, chill resistance, and erosion resistance, geotextiles can be made with woven fabrics and nonwoven fabrics. Nonwoven fabrics are composed of filaments or staple fibers via a nonwoven manufacturing process. As nonwoven fabrics have a high porosity, softness, and strength, they are suitable to be applied to unstable soils. In addition, nonwoven fabrics also have plane drainage with high surface friction, which allows for a bonding with soils. They can retain particles by preventing percolation, and also expel redundant moisture [1-8]. The physical properties of geotextiles are an important index. Geotextiles are expected to be mechanically improved, and they are thus incorporated with different methods or different materials in order to meet the requirements. There is a great diversity of geotextiles. Some geotextiles use identical material whereas others blend different fibrous materials. This study blends polypropylene (PP) and low melting point polyester fibers (LMP PET) with a specified ratio, after which they are needle punched at different depths and speeds. The tensile, tearing and bursting strength of PP/LMP PET composite geotextiles are tested as related to various needle punching depths, and thereby examines the relationship between needle punching depths and strengths.

2. Experimental 2.1. Material +

Corresponding author. Tel.: + 886-4-2451-8672 E-mail address: jhlin@fcu.edu.tw

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Polypropylene (PP) fibers (Formosa Advanced Technologies Co., Ltd., Taiwan, ROC) have a fineness of 3D, a length of 76 mm, and a melting point of 167 °C. Low melting point polyester (LMP PET) fibers (Far Eastern New Century Corporation) have a fineness of 4D, a length of 51mm, and a melting point of 110~135 °C.

2.2. Preparation of Composite Geotextiles PP fibers and LMP PET fibers are blended with a ratio of 80wt%:20wt%, after which they are processed with opening, blending, carding, and mat-forming. The mats are needle punched with nine combinations of needle punching speeds (200, 300, and 400 needles/min) and needle punching depths (0.3, 0.5, and 0.7 cm), and are then thermally treated at 130 °C for 30 minutes in order to form PP/LMP PET composite geotextiles.

2.3. Experimental Tests Tensile Strength Test PP/LMP PET composite geotextiles have a size of 180 mm×25.4 mm. A total of 10 samples are taken along the cross machine direction (CD) and machine direction (MD). The tensile strength of samples is measured by using a computer universal testing machines (HT2402, Hung Ta Instrument Co., Ltd., Taiwan, R.O.C.). The tensile speed is 300 mm/min and the distance between the clamps is 75 mm.

Tearing Strength Test PP/LMP PET composite geotextiles are trimmed into 75 mm×150 mm pieces, after which an isosceles trapezoid-shape is drawn. The short base of the trapezium is cut to a depth of 10 cm. The two legs of the trapezoid are held by the two clamps. A total of ten samples are taken for each specification. Samples are taken along the cross machine direction (CD) and machine direction (MD). The tearing strength test is measured with a computer universal testing machine (HT2402, Hung Ta Instrument Co., Ltd., Taiwan, R.O.C.). The test speed is 300 mm/min, and the distance between the clamps is 75 mm.

Bursting Strength Test PP/LMP PET composite geotextiles are trimmed into 150 mm×150 mm pieces. An Instron 5566 (USA) is used to measure the bursting strength of the samples at a speed of 100mm/min. A total of ten samples are used for each specification.

3. Results and Discussion 3.1. Effects of Needle Punching Speed and Depth on Tensile Strength of PP/LMT PET Composite Geotextiles a

Fig. 1: Tensile strength along the (a) CD and (b) MD of PP/LMP PET geotextiles in relation to the needle punching density and depth.

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Figure 1 (a, b) indicates that a high needle punching speed results in an increase in the tensile strength along the CD and MD of PP/LMP PET composite geotextiles. Regardless of the needle speeds, the tensile strength along CD is higher than that along MD, which is ascribed to the fact that the majority of fibers in composite geotextiles are aligned along the CD. With a specified needle punching depth, the tensile strength of PP/LMP PET composite geotextiles increases when the needle punching speed is increased. A high needle punching speed causes a higher interlocking between fibers. Namely, the fibers are entangled to a greater extent, which allows fibers to bear a heavier load. Therefore, the PP/LMP PET composite geotextiles have a higher tensile strength.

3.2. Effects of Needle Punching Density and Depth on Tearing Strength of PP/LMT PET Composite Geotextiles In comparison of Figure 2 (a) and (b), regardless of needle punching speed or needle punching depths, the tearing strength along the CD of PP/LMP PET geotextiles is higher than that along the MD. These results are due to the fiber orientation where most fibers in the geotextiles are arranged along the CD. In addition, the tearing strength along the CD and along the MD both increase as a result of the increasing needle punching depth or the needle punching speed, which indicates the same trend observed in their tensile strength. A high needle punching depth results in a denser structure and a higher entanglement level between fibers, and the strengths are thus enhanced. Moreover, the strength of geotextiles is also in relation to the needle punching speed. With a specified needle punching depth, the tearing strength is proportional to the needle punching speed. It is proven that with the constant needle punching duration, variations in needle punching speed has an influence on the interior fibrous structure of geotextiles, which in turn causes the difference in their tearing strength.

Fig. 2: Tearing strength along the (a) CD and (b) MD of PP/LMP PET geotextiles in relation to the needle punching density and depth.

3.3. Effects of Needle Punching Density and Depth on Bursting Strength of PP/LMT PET Composite Geotextiles The bursting strengths of composite geotextiles as related to different needle punching speeds (200, 300, and 400 needles/min) and different needle punching depths (0.3 cm, 0.5 cm, and 0.7 cm) are indicated in Figure 3. The combinations of needle punching speed (needles/min)/depth (cm) that can cause a significant increase in bursting strength include 300/0.3, 300/0.5, and 400/0.3. Compared to the needle punching speed 200 needles/min, the combinations of 300/0.3 and 300/0.5 increase the bursting strength by 53 % and 43 %, but the combination of 300/0.7 only increases the bursting strength by 10 %, which is only increased from 452.12 N (200 needles/min) to 504.88 N (300 needles/min). Similarly, in a comparison of the bursting strength associated with 200 needles/min, the combination of 400/0.3 also results in a significant increase in the bursting strength. However, the combinations of 400/0.5 and 400/0.7 only increase the bursting strength by 1 % and 6 %, respectively. In sum, the needle punching depth is high in relation to bursting strength of the composite geotextiles, whereas needle punching speeds barely have an influence on the bursting strength.

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Fig. 3: Bursting strength of PP/LMP PET geotextiles in relation to the needle punching density and depth.

4. Conclusions This study successfully creates PP/LMP PET composite geotextiles, and examines the influences of different needle punching speeds and needle punching depths on the properties of the composite geotextiles. The tensile strength, tearing strength, and bursting strength of the composite geotextiles increases when needle punching depth increases, and so is the case for the increasing needle punching speeds. The test results indicate that the geotextiles obtain different properties with different combinations of parameters, which enables their application according to different properties of soils.

5. Acknowledgements The authors would like to thank Ministry of Science and Technology of Taiwan, for financially supporting this research under Contract MOST 103-2622-E-034-001-CC3.

6. References [1] Y.P. Zhang, W.C. Liu, W.Y. Shao and Y. Yang, Geotext. Geomembranes., 37, 10, 2013. [2] M. Vandenbosschea, M. Jimenez, M. Casetta, S. Bellayer, A. Beaurain, S. Bourbigot, and M. Traisne, React. Funct. Polym., 73(1), 53, 2013. [3] E. M. Palmeira, J. Tatto and G. L.S. Araujo, Geotext. Geomembranes., 31, 1, 2012. [4] A. Rawal and M.M.A. Sayeed, ,Geotext. Geomembranes., 37, 54, 2013. [5] H.J. Koo and Y.K. Kim, Polym. Test., 24(2),181, 2005. [6] T.B. Ahn, S.D. Cho and S.C. Yang, Geotext. Geomembranes., 20, 135, 2002. [7] A. Rawal and M.M.A. Sayeed, Geotext. Geomembranes., 37, 54, 2013. [8] H.Y. Jeon, S.H. Kim, Y.I. Chung, H.K. Yoo and J. Mlynarek, Polym. Test., 22(7), 779, 2003.

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The 13th Asian Textile Conference Geelong, Australia, November 3 - 6, 2015

Highly Precise Nanofiber Web-based Dry Electrodes for Long-term Biopotential Monitoring Lu Jin1, Yu Jin Ahn1, Kap Jin Kim1+, Tong In Oh2, Eung Je Woo2 1

Department of Advanced Material Engineering for Information & Electronics, Kyung Hee Univeristy, Yongin-si, Gyeonggi-do, Korea. 2 Department of Biomedical Engineering, College of Electronics & Information, Kyung Hee Univeristy, Yongin-si, Gyeonggi-do, Korea.

Abstract. Although the accuracy of conventional Ag/AgCl gel type electrode has been medically verified, its performance degrades over time as the gel dries and also this electrode is disposable and can cause skin irritation and uncomfortable removal. In order to overcome such drawbacks of Ag/AgCl gel electrodes, many types of dry electrodes have been developed. Since the real performances of such dry electrodes are still doubtful, could not reach that of Ag/AgCl gel electrodes, or they have not been evaluated comprehensively, they have not still been applied to the medical fields requiring high quality biopotential recording. Hence, in the present study, thermoplastic polyurethane, poly(styrene-butadiene-styrene), and PVDF nanofiber webbased electrodes aimed at precise biopotential recording were prepared via electrospinning followed by improved electroless silver plating. Their intrinsic electrode properties such as contact impedance, step response, noise characterization, and waveform fidelity were investigated thoroughly using agar phantom, and then human subject tests were also carried out to determine the real performance in the medical field in terms of ECG, EMG, EEG, and EIT measurements. The experimental results showed that nanofiber web-based electrodes exhibited performance equivalent to the Ag/AgCl gel electrode in both phantom and subject tests.

Keywords: Nanofiber web-based electrode, Ag/AgCl gel electrode, Electrospinning, Biopotential

1. Introduction Ubiquitous health care systems, brain computer interface (BCI) techniques, bionic engineering, and electrical impedance tomography (EIT) monitoring system, etc. require unique electrodes not only having high precision and repeated usage, but also performing long-term monitoring [1-9]. For instance ubiquitous health care systems measure electrophysiological signal such as electrocardiography (ECG), electroencephalography (EEG), and so forth to monitor the human body and diagnose various ailments [8,9]. In addition BCI techniques utilize EEG signals to help communication disable people to spell words [3.4] and electromyography (EMG) signal is generally used to diagnose muscle disease and can be employed to handle artificial limbs in bionic engineering as well. Electrooculography (EOG), which is also vital and useful biopotential signal in ophthalmological diagnosis and HCI, has been used to handle a wheelchair and to manage computer mouse using specific algorithm. Although the accuracy of conventional Ag/AgCl gel type electrode has been medically verified, its performance degrades over time as the gel dries and also this electrode is disposable and can cause skin irritation and uncomfortable removal [1,2,5-7]. In order to overcome such drawbacks of Ag/AgCl gel electrodes, many types of dry electrodes have been developed. However, the real performances of dry fabric electrodes, which have good durability and conductivity, are still doubtful, could not reach that of Ag/AgCl gel electrodes, or they have not been comprehensively evaluated, they cannot be still applied to the medical fields requiring high quality biopotential recording. Therefore one of main issues related to dry electrodes should be how to measure more precisely without signal distortion and how to obtain the signal fidelity equivalent to that of Ag/AgCl gel electrode or even better. In our previous study, six kinds of electrodes [two kinds of nanofiber web-based electrodes (PEDOT coated PVDF nanofiber web electrode and Ag plated PVDF nanofiber web electrode, three kinds of fabric-based ———————————————————————————————————————————

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Corresponding author. Tel.: + 82-10-3318-2518 E-mail address: kjkim@khu.ac.kr electrodes with different plating materials (PET-Cu-Ni fabric electrode, PET-Cu-Ni-Au fabric electrode, and PET-Cu-Ni-Carbon fabric electrode), and conventional Ag/AgCl gel electrode] were examined, observing that the two nanofiber web-based electrodes exhibited better performance than any other fabric-based electrode. This is because fabric-based electrodes have higher contact impedances than nanofiber web-based electrodes due to differences in textile structure. Even though the two PVDF nanofiber web-based electrodes exhibited very comparable performance to the conventional Ag/AgCl gel electrode widely used in hospital, PVDF material does not seem suitable in consideration of its cost and mechanical properties [6]. Hence, in the present study, thermoplastic-polyurethane (TPU), poly(styrene-b-butadiene-b-styrene) (SBS) and poly(vinylidene fluoride) (PVDF) nanofiber web-based electrodes aimed for precise biopotential recording were prepared via electrospinning followed by improved electroless silver plating. First their intrinsic electrode properties such as contact impedance, step response, noise characterization, and waveform fidelity were compared with each other using agar phantom test. And then human subject tests were also carried out to determine the real performance in the medical field in terms of ECG, EMG, EEG, and EIT measurements. The biopotential detecting mechanism and some advantages of Ag plated nanofiber web (AgNFw) dry electrode would also be discussed more in the presentation.

2. Experimental 2.1. Preparation of silver nanoparticles contained nanofiber web 10% (w/v) TPU and 14% (w/v) PVDF solutions for electrospinning were prepared by dissolving TPU and PVDF in a binary-solvent system of THF/DMF (2/3 v/v), respectively. A ternary-solvent system of toluene/ THF/DMF (3/5/2 v/v/v) was used to prepare a 9 % (w/v) of SBS solution. And then a very small amount of silver nitrate, which is 1% on the weight of polymer, was added into each TPU, SBS, and PVDF solution to form Ag nanoparticles through mild reduction by DMF. Electrospinning was carried out using injection rate of 1.5 mL/h, a needle size of 27 gauge, and applying voltage of 18 kV for TPU and PVDF and 24 kV for SBS.

2.2. Electroless silver plating process Electroless silver plating technique is similar to the silver mirror reaction. Three kinds of solutions such as silver nitrate solution (0.1 M), sodium hydroxide solution (0.8 M), and dextrose solution (0.25 M) were prepared. Then the plating was conducted as follows; (1) A certain ratio of above three kinds of solutions (silver nitrate:sodium hydroxide:dextrose 10:5:1 v/v/v) was placed in three plastic container respectively. (2) Silver nitrate solution was mixed with sodium hydroxide solution with stirring. (3) If the brown precipitate is formed, ammonia solution was added dropwise until it dissolved. (4) The nanofiber web was dipped into alcohol, and then soaked in the mixed solution for 20 min. (5) The dextrose solution was added to the mixed solution with shaking for another 30 min to complete silver plating on the nanofiber web through reduction.

