TNT2016 Abstracts & Posters book

Abstracts & Posters Book

TNT2016 index

Foreword

04

Committees

06

Poster awards

07

Sponsors

08

Exhibitors

09

Speakers

13

Abstracts

21

Posters

151

On behalf of the International and Technical Committees, we take great pleasure in welcoming you to Fribourg (Switzerland) for the 17th “Trends in NanoTechnology” International Conference (TNT2016).

TNT2016

Foreword

TNT2016 is being held in large part due to the overwhelming success of earlier TNT Nanotechnology Conferences.

This high-level scientific meeting series aims to present a broad range of current research in Nanoscience and Nanotechnology worldwide, as well as initiatives such as MANA/NIMS, CIC nanoGUNE, Adolphe Merkle Institute, IBEC, DIPC, ICN2, etc. TNT events have demonstrated that they are particularly effective in transmitting information and promoting interaction and new contacts among workers in this field. Furthermore, this event offers visitors, exhibitors and sponsors an ideal opportunity to interact with each other.

This year, a Graphene one-day Symposium will again be organized within TNT2016 in collaboration with ICN2 (Spain).

Other specific sessions will take place: BioNanotechnology, Materials for Energy Applications, Nano-Characterization and Soft / Bio-Inspired Materials. In addition, a “Women in Science – Young Researcher Colloquium” will also be organized by the NCCR Bio-Inspired Materials within the framework of its Postdoctoral Fellowship Program for Women in Science.

One of the main objectives of the Trends in Nanotechnology Conference is to provide a platform where young researchers can present

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their latest work and also interact with high-level scientists. For this purpose, the Organizing Committee provides every year travel grants for students. In addition, awards will also be given to young PhD students for their contributions presented at TNT. Grants and awards are funded by the TNT Organization in collaboration with private bodies and several governmental/research institutions.

TNT is now one of the premier European conferences devoted to nanoscale science and technology.

We are indebted to the following Scientific Institutions, Companies and Government Agencies for their financial support: Phantoms Foundation, NIMS (Nanomaterials Laboratory) and MANA (International Center for Materials and Nanoarchitectonics), EMPA, NCCR Bio-Inspired Materials, Swiss Nanoscience Institute, NCCR Molecular Systems Engineering, NCCR MARVEL, LS Instruments, C’Nano GSO, MERCK, Donostia International Physics Center, Micronarc, ETH Zurich and FEI. We would also like to thank the following companies and institutions for their participation: CSI, Cordouan Technologies, neaspec, Micronarc, SwissLitho AG, LOT-Quantum Design/Andor Technology, Ferrovac GmbH, Gloor Instruments/WITec/ZEISS, Oxford Instruments, Physical Electronics GmbH, NCCR Bio-Inspired Materials, Nanotechnology and nanosurf.

In addition, thanks must be given to the staff of all the organizing institutions whose hard work has helped planning this conference.

TNT2016 fribourg (switzerland)

Organising Committee

TNT2016 TNT2016 fribourg (switzerland)

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TNT2016 Committees Organising Committee

Technical Committee

Jose-Maria Alameda (Universidad de Oviedo, Spain) Masakazu Aono (MANA / NIMS, Japan) Xavier Cartoixa (UAB, Spain) Antonio Correia (Phantoms Foundation, Spain) – Conference Chairman Gianaurelio Cuniberti (TUD, Germany) Pedro Echenique (DICP / UPV, Spain) Uzi Landman (Georgia Tech, USA) Jose Manuel Perlado Martin (IFN-ETSII / UPM, Spain) Jose Maria Pitarke (CIC nanoGUNE Consolider, Spain) Jose Rivas (Santiago de Compostela Univ., Spain) Juan Jose Saenz (DIPC, Spain) Josep Samitier (IBEC - Universitat de Barcelona, Spain) Frank Scheffold (University of Fribourg, Switzerland) Didier Tonneau (CNRS-CINaM, France) Christoph Weder (Adolphe Merkle Institute, Switzerland)

Viviana Estêvão (Phantoms Foundation, Spain) Pedro Garcia Mochales (UAM, Spain) Adriana Gil (CSIC, Spain) Conchi Narros Hernández (Phantoms Foundation, Spain) Joaquin Ramon-Laca (Phantoms Foundation, Spain) Jose Luis Roldan (Phantoms Foundation, Spain)

International Scientific Committee Masakazu Aono (MANA / NIMS, Japan) Emilio Artacho (CIC nanoGUNE Consolider, Spain) Robert Baptist (CEA / DRT / LETI, France) Andreas Berger (CIC nanoGUNE Consolider, Spain) Michal Borkovec (University of Geneva, Switzerland) Fernando Briones (IMM / CSIC, Spain) Jose Maria Gonzalez Calbet (UCM, Spain) Remi Carminati (Ecole Centrale Paris, France) Jose-Luis Costa Kramer (IMM / CSIC, Spain) Antonio Garcia Martin (IMM / CSIC, Spain) Raquel Gonzalez Arrabal (IFN-ETSII / UPM, Spain) Pierre Legagneux (Thales, France) Annick Loiseau (ONERA - CNRS, France) Ron Reifenberger (Purdue University, USA) Stephan Roche (ICREA/ICN2, Spain) Barbara Rothen-Rutishauser (Adolphe Merkle Institute, Switzerland) Josep Samitier (IBEC - Universitat de Barcelona, Spain)

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TNT2016 fribourg (switzerland)

TNT2016 Poster awards

Funded by

Award

Wiley-VCH Verlag GmbH

Book voucher (200 euros)

Wiley-VCH Verlag GmbH

Book voucher ( 150 15 0 euros)

Phantoms Foundation

Tablet

Phantoms Foundation

Tablet

TNT2016 Organisation

TNT2016 fribourg (switzerland)

Free registration to the 2017 2017 Conference

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TNT2016 Sponsors

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TNT2016 Exhibitors

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CSInstruments is a scientific equipment manufacturer specialized in the conception of Atomic Force Microscope and options designed for existing AFM (Nano-Observer AFM, Resiscope, HD-KFM, Magnetic modules …).

The Nano-Observer AFM microscope, flexible and powerful AFM, is designed with the ultimate technologies and offers innovative AFM modes compatible with graphene application such as: HD-KFM (High Definition KFM) or the ResiScope... Moreover It combines performance and ease of use (top/side view, intuitive software step by step…).

The ResiScope, unique system able to characterize electrical sample over 10 order of magnitude, offers unbeatable performance on Graphene characterizations…

It also provide new capabilities on soft sample with its innovative mode: Soft ResiScope (electrical characterization on soft sample).

Contact: info@csinstruments.eu Web: www.csinstruments.eu

Cordouan Technologies is specialized in designing, manufacturing and selling innovative devices for the physico-chemical characterization of nanoparticles (size, charge, form). Since 2007, we manufacture products, which come from transfer of innovative technologies, created and patented by prestigious research institutes, like the French Institute of Petroleum (IFP) or the Karlsruhe Institute of Technologies (KIT). Present in more than 30 countries around the world, our instruments equip some of the most prestigious industrial and research laboratories (Total, Rhodia, L'Oreal, ENS Paris and Lyon, CRPP, ENSPCI, STMicro-electronic, INRS, Dow Chemical, ARABLAB, Université of Waterloo, etc.) working on advanced applications such as: synthesis of polymers and functionalized metal nanoparticles, crude oil extraction and refining, quality control of cosmetic gels, development of special inks in colloidal form, nanoparticle vectorization for medicine, etc.

Contact: maelle.mainard@cordouan-tech.com Web: www.cordouan-tech.com

See the nanoworld: neaspec introduces the new nano-FTIR imaging and spectroscopy tool, with a wavelengthindependent spatial resolution of 10 nm, a factor of 1000 better than conventional FTIR. This cutting-edge technology allows you to gain new insights into solid-state system by directly measuring, e.g. plasmons-polaritons propagation, local electron mobility and by performing nanoidentification…

Contact: info@neaspec.com Web: www.neaspec.com

Micronarc is the dedicated micro-nanotech cluster and communication platform created by the governments of the seven cantons that constitute Western Switzerland.

Its primarily role is the development and promotion of the regional scientific, industrial and economic base in the sectors of micro and nanotechnology, as well as its educational structures, R&D facilities, technology transfer and inward investment.

To achieve its objectives, Micronarc manages and operates its internet portal www.micronarc.ch, organizes grouped booths at industry trade shows and scientific conferences; organizes professional and public events locally; provides information and networking possibilities and acts as a facilitator in establishing business relations.

Contact: info@micronarc.ch Web: www.micronarc.ch

NANO encompasses the understanding of the fundamental physics, chemistry, biology and technology of nanometre-scale objects. It offers cutting-edge research articles at the forefront of developments in all fields of nanotechnology research. As well as original research articles and Topical Reviews, the journal publishes Focus Collections on a regular basis, which features Invited Articles from highly active subject areas.

Web: iopscience.iop.org/journal/0957-4484

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SwissLitho is a young high-tech company with the vision to change the way nanostructures are commonly made.

Our unique nanolithography tools, called NanoFrazor, trace their origins to IBM Research Zurich. The NanoFrazor is based on Thermal Scanning Probe Lithography and is the first alternative to conventional mask-less lithography technologies. The unique features of the NanoFrazor are: − High resolution direct write nanolithography − 3D nanolithography at 10 nm lateral & 1nm vertical resolution − In-situ topography imaging − Closed-loop lithography − Stitching and overlay without using marker at sub5nm accuracy − No damage from charged particle beam − Thermal nano-scale experiments The NanoFrazor opens up new and unprecedented possibilities for nanofabrication in order to accelerate scientific and technological progress in all fields of nanotechnology. Since its foundation in 2012, SwissLitho has received many of the most prestigious national and international start-up and technology awards. In 2015 SwissLitho won one of the R&D 100 awards (also titled as "Oscars of Innovation") in the category Process/Prototyping.

LOT-QuantumDesign group is a leading European distributor of high-quality scientific instruments and components. The group offers components and systems used in material sciences, imaging, spectroscopy, photonics, nanotechnology and life science research.

The group was founded almost 45 years ago and now employs more than 140 staff across Europe.

Web: www.lot-qd.com Andor Technology is a global leader in the pioneering and manufacturing of high performance scientific imaging cameras, spectroscopy solutions and microscopy systems for research and OEM markets. Andor has been innovating the photonics industry for over 20 years and aims to continue to set the standard for high performance light measuring solutions that allow consumers to perform light measurements previously considered impossible. Through continuous dialogue with customers and strong teamwork, Andor continues to innovate ground-breaking products that improve the world in which we live. Andor Technology is part of Oxford Instruments plc, a leading provider of high technology tools and systems for industry and research.

Contact: info@swisslitho.com Web: www.swisslitho.com

The Physical Electronics GmbH is a stable partner for high-tech companies located in Munich, Germany, more than 21 years. Our core values are market-oriented approach, continuous improvement and excellent customer support. The Marketing of innovative ideas and the sale & service of fascinating products is our daily business. Areas of our expertise are in AFM-IR, an innovative combination of sub 50nm high spatial resolution IR Spectrometry and AFM microscopy, Surface Science and Nanomechanical Testing. Providing the highest possible level of After Sales Support for our customers, we have established a very effective service organization able to meet the requirements of Industry, Institutes and Universities.

Contact: eurosales@phi-europe.com Web: www.phi-europe.com

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Ferrovac was founded as a spin-off of the solid state physics laboratory of the Swiss Federal Institute of Technology (ETHZ) in Zurich, Switzerland. The company’s main area is the design and production of components and systems for ultra high vacuum technology as well as the development of scientific instruments for surface science and nanotechnology.Our valued customers benefit not only from standard-setting Swiss precision in manufacturing and engineering, but also from our accommodating, high quality services in support, repairs and consulting. Ferrovac's experts have profound knowledge of ultra high vacuum technology, experimental physics and scanning probe microscopy and our engineers work with the most advanced 3D-CAD technology.

Customization is our daily business: You name it, we build it...

We’d be happy to welcome you at our booth.

Contact: sales@ferrovac.com Web: www.ferrovac.com

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Gloor Instruments – inspiring high end solutions since 1976 Leading equipment and service provider in the field of electron microscopy, imaging and surface analysis in Switzerland. We share your enthusiasm for technology and (nano-)science and answer your questions with first class consulting and an experienced service team. As distributor of ZEISS SEM’s and WITec equipment in Switzerland we are happy to welcome you at our shared booth.

Contact: info@gloorinstruments.ch Web: www. gloorinstruments.ch WITec – focus innovations WITec has established itself as a market leader in the field of nano-analytical microscope systems (Raman, AFM, SNOM). Having emerged from the academic world, WITec maintains its research character today. This results in close customer contact, high performance, reliability and unparalleled flexibility as well as upgradeability.

The newest development is the award-winning WITec RISE mode for correlative Raman-SEM imaging which is now compatible with ZEISS MERLIN. Web: www.witec.de

Oxford Instruments offers flexible, configurable process tools and leading-edge processes for the precise, controllable and repeatable etching, deposition and growth of micro- and nano-structures. Our systems provide process solutions for the micro- and nanometre engineering of materials for semiconductor, optoelectronics, HBLED, PV, MEMS & microfluidics, high quality optical coatings and many other applications in micro- and nanotechnology.

These solutions are based on core technologies in: − Plasma Etch & Deposition − Atomic Layer Deposition (ALD) − Ion Beam Etch & Deposition − Deep Silicon Etch Systems − Magnetron sputtering Products range from compact stand-alone systems for R&D, through to batch tools and up to cassette-to-cassette and clustered platforms for production processing.

The National Center of Competence in Research (NCCR) Bio-Inspired Materials was launched in June 2014. Its vision is to establish an internationally recognized hub for smart materials research, education, and innovation. Its home institution is the University of Fribourg, with the University of Geneva and the Federal Institutes of Technology in Lausanne (EPFL) and Zurich (ETHZ) joining as participating institutions. Its operations team is based the Adolphe Merkle Institute, an interdisciplinary and independent center at the University of Fribourg that focuses on research and education in the domain of soft nanomaterials.

Web: bioinspired-materials.ch

Founded in 1997, Nanosurf is a Swiss based high-tech company providing scanning probe microscopes to customers around the globe.

The product range starts with very compact AFM and STM instruments, followed by state-of-the-art research atomic force microscope systems, all the way up to fully customized and comprehensive next-level solutions. Our customers in research, industry and teaching value the innovative approach, modularity, and ease of use of our products.

Nanosurf is global market leader for AFM-based single-cell and nano manipulation tools, AFM-based diagnostics and automatic nanomechanical analysis, AFM and STM for nanoeducation, compact and mountable AFM systems, and custom-built AFM systems.

Contact: info@nanosurf.com Web: www.nanosurf.com

Contact: plasma@oxinst.com Web: www.oxford-instruments.com/plasma

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TNT2016 Speakers

Index alphabetical order page

Ahmed Ali (Hanyang University, South Korea) Graphene-based Plasmonic Composite Nanostructures for Surface Enhanced Raman Scattering-based Biosensing Masakazu Aono (MANA / NIMS, Japan) Atomic Switch: From Invention to Practical Use and Future Prospects Hiroko Ariga (Hokkaido University, Japan) Direct measurements of oxygen vacancy in TiO2 single crystal by muon spin rotation spectroscopy Eunhye Baek (Dresden University of Technology, Germany) Negative photoconductivity of n-doped Si nanowire field-effect transistors Alexander A. Bagaturyants (National Research Nuclear University MEPhI, Russia) A theoretical analysis of the role of exciplexes in light emission in OLEDs: the structure and spectroscopic properties of α-NPD-BAlq exciplexes at an α-NPD/BAlq interface Manuel Bañobre-López (International Iberian Nanotechnology Laboratory, Portugal) Ultra-high transversal relaxivity and hyperthermia-induced drug delivery in superparamagnetic solid lipid nanoparticles Julio Bastos-Arrieta (Universitat Politècnica de Catalunya (UPC), Spain) Application of noble metal nanoparticles for kinetic studies, detection and quantification of uranium phases Irmgard Bischofberger (Massachusetts Institute of Technology, USA) Hydrophobic hydration: a matter of the mean energetics of water Ardemis A. Boghossian (École Polytechnique Fédérale de Lausanne, Switzerland) Nanobioptics: Engineering Optical Biosensors Based on Single-walled Carbon Nanotube (SWCNT) Fluorescence Alex Bondarchuk (CIC energiGUNE, Spain) Anomalous Non-Faradaic Capacitance in Vanadium Nitride Thin Films Ankita Borah (Toyo University, Japan) Hedgehog (Hh) pathway inhibitor loaded polymeric nanoparticles for anti-cancer therapy Dušan K. Božanić (Synchrotron SOLEIL, France) Angle-resolved Photoelectron Spectroscopy of Graphene Oxide-Based Aerosols by VUV Synchrotron Radiation Jasna Brujic (University of New York, USA) Cadherin adhesion in assemblies of lipid droplets Nico Bruns (Adolphe Merkle Institute, University of Fribourg, Switzerland) Combining the capsule-like protein thermosome with synthetic polymers to obtain nanoreactors and siRNA delivery agents Giuseppe Cantarella (ETH, Electronics Laboratory, Switzerland) Highly stretchable electronic devices using non-standard geometries

TNT2016 fribourg (switzerland)

Oral PhD Parallel session

Keynote Plenary Session

21 22

Oral Senior Plenary Session

Oral PhD Parallel session

23 24

Oral Senior Plenary Session

25

Oral Senior Plenary Session

26

Oral Senior Plenary Session

Invited Plenary Session

28 29

Invited Plenary Session

Oral Senior Plenary Session

30 31

Oral PhD Parallel session

32

Oral Senior Plenary Session

Keynote Plenary Session

33 34

Oral Senior Plenary Session

Oral PhD Parallel session

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35 36

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page Pietro Cataldi (Italian Institute of Technology, Italy) Effect of Graphene Nano-platelet Morphology on the Elastic Modulus of Soft and Hard Biopolymers: A Comparative Study Roberto Cerbino (Università degli Studi di Milano, Italy) Structure and dynamics of epithelial cell monolayers Menglin Chen (Aarhus University/Interdisciplinary Nanoscience Centre, Denmark) Ultraporous interweaving nanofibers for tissue engineering Gaurasundar Marc Conley (University of Fribourg, Switzerland) Superresolution Microscopy of thermosensitive Poly(N-isopropylacrylamide) microgel particles Huanyao Cun (EPFL - STI - IBI - LBEN, Switzerland) Nanotents - 2 nm void-formation and self-healing in 2D monolayers on metals Gero Decher (University of Strasbourg, France) Self-Assembly of Anisotropic Multi-Nano-Composites Ahmet Faik Demirörs (ETH Zürich, Switzerland) Periodically microstructured composite films made by electric- and magneticdirected colloidal assembly Fabio Donati (École Polytechnique Fédérale de Lausanne, Switzerland) Magnetism of Single Atoms on Graphene Mingdong Dong (iNANO-Aarhus University, Denmark) Two-Dimensional Materials Confined Water Barbara Drasler (Adolphe Merkle Institute, University of Fribourg, Switzerland) Hazard assessment of aerosolized graphene-related nanomaterial in human epithelial lung tissue in vitro Eric R. Dufresne (Yale, USA & ETH Zürich, Switzerland) How do living cells build photonic nanostructures?