2.3. Fabrication of silver plated nanofiber web dry electrodes For the realization of quantitative assessment of AgNFw dry electrodes, both size and shape of electrodes were strictly controlled. Eyelet of 9 mm in diameter, which is the same as that of metal part of Ag/AgCl electrode (3M Red Dot, USA), was adopted to fabricate AgNFw dry electrodes as shown in Fig. 1. It is noteworthy that a 3D woven fabric was placed between the metal eyelet and nanofiber web to provide AgNFw dry electrode with appropriate softness that plays an important role in skin-electrode contact condition.

2.4. Electrode properties on agar phantom system The key electrode properties of each AgNFw dry electrode such as contact impedance, step response, noise characteristic, and waveform fidelity were assessed using agar phantom test system.

2.5. Biopotential monitoring on human subject

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Human subject tests were carried out to determine the realistic performance of AgNFw dry electrode on human body in terms of ECG, EOG, EEG, and EMG measurements. All biopotentials were recorded simultaneously using both AgNFw dry electrodes and Ag/AgCl gel electrodes and two types electrodes were aligned as closely as possible to avoid the error caused by position difference.

(a)

(b)

(c)

Fig. 1: SEM images of (a) TPU nanofiber web and (b) silver plated TPU nanofiber web; (c) TPUAgNFw dry electrode (left) and Ag/AgCl gel electrode (right).

Fig. 2: Electrodes setup for biopotential recording. a) ECG measurement; b) EOG measurement; c) EEG measurements; d) EMG measurements.

3. Results and discussion 3.1. Contact impedance Fig. 3 displays both the resistive parts, R, and capacitive parts, C, of the contact impedance of electrodes. In term of the resistive part of each electrode, R values of three AgNFw dry electrodes were even lower than that of metal part of Ag/AgCl gel electrode. In addition the three AgNFw dry electrodes exhibited a little bigger mean C values than Ag/AgCl gel electrode, but the C value difference is not significant in the consideration of the comparable level less than 1 nF.

3.2. Step response In previous study the fabric based electrodes exhibited distinct signal distortion in step response test due to their porous textile structure which affects capacitive part of electrodes and causes signal distortion. As a current pulse with a 10 mA amplitude, 100 ms period, and 50% duty cycle was utilized in this test, three electrodes detected comparable voltage waveforms without signal distortion as shown in Fig. 4. This is because of compact structure of AgNFw dry electrodes which lead to less signal distortion.

3.3. Noise characterization Noise character of the electrode is one of decisive parameters to evaluate an electrode, when given the small signal amplitude of biopotential signals, especially EEG signal in the order of ÂľV. Noise power densities of four type electrodes were determined and the results indicate that TPU-AgNFw dry electrode exhibited lower noise level than the other electrodes.

3.4. Biopotential recording on human subject

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Human subject tests were carried out to determine the realistic performance of AgNFw dry electrode on human body in terms of ECG, EOG, EEG, and EMG measurements. The results show that AgNFw dry

electrodes exhibited comparable performances of Ag/AgCl gel electrode. More detailed, positive data we obtained will be given in the presentation and fully discussed. Fig. 3: Measured electrode contact resistances and capacitances. Values were averaged over the ten BIS frequencies ranging from 10 Hz to 500 kHz. Fig. 4: Step response of each electrode to a 100 ms period, 50% duty cycle square wave. a) TPU AgNFw dry electrode; b) SBS AgNFw dry electrode; c) PVDF AgNFw dry electrode; d) Ag/AgCl gel electrode.

4. Conclusion In this study AgNFw dry electrodes were designed and their performance were thoroughly examined through comparing with Ag/AgCl gel electrode. Moreover the detecting mechanism and some advantages of AgNFw dry electrode were discussed based on its structure. The results indicate that AgNFw dry electrodes have comparable performance to Ag/AgCl gel electrode. For realization of quantitative evaluation of AgNFw dry electrodes, just simple eyelet type was selected, but other applications are also available since AgNFw is thin, flexible as well as washable, even can be integrated in electric circuits directly. Future works aiming at developing prototypes with artifact-free function and extending some other applications are presently underway. 1

-1

0.2

0.4

Time [s]

0 -1

-1 0

1 Voltage [mV]

Voltage [mV]

1 Voltage [mV]

Voltage [mV]

0.2 Time [s]

0.4

0 -1

0.2 Time [s]

0.4

0.2

0.4

Time [s]

5. Acknowledgments This work was supported by Ministry of Health and Welfare of Korea (Grant No. HI14C0743).

6. References [1] Y.-H. Chen, M. de Beeck, L. Vanderheyden, E. Carrette, V. Mihajlović, K. Vanstreels, B. Grundlehner, S. Gadeyne P. Boon, C. Van Hoof, Sensors 14 (2014) 23758–23780. [2] C.T. Lin, L. De Liao, Y.H. Liu, I.J. Wang, B.S. Lin, J.Y. Chang, IEEE Trans. Biomed. Eng. 58 (2011) 1200–1207. [3] L.F. Nicolas-Alonso, J. Gomez-Gil, Sensors 12 (2012) 1211–1279. [4] S. Amiri, A. Rabbi, L. Azinfar, R. Fazel-Rezai, “A review of P300, SSVEP, and hybrid P300/SSVEP brain-computer interface systems. In Brain-Computer Interface Systems-Recent Progress and Future Prospects”, InTech: Rijeka, Croatia, 2013. [5] T.I. Oh, T.E. Kim, S. Yoon, K.J. Kim, E.J. Woo, R.J. Sadleir, Physiol. Meas. 33 (2012) 1603–1616. [6] T.I. Oh, S. Yoon, T.E. Kim, H. Wi, K.J. Kim, E.J. Woo, R.J. Sadleir, IEEE Trans. Biomed. Circuits Syst. 7 (2013) 204–211. [7] A.C. Myers, H. Huang, Y. Zhu, RSC Adv. 5 (2015) 11627–11632.

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[8] J. Yoo, L. Yan, S. Lee, H. Kim, H.J. Yoo, IEEE Trans. Inf. Technol. Biomed. 13 (2009) 897–902. [9] C.T. Lin, K.C. Chang, C.L. Lin, C.C. Chiang, S.W. Lu, S.S. Chang, B.S. Lin, H.Y. Liang, R.J. Chen, Y.T. Lee, L.W. Ko, IEEE Trans. Inf. Technol. Biomed. 14 (2010) 726–733.

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The 13th Asian Textile Conference Geelong, Australia, November 3 - 6, 2015

Preparation and Characterization of N-Octadecane Microcapsules Used for Textile Coating Xu Chen 1,2, Rui Wang1,2 + Xing Liu 1,2, Bingyang Wu 3 and Mengxuan Li 1,2 1

School of Textiles, Tianjin Polytechnic University, Tianjin 300387, China Tianjin and Education Ministry Key Laboratory of Advanced Textile Composite Materials, Tianjin Polytechnic University, Tianjin 300387, China 3 School of Material Science and Engineering, Tianjin Polytechnic University, Tianjin 300387, China. 2

Abstract. In order to enhance the utilization of phase change materials, microcapsuled phase change material was prepared. The melamine-urea-formaldehyde phase change microcapsules containing n- octadecane as phase change core material were prepared by an in situ polymerization using styrene maleic anhydride copolymer (SMA) as emulsifying agent. Surface morphology and thermal properties of microcapsules were characterized by using scanning electron microscopy (SEM), differential scanning calorimetry (DSC) and thermal gravimetric analysis (TGA). The results show that spherical microPCMs prepared has 142.58 μm diameter. The latent heats of the microcapsules were determined as 145.1 J/g. Microcapsules had good chemical stability. Keywords: n-octadecane, phase change microcapsule, thermal properties.

1. Introduction Microcapsule technology refers to solid, liquid or gas will be coated with film forming materials, forming a tiny container of about a few microns to hundreds of microns diameter [1].The shapes of microcapsules containing containing solid core material are the same as the solid, and the shapes of the microcapsules containing liquid or gas are usually spherical [2]. Phase change microcapsule technology has been the rapid development in nearly 30 years. Because particle size of the microcapsule is relatively small, and specific surface area is larger. Phase change heat enthalpy of the microcapsule is higher, therefore phase change microcapsule has the obvious effect of storing heat and adjusting temperature [3]. Because paraffin has the advantages of non-toxic, non-corrosive and low price, it become the mainstream core material [4]. The preparation methods of microcapsules have physical method and chemical method. Physical methods mainly include the phase separation and spray drying[5]. Chemical methods mainly include the in situ polymerization [6] and interfacial polymerization[7], etc. This study deals with preparation and characterization of melamine-urea-formaldehyde (MUF) microcapsules containing n-octadecane as phase change core material for thermal energy storage. The phase change microcapsules were prepared by an in situ polymerization using styrene maleic anhydride copolymer (SMA) as emulsifying agent. Surface morphology and thermal properties of microcapsules were characterized by using scanning electron microscopy (SEM), differential scanning calorimetry (DSC) and thermal gravimetric analysis (TGA).

2. Experimental 2.1. Materials N-octadecane used as core materials were purchased from Alfa Aesar, USA. Melamine (M) (Sigma– Aldrich, USA), urea (U) (Sigma–Aldrich, USA) and formaldehyde solution, 37 wt.-% in H2O (F) (Sigma– Aldrich, USA) were used as shell materials. Styrene maleic anhydride copolymer (SMA) were obtained from Tianjin Guangfu Technology Development co., LTD, China. +

Corresponding author. Tel.: + 86-022-8395 5378. E-mail address: wangrui@tjpu.edu.cn.

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2.2. Preparation of microcapsule A mixture of 3.5g melamine and 6.5g formaldehyde aqueous solution with distilled water was heated at 65 oC for 30 min until a clear MF prepolymer solution was obtained. The MF solution, emulsifiers, phase change materials, urea, distilled water were added to the reaction beaker. The reaction solution was stirred with 2000 r/min speed for 20 min at 40 oC. Then, the reaction beaker was removed into the 80 oC water bath. The reaction solution was agitated with a three-bladed low-shear mixing impeller for 4 h. The obtained suspension solution of microcapsule was washed with distilled water to remove unreacted molecules and polymers. Finally, microcapsules were obtained with vacuum filtration.

2.3. Methods 2.3.1. SEM Observation The morphology of the microcapsule was obtained by using scanning electron microscope (SEM, FEI, TM-1000).The diameters of microcapsule were measured by the SEM. More than 200 microPCMs were counted.

2.3.2. DSC Analysis Thermal properties of the microcapsule were measured by using a differential scanning calorimetry (DSC, NETZSCH, DSC200F3) at a linear heating or cooling rate of ±3 oC min−1 in a temperature range of -20 oC ~ 80 oC, protected by an argon atmosphere.

2.3.3. TG analysis Thermal stability of phase change microcapsules was obtained by using Thermo Gravimetric Analyzer(TGA, NETZSCH, STA449F3) at a scanning rate of 10 min-1 in the temperature range was 40 oC ~ 600 oC. The protecting gas was argon atmosphere.

3. Results and discussion 3.1. Microcapsules morphology As shown in Fig.1, the resulting core-shell microcapsules had relatively spherical shape. Surfaces of microcapsules were relatively rough. Particle size distribution of microcapsules is shown in Fig.1. 35

100

30 Average Diameter=142.58µm

10 20

Cumulative Number /%

Differential Number /%

80 25

5 0 50

100

150

200

250

0 300

Diameter /µm

Fig. 1: SEM image and particle size distribution of microcapsules

3.2. Thermal properties of microcapsules The DSC curves for microcapsules are presented in Fig.2. As can be seen from Fig.2, the temperatures of melting and freezing were determined as 28.9 and 26.6 oC for microcapsules, respectively. The latent heats of melting and freezing were 142.3 and 145.1 J/g for microcapsules. These results show that the thermal properties of microcapsules are quite satisfactory for energy storage applications.

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Fig. 2: DSC thermogram for microcapsules.

3.3. Thermal stabilities of microcapsules The Thermogravimetry (TG) curve had three steps for microencapsulated n-octadecane, as shown in Fig.3. The first step, microcapsule had an initial mass loss of about 7.5 % from 50 to 180 oC, which was due to the gasification of water. The second step was from 180 to 300 oC, which was caused by the decomposition of core and wall material evolution. As the internal pressure of the core materials built up with increasing temperature, the microcapsules burst at the particular temperature where the shell wall degraded beyond a critical level. The third step was from 300 to 600◦C because of further thermal decomposition of MUF. The above discussion implying that the MUF resin shells could prevent the n- octadecane from losing weight quickly. Thus thermal stabilities of microcapsules was increased to some extent.

Fig. 3: TG analysis of microcapsules.

4. Conclusions This study deals with preparation and characterization of melamine-urea-formaldehyde (MUF) microcapsules containing n-octadecane as phase change core material for thermal energy storage. The phase change microcapsules were prepared by an in situ polymerization. Surface morphology and thermal properties of microcapsules were characterized. The results show that spherical microcapsules has 142.58 μm diameter. The latent heats of the microcapsules were determined as 145.1 J/g. Microcapsules had good chemical stability.

5. References [1] LIN Heming, SI Qin, YANG Lei, et al. PCM nanocap- sules and smart thermoregulation cotton textiles made thereof[J]. Journal of Textile Research, 2009, 30 (5) :95－99. [2] Sanchez-Silva L, Rodriguez J F, Romero A, et al. Microencapsul-ation of PCMs with a styrene-methyl methacrylate copolymer shell by suspension-like polymerization[J] Chemical Engineering Journal, 2010,157(1):216-222.

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[3] Jin ZG, Wang YD, Liu JG, et al: Polymer, 49, 2008, 2903. [4] Zhang H, Wang X: Colloids and Surfaces A: Physicochemical and Engineering Aspects, 332(2) , 2009, 129. [5] Mehling H, Cabeza L F: Thermal energy storage for sustainable energy consumption, Springer, 2007, 257. [6] Wang Haiping. Preparation of epoxy resin microcapsules coated with polysulfone[J] China Plastics, 11, 2013, 48. [7] LI Bing, YU Ping, DAI Xiaodong, et al. Preparation and properties of microcapsules containingâ&#x20AC;&#x201C;olefin drag reducing polymer with poly (Urea-formaldehyde) as shell material[J]. Journal of Materials Engineering,2012,01:77-82+88.

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The 13th Asian Textile Conference Geelong, Australia, November 3 - 6, 2015

Preparation and Characterization of Super Absorbent Nonwoven Fabrics for Chronic Wound Care Chae-Hwa Kim, Jung-Nam Im, Tae-Hee Kim * 1

Technical Textile & Materials Group, Korea Institute of Industrial Technology, Ansan, Korea *thkim75@kitech.re.kr Abstract. The number of chronic wounds is increasing due to the ageing population, and higher levels of diabetes and obesity. Chronic wounds such as diabetic, venous, and pressure ulcers represent one of the biggest challenges to healthcare systems because the treatment is complicated, lengthy and expensive. Wound dressings for chronic wounds need to handle the excess amount of exudates from highly exuding wound and prevent wound infection. In this study, we developed antibacterial super absorbent nonwoven fabrics for chronic wound care. Super absorbent nonwovens were prepared by needle-punching and thermal bonding process in various mixing ratios of super absorbent fiber(SAF), antibacterial polyester fiber(PET) and LM staple fibers used as binders. To investigate the potential use of SAF-based nonwoven fabrics as wound dressing, liquid absorption behavior was studied by measuring liquid absorption ratio and liquid absorption ratio under pressure. Antibacterial activity was quantitatively evaluated against Staphylococcus aureus and Klebsiella pneumonia.

Keywords: super absorbent fiber (SAF), antibacterial polyester fiber (PET), wound dressing, nonwoven

1. Introduction Open wounds must often be managed for days to weeks until they can be closed or they heal by second intention. Most wounds will heal without complications. Basic wound care incorporates the principles of aseptic technique and gentle tissue handling. In addition, many wound care products are available that will potentially debride the wound without damaging healthy tissue, reduce infection, and improve the rate of wound healing [1]. The bacterial load of a chronic wound can be a significant factor for delayed healing. In addition, there is a relation between the concentration of the bacteria in the wound and the tendency of the wound to heal [2]. Selecting SAF as the absorption component affords significant benefits to medical device producers, patients and carers. Its fibrous form creates lightweight, soft and flexible fabrics. These offer precise absorbency control, fluid retention and porosity, with low dust and shedding performance. Enhanced absorption and retention levels also mean dressings need changing less frequently. Super absorbent can blend with other fibers to produce different non-woven fabrics. In this study, we developed antibacterial super absorbent nonwoven fabrics for chronic wound care. Super absorbent nonwovens were prepared by needle-punching and thermal bonding process in various mixing ratios of super absorbent fiber (SAF), antibacterial polyester fiber (PET) and LM staple fibers used as binders. We controlled the water absorption, water retention, and antibacterial property by adjusting the proportion between SAF, antibacterial PET, and LM fibers. To investigate the potential use of SAF-based nonwoven fabrics as wound dressing, liquid absorption behavior was studied by measuring liquid absorption ratio and liquid absorption ratio under pressure. Antibacterial activity was quantitatively evaluated against Staphylococcus aureus and Klebsiella pneumonia.

2. Experimental 2.1. Materials Super absorbent fibers (SAF, 9 denier, Type 112/52/10) were purchased from Technical Absorbent Ltd. Antimicrobial polyester filament fibers (POY, 120d/36f, 2.5 denier) were supplied by Hyosung Co.

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Ltd., and were crimped and cut to 51mm length. A low melting bonding staple fiber (LM, 2 denier.) were used as binder fibers.

2.2. Needle-punching and thermal bonding process Super absorbent nonwovens were prepared by needle-punching and thermal bonding process in various mixing ratios of super absorbent fiber (SAF), antibacterial polyester fiber (PET) and LM staple fiber as described in Table 1. Super absorbent nonwoven fabrics were prepared by a needle punching process using a pilot nonwoven system (Samhwa Machinery Co., Ltd., Korea). Briefly, SAF, PET and LM staple fibers were opened, mixed, carded, and then formed into a web. The web was cross-lapped and needle punched into a nonwoven with a base weight of 90 g/m2, and thermally bonded by passing though the heated rollers at upper side (180â&#x201E;&#x192;) and lower side (160â&#x201E;&#x192;). Table 1. Preparation of super absorbent nonwovens Process

Mixing ratio (wt%)

1 2 3 4 5 6 7 8 9

PET

SAF

Binder

80 70 60 50 80 70 60 50 50

0 10 20 30 0 10 20 30 30

20 20 20 20 20 20 20 20 20

Needle punching

Thermal bonding

2.3. Analyses 2.3.1. Absorptive properties Liquid absorption tests were performed based on modified BS EN 13726-1 test methods for evaluating primary wound dressings in accordance with British and European standards. Pieces of dry nonwoven (2 cm x 2 cm) were pre-weighed and subsequently added to a 0.9% saline solution for 10 min at room temperature. After hydration, the specimen mass was measured. The liquid absorption ratio (LAR) was calculated as follows: LAR (g/g) = (W2 - W1) / W1 (1) LAR (g/cm2) = (W2 - W1) / A (2) where W1 is the mass (g) of dry sample, W2 is the mass (g) of wet sample, A is the area . Liquid retention ratio under pressure (LRRP) was determined by pre-weighing wet nonwoven samples and measuring mass of samples after application of 40 mmHg for 1 min. LRRP was calculated by the following Equations: LRRP (g/g) = (W3 - W1) / W1 (3) LRRP (g/cm2) = (W3 - W1) / A (4) where W1 is the mass (g) of dry sample, W3 is the mass (g) of wet sample after application of 40mmHg pressure.

2.3.2. Antimicrobial test Antibacterial activity was quantitatively evaluated against Staphylococcus aureus and Klebsiella pneumonia according to Korean Standards KS K 0693:2011.

3. Results and Discussion

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Liquid absorption ratio (g/g) reflects the amount of fluid retained by the wound dressings on a gram per gram basis. This is the standard absorbency test for wound dressings. As shown in Figure 1, liquid absorption ratio and liquid absorption under pressure increased with increasing the mixing ratio of SAF up to 30%. Needle-punched nonwoven without thermal bonding process showed higher absorptive properties compared to that with thermal bonding process. .

Figure 1. Liquid absorptive properties of PET/SAF/LM nonwovens in accordance with mixing ratios of SAF.

As shown in Figure 2, needle-punched nonwoven without thermal bonding process showed the highest absorption capacity compared with the thermal bonded nonwovens. Thermal bonded nonwovens without needle punching process showed higher liquid absorption property than those prepared by both the needle punching and thermal bonding. While the needle-punched nonwovens provides the fibrous and sufficient porous 3-D structure for high liquid absorptive capacity, thermal bonding resulted in decrease of liquid absorbency due to interlocking fibers through the use of heat and pressure.

Figure 2. Liquid absorptive properties of SAF/PET/LM nonwovens in accordance with manufacturing process.

As shown in Table. 2, antimicrobial PET/SAF/LM(7:1:2) nonwoven showed 99.9% reduction of the test microorganism within 18hrs.

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Table 2: Antimicrobial test of PET/SAF/LM(7:1:2) nonwoven Antibacterial test (KS K 0693:2011) Test Strain 1 initial (Staphylococcus 18hr aureus) rate Test Strain 2 initial (Klebsiella 18hr pneumoniae) rate

Blank

PET/SAF/LM(7:1:2) nonwoven

2.1×104 <10 99.9 2.1×104 <10 99.9

2.1×104 <10 99.9 2.0×104 <10 99.9

4. Conclusions In this study, we developed the potential use of SAF-based nonwoven fabrics as wound dressing. The experimental results showed that the prepared dressings would have the optimal comprehensive performance, when the mixing ratio of PET/SAF/LM is 5:3:2. The high absorptive and antimicrobial properties make this developed wound dressing particularly suitable for use in chronic wound care.

5. References [1] Jacqueline R. Davidson, Current Concepts in Wound Management and Wound Healing Products,

Veterinary Clinics of North America: Small Animal Practice, Volume 45, Issue 3, May 2015, Pages 537–564 [2] Horst Braunwarth, Florian H.H. Brill, Antimicrobial efficacy of modern wound dressings:

Oligodynamic bactericidal versus hydrophobic adsorption effect, Wound Medicine, Volume 5, June 2014, Pages 16–20

6. Acknowledgement This work was funded by Korea Small & Medium Business Administration (S2171965).

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The 13th Asian Textile Conference Geelong, Australia, November 3 - 6, 2015

Preparation of chitosan/polyvinyl alcohol fibers without the use of acetic acid Chih-Kuang Chen1*, Ssu-Chieh Huang 1, Shih-Peng Chang1, Chun-An Lee1, Yu-Te Lin1, RongSiou Jhuo1 1

Department of Fiber and Composite Materials, Feng Chia University *Email: chihkuan@mail.fcu.edu.tw; 886-4-24517250 ext 3444

Abstract. Nanofibers have been emerged as a promising material for a variety of applications in filtration membrane, electrode materials, sensors, reinforcements, catalyst substrates scaffolds for tissue engineering, wound dressings, drug delivery systems. Of these applications, nanofibrous meshes (NFMs) have attracted the greatest deal of attention due to their unique structural properties such as high surface area, high interconnected porosity, and small pore size. Additionally, these material features that are able to mimic the structure of extracellular matrix (ECM) make NFMs ideal for the use of wound dressings and scaffolds. Despite of the advantages, NFMs have to possess biocompatibility and biodegradability, ensuring that there are no safety concerns on NFMs. In this context, chitosan (CS) has been extensively employed in the formation of NFMs due its great records in biosafety. However, the limited solubility of CS under neutral pH conditions has significantly hampered its biological applications. To solve this problem, carboxyl functionalized CS (CCS) was synthesized and characterized. CCS has demonstrated for its excellent solubility in de-ionized water. Subsequently, CCS was co-spun with polyvinyl alcohol (PVA) to prepare CCS/PVA nanofibers by electrospinning technique with de-ionized water as solvent. Factors of electrospinning procedure affecting the properties of CCS/PVA nanofibers were thoroughly discussed, including applied voltage, distance between injectors and collectors, and flow rate of electrospinning solution. Additionally, factors associated with the CCS/PVA solutions such as ratio of CCS/PVA and solid content have also been discussed. Lastly, the effects of viscosity as well as electric conductivity of CCS/PVA electrospinning solutions on the properties of resultant fibers are investigating currently.

Keywords: Nanofibers, Biodegradability, Chitosan, polyvinyl alcohol, Water solubility

1. Introduction The healing of wounds relies on several factors such as wounded environments, infection situations and the healing ability of patients themselves. To create a proper healing environment for promoting skin regeneration and bacterial infection, wound healing dressings are extensively used in different types of wounds such as chronic wounds resulting from foot ulcers and acute wounds arising from traumas[1]. In general, wound healing dressings are consisting of polymeric materials due to their flexibility and absorptibility. During recent years, a variety of polymers have been employed for the preparation of wound dressings, including polylactide (PLA), polycaprolactone (PCL), chitosan (CS) and polyvinyl alcohol (PVA)[2]. These polymers that possessed biodegradability or hydrophilicity can benefit the healing process of wounded sites. Noticeably, simultaneously having excellent biodegradability and hydrophilicity, CS has emerged as a promising polymeric material for preparing wound healing dressings. In addition to material properties, the material form also plays an important role on performances of resulting wound healing dressings. Several material forms have been utilized in dressing applications, including knitted fabrics, membrane and nanofiberous meshes

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(NFMs)[3]. As compared to other two types of material forms, NFMs exhibit advantages in high porosity, increased absorption area and enhanced gas permeability. Moreover, they enable effective infiltration of harmful bacteria to wounded sites by virtues of their small pore size of interconnected fibers[4]. In this context, CS-based NFMs have been massively used as dressing materials in wound care applications. Despite of the mentioned benefits from CS-based dressings, there are still numerous drawbacks when CS being converted to NFMs. For example, with pKa around 6.5, CS is only allowed to be dissolved in acid solution[5]. Accordingly, the complete removal of acids is required and becomes a challenge. Moreover, it is necessary for CS to be co-spun with other polymers due to its poor spinnability. These inherent problems significantly hamper their further clinical uses. To address these issues, carboxyl functionalized CS (CCS) that can be dissolved in de-ionized (DI) water was synthesized and characterized by NMR and IR. Sequentially, CCS was blended with hydrophilic PVA to co-spin into nanofibers. Factors affecting the properties of CCS/PVA NFMs in electrospinning process were investigated, including applied voltage, CCS/PVA weight ratio and solid contents of spinning solution.

2. Experimental section Preparation of CCS polymers. CCS polymers were synthesized according to the previous report[6]. The resulting polymers were characterized by 1H-NMR (Bruker Avance spectrometer) and IR (Bruker Tensor 27 system). All NMR spectra were measured at 400 MHz in D2O at 25 ยบC. For the solubility tests of CCS and CS in DI water, the concentrations of polymer solutions were 1 g/mL. The polymer solutions were prepared at room temperature with a mild stirring condition. Co-spinning of CCS/PVA nanofibers via electrospinning technique For preparing CCS/PVA NFMs, CCS polymers were mixed with PVA to form a transparent solution with solid contents of 3 wt% for further electrospinning procedures. The electrospinning was conducted at room temperature. The CCS/PVA solution was introduced to a plastic syringe with a metal needle with a diameter of 0.5 mm. The positive electrode of power supply was attached to the metal needle via a metal wire. The applied voltage was kept at 12 kV and the distance between needle-tip to collector was fixed in 21 cm. An aluminum foil was served as the collector. The collection time of NFMs was 24 h.

3. Results and discussion CCS polymers were synthesized via the previous reported synthetic procedures. The isolated yield was calculated to be 80%. The resulting polymers exhibited an appearance of pale yellow powders. According to the analysis results from NMR and IR, well-defined chemical structures of CCS polymers were successfully verified. To verify the solubility of CCS in DI water, a CCS polymer solution with a concentration of 1 g/mL was prepared. As shown in Figure 1, the appearance of CCS solution was transparent without any significant aggregations. In contrast to CCS solution, CS polymers possessed very poor solubility in DI water. A lot of

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precipitants were observed at the bottom of the vial. The results indicate that the carboxyl groups on the CCS backbone effectively enhanced the solubility of CCS in DI water. Carboxyl functionalities generally have pKa ranging from 3 to 4. Therefore, CCS polymers can be charged at neutral conditions, and showed improved solubility in DI water. CCS was blended with PVA to form a spinning solution. Using electrospinning process, CCS/PVA nanofibers were prepared under operating conditions of applied voltage: 12 kV, CCS/PVA weight ratio: 10/90 and solid contents of spinning solution: 4 wt%. As shown in Figure 2, resulting CCS/PVA fibers showed a clear fiberous structure with a fiber diameter of 200~300 nm, suggesting that CCS/PVA nanofibers can be prepared by electrospinning procedures.