Max Eisele (neaspec GmbH, Germany) From nanoscale spectroscopy towards photocurrent nanoscopy Klaus Ensslin (ETH Zürich, Switzerland) Fabry-Perot oscillations in bilayer graphene pn junctions Ruben Esteban (Donostia International Physics Center - DIPC, Spain) Emergence of quantum phenomena in the coupling of plasmons with molecules and quantum dots Steven B. Fairchild (Air Force Research Laboratory, USA) Nanostructured Anode and Cathode Materials for High Pulsed Power Electromagnetic (HPEM) Devices Omid Faizy-Namarvar (CEMES-CNRS, France) Designing all simple logic gates and half-adder circuit on a Si(100)-H surface Alke Fink (Adolphe Merkle Institute, University of Fribourg, Switzerland) Lock-in thermography: Using heat as an indicator for stability and distribution of magnetic nanoparticles in biological systems Wye Kay Fong (Monash University, Australia & ETH Zurich, Switzerland) Stimulating changes in complex nanostructures – lasers, acids and enzymes Leonard Francis (International Iberian Nanotechnology Laboratory, Portugal) Advanced Electron Microscopy Study of Gadolinium based compounds encapsulated within WS2 Nanotubes

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Oral Senior Graphene & 2D Materials Track A

Invited Plenary Session

Oral Senior Plenary Session

37 38 39

Oral Senior Plenary Session

40

Oral Senior Graphene & 2D Materials Track B

Keynote Plenary Session

41 42

Oral Senior Parallel Session

43

Invited Graphene & 2D Materials Track A

44

Invited Graphene & 2D Materials Track A

45

Oral Senior Plenary Session

Keynote Plenary Session

46 47

Oral Senior Parallel Session

48

Keynote Plenary Graphene & 2D Materials

49

Invited Plenary Session

50

Oral Senior Graphene & 2D Materials Track B

Oral Senior Parallel Session

51 52

Keynote Plenary Session

53

Invited Women in Science Symposium

54

Oral Senior Plenary Session

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Katharina M. Fromm (University of Fribourg, Switzerland) Nanomaterials meet Li-ion Batteries Fabio Giavazzi (University of Milan, Italy) Simultaneous characterization of rotational and translational diffusion of anisotropic particles by optical microscopy Franz J. Giessibl (University of Regensburg, Germany) New vistas for nanoscience opened by atomic force microscopy Peter Gnauck (Carl Zeiss Microscopy, Germany) Towards Sub-10 nm Nanofabrication of Plasmonic Devices using Multiple Electron and Ion Beams Michael Grätzel (École Polytechnique Fédérale de Lausanne - EPLH, Switzerland) Mesoscopic photosystems for electricity and fuel production from sunlight Thomas Greber (University of Zürich, Switzerland) Single layer boron nitride: From Nanomesh to smart membranes in liquids Oliver Gröning (EMPA, Swiss Federal Laboratories for Materials Testing and Research, Switzerland) On-surface synthesis and properties characterization of novel low-dimensional materials Peter Grutter (McGill University, Canada) Mechanically-Controlled Rewiring of Neuronal Circuits Florian Guignard (Adolphe Merkle Institute, University of Fribourg, Switzerland) Janus Dumbbells: A flexible template for colloidal chemistry Jakub Haberko (University of Fribourg, Switzerland) Photonic Bandgap Materials with Disorder Kazutoshi Haraguchi (Nihon University, College of Industrial Technology, Japan) Soft Nanocomposite Materials and Their Applications in Cell Harvest Systems and Antithrombogenic Coatings James Harden (University of Ottawa, Canada) Assembling biomimetic surfaces with modular amphiphilic proteins Felix Holzner (SwissLitho AG, Switzerland) Fabrication of sub-20 nm Metal Electrodes on 2D Materials without a Charged Particle Beam Byoung Ok Jun (Daegu Gyeongbuk Institute of Science & Technology (DGIST), Korea) Wireless thin film transistor with nanostructured magnetic core structure based on ZnO nanowires Julian Kalb (University of Konstanz, Germany) Positions-controlled growth of rutile TiO2 nanorods and their optical and electronic properties Ladislav Kavan (J. Heyrovsky Institute of Physical Chemistry, Czech Republic) Electrochemical Properties of TiO2 (Anatase, Rutile) Surfaces: Effects of Flatband Potential Ha Seong Kim (University of California, USA) Linear Shear Elasticity and Osmotic Pressure of Concentrated Disordered Ionic Emulsions Andras Kis (EPFL, STI-IEL-LANES, Switzerland) 2D dichalcogenide electronic materials and devices

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Oral Senior Plenary Session

56

Oral Senior Plenary Session

Keynote Plenary Session

57 58

Oral Senior Parallel Session

Keynote Plenary Session

59 61

Invited Graphene & 2D Materials Track B

62

Keynote Plenary Graphene & 2D Materials

Oral Senior Plenary Session

Oral Senior Parallel Session

Oral Senior Plenary Session

63 64 65 66

Oral Senior Plenary Session

Invited Plenary Session

67 68

Oral Senior Plenary Session

69

Oral PhD Parallel session

70

Oral PhD Parallel session

71

Oral Senior Plenary Session

73

Oral PhD Parallel session

Keynote Plenary Session

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74 75

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page Maksym Kovalenko (EMPA and ETH Zürich, Switzerland) Highly-Luminescent Colloidal Nanocrystals of Cesium Lead Trihalide Perovskites (CsPbX3, X=Cl, Br, I) Oleksandr Kovalenko (Université de Strasbourg, France) Magneto-plasmonic dynamics in gold nanoparticles Franciszek Krok (Jagiellonian University, Institute of Physics, Poland) Growth of hexagonal gold nanostructures during self-assembling on Ge(001) surface Margarita Krutyeva (Forschungszentrum Jülich, Germany) Synthesis and Structural Properties of Magneto-Elastomeric Nanocomposites Uzi Landman (Georgia Tech, USA) Small is different: emergent paradigms and atomically precise nano stuctures Thi Duy Hanh Le (Ho Chi Minh City University of Technology, Vietnam) Bio-inspired the natural amorphous silica source: the potential use of diatom particles for bone regeneration Bérengère Lebental (IFSTTAR - Ecole Polytechnique - CNRS, France) Carbon nanotubes micromechanical and chemical sensors: Reproducibility, reliability analysis and deployment in real use cases Jean-Marie Lehn (ISIS, University of Strasbourg, France) Towards adaptive functional materials and nanoarchitectures Jesus López-Sánchez (Universidad Complutense de Madrid, Spain) Sol-gel synthesis, micro-Raman studies and magnetic characterization of ε-Fe2O3 micro- and nanoparticles embedded in a SiO2 matrix Thomas Lorne (Institut Laue Langevin, France) Study of covalent grafting of Fluorescein Isothiocyanate on double-walled carbon nanotubes

Jeremy S. Luterbacher (EPFL, SB-ISIC-LPDC, Switzerland) Solution-processed nanostructured overcoats for renewable catalysis Patrick Maletinsky (University of Basel, Switzerland) Nanoscale magnetic imaging with single electronic spins Plinio Maroni (University of Geneva, Switzerland) Persistence Length of Cationic Dendronized Polymers From AFM Images Javier Martinez (Universidad Politécnica de Madrid, Spain) Graphene Solar Cells fabricated with an Automated Graphene Transfer System Nicola Marzari (NCCR MARVEL, EPFL, Switzerland) Computational Exfoliation of All Known Inorganic Materials

Wolfgang Meier (University of Basel, Switzerland) Functional polymer-lipid membranes

76 77

Oral Senior Plenary Session

Oral Senior Plenary Session

Keynote Plenary Session

78 79 80

Invited Women in Science Symposium

81

Oral Senior Graphene & 2D Materials Track B

Plenary Plenary Session

82 83

Oral PhD Parallel session

84

Oral PhD Parallel session

85

Invited Plenary Session

Invited Plenary Session

Oral Senior Plenary Session

Oral Senior Plenary Session

Keynote Plenary Session

86 87 88 89 90

Keynote

Claude Monney (University of Zürich, Switzerland) How fast can we melt ordered phase in low dimensional materials?

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Oral PhD Parallel session

Plenary Session

Mihai Mihaila (National Institute for R&D in Microtechnologies (IMT), Romania) Extended and local phonon mode identification in a silicon nanowire by 1/f noise spectroscopy Mohsen Moazzami Gudarzi (University of Geneva, Switzerland) Probing Nanometer-Ranged Attraction between Similar and Dissimilar Surfaces in Presence of Polyamine Cations

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Keynote Plenary Session

91

Oral Senior Parallel Session

92

Oral PhD Parallel session

94

Invited Plenary Session

95

TNT2016 fribourg (switzerland)

Lucas Montero de Espinosa (Adolphe Merkle Institute, University of Fribourg, Switzerland) Triggering large property changes in stimuli-responsive supramolecular polymers Thomas L. Moore (Adolphe Merkle Institute, University of Fribourg, Switzerland) Investigation into the Effects of Hydrodynamic Shear Stress on Nanoparticle-Cell Interactions Laura Moro (Biosensor Srl, Italy) Development of biomimetic D1 peptides as novel photosynthetic based-biosensors for environmental monitoring Alberto Morpurgo (University of Geneva, Switzerland) Exploring and engineering the electronic properties of 2D materials Arevik Musheghyan-Avetisyan (University of Barcelona, Spain) Low temperature PECVD growth of vertically oriented graphene nanowalls for supercapacitor applications Bálint Náfrádi (LPMC EPFL, Switzerland) Room temperature manipulation of long lifetime spins in metallic-like carbon nanospheres Miroslava Nedyalkova (Sofia University, Bulgaria) Molecular dynamics simulations of the spherical electrical double layer of a soft nanoparticle Sapun H. Parekh (Max Planck Institute for Polymer Research, Germany) Mechanically-induced protein structural changes in fibrin hydrogels using hyperspectral CARS microscopy Stuart S. P. Parkin (Max Planck Institute for Microstructure Physics, Germany) Spintronic and Ionitronic Computing Technologies Simone Peli (Università Cattolica del Sacro Cuore, Italy) Mechanical Properties of Ag Nanoparticle Thin Films Alain Penicaud (University of Bordeaux, France) Dissolving nanocarbons: how to prepare (single layer only) graphene in water Vladimir Popov (National University of Science and Technology "MISIS", Russia) Influence of phase transformations in metal matrix composites during mechanical alloying on intensification of nanodiamond reinforcing particles agglomerates destruction Milad Radiom (University of Geneva, Switzerland) Cis-to-Trans Isomerization of Carbon-Carbon Double Bond by Single Molecule Force Spectroscopy Sarah D. Rafiee (Adolphe Merkle Institute, University of Fribourg, Switzerland) Sensoresponsive nanomaterials to detect individual circulating tumor cells Dieter Richter (Jülich Centre for Neutron Science, Germany) A molecular view on supramolecular chain and association dynamics Grzegorz Rut (Jagiellonian University, Poland) Impact of trigonal warping on the pseudodiffusive transport in bilayer graphene Christian Schönenberger (University of Basel, Switzerland) PN Junction Based Devices in Ultra-Clean Graphene Dana Schonvogel (NEXT ENERGY EWE Research Centre for Energy Technology at the University of Oldenburg, Germany) Hybrids of Reduced Graphene Oxide and Metal Oxides as Catalyst Support in Fuel Cells Peter Schurtenberger (University of Lund, Sweden) Field-directed assembly of responsive colloids

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Oral Senior Parallel Session

96

Oral Senior Parallel Session

97

Oral Senior Parallel Session

Keynote Plenary Session

98 99

Oral PhD Parallel session

100

Oral Senior Parallel Session

101

Invited Women in Science Symposium

102

Oral Senior Parallel Session

Keynote Plenary Session

Oral Senior Plenary Session

Keynote Plenary Session

103 104 105 107

Oral Senior Parallel Session

108

Oral Senior Parallel Session

Oral PhD Parallel session

Keynote Plenary Session

110 112 113

Oral Senior Plenary Session

Keynote Plenary Session

114 115

Oral PhD Parallel session

117

Keynote Plenary Session

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119

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Speakers

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page Alessandro Sepe (Adolphe Merkle Institute, University of Fribourg, Switzerland) X-ray Nanotomography for Imaging Nanostructured Materials Juan Manuel Serrano Núñez (Sesderma Laboratories, Spain) Liposomes: Topical and Oral Bioavailability Aida Serrano (SpLine – ESRF, France & Inst. de Ciencia de Materiales de Madrid, Spain) Effect of X-ray irradiation on Co-Phthalocyanine thin films studied by Surface Plasmon Resonance Anushree Seth (Korea Basic Science Institute, South Korea) Nano/Micro-materials for immunomodulation: A promising approach for vaccine development and cancer immunotherapy Bruno F. B. Silva (International Iberian Nanotechnology Laboratory (INL), Portugal) Formation of normal and reversed nano-sized emulsions in a microfluidic device: insights into the formation mechanism from in-situ SAXS Pavel B. Sorokin (National University of Science and Technology "MISIS" , Russia) Two dimensional copper sheet. Experimental observation and theoretical investigation Henning Stahlberg (University of Basel, Switzerland) Nano-Scale Structural Characterization of Parkinson’s Disease Mariapaola Staropoli (Forschungszentrum Juelich, Germany) Supramolecular association in transiently branched polymer systems André R. Studardt (ETH Zürich, Switzerland) Additive Manufacturing of Biologically-Inspired Composites Ravi Sundaram (Oxford Instruments Plasma Technology, United Kingdom) CVD growth of 2 dimensional MoS2 and heterostructures with graphene Satoru Takakusagi (Hokkaido University, Japan) 3D structure determination of metals on a TiO2 single crystal surface: Effect of premodification with a mercapto compound on single metal dispersion Mei Chee Tan (Singapore University of Technology and Design, Singapore) Designing and Creating Low-Loss Infrared-Emitting Nanostructured Active Photonic Composites Irene Taurino (École Polytechnique Fédérale de Lausanne, Switzerland) Carbon and platinum nanostructured electrodes on miniaturized devices for biomedical diagnostics Javier Tejada Palacios (University of Barcelona, Spain) Experiments on triclinic Mn12 actetate mixed with a superconductor: enhanced tunneling, narrow zero field ressonance and Landau-Zener effect Philip Tinnefeld (TU Braunschweig, Germany) From Superresolution to Fluorescence Enhancement with DNA Origami Ricardo M. Trujillo (Lab. de Medios e Interfases (LAMEIN), DBI, FACET-UNT / INSIBIO-CONICET, Argentina) Multi-nanostructured auto-regenerative sensor for H2O2 quantification with enhanced sensitivity at zero potential Cristina Vicente Manzano (EMPA, Switzerland) The Influence of Thickness, Interpore Distance and Compositional Structure on the Optical Properties of Self-Ordered Anodic Aluminum Oxide Films Viola Vogel (ETH Zürich, Switzerland) The force-full fight of immune cells with bacteria

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Invited Plenary Session

Oral Senior Parallel Session

120 121

Oral Senior Plenary Session

123

Invited Women in Science Symposium

124

Oral Senior Plenary Session

125

Oral Senior Plenary Session

Keynote Plenary Session

Oral PhD Parallel session

Keynote Plenary Session

126 127 128 129

Oral Senior Graphene & 2D Materials Track B

130

Oral Senior Plenary Session

131

Oral Senior Plenary Session

132

Invited Women in Science Symposium

133

Invited Plenary Session

Keynote Plenary Session

134 135

Oral PhD Parallel session

136 Oral Senior Plenary Session

Keynote Plenary Session

138 139

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Mircea Vomir (IPCMS CNRS-Strasbourg University, France) Laser induced magnetization precession in cobalt ferrite nano-cubes Lukasz Walczak (PREVAC sp. z o.o. , Poland) The new generation of the hemispherical energy analyser in the novel surface science research Philipp Werner (University of Fribourg, Switzerland) Nonthermal symmetry-broken states and nonequilibrium criticality in correlated lattice models Bodo D. Wilts (Adolphe Merkle Institute, University of Fribourg, Switzerland) Extreme refractive index wing scale beads cause the bright colors in pierid butterflies Robert Wolkow (University of Alberta, Canada) Toward atom scale ultra low power electronic circuitry Tomaso Zambelli (ETH ZĂźrich, Switzerland) FluidFM for single-cell extraction followed by molecular analysis Arcady Zhukov (UPV/EHU and Ikerbasque, Spain) Effect of annealing on magnetic properties and domain wall dynamics of Fe-Ni based magnetic microwires Marketa Zukalova (J. Heyrovsky Institute of Physical Chemistry, Czech Republic) Li and Na insertion into TiO2 polymorphs and Li-Ti ternary oxides Andreas Zumbuehl (University of Fribourg, Switzerland) Faceted Vesicles from Interdigitating 1,3-Diamidophospholipids

Oral Senior

Michael Mayer (Adolphe Merkle Institute, University of Fribourg, Switzerland) Real-time shape approximation and 5-D fingerprinting of single proteins

Oral Senior

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Plenary Session

140

Oral Senior Plenary Session

142

Keynote Plenary Session

143

Oral Senior Plenary Session

Invited Plenary Session

Oral Senior Plenary Session

144 145 146

Oral Senior Plenary Session

Oral Senior Plenary Session

Oral Senior Plenary Session

Plenary Session

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147 148 149 150

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Speakers

TNT2016

page

Graphene-based Plasmonic Composite Nanostructures for Surface Enhanced Raman Scattering-based Biosensing

Ahmed Ali and Dong Woo Lim*

Department of BioNano Engineering and Department of Bionanotechnology Hanyang University, Ansan 426-791, South Korea

dlim@hanyang.ac.kr

Surface Enhanced Raman Scattering (SERS) has been of growing interest to engineer highly sensitive biosensors based on optical detection.

Especially, clustered metallic nanoparticles as SERS nanoprobes provide high sensitivity because of increased hot spot junctions. Although extensive research has been undertaken to develop highly sensitive SERS nanoprobes, there are some issues to be solved for the achievement of signal reproducibility and colloidal stability. In this study, we report a series of plasmonic composite nanostructures composed of two dimensional graphene-polymer hybrids and metallic nanoparticles for SERS-based biosensing applications. We hypothesized that different surface modifications of nanoscale graphene with various polymer architectures could be useful to have plasmonic organic-inorganic composite nanostructures as advanced SERS nanoprobes for biosensing. Nanoscale graphene (NG) with poly(ethylene glycol) conjugates induced metal nanoparticle (MNP) clustering and an effect of concentration of Raman reporter, graphene, graphene size on SERS intensity was studied with excellent control on clustered nanostructures.

Furthermore, graphene with stimuli-responsive polymer brushes controlled the loading density and clustering degree of MNPs on the graphene, resulting in stimuli-triggered enhancement of SERS signal. As a proof of concept that graphene-based plasmonic composite nanostructures would be usefulness as SERS nanoprobes, we showed the formation of sandwich-type immunocomplexes, which were composed of antibody-conjugated SERS nanoprobes and magnetic beads (MBs) as magnetic field-based separation agent in the presence of biological moieties. There was a linear correlation between Raman intensity and antigen concentration with minimal batch to batch

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variability.

In conclusion, graphene-based plasmonic composite nanostructures opens a new avenue as a new class of SERS nanoprobes for advanced biosensing and bioimaging applications.