4. Conclusions CCS has been proved to have excellent solubility in DI water. Additionally, CCS/PVA NFMs have been successfully prepared by electrospinning technique. The finding of optimal operating conditions for these newly developed NFMs is underway in our laboratory.

5. Acknowledgements We are grateful for MOST grants (103-2218-E-035-010 and 104-2221-E-035-078-MY2) for financial support.

Fig. 1. The appearance of CCS and CS polymer solutions.

Fig. 2. The SEM image of CCS/PVA nanofibers.

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References [1] [2] [3] [4] [5] [6]

M. Abrigo, S. L. McArthur, P. Kingshott, Macromol Biosci 2014, 14, 772. M. Z. Elsabee, H. F. Naguib, R. E. Morsi, Mat Sci Eng C-Mater 2012, 32, 1711. K. A. Rieger, N. P. Birch, J. D. Schiffman, J Mater Chem B 2013, 1, 4531. D. Liang, B. S. Hsiao, B. Chu, Adv Drug Deliver Rev 2007, 59, 1392. Y. A. Ping, C. D. Liu, G. P. Tang, J. S. Li, J. Li, W. T. Yang, F. J. Xu, Adv Funct Mater 2010, 20, 3106. Z. W. Jiang, B. Q. Han, H. Li, X. H. Li, Y. Yang, W. S. Liu, Carbohyd Polym 2015, 125, 53.

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The 13th Asian Textile Conference Geelong, Australia, November 3 - 6, 2015

Preparation and Characterization of the Fabricated PET Non-woven Fabric Mats Prepared by a High Voltage Dosing of Thermoplastic Polymer Powders and Melt-Fixing Process HeeDong Lee1, ChangWoo Nam1, SunYoung Moon2 and YoungHo Kim2, + 1

Department of ICT Textile & Apparel R&D Group, Korea Institute of Industrial Technology, Korea 2 Department of Organic Materials and Fiber Engineering, Soongsil University, Korea

Abstract. Conventional manufacturing methods for the production of floor or automobile mats have been used polymer solutions of organic solvents, which results many environmental problems such as large energy consumption and volatile organic compounds(VOCs). In this study, PET non-woven fabric mats were fabricated by an environmentally friendly process of using thermoplastic powders instead of polymer solutions, and some properties of the prepared mats were characterized. Thermoplastic powders with low melting points polyethylene(PE) were dosed and distributed into PET non-woven fabrics with the application of high voltage, and then they were melt-fixed at an high temperature. The uniformity and penetration depth of the dispersed powders were evaluated by dyeing the mats and comparing the cross-sections each others. The amount of total VOCs, formaldehyde, phthalate plasticizer, etc. were also analyzed by gas chromatography and liquid chromatography. Results reveals that this process can pass the severe VOCs regulation of car interiors.

Keywords: non-woven, polyethylene powder, high voltage, melt fixing, mat

1. Introduction Pollution is now a global issue, and therefore research into the development and application of environmentally friendly materials has been widely conducted. In particular, some examples of our efforts include carbon dioxide(CO 2 ) regulation to prevent global warming, and the regulation and prohibition of import and export of non-environmentally friendly products to prevent the expansion of pollution globally. In addition, there are few countries that do not import products made via non-environmentally friendly manufacturing processes, even if the product is manufactured using only environmentally friendly materials. Currently, flooring materials and artificial leathers used in mats and rugs for use in everyday life are processed to have air permeability usually by treating polyethylene threphthalate(PET) non-woven fabric base material with polymer organic solvent solution such as polyurethane to form pores therein. Organic solvents used in this process such as dimethylformamide(DMF) or dimethyl sulfoxide are harmful to the human body. In particular, DMF is known to be carcinogenic, so there are restrictions on the usage thereof. Therefore, research into the commercialization using environmentally friendly manufacturing methods and materials to manufacture these types of flooring materials and artificial leather products is ongoing. This study is a part of such research, in which we review the manufacturing of flooring material using PET non-woven fabric material to which organic solvent is not applied. In other words, thermoplastic polymer particles that have low melting point such as PE or polypropylene(PP) are infiltrated and dispersed into the inside of PET non-woven fabric and heat-fused to manufacture flooring material. This is an environmentally friendly method in which absolutely no organic solvent is used. This method involves supplying powder above the non-woven fabric to cause the polymer powder to infiltrate into the inside of the non-woven fabric base material, which makes it difficult for the powder to infiltrate fully into the inside of base material and to be evenly dispersed therein. However, polymer powder can easily infiltrate into the inside of the base material when high voltage is applied above and below the base material due to the creation of an electric gradient. The infiltrated polymer powder is then melt pressed to manufacture flooring material. In this study, PE powder was +

Corresponding author. Tel.: + 82-10-7488 4090 E-mail address: lhd0121@kitech.re.kr

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used as a polymer powder and the fabric base material to which powder was applied was PET non-woven fabric. The aforementioned high voltage process was used to manufacture flooring material, and the degree of uniformity of PE powder distribution within the manufactured flooring was evaluated. In addition, performance of the finished product was evaluated by analyzing toxic substances such as Total VOCs, formaldehyde, and phthalate plasticizers.

2. Experiment PE powder was supplied by the SFP Corporation (Korea). The has an average particle size of 37 ă&#x17D;&#x203A; and a density of 0.925g/cm3. The fabric product used for the base material was Soosung P&T Inc. (Korea)'s 5mm thick needle punched non-woven fabric (weight 330g/m3) . DC high voltage generator (AJEX Co.(UK), AJEF100D/N) was used for PET non-woven fabric by setting the voltage intensity to 50 kV to help PE powder to infiltrate into the inside of PET non-woven fabric. PE powder was added for 10 minutes to infiltrate into the inside of the PET non-woven fabric. The PE powder-infused PET non-woven fabricwas then heat treated for 15 minutes at 150â&#x201E;&#x192; in order to thermoset the PE powder inside of the PET fiber non-woven fabric base material. Field-emission scanning electron microscopy (FE-SEM, Hitachi SU-8010) was used to observe the impregnation depth of the resin in the manufactured non-woven fabric. A pollutant emission rate test was conducted to measure the emission rate by first wrapping each of the two specimens cut in 165 * 165mm squares with aluminium foil, then removing some of the aluminium foil to expose only a 149 * 149mm area after puttingthe square into a frame, and finally storing it in the central part of a small chamber for 7 days.

3. Results and Discussion Observation with microscopy and FE-SEM showed that, before heat treatment, thermo reactive resin was infiltrated and attached to fibers in the non-woven fabric like a flake of snow. It was additionally confirmed that, after heat treatment, the thermo reactive resin had fused and attached to non-woven fabric fibers like a transparent bead. It was confirmed that the thermo reactive resin used in impregnation of non-woven fabric was well infiltrated into the non-woven fabric base material and was evenly dispersed. It was further confirmed that the smaller the particle size becomes, the deeper the thermo reactive PE resin penetrates.

Fig. 1: Microscope image of non-woven fabric before(a) and after(b) heat treatment

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Fig. 2: FE-SEM image of impregnated non-woven fabric surface(c) and cross section(d) In order to find out how impregnated non-woven fabric prototype manufacturing affects endocrine disrupting chemicals, environmental hormones, and body-absorbing material; analysis of samples for phthalate and bisphenol A was performed. By analyzing thermo reactive resin in the non-woven fabric with respect to emission of various hazardous substances (Total VOCs, formaldehyde, phthalate plasticizer, bisphenol A), it was found that all hazardous substances analysis values were lower than the standard values.

Table 1: Emission amount of volatile organic compounds of impregnated non-woven

Volatile organic compounds

Limit of

Standard

detection

(μg/m3)

Emission amount (μg/m3)

(μg/m3)

Korea

China

Benzene

110

3↓

Toluene

1000

1100

736.3

Ethylbenzene

1000

1500

15.7

Xylene

870

1500

46.9

Stylene

220

260

3↓

Formaldehyde

0.1

210

100

15.6

Acetaldehyde

0.1

0.1 ↓

Acrolein

0.1

0.1 ↓

4. Conclusion Observation of surface and cross section images showed that thermo reactive resin was extensively infiltrated into the inner part of non-woven fabric and was evenly distributed. Analysis of SEM images showed that heat reactive resin was evenly dispersed and distributed on the surface of fibers, and it was confirmed that thermo reactive resin had infiltrated into the inner part of the fibers of the PET non-woven fabric to a depth of approximately 1 mm. This process shortens the manufacturing process and no solvent is used therein. Therefore, a clean production system incorporating the same is expected to become increasingly popular. Finally, this process is expected to have a great ripple effect within other industries, as this technology can be applied to interior materials manufacturing for luxury cars and interior flooring materials.

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5. Acknowledgement This work was supported by the Ministry of Trade, Industry and Energy of Republic of Korea (Grant number : 10045110).

6. References [1] J. Faber, K. Brodzik, A. G. Kopek, D. Lomankiewicz, J. Nowak, and A. Swiatek, Environ Nat Resour Res, 4, 156(2014). [2] D. C. Sin, X. Miao, G. Liu, F. Wei, G. Chadwick, C. Yan, and T. Friis, Mater Sci Eng, 30, 78(2010). [3] T. Y. Park and S. G. Lee, Fiber Polym, 14, 311(2013). [4] E. S. Jang, S. B. Khan, J. C. Seo, K. Akhtar, Y. H. Nam, K. W. Seo, and H. S. Han, Macromol Res, 19, 989(2011). [5] B. Kechaou, M. Salvia, B. Beaugriaud, D. Juve, Z. Fakhfakh, and D. Treheux, Express Polym Lett, 4, 171(2010). [6] B. Kechaou, C. Turki, M. Salvia, Z. Fakhfakh, and D. Treheux, Compos Sci Tecnol, 64, 1467(2004). [7] T. Temga, D. Juve, D. Treheux, C. G. Piecourt, and C. Jardin, Nucl Instrum Methods Phys Res Sect B, 245, 519(2006). [8] B. Hu, J. D. Freihaut, W. P. Bahnfleth, and B. Thran, Aerosol Sci Technol, 42, 513(2008).

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The 13th Asian Textile Conference Geelong, Australia, November 3 - 6, 2015

Study on Mixed media composed of UHMWPE Filaments and Microfibers Zhang Heng 1, Qian Xiaoming 1 + 1

School of Textile, Tianjin Polytechnic University, Tianjin, 300387, China

Abstract. Mixed medial with ultra-high molecular weight polyethylene (UHMWPE) filaments in the middle of two layers of microfibers were fabricated, and the feasibility of UHMWPE filaments webs produced by the aerodynamic reciprocating-reverberating progress and bonded by needle-punching and hydroentangling was investigate in this paper. Structure characters, stabbing resistances and comfort properties of the samples were investigated for the purpose of arguing the possibilities of mixed medial with UHMWPE filaments as stabresistance nonwovens. The results show that, UHMWPE filaments and microfibers in the mixed media were entangled each other, and the mixed media has a â&#x20AC;&#x153;treeâ&#x20AC;? structure, the penetration depth of the mixed media with UHMWPE filaments was 47.27mm for the impact energy was 23.5J. This paper can benefit for exploring new opportunities of UHMWPE filaments in protective field, the manufacturing technology of the samples also can promote popularization of stab-resistance material in civil protection.

Keywords: stabbing-resistance, UHMWPE filaments, nonwovens, aerodynamic-reciprocating laying process

1. Introduction The nonwovens as one of the important stab-resistance materials, were more often used in armor-body, due to the performances in softness, bursting and tearing strength. The stab-resistance nonwovens were made mostly of high-performance fibers, just as Ultra High Molecular Weight Polyethylene (UHMWPE) fibers, aramid fibers, carbon fibers and metal fibers [1, 2]. And the UHMWPE stab-resistance nonwovens have been investigate by several studies in weaving process, knitting process and needle-punching process, because the properties of UHMWPE fibers were extremely tensile strength and light[3]. Although previous studies provided efficient methods for manufacturing stabbing-resistance UHMWPE fabrics, the possibility of making filament nonwovens by hydroentangling process has seldom explored [4, 5]. This paper was aim to investigate the feasibility of UHMWPE filaments nonwovens were produced by the aerodynamic-reciprocating laying process and bonded by hydroentangling process. Therefore, the samples of stab-resistant nonwovens with UHMWPE filaments in the middle of two layers of microfibers were fabricated, and structure characters and stabbing-resistance were also discussed. This paper can benefit for exploring new opportunities of UHMWPE filaments in protective articles, the manufacturing technology of the samples also can promote popularization of stab-resistance material in civil protection, because the cost were greatly reduced.

2. Experiments 2.1.

Materials

UHMWPE filaments (Beijing Tongyizhong Specialty Fiber Technology & Development Co. Ltd.) and PET-PA6 hollow segmented pie bicomponent spunbond nonwovens (LangFang Chinatex Nonwovens CO., LTD) were used to make the stab-resistant nonwovens with UHMWPE filaments in the middle of two layers of microfibers at the nonwovens engineering center located at Tianjin polytechnic university. The properties of UHMWPE filaments and PET-PA6 hollow segmented pie bicomponent spunbond nonwovens were shown in Table 1 and Table 2. +

Corresponding author. Tel.: + 86-022-83955051. E-mail address: qxm@tjpu.edu.cn.

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diameter (μm) 16~22

Table 1. The properties of UHMWPE filaments density strength elongation (g/cm3) (cn/dtex) (%) 0.93~0.99 35.05 3.09

moisture regain (%) 0

Table2. The properties of PET-PA6 hollow segmented pie bicomponent spunbond nonwovens thickness weight per unit area porosity 2 （mm）（g/m ）（%） 0.21±0.05 40±4.4 85.56 2.2.