References [1] Ghulam Jalani, et al. Analyst, 138 (2013) 47564759.

[2] Chan Woo Jung, et al. Macromolecular Rapid Communications, 35 (2014) 56-65.

[3] Hong Deok Jang, et al. Journal of Biomedical Nanotechnology, (2016) accepted.

Figures

Figure 1. Cartoon for the preparation of stimuliresponsive graphene-based plasmonic composite nanostructures composed of gold nanorods (GNRs) and thermoresponsive poly(N-isopropylacrylamide-co-acrylic acid), poly(NIPAAM-co-AAc) brushes grown on nanoscale graphene (NG) via surface initiated atom-transfer radical polymerization. When Raman reporters were introduced to the GNRs, temperature-triggered collapse of p(NIPAAM-co-AAc) chains above the lower critical solution temperature (LCST) generated SERS signal higher than that observed below LCST, potentially because of decrease in distance between GNRs located on p(NIPAAM-co-AAc) brushes of the graphene.

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Atomic Switch: From Invention to Practical Use and Future Prospects 1

WPI Center for Materials Nanoarchitectonics (MANA), National Institute for Materials Science (NIMS), Tsukuba, Japan 2 Green Platform Research Laboratories, NEC Corp., Japan 3 MANA Satellite Laboratory, Department of Chemistry and Biochemistry, UCLA, Los Angeles, USA

In the early 2000’s, some of the present authors and co-workers invented and developed the atomic switch, which is different from the conventional CMOS transistor switch in the operation principle. Compared to the CMOS transistor, the atomic switch is characterized by: a) non-volatility, b) a small size, c) simple structure, d) low power consumption and e) reasonably high switching speed. More importantly, the atomic switch is highly tolerant not only to electric noise but also radiation. It is our pleasure to report that after about ten years of research in collaboration with NEC Corp, we have achieved the practical use of the atomic switch, in the form of NEC AtomSW-FPGA, which are effectively used in humanoids and space satellites, for example.

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M. Aono1, K. Terabe1, T. Hasegawa1, T. Nakayama1, T. Sakamoto2, T. Tsuruoka1, T. Ohno1, A. Nayak1, T. Tsuchiya1, A. Stieg3, J. Gimzewski3 AONO.Masakazu@nims.go.jp

In the meantime, we have found that atomic switches with a certain type of structures exhibit interesting characteristics analogous to the synapse of the human brain. Namely, their ON/OFF switching is controlled by the magnitude and frequency of input signals. This characteristic can be used to create novel types of nanodevices with interesting and useful functionalities.

Based on our various experiences in the development of the atomic switch described above, we have developed various nanoionic devices using a solid electrolyte. They are all-solidstate electric-double-layer transistors and related devices to explore novel electronic states of material in a limited nanoscale region.

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Direct measurements of oxygen vacancy in TiO2 single crystal by muon spin rotation spectroscopy

Hiroko Ariga1, Koichiro Shimomura2, Amba Pant2, Eiko Torikai3, Kanetada Nagamine4, Satoru Takakusagi1, Kiyotaka Asakura1

1

Catalysis research center, Hokkaido University, Sapporo, Hokkaido, Japan.

KEK, Ibaraki, Japan 3 Interdisciplinary Graduate School of Medicine and Engineering, Yamanashi University, Yamanashi, Japan 4 Department of Physics and Astronomy, University of California, Riverside, CA, USA 2

Muon is a lighter isotope of hydrogen and muon spin rotation (μSR) can be a powerful probe to specify the behavior and local structure of hydrogen inside materials. Recently accelerator based strong pulse muon facilities have been developed and has opened the new feasibility for μSR measurements using strong spin polarized muons with various kinetic energies. Titanium dioxide (TiO2) is the most widely used material as high efficiency photocatalysis.[1] One of the crucial and unrevealed issues are properties of defects, e.g. oxygen vacancies. Recently hydrogen dissolved in TiO2 during preparation process [2,3] forms impurity states in the band gap to change electron excitation process and electron conductivity. We applied μSR measurement on the TiO2 single crystal in order to understand the behavior and electronic properties of both defects and impurities.

The experiments were mainly carried out in the muon beam line at the J-PARC muon facility (MUSE). All the experiments are conducted under The atmosphere. TiO2 single crystal was reduced by annealing in UHV. In this contribution we will discuss the muon interaction with defect site of TiO2 by zero-field, longitudinal and transverse external field μSR spectra. Figure 1 shows the time dependence of zero-external field μSR spectrum of unreduced and

ariga@cat.hokudai.ac.jp

reduced TiO2 at low temperature. The faster relaxation was found in the reduced TiO2. We fitted the spectra with assumption that the magnetic field statistically distributed with Gaussian distribution (Kubo-Toyabe relaxation function). The spectrum of the stoichiometric TiO2 is well fitted with the magnetic field of 0.22 mT, which is a typical value for nuclear spins. The relaxation of spectra for the reduced TiO2 is fitted with the magnetic field of 0.28 mT. Those magnetic fields are not able to be explained only by nuclear magnetic moment of TiO2, but are able to be explained with nuclear magnetic moment of Hydrogen, which H-μ distance was 1.1 nm. The origin of relaxation in reduced TiO2 is muon interaction with Hydrogen in oxygen vacancies (fig. 1(c)).

We have also conducted μSR measurement with applying longitudinal and transverse external field.

Those results show stable sites of muon (hydrogen) and electron distribution in the reduced TiO2.

References [1] A. Fujishima, K. Honda, Nature 238 (1972) 37.

[2] X. Chen, L. Liu, P.Y. Yu, S.S. Mao, Science 331 (2011) 746.

[3] K. Shimomura, R. Kadono, A. Koda, K. Nishiyama, and M. Mihara, Phys. Rev. B 92 (2015) 075203.

Figure 1. Zero field μSR spectrum of (a) stoichiometric and (b) reduced rutile TiO2 at 15 K with error bar. Blue lines are fitting curve. (c) Structure model of muon stabilized site.

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Negative photoconductivity of n-doped Si nanowire field-effect transistors

Eunhye Baek1, Taiuk Rim2, Larysa Baraban1 and Gianaurelio Cuniberti1,3

1

eunhye.baek@nano.tu-dresden.de

Institute for Materials Science and Max Bergmann Center of Biomaterials, TU Dresden, 01062 Dresden, Germany 2 Department of Creative IT Engineering, Pohang University of Science and Technology, 37673 Pohang, Republic of Korea 3 Center for Advancing Electronics Dresden, TU Dresden, 01062 Dresden, Germany

Negative photoconductance is a rare effect, since the photoexcitation of charge carriers in e.g. metal or semiconductor materials normally enhances the channel conductivity. However, the inverse photoconductance in 0- or 1-dimensional nanostructures have been shown recently, as a consequence of the surface effects, such as surface plasmonic change in Au nanoparticles [1], photon assisted oxygen desorption on the surface in p-type ZnSe nanowires [2] and light induced hot-electron trapping of oxide surface in n-type InAs nanowires [3]. In spite of the enormous research and industrial demands for photovoltaic and solar cell application, the similar phenomenon has not been reported yet in silicon low dimensional structures.

References [1] H. Nakanishi et al., Nature, 460 (2009) 371375.

[2] X. Zhang, J. Jie, Z. Wang, C. Wu, L. Wang, Q. Peng, Y. Yu, P. Jiang, C. Xie, J. Mater. Chem., 21 (2011) 6736–6741.

[3] Y. Yang et al., Nano Lett. 15 (2015) 5875-5882.

Figures

In this study, we have studied the negative photoconductivity (NPC) of Si nanowire field-effect transistors (FETs) (Fig. 1(a)) with different doping concentration. N-doped devices show NPC behavior unlike undoped devices which have normal positive photoconductivity (PPC) by photoexcitation of electrons in Si NWs (Fig. 1(b)). The NPC originates from the number of channel carriers trapped by dopants, which are tuned by gate bias. The distinguishing feature of NPC of doped Si NWs is that the impurity trap is dominant source apart from the interfacial trap, contrary to other nanostructures. In addition, we have investigated NPC change with various illumination intensity and wavelength of light.

Finally, the NPC and the PPC components are extracted respectively, which have exponential dependency with light power intensity. This study would be very promising for both tunable optoelectronics and sensor application by surface charge engineering with functional molecules.

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Figure 1. (a) I-Vds curves of Si nanowire devices with various illumination intensity, Inset: schematic diagram the device, (b) Photoresponsivity (∆Id/Id0) change of Si nanowires FETs with different doping concentration by increasing light power intensity.

TNT2016 fribourg (switzerland)

A theoretical analysis of the role of exciplexes in light emission in OLEDs: the structure and spectroscopic properties of α-NPD−BAlq exciplexes at an α-NPD/BAlq interface

Alexander A. Bagaturyants, Igor A. Anger, Elena A. Rykova

Photochemistry Center RAS, ul. Novatorov 7a, Moscow, 119421 Russia; National Research Nuclear University MEPhI, Kashirskoye shosse 31, Moscow, 115409, Russia

bagaturyants@gmail.com

Light emission in layered OLEDs is often attributed to exciplexes formed at the interface between two neighboring layers of organic materials [1, 2]. In this work, the structure and spectroscopic properties of exciplexes formed at an interface between a layer of hole-transporting N,N'-di(naphthalen-2-yl)-N,N'diphenyl-benzidine (α-NPD) and a layer of electron transporting bis(2-methyl-8-quinolinato)(4phenylphenolato)aluminum (BAlq) have been investigated theoretically by multiscale (molecular dynamics, MD, and quantum chemistry, QC) simulations. Such an interface is typical for organic light-emitting devices. The GROMACS and ORCA packages have been used for MD and QC calculations, respectively. The two adjacent disordered layers have been constructed by simulating sequential gas-phase deposition of αNPD and BAlq onto a solid 3Å-thick tetragonal substrate formed by two layers of sp3-hybridized carbon atoms (as at a graphene surface). The thickness of both the α-NPD and BAlq layers is 10 nm; these layers contain 230 α-NPD and 250 BAlq molecules, respectively. Then, a central 5-nm slab has been cut from the constructed 20-nm bilayer at the interface (Fig. 1). Four α-NPD−BAlq pairs have been selected in this slab for the subsequent QC investigation. The geometrical parameters of these pairs (molecular complexes) have been fully optimized at the DFT PBE0/SV(P) level. The binding energies (BE) have been calculated as differences between the total energy of the geometrically optimized complex and the total energies of isolated molecules. The calculated BE are in the range from –17.4 to –21.5 kcal/mol. The energies of the first ten excited states in the studied complexes have been calculated using time-dependent density functional theory (TDDFT) with different exchange-

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correlation functionals taking into account different amounts of Hartree–Fock exchange (PBE0 and BHHLYP). The geometries of complexes in the first excited state have been calculated using the TDDFT/BHHLYP approximation with inclusion of the D3BJ dispersion corrections. The binding energies in the exciplexes have been were calculated as differences between the total energies of the complexes optimized in the first excited state (CT state) and the total energies of α-NPD in the ground state and BAlq in the first excited state. The calculated binding energies of the exciplexes are in the range from 21.9 to 34.1 kcal/mol.

References [1] Zhu Wen-qing, Jiang Xue-yin, Zhang Zhi-lin, J. Shanghai University (English Edition), 10 no. 2 (2006) 156–160.

[2] M. Carvelli, A. van Reenen, R.A.J. Janssen, H.P. Loebl, R. Coehoorn, Organic Electronics 13 (2012) 2605–2614.

Figures

Figure 1. Central layer with the interface.

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Ultra-high transversal relaxivity and hyperthermia-induced drug delivery in superparamagnetic solid lipid nanoparticles

Carolina L. Moura1,2, Juan Gallo2, Nágila M. P. S. Ricardo1 and Manuel Bañobre-López2

1

manuel.banobre@inl.int

Department of Organic and Inorganic Chemistry, Federal University of Ceará, CX 12200 Fortaleza, Brazil.

2 Advanced (magnetic) theranostic nanostructures Group, International Iberian Nanotechnology Laboratory, INL, Braga, Portugal.

Magnetic hybrid self-assemblies have been found to open new perspectives for biomedical and environmental applications [1]. In particular, solid lipid nanoparticles (SLNs) have received great interest as suitable bioactive encapsulating agents and carriers due to their biocompatibility, low toxicity and ability to influence the bioactive delivery profile [2,3].

Recently, hybrid organicinorganic solid lipid nanocomposites have been explored as a synergistic approach that combines the modified bioactive release induced by the lipidic encapsulation and the intrinsic physicochemical properties from the inorganic counterpart [4]. In this context, magnetic solid lipid nanocomposites (MSLNs) dual loaded with a bioactive compound and superparamagnetic iron oxide nanoparticles (SPIONs) were obtained showing good multifunctional performance as improved T2-contrast agents and heat generating sources in magnetic resonance imaging (MRI) and magnetic hyperthermia (MH), respectively.

A method based on oil-in-water emulsions was employed to prepare SLNs from carnauba wax containing different concentration of ~10 nm superparamagnetic oleic acid coated magnetite (Fe3O4@OA) nanoparticles.

Successful incorporation of the magnetic nanoparticles was confirmed by transmission electron microscopy (TEM), and the results showed that they accumulate preferentially inside the organic lipidic core. Dynamic light scattering (DLS) and ζ- potential measurements showed a relatively narrow size distribution of spherical-shaped magnetic nanocomposites with an average particle size of ~180 nm and a surface charge around -60 mV. In terms of magnetic characterization, hysteresis loops showed MSLNs to behave as

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superparamagnetic particles. Interestingly, MSLNs showed an anomalous ultra-high transversal relaxivity (r 2 ) with values higher than 900 mM(Fe) -1 s -1 , what clearly translated into dark contrast effects when sample phantoms were imaged at 3 T. On the other hand, an anticancer drug was encapsulated and its delivery profile assessed without and with the application of an oscillating magnetic field (MH). MH resulted to be efficient to externally induce a drug release increase. In vitro results will be also shown and discussed.

Acknowledgment: Edital CAPES/INL.

References [1] C. Sanson , O. Diou, J. Thévenot, E. Ibarboure, A. Soum, A. Brûlet, S. Miraux, E. Thiaudière, S. Tan, A. Brisson, V. Dupuis, O. Sandre and S. Lecommandoux. ACS Nano, 5 (2011), 1122.

[2] W. Mehnert and K. Mader., Adv. Drug Delivery Rev. 47 (2001), 165.

[3] E. Andreozzi, P. Wang, A. Valenzuela, C. Tu, F. Gorin, M. Dhenain and A. Louie, Bioconjugate Chem., 24 (2013), 1455.

[4] K. Oumzil, M. A. Ramin, C. Lorenzato, A. Hemadou, J. Laroche, M. J. Jacobin-Valat, S. Mornet, C.-E. Roy, T. Kauss, K. Gaudin, G. Clofent-Sanchez and P. Barthelemy, Bioconjugate Chem., 27 (2016), 569.

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Figures

Figure 1. (left) TEM image of MSLNs; (middle) T2-weighted MRI image of MSLNs; (right) Drug delivery profiles without and with applying MH.

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Application of noble metal nanoparticles for kinetic studies, detection and quantification of uranium phases

Julio Bastos-Arrieta1*, Alexandra Espriu1, Jose Muñoz2, Jordi Garcia-Orellana3, Mireia Baeza4, Cristina Palet5, Javier Giménez1, Ignasi Casas1 and Joan de Pablo1,6

1

julio.bastos@upc.edu

Dep. d’Enginyeria Química, Universitat Politècnica de Catalunya (UPC), Barcelona, Spain Institut de Ciència de Materials de Barcelona, 09193, Bellaterra, Spain 3 Departament de Física, Universitat Autònoma de Barcelona, 08193 Bellaterra, Spain 4 Dep. de Química, Universitat Autònoma de Barcelona, 08193 Bellaterra, Spain 5 Centre Grup de Tècniques de Separació(GTS) Universitat Autònoma de Barcelona, 08193 Bellaterra, Spain 6 Fundació CTM Centre Tecnològic, Plaça de la Ciència 2. 08240 Manresa, Spain 2

To assess the deep geological disposal that would store the Spent Nuclear Fuel (SNF), several studies have been centered in the SNF itself. It contains all the fission products and radioactive decay, such as I, Cs, Cm, Mo as well as epsilon particles. Moreover, the UO2 matrix is highly sensible to the redox conditions in its near field and it could be oxidized to the soluble state UO22+ Therefore, it is mandatory to design new detection methodologies and to evaluate the possible reactions (such as dissolution kinetics) in which SNF could be involved under such conditions. Nevertheless, ε-particles could avoid this oxidation and, therefore, protect the SNF. [1] Nowadays, it is mandatory to overcome with new efficient and low cost methodologies for the preparation of novel materials. Taking that into account, the incorporation of Nanomaterials such as noble metal nanoparticles (NPs) into bulk components has become a priority. NPs represent an alternative to conventional materials and have repercussion in fields like electronics, biochemical sensors, catalysis and energy. [2-5] In this communication we present the application of different metal noble NPs for different studies related with uranium phases. For example, the effect of Pd-NPs (analogue to ε-particles) on dissolution kinetics of UO2 under reducing conditions. In addition, the application of Ag-NPs for RAMAN-SERS detection of uranium phases (UO2 and UO3) is presented. As future perspectives, we present the preliminary results of an electrochemical sensor based on carbon nanotubes

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modified with Au-NPs [6], for the quantification of uranyl ion (UO22+) in water.

References [1] A. Martínez-Torrents, S. Meca, N. Baumann, V. Martí, J. Giménez, J. De Pablo, and I. Casas, “Uranium speciation studies at alkaline pH and in the presence of hydrogen peroxide using timeresolved laser-induced fluorescence spectroscopy,” Polyhedron, vol. 55, pp. 92– 101, 2013.

[2] M. a. Van Hove, “From surface science to nanotechnology,” Catal. Today, vol. 113, no. 3– 4, pp. 133–140, Apr. 2006.

[3] E. Serrano, G. Rus, and J. García-Martínez, “Nanotechnology for sustainable energy,” Renew. Sustain. Energy Rev., vol. 13, no. 9, pp.

2373–2384, Dec. 2009.

[4] F. Sanchez and K. Sobolev, “Nanotechnology in concrete – A review,” Constr. Build. Mater., vol. 24, no. 11, pp. 2060–2071, Nov. 2010.

[5] P. Misra, Metallic nanoparticles, First Edit.

Amsterdam, The Netherlands: Elsevier, 2009.

[6] J. Muñoz, J. Bastos-Arrieta, M. Muñoz, D. N. D. D. N. D. Muraviev, F. Céspedes, M. Baeza, M. Munoz, D. N. D. D. N. D. Muraviev, F. Céspedes, M. Baeza, M. Muñoz, D. N. D. D. N. D. Muraviev, F. Céspedes, M. Baeza, and M. Munoz, “Simple green routes for the customized preparation of sensitive carbon nanotubes/epoxy nanocomposite electrodes with Functional Metal Nanoparticles,” RSC Adv., vol. 4, no. 84, pp. 44517–44524, Aug. 2014.

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Hydrophobic hydration: a matter of the mean energetics of water

Irmgard Bischofberger1, Davide Calzolari2 and Veronique Trappe2

1

Department of Mechanical Engineering, MIT, Cambridge MA, United States Department of Physics, University of Fribourg, Fribourg, Switzerland

2

The enthalpically favored hydration of hydrophobic entities, termed hydrophobic hydration, impacts the phase behavior of numerous amphiphiles in water. We show experimental evidence that hydrophobic hydration is determined by the mean energetics of the aqueous medium. We investigate the collapse and aggregation of an amphiphilic polymer, poly-N-isopropyl acrylamide (PNiPAM), in aqueous solutions containing small amounts of alcohol and find that the thermodynamic characteristics defining the phase transitions of PNiPAM evolve relative to the solvent composition at which the excess mixing enthalpy of the water/alcohol mixtures becomes minimal.

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Such correlation between solvent energetics and solution thermodynamics extends to other mixtures containing neutral organic solutes that are considered as kosmotropes to induce a strengthening of the hydrogen bonded water network. This denotes the energetics of water as a key parameter controlling the phase behavior of PNiPAM and identifies the excess mixing enthalpy of water/kosmotrope mixtures as a gauge of the kosmotropic effect on hydrophobic assemblies.

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Nanobioptics: Engineering Optical Biosensors Based on Single-walled Carbon Nanotube (SWCNT) Fluorescence

Ardemis A. Boghossian

École Polytechnique FÊdÊrale de Lausanne (EPFL), Switzerland

The last decade has realized an onset of novel optical, SWCNT-based sensors that have been crucial in shaping a distinct generation of unconventional analytical tools. These optical nanosensors exploit the advantageous fluorescence properties of semiconducting SWCNTs, which benefit from stable and sensitive near-infrared emissions capable of deep-tissue sensing and imaging applications. SWCNTs are non-covalently wrapped in a variety of chemical moeities, including DNA, polymers, and proteins, that impart the SWCNT with selectivity towards specific analytes of interest.

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Recent research endeavors have largely focused on designing wrappings that control the sensor's selectivity by modulating the surface coverage of the nanotube in the presence of an analyte. In addition to selectivity, these wrappings also modulate fluorescence properties such as emission intensity; properties that play an integral role in determining the sensitivity limits of these sensors.

We have developed a model that explores the perturbations of SWCNT fluorescence emissions in the presence of a wrapping. By de-coupling the structural and chemical contributions of the polymer wrapping and challenging underlying assumptions of uni-dimensional contributions, this model enables a comparative approach towards achieving design rules for the rational engineering of sensor wrappings.

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Anomalous Non-Faradaic Capacitance in Vanadium Nitride Thin Films

A. Bondarchuk, E. Goikolea, Y. Zhang, T. Rojo and R. Mysyk

CIC energiGUNE, Miñano, Alava, Spain

abondarchuk@cicenergigune.com

Pseudocapacitive or electrochemically active materials can achieve capacitance values up to 10100 times higher than those obtained by materials working only using an electric double layer (EDL) mechanism. The pseudocapacitive behaviour of several transition metal oxides has been extensively studied in the last decades and assigned to redox (Raradaic) reactions occurring at the surface of the material. Very recently, transition metal nitrides such as MoxN, VN or TiN have emerged as promising electrode materials for electrochemical capacitors. These materials are relatively inexpensive and feature a high molar density, good chemical resistance, and, most importantly, in contrast to oxides, they exhibit a very high electronic conductivity value. An impressive gravimetric capacitance of 1300 F g-1 (surface capacitance ~3.3 mF cm-2) reported by Choi et al, 2006 [1] for nanosized vanadium nitride has stimulated considerable interest in vanadium nitride as a potential electrode material for energy storing systems – supercapacitors. The postulated mechanism of charge storage in vanadium nitride materials involves redox reactions in the thin surface layer of vanadium oxide while the core vanadium nitride serves exclusively as a conducting platform. In this study we have synthesized pure oxygen-free vanadium nitride films and have found that they are capable of delivering a surface capacitance of up to ~3 mF cm-2 at a potential scan rate of 3 mV s-1 and ~2 mF cm-2 at a potential scan rate of 1 V s-1 in aqueous electrolytes. Combining electrochemical testing with X-ray photoelectron spectroscopy characterization has revealed that redox reactions play no or little role in the electrochemical response of pure VN, in contrast to the common wisdom stemming from the electrochemical response of oxygen-containing films. An alternative charge storage mechanism (shown in the Figure 1) – space charge accumulation in a subsurface layer of ~100 nm –

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was put forward to explain the experimentally observed capacitance of VN films in aqueous electrolytes.

References [1] D. Choi et al., Adv. Mater., 18 (2006) 1178.

Figures

Figure 1. Charge storage at the electrolytesemiconductor interface. The charge accumulates in a subsurface layer of characteristic thickness∼30 nm. Total -1 -1 -1 measured capacitance at saturation Ctot = Csc + Cel , 2 here Ctot is ∼2-3 mF/cm .

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Hedgehog (Hh) pathway inhibitor loaded polymeric nanoparticles for anti-cancer therapy

A. Borah, V. Palaninathan, A. Ravindran, A. Rochani, S. Raveendran, T. Maekawa and D.S. Kumar

Bio Nano Electronics Research Center, Graduate School of Interdisciplinary New Science, Toyo University, Kujirai, 2100, Kawagoe, Saitama 350-8585, Japan

sakthi@toyo.jp

Targeting the self-renewal pathways (SRPs) in cancer has become one of the futuristic treatment strategies in order to prevent cancer relapse and drug resistance. The cause of cancer recurrence and multi drug resistance (MDR) is attributed to the presence of a sub-population of cells in solid tumors called as the cancer stem cells (CSCs). These CSCs are known to possess MDR pumps, SRPs, specialized niche and altered metabolism, ultimately leading to the failure of available treatments in order to eradicate them. One of the embryonic SRPs Hedgehog (Hh) pathway is found to be aberrantly active in most of the cancers such as basal cell carcinoma, brain tumors, pancreas, prostate, leukemia’s to name a few. Mutations in Hh pathway components and high expression of its ligands lead to progression in many cancers [1].

Most of the Hh pathway inhibitors available are used directly, however their successful clinical translation is hindered due to their limited aqueous solubility and poor bioavailability [2]. Hence, there arises the need for an appropriate nanoformulation of such compounds. In our work we propose to target the Hh pathway in cancer through nanomedicine approach. We have selected a novel Hh small molecule antagonist, specifically inhibiting the Gli 1/2 protein of the Hh pathway, which promises to be an aspiring candidate for future cancer therapy [3].

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We encapsulated the Hh antagonist in a FDA approved polymer and it was synthesized through the single emulsion-solvent evaporation method [4]. Our prepared nanoparticles were further characterized for their size distribution, surface morphology and surface chemistry using Zetasizer, SEM, TEM and XPS respectively. In vitro cell studies were carried out to assess the cytotoxicity of the prepared nanoparticles and the anticancer activity.

References [1] A. Borah, S. Raveendran, A. Rochani et al., Oncogenesis., (2015) 4:e177.

[2] D.D. Von Hoff, P.M. LoRusso, C.M. Rudin et al., N Engl J Med., (2009) 361:1164-1172.

[3] M. Lauth, A. Bergstrom, T. Shimokawa et al., Proc Natl Acad Sci USA., (2009) 104:84558460.

[4] A. Mathew, T. Fukuda, Y. Nagaoka et al., PLoS One., (2012) 7(3):e32616.

TNT2016 fribourg (switzerland)

Angle-resolved Photoelectron Spectroscopy of Graphene OxideBased Aerosols by VUV Synchrotron Radiation

Dušan K. Božanić, Gustavo A. Garcia and Laurent Nahon

Synchrotron SOLEIL, L’Orme des Merisiers, St. Aubin BP 48, 91192 Gif sur Yvette, France

dusan.bozanic@synchrotron-soleil.fr

DESIRS beamline of the SOLEIL synchrotron facility is dedicated to gas phase high resolution spectroscopy, as well as polarization-dependent photodynamics studies, in the 5 – 40 eV energy range. More specifically, the SAPHIRS endstation of DESIRS is equipped with the DELICIOUSIII electron/ion coincidence spectrometer [1], composed of a velocity map imaging and a 3D momentum imaging spectrometer on the electron and the ion side, respectively. This experimental set-up, coupled with a VUV tunable photon energy synchrotron source, allows for advanced photoelectron spectroscopy studies of gaseous, liquid and solid samples, including nanoparticles suspended in a carrier gas and brought into the interaction region via a dedicated aerodynamic lens [2].

TNT2016 fribourg (switzerland)

In this contribution we will present the results of the angle-resolved photoelectron spectroscopy of aerosol particles produced from polar dispersions of graphene oxide and reduced graphene oxide. In addition, the influence of the presence of the graphene derivatives on the photoemission of biomolecular aerosols will be demonstrated.

References [1] G.A. Garcia, B.K. Cunha de Miranda, M. Tia, S. Daly, L. Nahon, Rev. Sci. Instrum. 84 (2013) 053112.

[2] F. Gaie-Levrel, G. Garcia, M. Schwell, and L. Nahon, Phys. Chem. Chem. Phys. 13 (2011) 7024.

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Cadherin adhesion in assemblies of lipid droplets

Jasna Brujic

University of New York, USA

The regulation of cell-cell adhesion is important in cell motility, tissue growth, and for the mechanical integrity of tissues. Although the role of active cytoskeleton dynamics in regulating cadherin interactions is crucial in vivo, here we present a biomimetic emulsion system to characterize the passive E-cadherin-mediated adhesion between droplets. The visualization of a three-dimensional assembly of lipid droplets, functionalized with extracellular E-cadherin domains, reveals a hierarchy of homophilic interactions. First, the high interfacial tension of droplets facilitates trans cadherin-cadherin adhesion, which is strong enough to stabilize looser than random close packing configurations.

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Second, fluorescence enhancement shows that adding clustering agents, such as calcium or chelating ligands, favor the lateral cis adhesion of the already bound cadherin pairs over the clustering of monomer cadherin on the surface.

Finally, using an E-cadherin mutant that prevents the lateral interactions weakens trans-binding and eliminates clustering of thermal droplets. These results suggest that passive clustering, via calciuminduced dimerization or membrane ordering, contribute to the reinforcement of cell-cell contacts.

TNT2016 fribourg (switzerland)

Combining the capsule-like protein thermosome with synthetic polymers to obtain nanoreactors and siRNA delivery agents

Nico Bruns, Martin Rother, Martin G. Nussbaumer, Kasper Renggli

Adolphe Merkle Institute, University of Fribourg, Chemin des Verdiers 4, 1700 Fribourg, Switzerland

nico.bruns@unifr.ch

Protein cages, such as viral capsids, ferritins and chaperonins have become essential tools in bionanotechnology because of their well-defined, monodisperse, capsule-like structure. Combining them with synthetic polymers greatly expands the possibilities for their application.

These examples demonstrate that a wisely chosen combination of functional protein nanocapsules and polymers can lead to novel hybrid proteinpolymer nanoparticles with advanced properties.

The chaperonin thermosome (THS) is a hollow protein nanoparticle approx. 16 nm in diameter that can encapsulate macromolecular guests. Its unique features are two large pores (~7 nm) that allow diffusion of macromolecules into and out of the protein cage. Taking advantage of this intriguing nanostructure, the THS was developed into a nanoreactor for polymerization reactions that allows to confine atom transfer radical polymerization (ATRP) into the cavity of the protein. The polymers that were synthesized within the THS had a smaller molecular weight and a smaller molecular weight distribution than polymers synthesized in solution. Moreover, cationic polymers such as poly(amidoamine) (PAMAM) were conjugated into the THS, which converted the THS into a nanoreactor for the synthesis of gold nanoparticles. THS-polymer conjugates also proved to be promising delivery agents for small interfering RNA (siRNA). The polymer acted as an anchor for the oligonucleotide, allowing to load the THS with therapeutic payload.

THS-polymer conjugates efficiently delivered siRNA into cells, while being less toxic than conventional transfection agents.

[1] N. Bruns, K. Pustelny, L. M. Bergeron, T. A. Whitehead, D. S. Clark, Angew. Chem., Int. Ed., 48 (2009) 5666.

[2] K. Renggli, M. G. Nussbaumer, R. Urbani, T. Pfohl, N. Bruns, Angew. Chem., Int. Ed., 53 (2014) 1443.

[3] M. G. Nussbaumer, J. T. Duskey, M. Rother, K. Renggli, M. Chami, N. Bruns, Adv. Sci. 2016, DOI: 10.1002/advs.201600046, in press.

[4] M. Rother, M. G. Nussbaumer, K. Renggli, N. Bruns, invited review submitted to Chem. Soc. Rev. (2016).

TNT2016 fribourg (switzerland)

References

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Highly stretchable electronic devices using non-standard geometries 1

Electronics Laboratory, ETH, Gloriastrasse 35, Zurich, Switzerland Sensor Technology Research Center, University of Sussex, Richmond 3A7, Brighton, United Kingdom

Giuseppe Cantarella1, Alberto Ferrero1, Luisa Petti1, Christian Vogt1, Niko Münzenrieder2, Giovanni A. Salvatore1, Alwin Daus1, Stefan Knobelspies1, Lars Büthe1 and Gerhard Tröster1

2

In recent years, the demand for electronics with new functionality, such as low weight, flexibility and biocompatibility is constantly growing. Smart textiles [1], bio-integrated systems [2] and electronics-onskin are few of the countless applications that flexible electronics is enabling.

To date, a broad variety of technologies (e.g. organic materials, oxide semiconductors [3]...) and geometries (e.g. "wavy" layouts [4]) have been employed to realize electronic devices resistant to bending radii of a few tens of micrometers. The long way towards the fabrication of devices which can successfully sustain bending, but also stretching, passes from a deep analysis of the flexible substrate utilized, combined with the use of non-standard geometries, which minimize the strain experienced by the device.

Here, the realization of flexible electronic devices on a pillar-based elastomeric substrate is presented. After Finite Element Analysis (FEA) of the material properties and geometrical features (pillar height/width and pilllar-to-pillar distance) of the substrate (see Fig.1a), different materials have been evaluated to show which one better resist to mechanical strain. Based on an optimized geometry and device stack, a broad set of devices has been

giuseppe.cantarella@ife.ee.ethz.ch

electrically characterized while isotropic stretching (x- and y-direction) is applied (see Fig.1b).

Thanks to the biocompatibility of the substrate material and the high mechanical strain which can be experienced by the device, this new approach can pave the way for a new class of smart electronics for on-skin applications as well as for functional medical implants.

References [1] K. Cherenack et al., “Wearable electronics: woven electronic fibers with sensing and display functions for smart textiles,” Adv. Mat., vol. 22, no. 45, pp. 5071–5071 (2010).

[2] D.-H. Kim et al., “Dissolvable films of silk fibroin for ultrathin conformal bio-integrated electronics,” Nat. mat., vol. 9, no. 6, pp. 511– 517 (2010).

[3] N. Münzenrieder et al., “Stretchable and conformable oxide thin-film electronics,” Adv. El. Mat., 3, (2015).

[4] G. Cantarella et al., “Flexible In–Ga–Zn–O ThinFilm Transistors on Elastomeric Substrate Bent to 2.3% Strain", IEEE Electr. Dev. Lett., vol.36, no.8 (2015).

Figures Figure 1. (A) Finite Element Analysis (FEA) of the pillar-based geometry using Polydimethilsiloxane (PDMS) as flexible substrate showing areas of high and low strain in the stretched substrate; (B) photograph of resistors (Titanium/Gold) deposited on pillars.

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TNT2016 fribourg (switzerland)

Effect of Graphene Nano-platelet Morphology on the Elastic Modulus of Soft and Hard Biopolymers: A Comparative Study 1

Smart Materials, Istituto Italiano di Tecnologia, Via Morego 30, 16163 Genova, Italy Graphene Laboratories, Istituto Italiano di Tecnologia, Via Morego 30, Genova, Italy

2

Two bio-polyesters having diverse elastic (Young’s) moduli (soft and hard) were reinforced (0.1-5 wt.%) with various types of expanded graphite nanoplatelets (GnP flakes) [1]. Free standing biocomposites were fabricated by solvent casting and hot-pressing.

Detailed mechanical measurements were conducted in order to investigate the effect of GnP thickness and lateral size on the elastic modulus of both polymers. For comparison purposes other 2D and 3D nanoscale fillers were also used such as organoclay, MoS2, carbon black, Iron dioxide and silica nanoparticles (see Figure). Under solvent casting conditions, GnPs did not perform better compared to other model fillers in increasing the elastic modulus of the soft bio-polyester. On the other hand, GnPs increased the elastic moduli of the hard bio-polyester biocomposites more than other fillers. Due to hotpressing induced alignment of the 2D flakes with the polymer matrices, large (~ 1µm) many layer GnPs (≥8) induced better elastic moduli enhancement performance compared to other GnPs and 2D and 3D fillers at 3 wt.% concertation levels. Large many layer GnPs also suppressed elastic modulus decline of the soft bio-polyester due to heating near its melting point.

Pietro Cataldi1, Ilker S. Bayer1, Athanassia Athanassiou1, Gabriele Nanni1, Francesco Bonaccorso2, Vittorio Pellegrini2, Antonio Esau del Rio Castillo2 and Roberto Cingolani1,2 pietro.cataldi@iit.it

Figures

Figure 1. Photo of different films obtained with Hard and Soft biopolymer matrixes. At the top of the figure the two pure matrix are showed. Underneath some nanocomposites obtained with iron oxide (FeOx) and GnPs are displayed.

References [1] Jang et al., Journal of Material Science, 43 (2008) 5092.

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Structure and dynamics of epithelial cell monolayers

F. Giavazzi1, C. Malinverno2, S. Corallino2, G. Scita2 and R. Cerbino1

1

roberto.cerbino@unimi.it

Dipartimento di Biotecnologie Mediche e Medicina Traslazionale, Università degli Studi di Milano, Via F.lli Cervi 93, 20090 Segrate, Italy 2 IFOM Foundation, Institute FIRC of Molecular Oncology, via Adamello 16, Milano, Italy

The description and the understanding of the collective behaviour of large assemblies of cells represent a great challenge from a physicist’s point of view. In fact, the active nature of the constituents as well as the complexity and diversity of the involved interactions, complicate the use of familiar tools and concepts borrowed from equilibrium statistical mechanics. Nevertheless, in recent years some intriguing analogies have been drawn between the coarse-grained structure and dynamics of multicellular assemblies and relatively simple condensed matter systems, such as for instance a supercooled fluid approaching the glass transition [1]. In this work, we experimentally investigate the connection between spatial organization and collective motility patterns emerging in epithelial cell monolayers. Differential Dynamic Microscopy [2] analysis of time-lapse movies obtained during a timeframe comprising 48 hours reveals that the overall dynamics of the cells exhibits a transition from ballistic-like, persistent motion at short stage to a diffusive-like, disordered behaviour at the late stages of the investigated period. We find that these overall dynamics are altered by structural interactions that we determine quantitatively by calculating the structure factor S(q) of the cell monolayer, where q is the wave-vector of the density fluctuations in Fourier space. The structure factor, which for large q (length scales smaller than the average cell size) is reminiscent of that of a hard-disk system, exhibits for smaller q a growth that is indicative of ‘giant’ density fluctuations with amplitude much larger than expected from equilibrium statistical mechanics. This remarkable connection between the structural properties of the monolayer and its dynamics, in which density fluctuations with a wave vector q corresponding to a maximum in the structure factor decay slowly, is the analogue for active, non-equilibrium materials of the so-called

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De Gennes narrowing [3] observed in inert liquids and soft materials at equilibrium. This analogy is however very surprising in view of the fact that in equilibrium this slowing down for density fluctuations at the structural peak is attributed to the low free energy cost of such fluctuations, an argument that cannot be straightforwardly extended to non-equilibrium cases.