Nonwovens formation

Figure 1 shows the schematic drawing of manufacturing stabbing-resistance nonwovens with UHMWPE filaments in the middle of two layers of microfibers. Just as the Figure 1 shows, the nonwovens were manufactured by mixed media nonwoven technology. The UHMWPE filaments were unwound from the fiber tubes. These filaments are then carried to the reciprocating lay system by high-speed air-jets, and laid down onto a PET-PA6 hollow segmented pie bicomponent spunbond nonwovens to form a UHMWPE filament layer, at the same time, the UHMWPE filaments were separated efficiently. The PET-PA6 hollow segmented pie bicomponent spunbond nonwovens also put on the UHMWPE filament layer to shape the three-layer configuration of fiber webs. In the bonding stage, the three-layer fiber webs were firstly bonded by needlepunching progress to improve the degree of combination between the three fiber layers. The fiber layers were then subjected to the hydroentangling progress to consolidate the structure. The needle-punched density was 414.2 needles/cm2, and the total specific hydroentangling energy was 5745.18 KJ/Kg.

Fig. 1: Schematic drawing of manufacturing stabbing-resistance nonwovens with UHMWPE filaments in the middle of two layers of microfibers

2.3.

Tests.

Fig. 2: the dynamic-falling tester (left) and hammer beside a curves (right)

Tensile Property of the samples were tested by Instron 2365 Testing System (Instron, America) at a speed of 10 mm/min. The load-displacement curves (shown in Figure 2-right)) were obtained by driving the crosshead at a speed of 10 mm/min in Instron 2365 Testing System. The dynamic stabbing-resistance of the

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samples were tested by dynamic-falling tester (just as the Figure 2-left)) according to the GA 68-2008, and the impact energy was calculated by the Equation (1) [6].

E = mgh

(1.1)

E- impact energy, J; m- weight of hammer, kg; h-high, m;

3. More Results and discussion 3.1.

Structure characters

Five samples with different weight per unit area, were manufactured by the mixed media nonwoven technology, and the parameters were shown in Table 3. Flexural modulus increased when the weight per unit area of the samples was changed from 197±1.1 g/m2 to 348±8.1 g/m2, as listed in Table 3. The cross section (Figure 3-left) and surface (Figure 3-right) of the samples were tested by tabletop microscope (TM-1000). Figure 3 (left) clearly shown that, the samples consisting with UHMWPE filaments in the middle of two layers of microfibers, and the structure consolidation also has been formed by the UHMWPE filaments. The UHMWPE filaments and microfibers entangled each other also were found on the surface of the samples (Figure 3-right), which indicated that the three fiber layers combined closely.

No. 1# 2# 3# 4# 5#

thickness（mm ） 2.05±0.18 1.83±0.16 1.61±0.09 1.53±0.17 1.42±0.16

Table 3 Parameters of the samples weight per unit area (g/m2 porosity（% ）） 348±8.1 82.38 290±7.6 83.72 250±2.3 83.45 215±3.6 85.01 197±1.1 85.29

flexural modulus (kgf/cm2) 16.546 14.354 13.59 11.649 9.587

Fig. 3: Cross section (left), and surface (right) SEM images of the samples Load–displacement curves (left) and penetration depth as a function of impact energy (right)

3.2.

Stabbing Resistance

Fig. 4: Load–displacement curves (left) and penetration depth as a function of impact energy (right)

Page 709 of 1108

The load窶電isplacement curves were shown in Figure 4 (left), and penetration depth as a function of impact energy also shown in Figure 4 (right). It was interesting that, the loading was small when the curves contacted on the surface of samples. This may due to the fact that the samples easily appeared the deformation under the pressure of the curves [7]. And the loading significantly increased as the curves started touching the layer of UHMWPE filaments. The pseudo-plastic fracture characteristic of the samples also was found, due to the porosity, micro-crack and weak interface of the fibers. Just as the Figure 4(right), the penetration depth increased as the impact energy increased in a linear relationship, and the penetration depth was 47.27mm for the impact energy was 23.5J.

3.3.

Comfort properties

Fig.5 shown the air permeability (left) and moisture permeability (right) of the samples. It can been seen that the air permeability and moisture permeability decreased with the increasing of mass per unit area of the UHMWPE layer, this may be because the pore tortuosity increased as the increasing mass per unit area of the UHMWPE layer.

Fig. 5: Air permeability (left) and moisture permeability (right) of the samples

4. Conclusions The feasibility of UHMWPE filaments nonwovens producing by the aerodynamic-reciprocating laying process and bonded by hydroentangling process was investigate in this paper. The soft stab-resistance nonwovens of UHMWPE filaments consisting with UHMWPE filament in the middle of two layers of microfibers were manufactured by mixed media nonwoven technology(needle-punching and hydroentangling progress) .The structure characters and stabbing resistance were investigated to explore the feasibility of UHMWPE filaments nonwovens as oft stab-resistance nonwovens. The results show that, HMWPE filaments and microfibers were entangled each other under the impact of the needle-punching and hydroentangling, which indicated that the samples had the consolidation structure, and the penetration depth increased as the impact energy increased in a linear relationship, and the penetration depth was 47.27mm for the impact energy was 23.5J. This paper can benefit for exploring new opportunities of UHMWPE filaments in protective articles, the manufacturing technology of the samples also can promote popularization of stab-resistance material in civil protection, because the cost were greatly reduced.

5. Acknowledgements This work was financially supported by the Tianjin Natural Science Foundation (15JCZDJC38500)

6. References [1] Chen T F, Liao J Q, Liu G S: Carbon Vol. 41 (2003), p. 993-999. [2] Li T T, Wang. R: Fiber Polym Vol. 15 (2014), p. 315-321. [3] Liu A Q, Eileen I, J Fisher: J Eng Med Vol. 228(4) (2014), p. 418-426. [4] Chen H C., Lee K C., Lin J H, Koch M: J Mater Process Tech, Vol. 184(1) (2014), p. 124-130. [5] Kang T J, Hong K H, Yoo M R: Fiber Polym Vol. 11(5) (2010), p. 719-724. [6] Chung D D L: J Mater Sci Vol. 39(8) (2004), p. 2645-2661. [7] Shah S G S, Farrow A: J Occup Environ Hyg Vol.10(6), (2013), p. 312-327.

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The 13th Asian Textile Conference Geelong, Australia, November 3 - 6, 2015

Study on Production of Non-woven Fabric and Mesh Type Knit Fabric used for Medical Products using Biodegradable Polyester HeeDong Lee1, YoonCheol Park1, JaeYun Shim1 and YoungHwan Park1, + 1

Department of ICT Textile & Apparel R&D Group, Korea Institute of Industrial Technology, Korea

Abstract. Non-woven fabrics or mesh type knit fabrics must be produced in order to effectively use functional, biodegradable polyester as a raw material of soft structure materials in the medical industry. Although there are many different methods which may be used in the production of non-woven fabrics, it is critical that no chemical additives are involved in the production process thereof. Further, small quantity production must be possible. In this study, three methods are used to make soft-structured, biodegradable fabrics using Poly Glycolic Acid(PGA) and Poly Lactic-co-Glycolic Acid (PLGA). Non-woven fabrics are produced via a Needle Punching(NP) process or a Melt Blown(MB) process, and mesh type knit fabrics are produced by using a Flat Knitting(FK) process; and properties of the produced non-woven fabrics and mesh type knit fabrics are compared. In the case of NP non-woven fabrics, good webs are formed in the production process but the tensile strength of the non-woven fabric is low and the non-woven fabric must be thick enough to improve uniformity of the non-woven fabric. Additionally, we think that MB non-woven fabrics and mesh type FK fabrics are suitable for medical materials because the production yield of the NP non-woven fabric is very low. In the case of MB non-woven fabric, it is very difficult to determine a proper spinning temperature in the production process; however thin and light weight nonwoven fabrics can be produced. In the case of mesh type FK fabrics, the mesh type FK fabrics can be produced using a small quantity of yarn of 100∼200g, the production yield of the mesh type FK fabrics is very high, and they are suitable for use as a high quality, biodegradable material. Additionally, in the case of mesh type FK fabrics, they have superior stretch properties than conventional surgical mesh materials and are expected to be applied within areas where good stretch properties are necessary in the near future. Keywords: PGA, PLGA, Needle Punching, Melt Blown,Flat Knitting, Non-woven

1. Introduction In order to use functional medical biodegradable polyester material for soft structured products, non-woven fabrics or mesh type knit fabrics, must be carefully manufactured. Methods for making non-woven fabrics include needle punching, melt blowing, spunbonding, spunlacing, stitchbonding, and airlaying. Spunbond, spunlace, airlay non-woven fabrics are not suitable for the target application because it is difficult to produce in a small quantity (a minimum production run of 300kg is required) . Therefore, needle punching and melt blown processes are examined herein. Needle punching is a process that is used to create bonds between fibers by vertically entangling horizontally arranged webs with barbed needles. In order to minimize the introduction of foreign substances, chemicals were not used. Instead, only mechanical processes are employed. Webs are formed randomly in the melt blowing process when polymers are fused and discharged from an extruding machine and spinning nozzle, and fibers are dispersed by the vortex because they are stretched under conditions of high temperature and pressure. Only thermoplastic material is suitable for melt blowing because spinning must be possible after fusion, and ultra fine fibers of 1∼10μm can be manufactured. Since no solvent is used, this method is eco-friendly, and low-priced. Further, because it has high yield, it is applicable to industrial purposes. Also, small quantity production is possible and it is suitable for manufacturing using high quality medical polymers. In this study, three methods are used to make biodegradable, soft structured fabrics using PGA and PLGA. Non-woven fabrics are produced by using a Needle Punching (NP) process or a Melt Blown (MB) process, +

Corresponding author. Tel.: + 82-10-7488 4090 E-mail address: lhd0121@kitech.re.kr

Page 711 of 1108

and mesh type knit fabrics are produced by using a Flat Knitting (FK) process, and properties of the produced non-woven fabrics and mesh type knit fabrics are compared.

2. Experiment PGA yarn used in the experiment is a fully drawn yarn, 3 denier/48 filaments (total denier of 144) (Samyang corporation), and PGA/PLGA(1:9) chips used have a melt index of 8.09 (Samyang corporation).

2.1.

Manufacture of NP non-woven fabric

In order to manufacture PGA non-woven fabric using NP process, fibers should have crimps and should be cut in appropriate lengths. After 200 cones of the filament yarns(3denier/48 filaments x 4 plies) are prepared(114 x 4 x 200 = 115,200 denier), crimping is performed and filment yarns of the 200 cones are cut into staple fibers. In the NP carding process, fibers can be evenly distributed and entangled well only when the fibers have crimps. In particular, because PGA fibers have high tensile strength and their surfaces are smooth, crimps must be formed like the image below for them to be applied in NP process. NP is performed after PGA fibers with crimps undergo carding process.

Fig. 1: Needle Punching Process of PGA yarn

2.2.

Manufacture of PGA and PLGA MB non-woven fabric

After drying PGA and PLGA chips in a dry oven at 60℃ for more than 2 hours, MB spinning may be performed upon setting the spinning temperature to 260℃ for PGA and 240℃ for PLGA, with the air temperature set to 320℃ for PGA and 300℃ for PLGA. Adjustment of the weight of the MB non-woven fabric per m2 was performed by changing a conveyor belt speed.

2.3.

Manufacture of PGA FK mesh

Three types of knit fabrics(plain, link-link, and full needle stitch) were manufactured using SCG-122SN (Shimaseiki Korea)

Page 712 of 1108

3. Results and Discussion In the case of NP non-woven fabrics, webs were formed well in the manufacturing process, but the tensile strength of the non-woven fabric was low and the thickness thereof should be high enough to improve the evenness of the non-woven fabric. Additionally, it was concluded that MB non-woven fabric and FK mesh fabric are suitable for medical materials because the production yield is very high. Although it was very difficult to set a proper spinning temperature for MB manufacturing process, thin and low weight non-woven fabrics could be manufactured. In the case of mesh type FK fabrics, mesh type knit fabrics may be produced using a small quantity of yarn of 100~200g by the FK process, and because production yield is very high, it can be used for high quality, biodegradable material. Although full needle stitch knit fabrics has the most excellent shape stability, it was concluded that link-link knit fabrics also will display an excellent shape stability after hot press. It was concluded that link-link knit fabrics can be utilized for various purposes because their elasticity is excellent in both directions and their thicknesses are very low. Mesh type knit fabrics manufactured by the flat knitting process are expected to be used from now on for various purposes and for areas that need elasticity because unlike the conventional surgical mesh fabric, they have excellent elasticity. Plain

Link-link

Full needle stitch

Severe curling

Slight curling

No curling

Fig. 2: Cutting test of three types of fabrics

4. Conclusion Generally when fibers are manufactured with ester polymer, yarns will have the strength of 4-5g/d, however, FDY PGA yarns will have a higher strength of 8g/d (Strong yarnâ&#x20AC;&#x2122;s general strength standard is 10g/d). Such characteristic of PGA shows high rigidity. In order to apply PGA materials for soft structured products, mesh type knit fabrics manufactured with flat knitting process which have higher flexibility and softness will be more suitable than MB non-woven fabrics. Various processes were studied to manufacture soft structure non-woven fabric or mesh knit fabric; manufacturing processes of NP non-woven fabric, MB non-woven fabric, and flat knit mesh fabric using PGA, PLGA chips or fibers were established. Therefore, MB non-woven fabric and flat knit mesh fabric were

Page 713 of 1108

determined to be suitable; it is possible to manufacture thin and low weight MB non-woven fabric, and it is anticipated that flat knit mesh fabric can be applied to areas that require elasticity.

5. Acknowledgement This work was supported by the Ministry of Trade, Industry and Energy(MOTIE, Republic of Korea, Grant number : 10047811).

6. References [1] A. Phatak, D. W. Giles, C. W. Macosko and F. S. Bates, Polymer, 48, 3306(2007). [2] E. IrzmaĹ&#x201E;ska, A. Brochocka, K. Majchrzycka, Fibres Text. East. Eur., 20, 95(2012).