References [1] T.E. Angelini, E. Hannezo, X. Trepat, M. Marquez, J.J. Fredberg, D.A. Weitz, PNAS, 108, (2011) 4717.

[2] R. Cerbino, V. Trappe Phys. Rev. Lett. 100, (2008) 188102; F. Giavazzi, R. Cerbino J. Opt. 16, (2014) 083001.

[3] P. G. de Gennes, Physica A 25, (1959) 825.

Figures

Figure 1. Composite figure containing an image of a cell monolayer at large density, a Voronoi tessellation of one portion of it, and the structure factor S(q) of the monolayer.

TNT2016 fribourg (switzerland)

Ultraporous interweaving nanofibers for tissue engineering

Menglin Chen

Interdisciplinary Nanoscience Center, Aarhus University, Gustav Wieds Vej 14, Aarhus DK-8000, Denmark

Menglin@inano.au.dk

In the field of tissue engineering, integration of micro-porosity, nano-topogaphical features and weattability into one three-dimensional (3D) scaffold remains a challenge. Here we report that a nanoscale immiscible polymer blend solution electrojet can assemble into ultraporous interweaving microfibers. The hierarchical porosity influenced cell infiltration, proliferation and differentiation significantly.

Multi-lamellar cylindrical structure was originated from a blend of PCL and PEO in DCM/DMF mixed solution when the ratio between each component reached a threshold and where the electrospinning parameters were delicate controlled. The morphology, crystallinity, surface chemistry and wettabilities were characterized to understand the mechanism of formation. The interplay of the two semi-crystalline polymers and the pair of solvents/non-solvents with the electrospinning processing parameters was found to be critical for the formation of the unique structure. [1]

References [1] Li Y; Rubert, M; Yu Y; Dong, M; Besenbacher, F; Chen, M*. Nanoscale, 2014, 6, 3392-402, highlighted in Global Medical Discovery June 23, 2014, https://globalmedicaldiscovery.com/keynanotechnology-articles/ultraporous-interweavingelectrospun-microfibers-from-pcl-peo-binary-blendsand-their-inflammatory-responses/ [2] Li, Y; Gregersen, H; Nygaard, J; Cheng, W; Huang, Y; Dong, M; Besenbacher, F; Chen, M*.

Nanoscale, 2015, 7, 14989 – 14995.

Figures

The hydrophilic, hierarchically porous fibers were appilied in culturing fibroblasts and studied the cell infiltration and colonization. Compared to the tightpacked, hydrophobic PCL scaffold, the hydrophilic, micro-porous fibers enhanced the cell infiltration and colonziation significantly. Moreover, the unique nano-topographical environment that may stimulate cells in a drastically different manner from that of traditional solid, smooth electrospun fibers, which holds great potential in reconstructing tissues that require strong contractile forces. (Fig) [2].

Acknowledgements This work was supported by the Danish Council for Strategic Research, Aarhus University Research Foundation and Carlsberg foundation.

TNT2016 fribourg (switzerland)

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| 39

Superresolution Microscopy of thermosensitive Poly(N-isopropylacrylamide) microgel particles

Gaurasundar Marc Conley1, Sofi Nöjd2, Marco Braibanti1, Peter Schurtenberger2 and Frank Scheffold1

1

Department of Physics, University of Fribourg, CH-1700 Fribourg, Switzerland Physical Chemistry, Department of Chemistry, Lund University, 221 00 Lund, Sweden

2

Hierarchical polymer structures such as pNIPAM microgels have been extensively studied for their ability to undergo significant structural and physical transformations that can be controlled by external stimuli such as temperature, pH or solvent composition. Despite this plethora of published work many fundamental questions remain unresolved. The mechanism that leads to the volume phase transition of PNiPAM microgels for example is not well understood and it’s consequences towards the microgel architecture on nanoscopic length scales are unclear. It is still a puzzle, for example, that even in the collapsed state microgel particles contain a substantial amount of water. Moreover, the transition between swollen and collapsed microgels is less abrupt than expected for a phase transition and shows hysteresis. However, it is unclear to what extent these observations can be associated to individual particle properties or whether polydispersity in the ensemble of microgel particles is responsible. Scattering techniques are not well apt to answer any of these questions since they only provide access to ensemble averaged structural information in reciprocal space. Single particle observations in situ have so far been hindered by insufficient resolution, with optical microscopy, or contrast, with cryo-TEM. However, in recent years super resolution microscopy techniques have emerged that in principle can provide nanoscopic optical resolution.

highly compressed, a feature not directly visible using other techniques.

References [1] G. Conley, S. Nöjd, M. Braibanti, P. Schurtenberger, and F. Scheffold, Colloids and Surfaces A 499, 18-23 (2016).

Figures

Figure 1. 3D dSTORM image of the swollen microgel particles.

Here we discuss in-situ superresolution microscopy of dye-labeled submicron sized PNiPAM microgels [1]. We use direct STochastic Optical Reconstruction Microscopy (dSTORM) to image single microgels at different stages of the volume phase transition with resolutions of 20-30 nm.

Moreover, we reveal their faceted structure when

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TNT2016 fribourg (switzerland)

Nanotents –2 nm void-formation and self-healing in 2D monolayers on metals

Huanyao Cun1, 2*, Marcella Iannuzzi3, Adrian Hemmi2, Silvan Roth2, Jürg Osterwalder2 and Thomas Greber2

1

huanyao.cun@epfl.ch hycun1@physik.uzh.ch

Laboratory of Nanoscale Biology, Institute of Bioengineering, School of Engineering, EPFL, 1015 Lausanne, Switzerland 2 Physik-Institut, Universität Zürich, Winterthurerstrasse 190, Zürich, Switzerland 3 Chemistry-Institut, Universität Zürich, Winterthurerstrasse 190, Zürich, Switzerland

At room temperature, it is quite challenging to immobilize single atoms, in particular the least reactive noble gases. Conventional ion implantation possesses this capability, but it does not permit much control over the randomness of the involved processes. However, with the single layers of hexagonal boron nitride (h-BN) or graphene, siteselective immobilization of atoms at surfaces becomes feasible [1]. The h-BN nanomesh is a corrugated honeycomb structure, which consists of two bonding regions, the ’pores’ with 2 nm diameter, and the surrounding ’wire’ regions where the h-BN is weakly bonding to the substrate [2,3].

In the present study, we demonstrate that the h-BN nanomesh, which acts as ultimately thin “rainfly”, can trap argon atoms at distinct subsurface sites and form so-called "nanotents" structure (Figure 1).

Remarkably, these “nanotents” are stable at room temperature and survive exposure to air. In-situ variable temperature measurements show that nanotents decrease in number while growing in size upon annealing to 450 K [4]. Further annealing to 900 K induces the “can-opener” effect: highly regular 2 nm h-BN flakes or “lids” are cut out from the h-BN monolayer and 2 nm voids form on the hBN surface. We assign the "can-opener" effect to the vacancy defects generated during the Ar penetration. Higher temperature (> 1000 K) annealing treatment leads to the “self-healing” of the h-BN monolayer [5]. Systematic measurements reveal that the entire process, including nanotent formation, “can-opener” effect and nanomesh “self-healing”, is well controlled and repeatable.

The study bases on scanning tunneling microscopy, photoemission, molecular dynamics and density functional theory calculations. The reported effects are robust and quite general: they are also observed in graphene on ruthenium [6], for neon

TNT2016 fribourg (switzerland)

and rubidium atoms [7]. Such nanoporous 2D membranes then can be transferred on arbitrary substrates.

References [1] H. Y. Cun et al., Nano Lett., 13 (2013), 20982103. Chosen as Science Editors’ Choice (April 2013) and highlighted in Nature Physics (May 2013).

[2] M. Corso et al., Science, 303 (2004), 217-220.

[3] S. Berner et al., Angew. Chem. Int. Ed., 46 (2007), 5115-5119.

[4] H. Y. Cun et al., ACS Nano, 8 (2014), 10141021.

[5] H. Y. Cun et al., ACS Nano, 8 (2014), 74237431.

[6] H. Y. Cun et al., Surf. Sci., 634 (2015), 95-102.

[7] L. H. de Lima et al., Rev. Sci. Instrum., 84 (2013), 126104.

Figures

Figure 1. Schematic illustration displays the two-step process of Ar implantation upon ion irradiation (1) and the “can-opener” effect induced by subsequent annealing (2).

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| 41

Self-Assembly of Anisotropic MultiNano-Composites

Gero Decher

University of Strasbourg, France

A major roadblock in materials science lies in the controlled preparation of composites composed of more than two components, so-called multicomposites and this holds especially true for nanoscale multicomposites. This is due to the fact that phase separation phenomena at the microand nanoscale often prevent to organize the individual components in a composite with precise distances between them. Over the last 20 years our team has focused on the development of onedimensional multicomposites, so-called Layer-byLayer (LbL) assembled films, in which the sequence of different materials and the distances between them are precisely controlled along the layer normal.

An even greater challenge in materials science lies in the preparation of anisotropic materials which possess physical properties, for example optical, electronic or mechanical properties that differ in different directions of space. While materials science has made enormous progress over the last decades, especially with respect to composites and nowadays also nanocomposits, the methods available for preparing anisotropic composite materials are still extremely limited.

do so while additionally controlling the anisotropy of the composite. The latter aspect, the anisotropy of the nanocomposite film, will for the present porpose not be brought about by external electrical or magnetic fields nor will it be brought about by surface templating or mechanical stretching since all of these techniques would impose severe restrictions with respect to the requirements for the size and the chemical nature of the materials onto which the composite films can be deposited.

For keeping the alignment method as general as possible we have recently developed grazing incidence spraying as a LbL-compatible technique based on liquid shear for aligning anisotropic nanoparticles with moderate to high aspect ratios in the form of LbLmonolayers on surfaces.

Here we discuss the preparation and the anisotropic properties of thin films composed of cellulosic nanofibrils and of silver nanowires. The first materials we made have already shown highly interesting properties. Cellulose nanofibrils allow to prepare biodegradable transparent objects with the tensile strength of steel and silver nanowires allow to challenge some of the plasmonic properties of metallic nanostructures that could previously only be prepared by nanolithography

Particularly interesting components for the preparation of anisotropic multicomponent materials are anisotropic nanoparticles, such as nanofibrils, nanowires or nanorods whose physical properties can easily be tuned by varying their aspect ratio. While the physical properties of such nano-objects are often highly anisotropic at the single particle level, their controlled integration into composites or multicomposites is even more difficult then the integration of their spherical counterparts. This is due to the fact that one does not only have to control the dispersion of the particles in a for example polymeric matrix, but to

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TNT2016 fribourg (switzerland)

Periodically microstructured composite films made by electric- and magnetic-directed colloidal assembly

Ahmet Faik DemirĂśrs1, Diana Courty2, Rafael Libanori1 and AndrĂŠ R. Studart1

1

dlim@hanyang.ac.kr

Complex Materials, Department of Materials, ETH Zurich, 8093 Zurich, Switzerland Laboratory for Nanometallurgy, Dep. of Materials, ETH Zurich, 8093 Zurich, Switzerland

2

Living organisms combine soft and hard components to fabricate composite materials with outstanding mechanical properties[1]. The optimum design and assembly of the anisotropic components reinforce the material in specific directions against multidirectional external loads[2]. Although nature does it quite readily, it is still a challenge for material scientists to control the orientation and position of the colloidal components in a matrix. Here, we use external electric and magnetic fields to achieve positional[3] and orientational[4] control over colloid-polymer composites to fabricate mechanically robust materials to capture some of the essential features of natural systems. We first investigated the assembly of spherical micron-sized colloids using dielectrophoresis, as these particles provided an easily accessible and instructive length scale for performing initial experiments. We used dielectrophoresis for spatial control of reinforcing anisotropic components and magnetic fields to provide control over the orientation of these reinforcing constituents. The obtained composites with different orientational and spatial reinforcement showed enhanced mechanical properties, such as wear resistance, which exhibits similarities to tooth enamel.

Figures

Figure 1. Sample cell design and electric field strength simulations over the microfabricated electrode.

References [1] A. R. Studart, Adv. Mater. 2012, 24, 5024.

[2] A. R. Studart, Adv. Funct. Mater. 2013, 23, 4423.

[3] A. F. DemirĂśrs, P. P. Pillai, B. Kowalczyk, B. A. Grzybowski, Nature 2013, 503, 99.

[4] A. F. Demirors, P. M. Johnson, C. M. van Kats, A. van Blaaderen, A. Imhof, Langmuir 2010.

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Magnetism of single atoms on graphene

Fabio Donati

Institute of Physics, Ecole Polytechnique Fédérale de Lausanne (EPFL), Station 3, CH-1015 Lausanne, Switzerland

fabio.donati@epfl.ch

Single atoms adsorbed on a surface represent a paradigm for investigating the ultimate size limit of a magnet. The main request for their use in information storage and computation is the magnetic bistability, which requires protecting the magnetization of an atom against thermal fluctuations and quantum tunneling. Different strategies have been attempted in this direction, aiming to increase the magnetic anisotropy energy of the adsorbed atom, decouple its spin from the conduction electron of the substrate, and tailor the angular symmetry of the crystal field of the surface [1]. Graphene, with its six-fold symmetric adsorption site is expected to provide close to purely uniaxial crystal field. In addition, its extremely high stiffness allows the suppression of spin-phonon coupling. These two elements are the key to obtain single atom magnets with long magnetic lifetimes, as recently demonstrated for Ho atoms on MgO/Ag(100) [2].

Here, I will present the recent advancements in the field of magnetic atoms on graphene. First, I will show how graphene can be successfully used to induce a large magnetic anisotropy in adsorbed Co atoms [3]. In addition, the direction of the easy magnetization axis of Co atoms can be controlled by growing graphene on different supporting metal substrates; while Co atoms on graphene/Pt(111) and graphene/Ir(111) show preferential magnetization orientation along the surface plane, Co on graphene/Ru(0001) exhibit a strong perpendicular magnetic anisotropy [4]. In all cases, the Co atoms exhibit paramagnetic behavior, indicating short magnetic lifetimes. Second, I will describe how graphene can be used to tailor the magnetic coupling between adsorbed Co atoms and a supporting ferromagnetic substrate. Co atoms on graphene/Ni(111) occupy two distinct adsorption sites, with different magnetic coupling to the

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underlying Ni(111) surface. Moreover, we observe a transition from antiferromagnetic to ferromagnetic coupling increasing the Co particle size from single atoms to few-atom clusters [5].

Finally, I will discuss the possibility of using graphene as a supporting substrate for rare earth atoms to obtain single atom magnets with long magnetic lifetimes.

References [1] I.G. Rau, S. Baumann, S. Rusponi, F. Donati, S. Stepanow, L. Gragnaniello, J. Dreiser, C. Piamonteze, F. Nolting, S. Gangopadhyay, O. R. Albertini, R. M. Macfarlane, C. P. Lutz, B. Jones, P. Gambardella, A. J. Heinrich, and H. Brune, Science 344 (2014) 988.

[2] F. Donati, S. Rusponi, S. Stepanow, C. Wäckerlin, A. Singha, L. Persichetti, R. Baltic, K. Diller, F. Patthey, E. Fernandes, J. Dreiser, Ž. Šljivančanin, K. Kummer, C. Nistor, P. Gambardella, H. Brune, Science, 352 (2016) 318.

[3] F. Donati, Q. Dubout, G. Autès, F. Patthey, F. Calleja, P. Gambardella, O.V. Yazyev, and H. Brune, Phys. Rev. Lett. 111 (2013) 236801.

[4] F. Donati, L. Gragnaniello, A. Cavallin, F. D. Natterer, Q. Dubout, M. Pivetta, F. Patthey, J. Dreiser, C. Piamonteze, S. Rusponi, and H. Brune, Phys. Rev. Lett. 113 (2014) 177201.

[5] A. Barla, V. Bellini, S. Rusponi, P. Ferriani, M. Pivetta, F. Donati, F. Patthey, L. Persichetti, S. K. Mahatha, M. Papagno, C. Piamonteze, S. Fichtner, S. Heinze, P. Gambardella, H. Brune, and C. Carbone, ACS Nano 10 (2016) 1101.

TNT2016 fribourg (switzerland)

Two-Dimensional Materials Confined Water

Mingdong Dong

The Interdisciplinary Nanoscience Center (iNANO), Aarhus University, Denmark

The adsorbed water thin layer on the two dimensional (2D) interface under ambient condition has different structural and dynamic behaviors, comparing to those of bulk water. It is also considered as a fundamental important field, due to its relevance in many aspects of daily life.

However, the knowledge of the interfacial water adlayers are still lack and many findings and theories are still under debate. [1] I am interested in the structural and dynamic behaviors of the confined water layer between 2D material interfaces. In this presentation, I am going to review the recent results focusing on the exploration of the confined water between 2D materials and various surfaces under ambient conditions. Subsequently, I will introduce the recent results in my group, which studies the water adlayer growth and structures between hydrophilic and hydrophobic (graphene) interfaces. [2] The icelike water adlayers have been identified, which are confined between hydrophobic graphene and hydrophilic substrate. Via varying the temperature, their nucleation process has been discussed. And it is found that, on one hand, the packing structures of the ice-like water adlayers are determined by that of hydrophilic interface; one the other hand, the graphene guides the orientation of the confined water domains. In the end, all of the obtained knowledge has been discussed, by comparing to the phenomena of the confined water between 2D hydrophilic interfaces, like MoS2. These new finding potentially can be utilized to understand the boundary condition for water structures and dynamic behaviors at interfaces, and the aqueous interfacial chemistry.

TNT2016 fribourg (switzerland)

References [1] Two-Dimensional Material Confined Water, Li, Q.; Song, J.; Besenbacher F.; Dong, M.; Accounts of Chemical Research, 2015, doi: x.doi.org/10.1021/ar500306w [2] Evidence of Stranski–Krastanov growth at the initial stage of atmospheric water condensation. Song, J.; Li, Q.; Wang, X. F.; Li, J. Y.; Zhang, S.; Kjems, J.; Besenbacher, F.; Dong, M.; Nature Communication, 2014, 5, 4837.

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Hazard assessment of aerosolized graphene-related nanomaterial in human epithelial lung tissue in vitro

Barbara Drasler1, Melanie Kucki2, Alke PetriFink1, Barbara RothenRutishauser1, Peter Wick2

1

barbara.drasler@unifr.ch

BioNanomatrials group, Adolphe Merkle Institute, University of Fribourg, Chemin des Verdiers 4, 1700 Fribourg, Switzerland 2 Laboratory for Particles-Biology Interactions, Empa - Swiss Federal Laboratories for Materials Science and Technology, Lerchenfeldstrasse 5, 9014 St. Gallen, Switzerland

Graphene-related materials (GRM) have promising properties for a wide range of new high-technology applications such as in electronics, photonics, and energy storage, resulting in mass production.

However, concerns have been raised regarding their possible interaction with humans during the life-cycle, especially with the respiratory system, as being the primary route of exposure for airborne particles [1]. It has been shown that GRM can be respirable and thus can deposit beyond the ciliated airways following inhalation, resulting in pulmonary inflammation [2]. In the current study a 3D in vitro model of the human epithelial lung tissue barrier composed of epithelial cells, macrophages and dendritic cells [3] has been used for evaluating cell membrane permeability, (pro)inflammatory response (tumour necrosis factor alpha and interleukin-8 detection), as well as cell viability and oxidative stress induction after exposure to aerosolized GRM at different concentrations, corresponding to relevant GRM doses after inhalation exposure [4] (ranging from 0.2 to 1.5 Âľg/cm2). Material aerosolization was performed using the commercially available nebulizer VitroCellÂŽCloud system, coupled to the Quartz Crystal Microbalance for assessment of the aerosolized material deposition; the latter was additionally visualized using transmission electron microscopy (TEM, FEI Tecnai spirit) (Fig. 1). First results have shown that nebulization of graphene oxide (GO) resulted in a dose-dependent material deposition. None of the investigated parameters was elevated for all the concentrations tested.

Further investigations are ongoing to assess effects after a prolonged exposure to GO and different types of GRM such as graphene nanoplatelets, which are forecast to represent a majority of the market value of the graphene market in the year 2026 [5].

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References [1] Oberdorster G, Stone V, Donaldson K, Nanotoxicology, 1 (2007) 2-25.

[2] Schinwald A, Murphy FA, Jones A, Macnee W, Donaldson K, Acs Nano 6 (2012) 736-746.

[3] Rothen-Rutishauser BM, Kiama SG, Gehr P, Am J Resp Cell Mol 32 (2005) 281-289.

[4] Su WC, Journal of Occupational and Environmental Hygiene 13 (2016) 48-59.

[5] Ghaffarzadeh K. Report: Graphene, 2D Materials and Carbon Nanotubes: Markets, Technologies and Opportunities 2016-2026.

Published by: IDTechEx, March, 2016. (http://www.idtechex.com/research/reports/g raphene-2d-materials-and-carbon-nanotubesmarkets-technologies-and-opportunities-20162026-000465.asp).

Figures

Figure 1. Transmission electron micrograph aerosolized (nebulized) graphene oxide.

TNT2016 fribourg (switzerland)

of

How do living cells build photonic nanostructures?

Eric R. Dufresne

Department of Materials, ETH Zurich, Switzerland

Birds and insects produce structural color with a staggeringly diverse set of nanostructures. These structures are made with astonishing precision and accuracy across cells and individuals. We know very little about how living organisms accomplish this.

Here, I will describe our preliminary understanding of the development of amorphous nanostructures in birds and periodic structures in butterflies.

TNT2016 fribourg (switzerland)

september 05-09, 2016

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From nanoscale spectroscopy towards photocurrent nanoscopy

Max Eisele

neaspec GmbH, Bunsenstrasse 5, 82152 Martinsried, Germany

max.eisele@neaspec.com

Nanoparticles, nanocrystal and single-layer materials like graphene are of fundamental interest for novel plasmonic and opto-electronic devices due to their unique size-dependent characteristics, their tunability and their broad application range.

Depending on the local environment, their properties can, however, strongly vary on the nanometer length-scale, reducing the macroscopic performance of such novel devices. The need to resolve and understand local influences calls for analysis tools, which are capable of capturing the optical and electronic properties on the 10nanometer length-scale.

surface potentials, the number of layers, and local strain on the electron dynamics in such materials.

Latest developments in s-SNOM even incorporate correlation microscopy by combining near-field microscopy with photocurrent nanoscopy [10]. The symbiosis of such complementary measurement techniques opens up a complete new research field for nano-spectroscopy, bringing together optical, opto-electronic and electronic analysis on the nanoscale in a complete non-destructive and noninvasive way.

References This talk introduces the latest advances in the field of scattering-type scanning near-field optical microscopy (s-SNOM) to perform standard Fourier transform infrared spectroscopy with an unprecedented spatial resolution of ~10 nm (nanoFTIR). This technique has already proven itself vital for modern nanoscopy and has been used in applications such as chemical identification [1], free-carrier profiling [2], or the direct mapping of propagating plasmons [3,4] and polaritons [5]. nano-FTIR allows us for the first time to directly trace the optical properties of e.g. single layer materials within the entire midinfrared spectral range with highest spatial resolution, routinely extracting valuable information like the local conductivity, intrinsic electron-doping, absorption or the complex-valued refractive index.

[1] F. Huth et al., Nano Letters, 12 (2012) 3973.

[2] J. M. Stiegler et al., Nano Letters, 10 (2010) 1387.

[3] J. Chen et al., Nature, 487 (2012) 77.

[4] Z. Fei et al., Nature, 487 (2012) 82.

[5] E. Yoxall et al., Nature Photonics, 9 (2015) 674.

[6] M. Eisele et al., Nature Photonics, 8 (2014) 841.

[7] M. Wagner et al., Nano Letters, 14 (2010) 894.

[8] G. X. Ni et al., Nature Photonics, 10 (2016) 244.

[9] M. A. Huber et al., Nano Letters, 16 (2016) 1421.

[10] A. Woessner et al., Nature Communications, 7 (2016) 10783.

Recently, nano-FTIR has been extended towards ultrafast experiments with up to 10-femtosecond temporal resolution. Carrier-relaxation dynamics in semiconductors [6], graphene [7,8], or intricate materials like vanadium dioxide [9] can now directly be observed on their natural time and length-scale, revealing key insights into the role of

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TNT2016 fribourg (switzerland)

Fabry-Perot oscillations in bilayer graphene pn junctions

Klaus Ensslin

ETH Zürich, Switzerland

Interference of particles is a manifestation of the wave nature of matter. A well-known realization is the Fabry-Pérot interferometer, where a photon bounces back and forth between two coplanar semitransparent mirrors. Partial waves transmitted after a distinct number of reflections within this cavity interfere and give rise to an oscillatory intensity of the transmitted beam as the mirror separation or the particle energy is varied. In solidstate physics, graphene has proven to be a suitable material for probing electron interference at cryogenic temperatures. However, in single-layer graphene (SLG) the realization of FP interferometers is challenging. The absence of a band gap and the Klein tunneling hamper the efficiency of sharp potential steps between the nand p-type regions, which play the role of the interferometer mirrors. Theory suggests that smooth barriers enhance the visibility of interference due to Klein collimation. Recently, ultraclean suspended SLG devices have shown FP interference with stunning contrast using cavity sizes of more than 1 μm.

TNT2016 fribourg (switzerland)

Here we report the experimental observation of Fabry-Pérot interference in the conductance of a gate-defined cavity in a dual-gated bilayer graphene device. The high quality of the bilayer graphene flake, combined with the device’s electrical robustness provided by the encapsulation between two hexagonal boron nitride layers, allows us to observe ballistic phase-coherent transport through a 1-μm-long cavity. We confirm the origin of the observed interference pattern by comparing to tight-binding calculations accounting for the gate-tunable band gap. The good agreement between experiment and theory, free of tuning parameters, further verifies that a gap opens in our device. The gap is shown to destroy the perfect reflection for electrons traversing the barrier with normal incidence (anti-Klein tunneling). The broken anti-Klein tunneling implies that the Berry phase, which is found to vary with the gate voltages, is always involved in the Fabry-Pérot oscillations regardless of the magnetic field, in sharp contrast with single-layer graphene.

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Emergence of quantum phenomena in the coupling of plasmons with molecules and quantum dots Donostia International Physics Center DIPC Paseo Manuel de Lardizabal 4, 20018 Donostia-San Sebastián, Spain

R. Esteban

ruben_esteban@ehu.eus

Metallic nanostructures are often called plasmonic nanoantennas due to their capability to exploit the collective resonances of the free electrons, called plasmons, to manipulate light at the nanoscale.

Notably, these structures can confine light in extremely low volumes, leading to a very large local density of states and to large coupling strengths with nearby emitters (Figure 1), such as quantum dots or molecules.

effects of potential interest to experiments, such as unexpected nonlinearities and large photon correlations. An improved understanding of the emitter-plasmon coupling at the quantum level in complex scenarios opens possibilities for new phenomena to emerge for fundamental studies and novel applications.

The behavior of these systems can typically be understood from classical electromagnetic calculations, but the constant improvement of fabrication techniques makes it possible to reach situations where purely quantum effects [1] could appear. In this talk, two situations of interest are considered. First, the regime of strong coupling provides a bridge between the classical and quantum worlds, where key phenomena such as Rabi splitting or anti-crossing can be understood classically but other effects such as the JaynesCummings ladder are of purely quantum origin. In the talk, we first briefly discuss the possibility to reach strong coupling at the single emitter level with phononic antennas [2] –a close relative of the plasmonic ones- and then focus on how the characteristic anti-crossing of the strong coupling regime affects the photoluminescence signal [3].

[1] M. S. Tame, K. R. McEnery et al, Nature Physics, 9, 329-340 (2013).

[2] R. Esteban, J. Aizpurua and G. W. Bryant. New Journal of Physics 16, 013052 (2014).

[3] D. Melnikau, R. Esteban et al., Journal of Physical Chemistry Letters 7, 354-362 (2016).

[4] R. Zhang, Y. Zhang et al., Nature 498, 82 (2013).

[5] W. Zhu and K. B. Croizier, Nat. Commun. 5, 5228 (2014).

[6] P. Roelli, et al., Nano Lett. 15, 3410 (2015).

[7] M. K. Schmidt, R. Esteban, et al., ACS Nano, DOI: 10.1021/acsnano.6b02484.

On the other hand, in Surface Enhanced Raman Spectroscopy (SERS) plasmons strongly enhance the Raman signal from nearby molecules. State-of-theart experimental results [4,5] may already operate in situations beyond conventional classical treatments. A new quantum model has been recently presented that describes the SERS process in a framework formally identical to that used to describe quantum optomechanical systems [6,7].

We apply a rigorous quantum treatment of this optomechanical framework and discuss several

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References

Figures

Figure 1. A plasmonic antenna, for example two spheres separated by a narrow gap, can interact strongly with nearby molecules, up to the point where strong coupling can be reached. The molecule-emitter interaction allows to manipulate light at the nanoscale, and can lead to emission at frequencies ω’ different than the incoming light at ω, for example due to Raman processes or photoluminescence. In this talk, we apply quantum descriptions to gain new understanding on the coupling and on the emitted light.

TNT2016 fribourg (switzerland)

Nanostructured Anode and Cathode Materials for High Pulsed Power Electromagnetic (HPEM) Devices

Steven B. Fairchild

Air Force Research Laboratory, Materials and Manufacturing Directorate, Wright-Patterson Air Force Base, OH 45431, USA

High Pulsed Power Electromagnetic (HPEM) devices are used in numerous applications including vacuum electronics, particle accelerators, and microwave generators. Stable, long term HPEM device operation is hampered by plasma formation in the anode-cathode gap region which results in pulse shortening and cathode damage caused by ion back bombardment. Plasma originates from gas molecules that are desorbed from both the cathode and anode surfaces when heated. Secondary electron emission (SEE) from the anode surface leads to ionization of the molecules near the surface. Improved materials for electron beam emission and collection are needed to mitigate these effects, and novel nanostructured materials have shown considerable promise towards this realization.

H2 outgassing and SEE by factors of three and two respectively over a bare nickel surface. Additionally, metallic anode samples were treated with the laser surface melting (LSM) technique to further reduce hydrogen outgassing. The samples were irradiated with a continuous high energy laser beam which resulted in melting, flow and re-solidification of the surface which decreased the number of grain boundaries through which hydrogen can diffuse.

The data show at least a five-fold reduction in hydrogen outgassing from the LSM treated sample, compared to those that were untreated. Graphene applied to an LSM treated metallic surface offers the ideal combination of reduced SEE and H2 outgassing for anodes. Experimental results for these layered structures will be discussed.

References Field emission (FE) cathodes made from carbon nanotube (CNT) fibers have demonstrated high emission currents, low turn-on voltages and long lifetimes. The CNT fibers were ~50um in diameter and showed increasing electrical and thermal conductivity with increasing fiber alignment. Fiber alignment was characterized with wide angle x-ray diffraction and fiber morphology was investigated with SEM and scanning 3D X-ray microscopy with 50 nm resolution. Stable field emission currents exceeding 1 mA for 10 hours and at an operating field strength of < 1V/Âľm were achieved [1].

Residual gas analysis (RGA) was used to identify the species desorbed during field emission which showed a sharp threshold for H2 desorption at an external field strength that coincides with a breakpoint in the FE data [2]. Graphene was used to improve anode material performance during electron beam collection experiments. Hydrogen outgassing was induced by repeated pulses (60 s duration) of 60 keV electrons onto anode material samples and recording the H2 signal with a line of sight RGA. A nickel â&#x20AC;&#x201C; graphene surface reduced the

TNT2016 fribourg (switzerland)

[1] S. B. Fairchild et al 2015 Nanotechnology 26 105706.

[2] P. T. Murray et al 2013 Appl. Phys. Lett. 103 053113.

Figures

Figure 1. (a) CNT fiber cathode. (b) SEM images of CNT fiber samples A,B,C, and D with corresponding orientation parameters as determined by wide angle xray diffraction of Sd = 0.34, 0.43, 0.64, and 0.80. (c) Corresponding field emission data for fiber samples A,B,C, and D [1].

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Designing all simple logic gates and half-adder circuit on a Si(100)–H surface

Omid Faizy Namarvar1 Ghassen Dridi1 and Christian Joachim1,2

1

CEMES-CNRS, 29 rue J. Marvig, 31055 Toulouse Cedex, France WPI-MANA, National Institute for Material Sciences, 1-1 Namiki, Tsukuba, Ibaraki, Japan

2

Belonging to the Quantum Hamiltonian Computing (QHC) branch of quantum control [1-2], atomicscale Boolean logic gates (LGs) with two inputs one output (OR, NOR, AND, NAND, XOR, NXOR) and - two outputs (half-adder circuit) were designed on a Si(100)-(2×1)–H surface following the experimental realiza-tion of a QHC NOR gate [3] and the formal design of an half adder with 6 quantum states in the calculating block [4]. The logical inputs are determined by two nearest neighbor crossing surface Si dangling bonds, which can be, for example, activated by adding or extracting two hydrogen atoms per input. QHC circuit design rules together with semi-empirical full valence K-ESQC transport calculations were used to determine the output current intensity of the designed LGs when interconnected to the metallic nano-pads by surface atomic-scale wires. Our calculations demonstrate that the proposed devices can reach a “0” to “1” logical output ratio up to 10 000 for a running current in the 0.2 µA range for 50 mV to 150 mV bias voltage around the nano-pads Fermi level.

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References [1] N. Renaud and C. Joachim, Phys. Rev. A, (2008), 78, 062316.

[2] W. H. Soe et al; Phys. Rev. B: Condens. Matter, (2011), 83, 155443.

[3] M. Kolmer, et al; Nanoscale (2015), 7, 12325– 12330.

[4] G. Dridi, R. Julien, M. Hliwa and C. Joachim, Nanotechnology, (2015), 26, 344003.

TNT2016 fribourg (switzerland)

Lock-in thermography: Using heat as an indicator for stability and distribution of magnetic nanoparticles in biological systems

Alke Fink

Adolphe Merkle Institute, & Chemistry Department, University of Fribourg, 1700 Fribourg, Switzerland

Magnetic nanoparticles (MNPs) and their ability to convert magnetic energy into heat are currently explored around the globe for various kinds of biomedical applications, with a particular emphasis on hyperthermia treatment. The heating power of these materials is dictated by a myriad of internal (e.g. NP size, polydispersity or crystallinity) and external (e.g. magnetic field strength or frequency) phenomena. However, experimentally conveying the effective heating power is not always straightforward, reproducible or easily feasible with conventional methods (e.g. fiberoptic cables, thermocouples or standard IR imaging). Variations among synthetic batches are not promotive either, as this requires every individual sample to be investigated and validated before administration.

Compared to conventional techniques, this approach is fast, sensitive, non-invasive alternative and capable of probing multiple and dilute specimens simultaneously. In turn, this would contribute in speeding up screening procedures or facilitating comparative studies.

Acknowledgements This work was supported by the Swiss National Science Foundation (126104, PP00P2-123373/1 and PP00P2133597/1), the Adolphe Merkle Foundation, the University of Fribourg and the Zurich University of Applied Sciences (ZHAW). Financial support from the Swiss National Science Foundation through the National Centre of Competence in Research BioInspired Materials is gratefully acknowledged.

Our group is thus dedicated to developing more reliable and precise experimental methods to evaluate the heating power of the respective MNPs. In this context, we present an abstract approach based on lock-in thermography to rapidly screen the thermal signatures of the MNPs at unprecedented thermal resolutions to subsequently evaluate their therapeutic potential.

Superparamagnetic iron oxide nanoparticles exposed to an alternating magnetic field (AMF) were used as model NPs to validate the setup, and their thermal properties were investigated in different states of matter. This included NPs in liquid, semi-solid and aggregated state.

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Stimulating changes in complex nanostructures – lasers, acids and enzymes

Wye-Khay Fong1,2, Raffaele Mezzenga2, Ben J Boyd1

khay.fong@monash.edu 1

Drug Delivery, Disposition and Dynamics, Monash Institute of Pharmaceutical Sciences, Monash University, 381 Royal Parade, Parkville, Victoria 3052, Australia 2 Food and Soft Materials Science, Department of Health Science and Technology, ETH Zurich, Schmelzbergstrasse 9, CH-8092 Zurich, Switzerland

Stimuli responsive nanomaterials are being developed as novel approaches to overcome complicated drug delivery issues such as those found in the treatment of cancer. These responsive materials have been of recent interest in the drug delivery field as it can take advantage of enzymes that are over-expressed in diseases such as cancer in order to trigger the release of encapsulated molecules. These ‘smart’ materials have the potential to provide early detection of disease and provide site selective drug release, thereby minimising exposure of healthy tissues to toxic drug, whilst maximising drug effectiveness.

References

My research utilises lipid based lyotropic liquid crystalline materials for this purpose. These biocompatible, multi-compartmental matrices can accommodate drug molecules with a wide range of physicochemical properties. The retention and release of drug from these materials is dependent on the internal nanostructure of the gel, whereby release characteristics can be tailored by selection of materials that form phases with specific dimensions of internal aqueous channels.

Figures

Manipulating environmental variables, such as temperature [1] and pH [2], and the incorporation and activation of responsive molecules or nanoparticles, such as gold nanorods [3], photochromics [4] and digestible amphiphiles [5], can enable switching between different LC phases and so provide opportunity to trigger release of encapsulated material. Additionally, as these materials are thermodynamically stable in excess water, they can be dispersed into nanostructured particles. This presentation will give a short overview of the triggers that we have utilised in order to exert exquisite control over the nanostructures formed.

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[2] [3] [4] [5]

[1] W.K. Fong, T. Hanley, B.J. Boyd, J Contr Release, 135 (2009) 218-226.

R. Negrini, W.K. Fong, B.J. Boyd, R. Mezzenga, Chem Comm, 51 (2015) 6671-6674.

W.K. Fong, T.L. Hanley, B. Thierry, N. Kirby, B.J. Boyd, Langmuir, 26 (2010) 6136-6139.