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The 13th Asian Textile Conference Geelong, Australia, November 3 - 6, 2015

Superhydrophobic Nonwoven Prepared from Biopolymer Derivatives Hiroaki Yoshida + Faculty of Textile Science and Technology, Shinshu Universiy

Abstract. Construction of superhydrophobic materials bio-inspired by nature attracts many scientists. One of the big challenges in this field is the fabrication of these materials using biopolymers from the viewpoint of green chemistry and environmental chemistry. Here, superhydrophobic and biodegradable nonwovens are created by electrospinning from a naturally-derived biopolymer, poly(γ-glutamic acid) (γ-PGA), modified with L -phenylalanine. The contact angle of a water droplet on the materials is 154°, and the droplet remains stuck to the surface even if it is inverted, suggesting a petal-type superhydrophobic property. Biodegradability and post-functionalization of the nonwovens as well as cell adhesion on the superhydrophobic surfaces are also evaluated. As far as we know, this is the first report to prepare biodegradable materials showing a petal-type superhydrophobicity. It is believed that the material design and processing shown here are applicable to various bioresources and such functional materials will become a new type of functional materials satisfying some of the requirements in biomedical and environmental science.

Keywords: superhydrophobicity, biodegradability, petal effect, poly(amino acid), electrospinning

1. Introduction Superhydrophobic surface seen in a lotus leaf or a rose petal has long attracted scientists in many fields. Inspired by such natural properties, a variety of superhydrophobic surfaces have been artificially constructed by tuning a surface with chemicals showing low surface free energy and by introducing the topological structure of the surface [1]. Although almost all of the surfaces are created from non-degradable components, there are quite a few reports on superhydrophobic surfaces composed of biodegradable materials. As far as we know, Osawa et al. reported that a micro-patterned poly(ε-caprolactone) surface constructed by a replica method showed superhydrophobic and antibacterial properties [2]. Mano et al. developed superhydrophobic poly(L-lactic acid) films by phase separation and showed poor bacteria adhesion on the surfaces [3]. Indeed, these kinds of superhydrophobic and biodegradable surfaces would not only become a new class of functional materials from the viewpoint of green chemistry and environmental chemistry, but also be intriguing for biomedical and environmental applications. Therefore, the use of various biopolymers such as polypeptides and polysaccharides besides polyesters shown above for the preparation of superhydrophobic materials is still of significant interest. In this presentation, we focused on electrospinning which is a simple, versatile approach for producing amazingly long fibers with micro- to nanometer-sized diameters from different types of synthetic and biobased polymers. Various superhydrophobic nonwovens with rough surface structures have been developed by electrospinning, but there is no report on the preparation of superhydrophobic nonwovens composed of only bioresources. Nonwovens prepared by such a simple and versatile technology would be meaningful in industrial applications.

Corresponding author. Tel.: +81-268-21-5457. E-mail address: hiroaki_y@shinshu-u.ac.jp

Page 715 of 1108

2. Results and Discussion According to a previous report [4], a series of poly(γ-glutamic acid) (γ-PGA) with 18, 31, 42, 66, 80, and almost 100% grafting degrees of L-phenylalanine ethylester (γ-PGA-Phe) were synthesized, and γ-PGA-Phe polymers with more than 30% degrees were used for the electrospinning experiments because of their good solubility into 1,1,1,3,3,3-hexafluoroisopropanol (HFIP). Electrospinning of the γ-PGA-Phe solutions onto an aluminium substrate was tested. A representative experiment was performed by using 20% (w/v) γ-PGA-Phe-80 solution with an applied voltage of 20 kV, collection distance of 20 cm, and a flow rate of 0.50 mL/hour. The obtained fibers were homogeneous and 660 ± 220 nm in diameter (Figure 1a), and bulk nonwovens could be easily peeled off from the substrates after 2 h electrospinning (Figure 1b). At a concentration of more than 15%, the diameter of γ-PGA-Phe-80 fibers decreased with increasing polymer concentration. On the other hand, as the concentration decreased below 15%, finer fibers containing beads were produced. Water solubility of the nonwovens was similar to that of the original polymers, and γ-PGA-Phe-66, -80, and -100 nonwovens were stable in water for over 1 month. FT-IR spectra did not show any difference between the original polymers and the obtained fibers, suggesting that the chemical structure of the polymers in the fibers was close to the original structures.

(a)

(b)

10 µm

1 cm

Figure 1. (a) SEM image and (b) photograph of γ-PGA-Phe nanofibers by electrospinning.

Surface wettability of water-insoluble γ-PGA-Phe-66, -80, and -100 nonwovens was evaluated by measuring the contact angle (CA) of a 1 μL water droplet on a nonwoven fixed onto a glass plate over 5 min. The initial CA increased with increasing grafting degrees, and it is surprising that the value of γ-PGA-Phe-100 nonwovens was 154°, suggesting superhydrophobicity (Figure 2). γ-PGA-Phe-66 nonwovens with the least grafting degree showed the lowest hydrophobicity of the three and the CA reduced as time went by. In contrast, the droplets on the others were very stable and kept their shapes even after 30 min incubation. The change in wettability was also monitored by controlling protonation/deprotonation of the carboxylic groups remaining in the polymers. The γ-PGA-Phe-66 nonwovens had significantly improved hydrophobicity when kept in acidic conditions for over 5 min, and γ-PGA-Phe-80 nonwovens became superhydrophobic under acidic conditions (Figure 2). Such results clearly show the increased hydrophobicity by protonation of the carboxylic groups in the polymers. On the other hand, the CA decrement was clearly observed for all samples when alkaline droplets were used, indicating that the nonwovens became more hydrophilic by deprotonation of the carboxylic groups in the polymers and even the γ-PGA-Phe-100 samples contained carboxylic groups. Surface root-mean square roughness of these samples was compared with a 3D laser scanning microscope, but a big difference was not observed. The CA on the γ-PGA-Phe-100 castfilms prepared as a control was approximately 70°, much smaller than that on the corresponding nonwovens. The surface structures were smoother and the roughness was about 2.0 μm. Furthermore, water droplets put on the nonwovens were stably adhered and stayed still on the surface, even if it was turned over (Figure 2). It is known that this phenomenon is characteristic of a petal-type superhydrophobic surface. From these results, we concluded that the surface wettability resulted from the rough, fibrous morphology as well as from the hydrophobic difference at the molecular level.

Page 716 of 1108

Contact angle (CA) / o

165

154o

160

γ-PGA-Phe-100

155 150

150o γ-PGA-Phe-80

145 140 135 130

γ-PGA-Phe-66

125 120 0

30 60 90 120 150 180 210 240 270 300

Time / s Figure 2. (a) Change of water contact angles on γ-PGA-Phe nonwovens over 5 min. A red line means CA on γ-PGAPhe-80 nonwovens over 5 min under the acidic condition.

3. Conclusion We prepared biodegradable nonwovens exhibiting a petal-type superhydrophobicity made only of bioresources for the first time. The nonwovens could be prepared by simple electrospinning of γ-PGA modifi ed with a hydrophobic amino acid. The wetting property was easily tuned depending on the amount of hydrophobic moieties We believe that the material design and processing can be applied to various biodegradable polymers and is of significant importance for academic research as well as for practical applications. Furthermore, such functional materials would satisfy some of the requirements in green chemistry and environmental chemistry. More detailed information would be given somewhere [5].

4. References [1] H. Zhu, Z. Guo, W. Liu, Chem. Commun. 2014, 50, 3900-3913. [2] X. Feng, L. Jiang, Adv. Mater. 2006, 18, 3063-3078. [3] W. Song, D. D. Veiga, C. A. Custodio, J. F. Mano, Adv. Mater. 2009, 21, 1830-1834. [4] M. Matsusaki, K. Hiwatari, M. Higashi, T. Kaneko, M. Akashi, Chem. Lett. 2004, 33, 398-399. [5] H. Yoshida, D. Klee, M. Möller, M. Akashi, Adv. Funct. Mater. 2014, 24, 6359-6364.

Page 717 of 1108

The 13th Asian Textile Conference Geelong, Australia, November 3 - 6, 2015

Synthesis and Characterization of Biopolyurethanes using Vegetableoil Based Polyols for Breathable Textile Coatings Hyunsang Cho +, Sungchan Baek, Seunghoon Lee, Hyun Jeong Kim, Hyunki Kim and Joonseok Koh Department of Organic and Nano System Engineering, Konkuk University, Seoul 143-701, South Korea

Abstract. Biopolyurethanes using vegetable oil-based polyol was synthesized and their properties were investigated in a comparative manner. Biopolyurethanes were synthesized by one-shot method in which polyol, diisocyanate and extenter are all mixed simultaneously. The chemical structures, molecular weight and thermal properties of the prepared biopolyurethane film were characterized by using instrumental analysis.

Keywords: Biopolyurethane, Biopolyol, Caster oil, corn oil

1. Introduction The availability of energy was admitted to be key for the future development; the necessity of a steady transition to a broader and more sustainable mix of energy sources was pointed out as a major objective. At this point, scientists have a new pathway to confront the current challenges of the society, which is the Green Chemistry. The priorities of this way should be the human health and the protection of the Earth, maintaining the equilibrium between society, economy and environment. Several advances have been made in the field of chemistry concerning the seventh principle of the Green Chemistry which says â&#x20AC;&#x153;A raw material or feedstock should be renewable rather than depleting whenever technically and economically practicable.â&#x20AC;? Plants are the most important renewable resource. In this study, bio-polyurethanes using vegetable oil-based polyol was synthesized and their properties were investigated in a comparative manner. Caster oil-based polyol and corn oil-based polyol was used as a biopolyols. Biopolyurethanes were synthesized by one-shot method in which polyol, diisocyanate and extenter are all mixed simultaneously. The chemical structures, molecular weight and thermal properties of the prepared biopolyurethane film were characterized by using instrumental analysis.

2. Experimental 2.1.

Materials

The diisocyanate used, MDI, is purchased from Sigma Aldrich. Four kind of polyols and 1,4butanediol(1,4-BDO) were provided from BSG which is Korean company at Daegu, South Korea and they have invested caster oil-based polyol(CAP), and corn oil-derived polyol(COP). DMF was used for solvents, is purchased from SAMCHEON Chemical, South Korea.

2.2.

Polyurethane synthesis

Polyurethanes were synthesized by a one-step polymerization method. Molar ratio of polyols; diisocyanates; chain extenders were kept constant 1:3.45~3.48:2.5. Measured polyols, MDI, 1,4-BDO, DMF were placed in a four-necked flask equipped with a stirrer, nitrogen inlet, and additional funnel and setted the temperature at 45 oC by a circulated oil. The temperature was slowly going up to 90 oC. After 1 hour from it had reached to 90 oC, 15% amount of total MDI were putted in the flask. After 1 hour from that time, 10% amount of total MDI were putted in the flask. After 1 hour from that, 5% amount of total MDI were finally +

Corresponding author. Tel.: + 82-2-450-3512. E-mail address: 06sang@naver.coms.

Page 718 of 1108

putted in the flask. After mixing for 1 hour more, the final product were gathered and casted 10mm film onto a release paper and cured for 24 hours in an oven at 80 oC.

2.3.

Characterization

Chemical structure of the synthesized polyurethane was confirmed by using FT-IR and 1H-NMR and its molecular weight and molecular weight distribution was determined by using a GPC.

2.4.

TGA analysis

Thermal property of the synthesized polyurethane was analyzed by TGA.

2.5.

Tensile test

Tensile test of the synthesized polyurethane was was carried out by using an Instron 5584.

3. Results and Discussion 3.1.

Characterization

FT-IR spectra of the synthesized polyurethanes is shown in Fig. 2. The characteristic peak for N-H group in urea linkage, C-H group and C=O linkage of polyurethane were observed around 2950cm-1, 3300cm-1, 1720cm-1. CAP, COP are influenced to have O-H peaks around 3600cm-1. Itâ&#x20AC;&#x2122;s caused by the differences of composition of polyols.

Fig. 1: FT-IR spectrum of the synthesized polyurethanes

The molecular weight is estimated by GPC. It is shown in Table 1 and Fig. 2.

Table 1: GPC Analysis of polyurethanes Sample CAP 100% CAP/PEG 50%/50% COP 100% COP/PEG 50%/50% PTMG 100% PTMG/PEG 50%/50%

Mn 91,260 79,220 105,700 79,600 80,970 73,690

Mw 215,900 189,900 268,800 181,800 189,800 220,600

PDI 2.36 2.39 2.52 2.28 2.34 2.99 Fig. 2: molar mass of polyurethanes

The characteristic proton NMR peaks of the synthesized polyurethanes are assigned in Fig. 3.

Page 719 of 1108

Fig. 3: 1H-NMR results of polyurethanes

3.2.

TGA analysis

All polyurethanes have similar degradation temperature around 300â&#x201E;&#x192; and the polyurethanes containing CAP showed the highest thermal stability.

Fig. 4: TGA spectrum of the synthesized polyurethanes

3.3.

Tensile properties

Tensile strengths of the synthesized polyurethanes are shown in Fig. 4. The polyurethane containing PEG structure in their backbone exhibited lower tensile strength compared with that containing COP, CAP or PTMG only. 60 CAP 100% CAP/PEG COP 100% COP/PEG PTMG 100% PTMG/PEG

Tensile Strength (MPa)

Fig. 4: Tensile strength of polyurethanes

4. Conclusions

Page 720 of 1108

Bio-polyurethanes containing caster oil-based polyol or corn-derived polyol more than 25wt% were successfully synthesized. All polyurethanes have similar degradation temperature around 300oC and the polyurethanes containing CAP showed the highest thermal stability. In terms of tensile strengths, the introduction of PEG into the polyurethane backbone decreased the tensile strength.

5. Acknowledgement This work was supported by the Industrial Technology Innovation Program (Advanced Technology Center, 10045679, Development of green-market deal with convergence textile products and high-function of breathable-waterproof PU film using plant-derived polyol) funded by the Ministry of Trade, industry & Energy(MI, Korea). This research was supported by Basic Science Research Program through the National Research Foundation of Korea(NRF) funded by the Ministry of Education(NRF-2014R1A1A2058758)

6. References [1] Kaneyoshi Ashida, Polyurethane and Related Foams, Taylor & Francis, 2007 [2] Silva, R. V., et al. "Fracture toughness of natural fibers/castor oil polyurethane composites." Composites science and technology 66.10 (2006): 1328-1335. [3] Athawale, Vilas, and Suresh Kolekar. "Interpenetrating polymer networks based on polyol modified castor oil polyurethane and polymethyl methacrylate." European polymer journal 34.10 (1998): 1447-1451. [4] Ogunniyi, D. S. "Castor oil: A vital industrial raw material." Bioresource technology 97.9 (2006): 1086-1091. [5] The Polyurethane Society of Korea, Polyurethanes, Kudok, 2006. [6] Koo, Gwang-Hoe, and Jin-Ho Jang. "Breathable Waterproof Finish of PET Fabrics via Microporous UV Coating of Polyurethane Diacrylate." Textile Coloration and Finishing 22.3 (2010): 239-245.