W.K. Fong, N. Malic, R.A. Evans, A. Hawley, B.J. Boyd, T.L. Hanley, Biointerphases, 7 (2012) 3.

W.K. Fong, S. Salentinig, C.A. Prestidge, R. Mezzenga, A. Hawley, B.J. Boyd, Langmuir, 30 (2014) 5373-5377.

Figure 1. Lyotropic liquid crystalline materials can be specifically designed to be responsive to stimuli such as temperature, pH, light and enzymes. Upon exposure, these materials will change nanostructure on-demand, resulting in the triggered release of encapsulated contents.

TNT2016 fribourg (switzerland)

Advanced Electron Microscopy Study of Gadolinium based compounds encapsulated within WS2 Nanotubes

Leonard Deepak Francis

International Iberian Nanotechnology Laboratory, Avenida Mestre Jose Veiga, 4715-330 Braga, Portugal

leonard.francis@inl.int

The hollow interiors of nanotubes could host the growth or filling of foreign elements or compounds to obtain hetero-structures. The growth of these materials in the confined one dimensional space lead to novel properties. Capillary filling serves as a method to enable filling of carbon nanotubes and inorganic nanotubes including those of BN and WS2 [1,2] In this work, considering the biocompatibility of WS2 and paramagnetic property of gadolinium (III) compounds, capillary filling is employed to nanotubes (X=Cl, Br, obtain GdX3@WS2 I). Gadolinium based compounds find important applications in medical imaging and diagnosis. Thus the precise determination of the structure and composition is detrimental in its further application. In the present case the morphology, structure and chemical composition of the synthesized GdI3 filled WS2 NTs is investigated using aberration corrected scanning/transmission electron microscopy and associated spectroscopic techniques (Electron Energy Loss Spectroscopy (EELS) and Energy Dispersive X-Ray Analysis (EDS)).

The three-dimensional morphology is investigated using Scanning Transmission Electron Microscopy (STEM) tomography but obtaining three dimensional compositional information is nontrivial due to the presence of multiple high atomic number elements.

Therefore, EDS-STEM tomography [3] is employed to map the chemical composition in three dimensions. In order to reduce the beam induced effects on the specimen, tomography experiments were carried out at 80 kV in the present case. In view of the long duration of electron beam exposure necessary to perform EDSSTEM tomography, electron irradiation studies are carried out to optimize the EDS-STEM tomography conditions. The experimental observations are adequately supported by carrying out Molecular Dynamics Simulation in order to elucidate the difference in behavior of the various halides (GdI3

TNT2016 fribourg (switzerland)

vs GdCl3 vs GdBr3) towards their affinity to fill the interior of the WS2 Nanotubes. [4]

References [1] Ronen Kreizman, Andrey N. Enyashin, Francis Leonard Deepak, Ana Albu-Yaron, Ronit Popovitz-Biro, Gotthard Seifert, and Reshef Tenne, Adv. Funct. Mater., 20 (2010) 2459– 2468.

[2] Elok Fidiani, Pedro M. F. J. Costa, Anja U. B. Wolter, Diana Maier, Bernd Buechner, and Silke Hampel, J. Phys. Chem. C, 117 (2013) 16725−16733.

[3] Georg Haberfehlner, Angelina Orthacker, Mihaela Albu, Jiehua Li and Gerald Kothleitner, Nanoscale, 6 (2014) 14563–14569.

[4] E. A. Anumol, Andrey Enyashin, Nitin M. Batra, Pedro M. F. J. Costa and Francis Leonard Deepak, Submitted, 2016.

Figures

Figure 1. Cartoon a) Volume rendering of EDS-STEM tomograms of GdI3@WS2 nanotube. b) Vertical orthoslice of the nanotube. c) and d) Orthoslices along the nanotube cross section. Greyscale images represent HAADF. The elements are color coded as blue for W, yellow for Gd, green for S and red for I.

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Nanomaterials meet Li-ion Batteries

Katharina M. Fromm, Nam Hee Kwon, Aurelien Crochet, Jean-Pierre Brog, Sivarajakumar Maharajan, Herve Yao

Department of Chemistry, University of Fribourg, Chemin du MusĂŠe 9, 1700 Fribourg, Switzerland

Katharina.fromm@unifr.ch

Layered LiCoO2 is one of the most frequently used cathode materials in todayâ&#x20AC;&#x2122;s Li-ion batteries. The micron scale material is typically produced via solidstate synthesis methods at high temperature >800°C and over several days. Due to the large particle sizes, only half of the lithium ions can be used for the functioning of the battery. Nanoscale cathode materials have the advantage that the lithium ion diffusion path lengths are much shorter, hence extraction and reinsertion of Li+ into the cathode material becomes faster and a higher ratio of cations is thus available for the electrochemical reaction.

On the anode side of current batteries, one of the major challenges is the large expansion of the material upon lithium ion insertion. This leads to crack formation and detachment of the active material from the current collector and hence to a decreased of performance. We therefore design nanorattles where an electron- and ion conductive material forms a shell around the anodenanoparticles. A void between shell and particle allows the particle to swell upon lithium ion insertion without breaking of the shell. This concept will be exemplified using tin as the anode active material (Fig. 1)

We developed therefore a synthetic access to multi-gram scale nano-LiCoO2, which will be presented. Furthermore, this material was tested in half-cells with lithium metal as counter electrode to confirm its electrochemical properties. Another new cathode material, LiMnPO4, is based on the olivine-type structure, featuring lithium ion channels. We will present its synthesis, the different particle shapes and sized which we obtain as a function of reaction conditions, as well as the exciting electrochemical results. [1]

Finally, we propose new ionic liquid based electrolytes for applications in high voltage batteries.

References [1] N. H. Kwon, J.-P. Brog, S. Maharajan, A. Crochet, K. M. Fromm, Chimia 69 (2015) 734736.

Figures

Figure 1. Schematic representation of nanorattle formation.

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TNT2016 fribourg (switzerland)

Simultaneous characterization of rotational and translational diffusion of anisotropic particles by optical microscopy

Fabio Giavazzi, Davide Piotti, Catalina Haro-Pérez and Roberto Cerbino

Department of Medical Biotechnology and Translational Medicine, University of Milan, Italy

fabio.giavazzi@unimi.it

We probe the roto-translational Brownian motion of anisotropic particles in suspension with simple and straightforward optical microscopy experiments that do not require positional or rotational particle tracking. In a first configuration, we acquire a movie of the suspension placed between two polarizing elements and we extract the translational diffusion coefficient DT and the rotational diffusion coefficient DR from the analysis of the temporal correlation properties of the spatial Fourier modes of the intensity fluctuations in the movie [1,2]. Our method is successfully tested with a dilute suspension of birefringent spherical colloidal particles, whose roto-translational dynamics is found to be well described by theory. In a second configuration, the sample is observed with dark-field illumination. By extending the recently introduced Dark-field differential dynamic microscopy [3], we show that in this condition an extreme sensitivity can be achieved in the detection of the rotational dynamics of particles with a shape anisotropy. This scheme is successfully applied to study of the roto-translational diffusion of fractal aggregates of gold nanoparticles and nonmotile bacteria. The simplicity of our approach makes these methods a viable alternative to particle tracking and depolarized dynamic light scattering.

References [1] F. Giavazzi and R. Cerbino, J. Opt., 16 (2014) 083001.

[2] F. Giavazzi, C. Haro-Pérez and R. Cerbino, J. Phys.: Condens. Matter 28 (2016) 195201.

[3] A.V. Bayles, T.M. Squiresa and M.E. Helgeson, Soft Matter 12 (2016) 2440.

TNT2016 fribourg (switzerland)

Figures

Figure 1. (a) Symbols: intermediate scattering function f(q, ∆t) obtained in the polarized microscopy experiment with a suspension of optically anisotropic colloidal -1 particles for different wave vector in the range 0.38 µm -1 <q< 3.93 µm .(b) Decorrelation rates obtained from the fit of the structure functions obtained in the polarized (blue squares and orange circles) and bright-field (yellow triangles) microscopy experiments. Lines are best fits of the data with the expressions predicted by the theory for the rototranslational diffusion of a sphere.

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New vistas for nanoscience opened by atomic force microscopy

Franz J. Giessibl

Experimental and Applied Physics, University of Regensburg, 93053 Regensburg, Germany

Atomic force microscopy (AFM) and scanning tunneling microscopy (STM) image surfaces with atomic resolution and enable local spectroscopies such as of current versus voltage and forces versus distance. In the past, STM and AFM used to be separate techniques that required their own instrumentation. The introduction of the qPlus force sensor [1] enabled combined STM and AFM capability, allowing highly precise imaging and spectroscopy functions and measuring the forces that act during atomic manipulation [2]. While STM had better spatial resolution than AFM in the past, the situation is reversed now with modern AFM [3].

Angular dependencies of chemical bonding forces have been observed before for Si tips interacting with Si surfaces [4], W tips interacting with graphite [5] and similarities exist between metal tips interacting with CO molecules on Cu and Si adatoms [6]. In the latter two cases, light atoms such as carbon or oxygen interacted with much heavier and much larger metal atoms. Gross et al. established that CO is an excellent probe for organic molecules. For example, pentacene can be imaged at excellent resolution with CO terminated tips [7], although the softness of CO on tips can lead to image distortions [8,9]. Tips made of permanent magnets such as CoSm allow to resolve the spin order in the antiferromagnetic insulator nickel oxide [10]. Complex surface terminations of the topological insulator TlBiSe2 have been determined by AFM [11]. The stiff cantilever/small amplitude technique used here also allows true atomic resolution in ambient conditions [12], and small iron clusters on Cu (111) are resolved by force microscopy [13]. Very recently, AFM has provided important insights into inelastic tunneling spectroscopy [14]. In summary, we see many exciting avenues in nanoscience research that open up with combined STM and AFM.

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References [1] F. J. Giessibl, Appl. Phys. Lett. 73, 3956 (1998).

[2] M. Ternes et al., Science 319, 1066 (2008).

[3] J. Welker, F. J. Giessibl, Science 336, 444 (2012).

[4] F. J. Giessibl, S. Hembacher, H. Bielefeldt, J. Mannhart, Science 289, 422 (2000).

[5] S. Hembacher, F. J. Giessibl, J. Mannhart, Science 305, 380, (2004).

[6] J. Welker, J. Weymouth, F. J. Giessibl, ACS Nano, DOI: 10.1021/nn403106v (2013).

[7] L. Gross et al. Science 325, 1110 (2009).

[8] A. J. Weymouth, Th. Hofmann, F. J. Giessibl, Science 343, 1120 (2014).

[9] M. Neu et al., Phys. Rev. B 89, 205407 (2014).

[10] F. Pielmeier, F. J. Giessibl, Phys. Rev. Lett. 110, 266101 (2013).

[11] F. Pielmeier et al., N. J. Phys. 17, 023067 (2015).

[12] D. Wastl, J. Weymouth, F. J. Giessibl, Phys. Rev. B 87, 245415 (2013).

[13] M. Emmrich et al., Science 348 308 (2015).

[14] N. Okabayashi et al., Phys. Rev. B 93, 165415 (2016).

Figures

Figure 1. AFM image of a Fe trimer next to a Fe dimer on Cu(111) [13].

TNT2016 fribourg (switzerland)

Towards Sub-10 nm Nanofabrication of Plasmonic Devices using Multiple Electron and Ion Beams

Peter Gnauck

Carl Zeiss Microscopy, Carl Zeiss Str. 22, Oberkochen, Germany

peter.gnauck@zeiss.com

Direct write focused ion beam (FIB) machining represents the quickest, most flexible method to fabricate nano-devices for prototyping and research applications. The use of a FIB combined with SEM allows for immediate inspection and refinement steps in the patterning, assuring the desired fidelity. This technology has thus found wide-spread use in fields such as photonics, nanofluidics, TEM sample preparation, integrated circuit modification, and MEMS. Conventional gallium FIB based on the liquid metal ion source (LMIS) has many notable drawbacks which include the lower limit for feature sizes that can be achieved and Ga implantation.

As an illustrative example of machining over multiple length scales, we show here an example of a double bowtie plasmonic device, inspired by the work of Zhang and co-workers. The device consists of four equilateral triangles patterned into 17 nm thick Au films by electron beam lithography. These elements face into one another giving a shape like two crossed bowties. The dimensions of the device are critical to determine the resonant wavelength.

The requirements are that the triangles have a side length of approximately 85 nm, with a radius of curvature of 10 nm at the vertices, and a gap between the points of the triangles of about 30 nm.

The gaps are varied to alter the plasmonic response of the device. To date, lithographic methods are necessary to form such small objects since traditional Ga FIB does not have the requisite machining precision.

The ORION NanoFab allows these devices to be made by direct write using three different ion species and completely obviating the need for lithographic processing. The critical dimension can in fact be reduced even further. A three step approach was used to fabricate a double bowtie

TNT2016 fribourg (switzerland)

structure in a 100 nm thick gold film on a glass substrate. During the first step, Ga FIB is used to open up a 1 µm square window into the film, while leaving behind a square island 200 nm wide in the center. The second step consisted of using the neon beam in the gas field ion source to machine slits in the island which form a cross. as demonstrated in Figure 1. The sidewall angle of the created features is 82º, this could be improved with trimming by helium [4]. Finally, helium ion milling is utilized to separate the four triangular elements as represented in Figure 2. A top-down view of the completed device is presented in Figure 2. The active area of the device had never been exposed to the Ga beam. The fact that the results can be inspected immediately in-situ, using helium ion microscopy (HIM), also provides the quick feedback and process control. Extremely tight dimensions can be maintained in the most critical area. Figure 3 shows the center of the bowtie structure. The image has been filtered to highlight the edges for measurement purposes. The distance between the triangle vertices is 10 nm (line drawn on image), and the radius of curvature of the vertices is also 5 nm (circle drawn on image).

References [1] Z. Zhang, et al., Nano Letters, 9, 4505 (2009).

[2] J Notte, “Charged Particle Microscopy: Why Mass Matters”, Microscopy Today, 20(5), 1622 (2012).

[3] http://www.srim.org/ [4] Larry Scipioni, et al., J. Vac. Sci. Technol. B 28(6), C6P18 (2010).

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Figures

Figure 1. Machining of island with neon beam to form arms of double bow tie structure. Helium ion imaging.

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Figure 2. Top down image of final device. Helium ion imagin.

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Figure 3. Edge-enhanced HIM image of center 100 nm area of double bow tie structure. Line drawn on image is 10 nm. Circle has radius of 5 nm.

TNT2016 fribourg (switzerland)

Mesoscopic photosystems for electricity and fuel production from sunlight

Michael Grätzel

EPFL, Switzerland

Mesoscopic photovoltaics have emerged as credible contenders to conventional p-n junction photovoltaics [1-3]. Mimicking light harvesting and charge carrier generation in natural photosynthesis, dye sensitized solar cells (DSCs) were the first to use three-dimensional nanocrystalline junctions for solar electricity production, reaching currently a power conversion efficiency (PCE) of over 14% in standard air mass 1.5 sunlight, Remarquably the PCE rises to 26% in diffuse ambient light matching the performance of GaAs photovoltaics. By now, large-scale DSC production and commercial sales have been launched on the multi-megawatt scale for application in building integrated PV and light weight flexible power sources. Recently, the DSC has engendered the stunning rise of perovskite solar cells (PSCs) [4-6]. Today’s state of the art devices employ metal halide perovskite of the general composition ABX3 as light harvesters, where A stands for methylammonium, formamidinium or caesium, B denotes lead or tin and X iodide or bromide. Carrier diffusion lengths in the 100 nm - micron range have been measured for solution-processed perovskites and certified power conversion efficiencies (PCEs) attain 22 %, exceeding the PCE of polycrystalline silicon solar cells. These photovoltaics show intense electroluminesence matching the external quantum efficiency of silicon solar cells. and Voc values close to 1.2 V for a 1.55 eV band gap material. This renders perovskite-based photosystem very attractive for applications in tandem cells and for the generation of fuels from sunlight mimicking natural photosynthesis [7,8].

TNT2016 fribourg (switzerland)

References [1] B.O’Regan and M. Grätzel. “A Low Cost, High Efficiency Solar Cell based on the Sensitization of Colloidal Titanium Dioxide,” Nature 353 (1991) pp 7377-7381.

[2] M. Grätzel, “Photoelectrochemical Cells,” Nature 353 (2001) pp 7377-7381.

[3] A.Yella, H.-W. Lee, H. N. Tsao, C. Yi, A.Kumar Chandiran, Md.K. Nazeeruddin, EW-G .Diau,,C.-Y Yeh, S. M. Zakeeruddin and M. Grätzel,“Porphyrin-based Solar Cell with Co(II/III) Redox Electrolyte Exceed 12% Efficiency,“ Science 629 (2011) pp 334-341.

[4] M. Grätzel, Light and Shade of Perovskite Solar Cells, Nature Mat. 13 (2014) pp 838-842.

[5] J. Burschka, N. Pellet, S.-J. Moon, R.HumphryBaker, P. Gao1, M K. Nazeeruddin and M. Grätzel, „Sequential deposition as a route to high-performance perovskite-sensitized solar cells“ Nature 499, (2013),pp 316-3199.

[6] X.Li, D. Bi, C.Yi, J.-D.Décoppet, J.Luo, S.M. Zakeeruddin, A Hagfeldt and M.Grätzel, A vacuum flash–assisted solution process for highefficiency large-area perovskite solar cells Science (2016) 10.1126/science aaf8060.

[7] J. Luo, J.-H. Im, M.T. Mayer, M. Schreier, Md.K. Nazeeruddin, N.-G. Park, S.D.Tilley, H.J. Fan, M. Grätzel, Water photolysis at 12.3% efficiency via perovskite photovoltaics and Earth abundant catalysts Science, 345, (2014), pp 1593-1596.

[8] M.Schreier L. Curvat, F. Giordano, L. Steier, A. Abate, S.M. Zakeeruddin, J. Luo, M. Mayer and M:Grätzel, "Efficient photosynthesis of carbon monoxide from CO2 using perovskite photovoltaics" Nature Commun. 6, (2015) , pp 7326-7332.

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Single layer boron nitride: From Nanomesh to smart membranes in liquids

Thomas Greber

Physik-Institut, University of Zürich, Switzerland

In the slipstream of graphene, hexagonal boron nitride emerged as another important twodimensional material with similar stability and lattice constant, though as an insulator with different affinity to ions. I will briefly review the single layer of h-BN superhoneycomb on rhodium metal (nanomesh) as a significant modifier of the surface properties [1] with strong lateral electrical fields on the nanometer scale [2].

Then recent results of the use of this interface system in view of an ultimately thin membrane are discussed. Intercalation of hydrogen in vacuum [3] and in a liquid electrolyte (see Figure 1) [4] are first examples. I will also show on to produce 2 nm holes (nanovoids) in the nanomesh with the can-opener effect [5], how such single domain h-BN may be exfoliated and how it may eventually be applied as smart membranes in liquids.

Financial support by the Swiss National Science Foundation and the European Commission Future

and Emerging Technologies Flagship Graphene is gratefully acknowledged.

References [1] M. Corso et al. Boron nitride nanomesh, Science, 303 (2004) 217.