Page 721 of 1108

The 13th Asian Textile Conference Geelong, Australia, November 3 - 6, 2015

Synthesis and Application of UV Curable Oligomer for Pressuresensitive Adhesive Seoho Lee, Seung Hyun Lee, Hanna Park, Min Hee Kim, Ryong You, and Won-Ho Park* + *Department of Advanced Organic Materials and Textile System Engineering, Chungnam National University, Daejeon, Korea

Abstract. Synthesis and application of UV curable oligomer for pressure-sensitive adhesive are presented. UV oligomers that can give the UV curable properties to the general acrylic pressure-sensitive adhesive were prepared by simply blending isophorone diisocyanate (IPDI), acrylic monomer containing active hydroxyl groups such as 2-hydroxyethyl methacrylate (2-HEMA), 2-hydroxyethyl acrylate (HEA) or 4-hydroxybutyl acrylate (4-HBA), polymerization-inhibitor and catalysts. UV curable pressure-sensitive adhesives were prepared by mixing UV oligomers, acrylic pressure-sensitive adhesives and photo-initiator. We monitored difference of NCO groups remaining in UV oligomers according to different types of acrylic monomers and mixing methods by Fourier transform infrared (ATR–FTIR) spectroscopy and nuclear magnetic resonance (NMR). Properties (180° peel strength, ball tack, holding power and gel fraction) of UV curable pressuresensitive adhesives were measured. Keywords: UV oligomer, isocyanate, photoinitiator, acrylate, adhesive, etc.

1. Introduction Pressure-sensitive adhesives (PSAs) are being used for a wide range of self-adhesive materials represented by adhesive double-sided, one-sided or carrier-free tapes, adhesive labels, protective foils as technical products and medical pads, hydrogels and biomedical. The oldest PSA is a blend of a natural rubber and a rosin ester tackifier from a toluene and heptane solution. In the 1970s, both solution and emulsion polymerizations of low-glass-transition-temperature (Tg) acrylics such as poly(butyl acrylate) and poly(2-ethylhexyl acrylate) gave inherently tacky PSAs without the need of an added tackifier. Recently, under diverse PSA based on suitable kinds of polymers, such as acrylic, rubber, silicones, polyurethanes, polyesters, polyether, and ethylene-vinyl acetate copolymers (EVA) even acrylic offer promising advantages in comparison to other groups of polymers. Acrylic types of pressure-sensitive adhesives (PSAs) can be prepared by copolymerizing acrylic monomers, such as 2-ethylhexyl acrylate, butyl acrylate, and isooctyl acrylate. The versatility of acrylic PSAs results from how they can be formulated to have various thermal and viscoelastic properties, even in the absence of tackifiers. Crosslinking is a technique used very widely to alter polymer properties. Typical crosslinking methods are based on the chemical reaction that takes place at elevated temperatures, although room-temperature (RT) curing is also known. Recently, UV-curable coating applications have gained wide interests, due to their special advantages such as lower energy consumption, less environmental pollution, lower process costs, high chemical stability and very rapid curing even at ambient temperatures. In this study, UV oligomers that can give the UV curable properties to the general acrylic pressure-sensitive adhesive were prepared by simply blending isophorone diisocyanate (IPDI), acrylic monomer containing active hydroxyl groups such as 2-hydroxyethyl methacrylate (2-HEMA), 2-hydroxyethyl acrylate (HEA) or 4hydroxybutyl acrylate (4-HBA), polymerization-inhibitor and catalysts. UV curable pressure-sensitive adhesives were prepared by mixing UV oligomers, acrylic pressure-sensitive adhesives and photoinitiator. We monitored difference of NCO groups remaining in UV oligomers according to different types of acrylic monomers and mixing methods by Fourier transform infrared (ATR–FTIR) spectroscopy and nuclear magnetic

Corresponding author. Tel.: + 82-42-821 6613. E-mail address: parkwh@cnu.ac.kr.

Page 722 of 1108

resonance (NMR). Properties (180° peel strength, ball tack, holding power and gel fraction) of UV curable pressure-sensitive adhesives were measured.

2. Experimental 2.1.

Materials

Acrylic monomer 2-hydroxy ethyl methacrylate (2-HEMA : Samchun Chemical Co. Ltd, Korea), 2hydroxy ethyl acrylate(2-HEA : Samchun Chemical Co. Ltd, Korea), 4-hydorxy butyl acrylate (4-HBA : Samchun Chemical Co. Ltd, Korea) were used without further purification. Isophorone diisocyanate (IPDI : Tokyo Chemical Industry Co. Ltd, Japan) with two NCO groups was also used without further purification. The catalyst dibutyltin dilaurate (DBTDL : Aldrich Chemical Co. Ltd, USA) and polymerization inhibitor hydroquinone monomethyl ether (MEHQ : Samchun Chemical Co. Ltd, Korea)) were used. Additionally, propylene imine (PI : Samchun Chemical Co. Ltd, Korea ) was used as monomer. The PSAs were obtained from AK chemtech Co. Ltd (Korea). An photoinitiator Irgacure 184(Ciba Specialty Chemicals Co.) and thermal initiator X-500 (AK chemtech Co. Ltd, Korea) were used.

2.2.

Acrylic oligomer synthesis

The acrylic oligomer was synthesized in five-necked flask equipped with a reflux condenser, an impeller, N2 purge and thermometer. Different formulations were tested. Content of IPDI was equal for all synthesis; the differences were type of acrylic monomers (2-HEMA, 2-HEA, 4-HBA), contents of acrylic monomers, input speed of acrylic monomers. The basic system was that IPDI was prepared in the flask, acrylic monomers were added in flask. They were stirred with IPDI for 2 h using mechanical stirrer at 50℃. After reaction time, they were allowed to warm to 60℃ in a nitrogen atmosphere and then stirring the mixture had the aging time for 2 h. Cooling mixture to 25℃, PI was added at a constant rate in 1 h.

2.3.

Preparation of syrup

Acrylic oligomer and acrylic-based pressure-sensitive adhesive was added prior to verify the effect of curing the pressure-sensitive adhesive prepared according to the acrylic oligomer and a photo-initiator (Irgacure 184: 1phr) or thermal initiator (X-500: 1phr) was added at a constant rate. Syrup was prepared with stirring the mixture at a constant speed of 400rpm, purging nitrogen at room temperature for 15 minutes.

2.4.

Preparation of PSA films

The samples were coated to a 25 μm thickness on polyethylene terephthalate (PET, SKC Co. LTD.,South Korea) films, and dried in a 70℃ oven for 10 min. The specimens were cut into 25 mm wide samples.

2.5.

Characterization acrylic oligomer structure

Changes in the synthesis of acrylic oligomer were anaylyzed by Attenuated Total Reflectance - Fourier transform infrared spectroscopy (ATR-FTIR : Alpha·p, Bruker Co. Ltd, USA) and Nuclear magnetic resonance (NMR Bruker Co. Ltd, USA).

2.6.

Characterization of PSA film

The gel content indicates the degree of crosslinking. The weight of the samples was measured. The samples were then immersed in toluene for 24 hours at room temperature, and the insoluble polymers were removed by filtration through a 200 mesh wire net. The samples were then dried at 70℃ until they reached a constant weight. The gel content were calculated using the following equation:

where W 0 is the weight before immersion, and W 24 is the weight after immersion. The acrylic PSAs films prepared were attached to a stainless steel substrate and a 2 kg rubber roller was passed over them twice. The 180° peel strength was measured using universal test machine (UTM : Instron Co. Ltd, USA) after sample was left to stand at room temperature for 24 h. The peeling speed was 300 mm/min, and the average strength of peeling period was measured 5 times. The ball tack was measured flow KS T 1028 Rule. The cohesion force was measured by checking both the shear adhesion failure temperature (SAFT). For

Page 723 of 1108

SAFT, the samples, 25 mm x 25 mm size were attached to a stainless steel substrate by rolling with a 2 kg rubber roller twice, and then loaded with a 500 g weight. The samples were held in the oven with a heating rate 0.4℃ /min, and the temperature when shear failure occurred was checked.

3. Results and discussion The ATR-IR & NMR results of acrylic oligomers before adding PI, the -NCO peak was decreased considerably with increasing acrylic monomers content, input speed of acrylic monomers did not affected to ATR-IR & NMR results of mixtures and different of acrylic oligomers also did not affected to mixture’s structure. After adding PI into the mixture, -NCO peak was not showed in the ATR-IR & NMR results of acrylic oligomers (not shown in data). The gel content was calculated to determine the degree of curing of acrylic PSAs by measuring the insoluble material remaining. The gel content was increased gradually increasing contents of the acrylic oligomer, as shown in Figure 1(a).

Fig. 1: (a) : gel fraction of PSAs, (b) : 180° peel strength of PSAs The amount of acrylic oligomer content also affected the adhesion properties. The average of the peel strength decreased considerably with increasing acrylic oligomer content, as shown in Figure 1(b). In the case of the ball tack, there was a slight decrease with increasing acrylic oligomer content. The acrylic oligomer also affected the increase in SAFT and thermal resistance (not shown in data).

4. References

Page 724 of 1108

[1] Kajtna J, Likozar B, Golob J, Krajnc M. The influence of the polymerization on properties of a

nethylacrylate / 2-ethylhexylacrylate pressure-sensitive adhesive suspension. Int J Adhes Adhes 2008;28:382–90. [2] Guoliang W, Yue J, Lei Y, Songjun Z, Puren Y, Weijian X. A novel UV-crosslinked pressure-sensitive

adhesive based on photoinitiator-grafted SBS. Int J Adhes Adhes 2010;30:43–46. [3] Anil K, Dayal S, Utpal K, Sunil S, Jolanta S, Zbigniew C, Rakesh K. Effect of crosslinkers on adhesion

properties of electron beam curable polyurethane pressure sensitive adhesive. Int J Adhes Adhes 2013;41:73-79. [4] Hou-Hsein C, Chich-Kuen W, Kuang Sein C, Chen-Yueh C. Removable acrylic pressure-sensitive

adhesives activated by UV-radiation. J Polym Res 2014 21:472. [5] Zbigniew C, Agnieszka K, Janina K, Jolanta S. UV-crosslinkable acrylic pressure-sensitive adhesives for industrial application. Polym. Bull. 2012 69:71–80 [6] Webster I. The development of a pressure-sensitive adhesive for trauma-free removal.. Int J Adhes Adhes 1999 19:29–34

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The 13th Asian Textile Conference Geelong, Australia, November 3 - 6, 2015

Synthesis and fluorescent properties of water-soluble chitosan oligomer with fluorophore Hun Min Lee 1, Won Ho Park Department of Advanced organic materials and Textile System Engineering Chungnam National University, Daejeon, Korea

Abstract. In the past few decades, a great interest has been focused on a naturally occurring class of polymers called chitosan for their large amount in nature, biodegradability and extensive applications. Water-soluble chitosan oligomer is composed of β-(1,4)-2-amido-2-deoxy-D-glucan and β-(1,4)-2-acetoamido-2-deoxy-Dglucan(acetylglucosamine), and the low molecular weight substances obtained by acidic or enzymatic hydrolysis of chitosan. Until now, many researchers have examined chitosan oligomer as a promising material for biomedical applications on account of its good biocompatibility, biodegradability, antimicrobial activity and wound healing effects. Dye-labeled chitosan can be also employed in bio-imaging system, because it has low toxicity. Some dyes, such as Alexa Fluor, Cibacron Blue and fluorescein isothiocyanate (FITC), have been employed to create dye-labeled chitosan particulate systems. However, a greater part of approaches have been developed for the synthesis of dye-labeled chitosan molecular system using chemical reagents due to its low solubility. Numerous researches have addressed the utilization of chitosan as a fluorescence probe. These methods have a limited application in the medical and pharmaceutical fields, because most of them may be environmentally toxic or biologically hazardous. Herein, we focused on the environmentally friendly approach using a water-soluble chitosan derivative for bio-imaging. We report on the simple synthesis and optical properties for FITC-labeled chitosan oligomer in distilled water.

Keywords: chitosan oligomer, silver chloride nanoparticle, fluorescent

1. Introduction Nowadays, fluorescent natural polymers are of interest because of their promising applications in biological/biomedical labeling, tracking, monitoring, imaging, and diagnostics, particularly in drug delivery systems, tissue engineering, and cancer imaging. Although a unique feature of natural polymers compared with synthetic ones is their ability to undergo biodegradation, most of the studies thus far have been carried out with synthetic polymers. Organic fluorophores can be attached to the polymer chains through covalent or noncovalent linkages and exhibit fluorescence from short to very long wavelengths, depending on their nature. The synthesis of fluorescent polymers is generally carried out using two established methods. The first is through the polymerization of fluorescent monomers, and the second is via the attachment of fluorescent moieties to the polymer backbone. To preserve the properties of the natural polymer, the latter method is often more useful. Derivatization of polymer backbones, in this case, addition of fluorophores, is often done to enable them to be used to meet a specific function, and this is often monitored by a specific detection event, such as fluorescence or absorption in the visible region, or at a long wavelength. Reagents used for derivatization may be divided into four groups: nonfluorescent reagents, fluorogenic reagents that are generally nonfluorescent but that react with target compounds to form conjugated fluorescent cyclic molecules, fluorescent reagents having a highly fluorescent aromatic group (fluorophore), and redox active reagents that are often employed in electrochemistry. Chitosan (CHI) is a natural polymer consisting of 1,4linked N-acetyl-D-glucosamine (GlcNAc) and D-glucosamine (GlcN) subunits. CHI is nontoxic, biocompatible, and biodegradable and has mucoadhesive properties; therefore, it has attracted significant 

Corresponding author. Tel.: + 82-042-821- 6613. E-mail address: parkwh@cun.ac.kr.

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interest in a broad range of scientific areas, particularly in biomedical and pharmaceutical research. Recently, various fluorescent CHI derivatives were synthesized by covalently attaching fluorescent groups such as fluorescein isothiocyanate (FITC), rhodamine B isothiocyanate, naphthalimide derivatives, 1-pyrenebutyric acid N-hydroxyl succinamide ester (PSE), xanthene dye Rose Bengal, Rose Bengal, 1-naphthylacetic acid, anthracene-9-carboxaldehyde, anthracene-9-carboxylic acid, 2-(2â&#x20AC;˛-hydroxyphenyl)- benzoxazole,18 dansyl chloride, and N-hydroxy-succinimide functionalized cyanine and cyanine to the primary amino groups in CHI. Moreover, fluorescent CHI nanoparticles were prepared for use as nanoprobes or nanocoating for sensing, imaging, or bone repair in biological applications. Herein, we focused on the environmentally friendly approach using a water-soluble chitosan derivative for bio-imaging. We report on the simple synthesis and optical properties for FITC-labeled chitosan oligomer(CHI-FITC) in distilled water.

2. Experimental CHI-FITC having various degrees of FITC chromophore substitution were prepared. The derivatives were synthesized through reaction of the amine groups in CHI with the FITC isothiocyanate groups in ethanol. The general procedure was as follows: CHI (0.6 g) was dissolved in 2% (w/v) water (30 mL) at room temperature with stirring. After complete CHI dissolution, a solution of FITC (10, 30, 50 mg) in 100 mL of ethanol was added to the CHI solution. The mixture was intensively stirred using a magnetic stirring bar for 24 h with protection from light. After the reaction was completed, the mixture was centrifugated(4,000 rpm, 10 min) and washed by ethanol. The degree of N-substitution (DS) of FITC units in the derivatives were determined using 1H NMR spectroscopy. CHI-FITC with different DS values (0.01, 0.03, 0.04) are subsequently represented as CHI-10FITC, CHI-30FITC and CHI-50FITC respectively.

3. Results and Discussion

Fig. 1: 1H NMR spectra of CHI-50FITC

The composition of FITC-CHI was determined by FT-IR and 1H NMR. CHI-FITC exhibits the characteristic bands of benzene ring vibrations at 1458, 1535, and 1593 cm-1, while the N=C=S (isothiocyanate) vibrations of FITC disappeared at 2038 cm-1 due to the aminosilanization reaction. The characteristic Î´ value of aromatic proton form from 6.3 to 8 ppm appeared, and the degree of substitution (DS) was increased with the increase of the FITC concentration. The maximum

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fluorescence emission exhibited at 528 nm when the excitation wavelength was set at 400 nm, and also increased with the increase of the DS.

4. Conclusion

In this work, we synthesized FITC-labeled chitosan oligomer as s water-soluble fluorophore by environmentally friendly method using distilled water. The composition of FITC-CHI was determined by FTIR and 1H NMR and the degree of substitution (DS) was increased with the increase of the FITC concentration. CHI-FITC is reacted with silver nitrate to form the silver nanoparticles and the intensity of fluorescence was quenched because FITC was changed to fluorescence resonance energy transfer(FRET) by forming silver nanoparticles. In the efforts to use the distilled water as a reaction solvent, the simple process to prepare FITClabeled CHI oligomer using benign condition is expected to be providing numerous benefits and compatibility for pharmaceutical, bio-medical, bio-sensing applications. And we will investigate the change of fluorescence intensity at various experimental conditions such as pH, temperature, and ratio of reactants.

5. References [1] Om Parkash Siwach. & P. Sen., Fluorescence properties of Ag nanoparticles in water. Solid State Communications, Spectrochimica Acta Part A 69 pp. 659–663, 2008. [2] Pattarapond Gonil & Satit Puttipipatkhachorn., Synthesis and Fluorescence Properties of N-Substituted 1-Cyanobenz[f ]isoindole Chitosan Polymers and Nanoparticles for Live Cell Imaging, Biomacromolecules 15 pp. 2879−2888, 2014. [3] Carolina A. Sabatini & Marcelo H. Gehlen., Fluorescence Modulation of Acridine and Coumarin Dyes by Silver Nanoparticles, J Fluoresc 17 pp. 377–382, 2007. [4] Zhengbo Chen & Kai Li., Chitosan-functionalized gold nanoparticles for colorimetric detection of mercury ions based on chelation-induced aggregation, Microchim Acta 182 pp. 611–616, 2015

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The 13th Asian Textile Conference Geelong, Australia, November 3 - 6, 2015

The Effect of Structure of Socks on Plantar Pressure Distribution Zeynab Soltanzadeh1 , Saeed Shaikhzadeh Najar1 + , Mohammad Haghpanahi2 and Seyedpezhman Madani 3 1

Amirkabir University of Technology, Faculty of Technical and Engineering, Department of Textile Engineering, Tehran, Iran 2 Iran University of Science and Technology, Faculty of Technical and Engineering, Department of Mechanics, Tehran, Iran 3 Department of Physical Medicine and Rehabilitation, Medical School, Iran University of Medical Sciences, Tehran, Iran

Abstract. Calluses occur when there is intermittent pressure at some part of the foot. During rubbing, the shearing forces rupture the flesh under a callus, the outer skin becomes loose and fluid collects beneath it, forming a blister. If the pressure and shearing continue, the blister breaks down and bacteria invade. The necrotic area gets infected. Finally, a deeper cavity forms as an ulcer. It is reported that about 15% of diabetics will experience significant foot problems during their lives, and each year 86 000 will have a lower limb amputated because of foot complications. The effect of structure of socks on plantar pressure distribution is investigated. Using the pedobarograph (EMED STABYLOPRO) we have studied five candidate persons. Each participant tests all eight different models (Barefoot and seven different structures of socks). The double cross tuck (DCT) structure exhibits the lowest plantar pressure and hence would be more suitable for socks.

Keywords: Plantar Pressure Distribution, Socks Structures

1. Introduction The human foot is an immensely practical, beautifully designed structure built to bear many times its weight, thousands of times a day and bounce back ready for more. During walking, a foot rubs against its footwear and can be susceptible to malfunction. There are at least 300 types of foot problem. Many of them result from poorly fitting footwear. The most frequent foot problems are blisters, corns and calluses, and all of them are related to pressure. At times, such foot problems can have life-altering consequences, especially for people with diabetes [1]. The concept of sport-specific socks emerged during the 1970s from the invention of the roll top sock, by James Throneburg, owner of THOR LO, Inc., sock company (Rockwell, NC) [2]. Early patented designs from THOR LO placed extra padding in strategic locations of a sock to provide protection during running, tennis, skiing, and cycling. Over the next 30 years, numerous manufacturers have emerged, offering myriad designs for virtually every sport in which shoes are worn. In some cases, the use of a sport-specific sock is valid, while many models and designs have questionable unique functions [2]. Measurement of foot pressure distribution (FPD) is clinically useful for evaluation of foot and gait pathologies. High peak plantar pressures (PPP) during walking in people can cause skin breakdown and develop foot ulcers. In recent years, different shapes of insole have been used to reduce pressure in the rear-foot. Although a total insole contact can moderate pressure, the extra volume completely touching the mid-foot region sometimes induces an uncomfortable feeling near the arch during walking [3]. +

Corresponding author. Tel.: + 98-21-64542613. E-mail address: saeed@aut.ac.ir

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Considerable research has also been conducted on specialized sports hosiery to determine physiologic benefits. This research has suggested that athletic socks can provide significant reduction of plantar pressures [4-12], reduced impact shock [13], reduced incidence of friction blisters [14, 15], and reduced symptoms of venous insufficiency [16, 17]. These medical benefits, validated by scientific study, gave rise to a new category of socks known as therapeutic hosiery, designed for patients with diabetes and athletic. In this research work, the effect of structure of socks on plantar pressure distribution is investigated. Using the pedobarograph (EMED STABYLOPRO) we have studied five candidate persons. Each participant was asked to test all eight different models (Barefoot and seven different structures of socks). Static plantar pressures were measured in standing mode.

2. Methods and Materials To produce the socks, a single jersey flat knitting machine (Motec Silver Model with 156 needles and 3.75 inch diameter) was used. The same cotton yarn (20/1) and Lycraâ&#x201E;˘ yarn (50) are knitted for all the socks. Seven different structures of socks (Fig 1) were produced. Five healthy asymptomatic participants were candidate. Age (years), height (cm), weight (kg), and body mass index (BMI) (kg/m2) were determined for each of the study participants at baseline. All participants had normal feet, the absence of any apparent disturbance in the observed walking pattern; absence of significant structural abnormalities in the feet or legs; absence of corns, excessive callus formation, or other lesion of the feet or legs; freedom from complaints of discomfort, disability, or excessive fatigue during prolonged standing. Time-integral mean plantar pressures were measured during barefoot walking using the pedobarograph (EMED STABYLOPRO). Each participant was asked to test all eight different models (Barefoot and seven different structures of socks that are provided in Fig 1). Static plantar pressures were measured in standing mode.

(a)

(b)

(c)

(f)

(g)

(d)

(e) Fig. 1: The structures of socks (a) plain, (b) single cross tuck, (c) mock rib inlay,(d) cross miss, (e) mock rib, (f) double cross tuck, (g) double cross miss

With the restructuring of the fabric, fabric thickness, compressibility module, contact area and plantar pressure distribution vary.

3. Results and Discussion The effect of structure of socks on plantar pressure redistribution of persons was evaluated. The peak plantar pressures (PPP), forceâ&#x20AC;&#x201C;time integral (FTI) and contact area were measured. In general, tuck loops reduce fabric length and length- wise elasticity and increase course density and thickness of fabric because the higher yarn tension on the tuck and held loops causes them to rob yarn from adjacent knitted loops, making them smaller and providing greater stability and shape retention [18]. As the loops come

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closer to each other due to increased course density, overlapping of loops takes place, which enhances the higher fabric thickness. On the other hand, in knit-tuck structure the fabric width is increased and hence the wale density is decreased because tuck loops pull the held loops downwards, causing them to spread outwards and make extra yarn available for width- wise extensibility [18]. In knit-miss structures that incorporating float stitches tend to exhibit fain horizontal lines. A float stitch or welt stitch is composed of a held loop, one or more float loops and knitted loops. It is produced when a needle holding its old loop fails to receive the new yarn that passes, as a float loop, to the back of the needle and to the reverse side of the resultant stitch, joining together the two nearest needle loops knitted from it. The float stitch shows the missed yarn floating freely on the reverse side of the held loop. This is the technical back of single-jersey structures [18]. Table 1: The results of plantar pressure Barefoot plain single cross tuck mock rib inlay cross miss mock rib double cross tuck double cross miss

PPP (kPa) 380 365 345 350 370 365 330 375

FTI (NS) 553.5 507 492.8 490 520 508.5 486.9 520.2

Max Area (cm2) 137 139.3 142 140.8 138.5 139.8 144.4 138.5

As shown in Table 1 all the socks are reduced the peak plantar pressure (PPP) and decrease contact area. The double cross tuck structure exhibits the lowest peak plantar pressure (PPP) and hence would be more suitable for socks.

4. Conclusion This study aims to evaluate the effects of structural of socks on the changes of plantar pressure. The barefoot plantar pressure distribution was compared with the plantar pressure distribution with socks. All the socks are believed to be efficient in evenly reduced the plantar pressure and decrease contact area. As a result, all the socks in this study can prevent the foot of diabetic patients from peak plantar pressure (PPP). Therefore, greatly reduce the chances for corns and calluses formation and ulceration development of the diabetic patients.

5. References [1] Li, Y. and X.-Q. Dai, Biomechanical engineering of textile and clothing. 3 ed. 2006. [2] Werd, M.B. and E. Leslie Knight, Athletic Footwear and Orthoses in Sports Medicine. 2nd ed. 2010: springer. [3] HSU, Y.C. and Y.W. GUNG, Using an Optimization Approach to Design an Insole for Lowering Plantar Fascia Stress—A Finite Element Study. Annals of Biomedical Engineering, 2008. 36(8): p. 1345–1352. [4] Veves, A., E.A. Masson, and D.J.S. Fernando, Use of experimental padded hosiery to reduce abnormal foot pressures in diabetic neuropathy. Diabetes Care, 1989. 12: p. 653-655. [5] Veves, A., E.A. Masson, and D.J.S. Fernando, Studies of experimental osieryin diabetic neuropathic patienets with high foot pressures. Diabetes Care, 1990. 7: p. 324-326. [6] Veves, A., E.M. Hay, and A.J.M. Boulton, The use of specially padded hosiery in the painful rheumatoid foot. The Foot, 1992. 1: p. 175-177. [7] Flot, S., V. Hill, and W. Yamada, The e ffect of padded hosiery in reducing forefoot plantar pressures. Int J Low Extrem Wounds, 1995. 2: p. 201–205.

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[8]

Donaghue, V., M. Sarnow, and J. Guirini, Longitudinal in-shoe foot pressure relief achieved by specially

designed footwear in high risk diabetic patients. Diabetes Res Clin Pract, 1996. 31: p. 109–114. [9]

Garrow, A., C. van Schie, and A. Boulton, Efficacy of multilayered hosiery in reducing in-shoe plantar

pressure in high risk patients with diabetes. Diabetes Care, 2005. 28: p. 2001-2006. [10] Blackwell, B., R. Aldridge, and S. Jacob, A comparison of plantar pressure in patients with diabetic foot ulcers using different hosiery. Int J Low Extrem Wounds, 2002. 1(3): p. 174-178. [11] Dai, X.-Q., et al., Effect of sock on biomechanical responses of foot during walking. Clin Biomech, 2006. 21(3): p. 314–321. [12] Blackmore, T., N. Ball, and J. Scurr, The effect of socks on vertical and anteroposterior ground reaction forces in walking and running. The Foot, 2011. 21: p. 1-5. [13] Howarth, S. and K. Rome, A short-term study of shock-attenuation in different sock types. Foot, 1996. 6: p. 5-9. [14] Herring, K. and D. Richie, Friction blisters and sock fiber composition. J Am Podiatr Med Assoc 1990. 80: p. 63–71. [15] Herring, K.M. and D.H. Richie, Comparison of cotton and acrylic socks using a generic cushion sole design for runners. J Am Podiatr Med Assoc 1993. 83: p. 515–522. [16] Brown, J. and A. Brown, Nonprescription, padded, lightweight support socks in the treatment of mild to moderate lower extremity venous insufficiency. JAOA, 1995. 95: p. 173–181. [17]

Ali, A., M.P. Caine, and B.G. Snow, Graduated compression stockings: physiological and perceptual

responses during and after exercise. J Sports Sci, 2007. 25: p. 413–419. [18] Spencer, D.J., Knitting Technology. 2 ed. 1989, Cambridge, England: Woodhead. 90.