[2] H. Dil et al. Surface trapping of atoms and molecules with dipole rings, Science 319, (2008) 1824.

[3] T. Brugger et al. Nanotexture switching of single-layer hexagonal boron nitride on rhodium by intercalation of hydrogen atoms, Angewandte Chemie Int. Ed. 49 (2010) 8120.

[4] S. Mertens et al. Switching stiction and adhesion of a liquid on a solid, Nature (2016).

[5] H.Y. Cun et al. Immobilizing Individual Atoms beneath a Corrugated Single Layer of Boron Nitride, Nano Letters 13 (2013) 2098, TwoNanometer Voids in Single-Layer Hexagonal Boron Nitride: Formation via the “Can-Opener” Effect and Annihilation by Self-Healing, ACS Nano 8 (2014) 7423.

Figures

Figure 1. Dynamic contact angle measurements. (1) Advancing, (2) receding for corrugated and (3) advancing (4) receding for flat h-BN/Rh(111). The contact angle hysteresis is evident, and is due to the switching of the 0.1 nm h-BN corrugation upon hydrogen intercalation. Capillary outer diameter 850 μm. From [4].

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TNT2016 fribourg (switzerland)

On-surface synthesis and properties characterization of novel lowdimensional materials

Oliver Gröning

Empa, Swiss Federal Laboratories for Materials Testing and Research Überlandstrasse 129. CH-8600 Dübendorf, Switzerland

In recent years on-surface chemical synthesis routes have succeeded in producing atomically precise nanostructures, whose synthesis cannot be achieved by standard wet chemical processes. This circumstance is due to a great extend to the usually insoluble nature of the products. In this respect, particular attention has been devoted to graphene derived carbon nanostructures such as graphene nanoribbons (GNR) and regular 2D carbon networks [1,2]. In our presentation we will review the recent developments in the field of on-surface chemical synthesis with a particular emphasis on the importance UHV-analytical and computational tools in understanding the physicochemical processes involved in the synthesis and in assessing the electronic properties of the produced nanostructures. The first part of the presentation will mainly touch the role of specific molecular precursors for the synthesis of graphene derived 2D and 1D nanostructures. We will discuss the electronic properties of these novel nanomaterials and their prospects to be used in future electronic devices.

surfaces of PdGa can induce 99% chiral adsorption selectivity of prochiral 9-Ethynylphenantrene (9-EP) at room temperature. Similarly high chiral selectivity can be achieved in producing prochiral 9EP trimers, which shows the potential of achieving highly asymmetric chemical synthesis on a high temperature stable metallic catalyst.

References [1] J. Cai, et al.,Nature 466, 470 (2010).

[2] M. Bieri, et al., JACS 132 16669, (2010).

[3] M. Armbrüster, M. Kovnir, M. Behrens, D. Teschner, Y Grin, and R. Schlögl, JACS 132, 14745 (2010).

[4] J. Prinz, C. A. Pignedoli, Q. S. Stöckl, M. Armbrüster, H. Brune, O. Gröning, R. Widmer, D. Passerone JACS 136, 11792 (2014).

[5] J. Prinz, O. Gröning, H. Brune, and R. Widmer, Angew.Chem. 127, 3974 (2015).

In the second part the question, how the chemical synthesis can be guided by specific atomic surface structures will be addressed. In this context, we will turn our attention to the PdGa compound, which has been found to combine high selectivity and activity in acetylene semi-hydrogenation [3]. We will discuss the non-trivial atomic structure of the (111) and (-1-1-1) PdGa surface, which differ significantly in the local structure of the top most Pd atoms and therefore are model surfaces to study active site isolation and ensemble effects on catalyst selectivity [4]. We will then explore the possibilities of chiral selective adsorption and synthesis on these surfaces made possible by the intrinsic chiral nature of the P213 space group PdGa belongs to [5]. We show that the intrinsically chiral

TNT2016 fribourg (switzerland)

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Mechanically-Controlled Rewiring of Neuronal Circuits

Peter Grutter

grutter@physics.mcgill.ca

Department of Physics, McGill University, Montreal (Qc), Canada

www.physics.mcgill.ca/~peter

We have used atomic force microscopy to present spatially and temporally well defined chemical stimuli to neurons to induce the formation of synapses [1]. For the first time this allow the determination of relevant times to signal cascades leading to the formation of functioning synapses [2]. We have furthermore succeeded in forming a synapse to an artificial structure – a suitably coated polystyrene bead attached to an AFM tip. Using rat neurons, suitable custom developed microfluidic systems and micro and nano tools we show that new, functional neurites can be created and precisely positioned to directly (re)wire neuronal networks [3]. We show that the adhesive contact made onto an axon or dendrite can be pulled to initiate a new neurite that can be mechanically guided to form new synapses at up to 0.8 mm distance in less than 1 h. The extension rates achieved is at least 60 times faster than previously reported ‘natural’ growth rates. Our findings challenge current understanding of the limits of neuronal growth and have direct implications for the development of new therapies and surgical techniques to achieve functional regeneration after trauma and in neurodegenerative diseases. It also opens the door for the direct wiring of robust brainmachine interfaces as well as investigating fundamental aspects of neuronal signal processing and neuronal function.

Figures

Figure 1. Live neurons reconnected by AFM manipulation. Double patch clamp demonstrate functionality.

References [1] A. L. Lucido et al., J. of Neuroscience 29, 12449 (2009).

[2] F. Suarez Sanchez et al., Dev. Neurobiol. 73, 98 (2013).

[3] M.H. Magdesian et al, J. Neuroscience 6, 979 (2016).

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TNT2016 fribourg (switzerland)

Janus Dumbbells: A flexible template for colloidal chemistry

Florian Guignard, Marco Lattuada

Adolphe Merkle Institute, University of Fribourg, Chemin des Verdiers 4, 1700 FRIBOURG, Switzerland

Florian.guignard@unifr.ch

The recent development of nanotechnology led to an increased amount of scientist working on nanoparticles worldwide. However, most of the studies are focusing on spherical isotropic nanoparticles, which are the easier to prepare. We used a described procedure [1,2] to prepare shapeanisotropic, asymmetrically-functionalized dumbbells nanoparticles covering a good range of size and aspect ratio. We then used the presence of silane groups on one hemisphere of the dumbbells only to selectively functionalize the nanoparticles [1], creating different types of hybrids.

The hydrolysis and condensation of a silane precursor covered one bulb with a thin layer of silica. Upon removal of the polymeric template, we prepared silica nanobowls bearing a well-defined opening in their shell. Calcination of the template at 550 °C led to purely hydrophilic silica nanobowls, while the dissolution of the template in THF gave birth to Janus nanobowls having a thin polymer layer on their inner side. We proved the different reactivity of the inside and outside surfaces by selectively binding oppositely-charged silica nanoparticles. They selectively adhered outside the Janus nanobowls, while they were present both inside and outside the nanobowls prepared by calcination [2].

that it is possible to change the types of chain-like structures obtained by tuning the aspect ratio of the dumbbells.

Using the same dipolar dumbbells, we prepared Janus nanomotors by selectively attaching citratecoated platinum nanocrystals on one hemisphere.

The resulting nanoparticles can undergo selfpropulsion when place in a solution containing hydrogen peroxide fuel.

The catalytic decomposition of the fuel is only taking place on one side of the dumbbells, generating a gradient which leads to effective propulsion.

Finally, we made the dumbbells temperatureresponsive by growing some poly-Nisopropylacrylamide brushes on one hemisphere.

We first attached an initiator to the dumbbells by silane chemistry, and then used a surface initiated atom transfer radical polymerization (ATRP) to grow the PNIPAM chains. This renders the dumbbells hydrophilic below 32 °C (PNIPAM LCST), and amphiphilic above. We showed that it is possible to induce aggregation between the dumbbells by hydrophobic interactions above LCST. These stimuli-responsive nanoparticles have also been used to prepare multiple Pickering emulsions.

References Magnetic anisotropic nanoparticles were prepared either by attaching negatively charged Superparamagnetic Iron Oxide Nanoparticles (SPIONS) on dipolar dumbbells, or by preparing dumbbells with commercially available magnetic beads as seed nanoparticles. In both cases, we obtained asymmetric dumbbells with magnetic nanoparticles only on one side. We then studied the impact of shape-anisotropy on the directed self-assembly of these nanoparticles in the presence of an external magnetic field. We showed

TNT2016 fribourg (switzerland)

[1] F. Guignard, M. Lattuada, Chimia (Polymer and Colloid Highlights), 67, 829 (2013).

[2] F. Guignard, M. Lattuada, Langmuir, 2015, 31 (16), 4635â&#x20AC;&#x201C;4643.

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Photonic Bandgap Materials with Disorder

N. Muller, S. Aeby, C. Marichy, J. Haberko and F. Scheffold

Department of Physics and Fribourg Center for Nanomaterials, University of Fribourg, Chemin du Musée 3, CH-1700 Fribourg, Switzerland

Structured dielectric materials in three dimensions can exhibit photonic properties that allow control of the propagation of light. For crystalline structures, a complete or incomplete photonic bandgap emerges and the propagation of light is hindered or even completely suppressed over a certain range of wavelengths. Full photonic bandgaps open up for dielectric materials with a sufficiently high refractive index contrast. Embedding defect sites in an otherwise perfect crystalline lattice such as a woodpile photonic crystal allows for the appearance of defect states in the bandgap and for the trapping of light in three dimensions. Interestingly, it appears that many of these unique properties are not tied exclusively to crystalline structures. In a recent numerical study Florescu et al. demonstrated that particular designer disordered materials could display large, complete photonic bandgaps in two dimensions [1]. Mapping hyperuniform point patterns with shortrange geometric order into tessellations allows the design of interconnected networks that give rise to enhanced photonic properties.

Here we present experimental results for the fabrication of ordered and disordered photonic structures made from high refractive index materials such as TiO2 and silicon [2-5]. First, the structures were fabricated via direct laser writing in polymer by adapting the standard writing protocol presented in [2]. A substantial increase in the material refractive index is necessary to observe a photonic gap. To this end we employ ZnO and TiO2 infiltration [3-5] combined with the well-established silicon double inversion method [5]. This multi-step replication technique consists of successive infiltration and etching processes. The high quality of the resulting structures is illustrated by focused ion beam etching coupled to a scanning electron microscopy images as well as a pronounced and angular independent transmittance dip in the spectral response, measured

by Fourier Transform Infrared spectroscopy [3,6].

Moreover we study experimentally and numerically

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the influence of random and correlated defects in periodic woodpile structures and the role of shortrange order and hyperuniformity in the formation and robustness of bandgaps.

References [1] Florescu, M., Torquato, S., Steinhardt, P. J., PNAS, Vol. 106 (2009) 20658–20663.

[2] Haberko, J., Muller, N., and Scheffold, F., Phys.

Rev. A, 88 (2013) 043822.

[3] Muller, N., Haberko, J., Marichy, C., and Scheffold, F., Adv. Opt. Mat, 2 (2014) 115–119.

[4] C. Marichy, N. Muller L.S. Froufe-Pérez and F. Scheffold, Scientific Reports, Scientific Reports 6, 21818 (2016).

[5] Muller, N., Haberko, J., Marichy, C. and Scheffold, F., manuscript in preparation.

[6] Froufe-Pérez, L. S., Engel, M., Damasceno, P. F., Muller, N., Haberko, J., Glotzer, S.C., and Scheffold, F., submitted, http://arxiv.org/abs/1602.01002

Figures

Figure 1. Top view scanning electron micrograph of a hyperuniform photonic network fabricated by direct laser writing in a polymer photoresist [2]. Scale bar 5 μm.

TNT2016 fribourg (switzerland)

Soft Nanocomposite Materials and Their Applications in Cell Harvest Systems and Antithrombogenic Coatings

Kazutoshi Haraguchi

Dep. Applied Molecular Chemistry, College of Industrial Technology, Nihon University, 1-2-1 Izumi-cho, Narashino, Chiba 275-8575 Japan

haraguchi.kazutoshi@nihon-u.ac.jp

Novel soft nanocomposite materials, such as nanocomposite hydrogels (NC gels) [1] with unique organic (polymer)/inorganic (clay) network structure, transparent soft nanocomposite films (M-NC) [2] with unique clay-network morphology consisting of core(polymer)â&#x2C6;&#x2019;shell(clay) nanospheres, new stimuliresponsive NC gels (MDNC gels),[3] and amphiphilic block copolymers (MDM) [4] with triblock or 4-arm block architectures, have been developed.

All NC gels and M-NCs were synthesized by in-situ free radical polymerization in aqueous media in the presence of exfoliated clay platelets, and obtained as flexible and transparent soft materials in various forms such as thin film, rod, hollow tube, sphere, etc. Owing to these unique network structures, all NC gels and M-NCs showed extraordinary high mechanical properties such as ultrahigh elongation and widely controlled modulus and strength. In addition, the NC gels and M-NCs exhibited a number of new characteristics related to optical anisotropy, stimulus sensitivity, surface properties, self-healing, biocompatibility and cell culture. [5] In the presentation, we outline the novel features of these soft nanocomposites and demonstrate the potential as soft culture substrates with capability of thermoresponsible cell adhesion/detachment useful for a living cell harvest system.

TNT2016 fribourg (switzerland)

MDM block copolymers composed of hydrophobic (poly(2-methoxyehtyl acrylate): M) and hydrophilic (poly(N,N-dimethylacrylamide): D) segments were prepared by RAFT polymerization through a versatile one-pot synthesis. The two opposing characteristics of high protein repellency and good substrate adhesion were achieved by the combined effects of the molecular architecture of block copolymers, the low glass transition temperature, and the low protein adsorption capability of each segment. The resulting coated surfaces showed superior protein repellency and antithrombogenicity. [6]

References [1] K. Haraguchi, et al., Adv. Mater., 16 (2002) 1120; Angew. Chem. Int. Ed., 44 (2005) 6500; Biomacromolecules, 7 (2006) 3267.

[2] K. Haraguchi, et al., Adv. Mater., 18 (2005) 2250; J. Biomater. Sci., 22 (2011) 2389.

[3] K. Haraguchi, et al., Macromolecules, 45 (2011) 385; J. Biomed. Mater. Res. A., 101A (2013) 537.

[4] K. Haraguchi, et al., Biomacromolecules, 15 (2014) 1992.

[5] K. Haraguchi, Adv. Polym. Sci., 267 (2015) 187.

[6] K. Haraguchi, et al., ACS Biomater. Sci. Eng., 1 (2015) 352.

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Assembling biomimetic surfaces with modular amphiphilic proteins

F. Wan, S. Fischer, Z. al-Rekabi, S. Dick, J. L. Harden

University of Ottawa, Department of Physics, Canada

Amphiphilic secondary structures are ubiquitous in natural proteins, where they serve a wide variety of functions from specific binding ligands to structural elements in supramolecular assemblies. This talk describes the use of amphiphilic motifs in modular protein polymers as a strategy to achieve directed self-assembly of bioactive surfaces. These proteins are designed to include independent elements that direct their assembly onto hydrophobic surfaces, and that display functional peptide sequences to the aqueous solution phase (Figure 1). The associating domains are comprised of amphiphilic helices or beta sheets. These associating elements are linked to water soluble, disordered domains that display sequences with specific cell binding and signaling motifs or sequences that serve as templates for biomineralization. The molecular and interfacial properties of several systems and their potential for supporting attachment, growth and proliferation of a variety of cell types (Figure 2) will be presented, and potential biomedical applications will be discussed.

Figures

Figure 1. Surface functionalized with amphiphilic diblock protein motif.

Figure 2. HFF cell response to bioactive (L) & bio-neutral (R) protein surfaces.

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TNT2016 fribourg (switzerland)

Fabrication of sub-20 nm Metal Electrodes on 2D Materials without a Charged Particle Beam 1

SwissLitho AG, Technoparkstrasse 1, Zurich, Switzerland IBM Research â&#x2C6;&#x2019; Zurich, Rueschlikon, Switzerland

holzner@swisslitho.com

2

Charged particle beams for the fabrication of devices comprising sensitive nanowires or 2D materials often lead to unwanted influence or damage of electronic properties of the device [1]. Still, electron beam lithography (EBL) in combination with lift-off is the most commonly used method to fabricate prototypes of such devices.

Thermal Scanning Probe Lithography (t-SPL) [2, 3] is an alternative mask-less lithography technique which is also commercially available since 2014. It provides similar speed (up to 20 mm/s) and resolution (10 nm half-pitch) as EBL, but without charged particles involved. Here, we present two recently developed lift-off techniques for t-SPL that have enabled the creation of complex sub-20 nm Au, Pt and Ni structures and devices without the usage of high energy charged particle beams [4].

Thermal Scanning Probe Lithography (t-SPL) uses a heated silicon tip to locally decompose and evaporate a thermally responsive resist [5], usually PPA (polyphthalaldehye). A two-layer or three-layer process in combination with wet or dry etching is demonstrated to create a suitable under-cut for liftoff, respectively. During the t-SPL process the heated tip only influences the top PPA layer and leaves the underlying substrate unharmed. This is in contrast to beam based technologies like EBL or Focused Ion Beam (FIB) where most of the energy is actually deposited in the substrate and vacancies in graphene or other 2D materials can be created.

We demonstrate the capabilities of the new t-SPL liftoff processes by fabrication of transistors with improved performance (See Figure1). 50 nm wide fingered top gates have been fabricated with nanometer overlay accuracy. The superb switching behavior of the transistor shows the absence of trapped charge in the gate oxide, which usually occurs during EBL fabrication of such devices and prevents proper device operation.

TNT2016 fribourg (switzerland)

Felix Holzner1 Heiko Wolf2, Colin Rawlings2, Urs Duerig2, Armin W. Knoll2, Martin Spieser1, Simon Bonanni1 and Philip Paul1

Acknowledgments: We thank P. Mensch and S. Karg for providing InAs nanowires and performing the transport measurements, U. Drechsler for cantilever fabrication, and R. Allenspach and W. Riess for fruitful discussions.

The research leading to these results received funding from European Unionâ&#x20AC;&#x2122;s Seventh Framework Program FP7/2007-2013 under Grant Agreement No. 318804 (SNM).

References [1] S. F. Karg, V. Troncale, U. Drechsler, P. Mensch, P. Das Kanungo, H. Schmid, V. Schmidt, L. Gignac, H. Riel, B. Gotsmann, Nanotechnology 25 (2014), 305702.

[2] D. Pires, J.L. Hedrick, A. de Silva, J. Frommer, B. Gotsmann, H. Wolf, M. Despont, U. Duerig, A.W. Knoll, Science 328 (2010), 732-735.

[3] P.C. Paul, A.W. Knoll, F. Holzner, M. Despont, U. Duerig, Nanotechnology 22 (2011), 275306.

[4] H. Wolf, C. Rawlings, P. Mensch, J.L. Hedrick, D.J. Coady, U. Duerig and A. Knoll, J. Vac. Sci. Technol. B 33 (2015), 02B102.

[5] C. Aso, S. Tagami and T. Kunitake, J. Polym. Sci. A-1 (1969), 497-511.

Figures

Figure 1. a) The gate electrodes of InAs nanowire transistor fabricated using the tSPL and lift-off. b) Switching behavior of the transistor. c) Schematic of the InAs nanowire transisto.

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Wireless thin film transistor with nanostructured magnetic core structure based on ZnO nanowires

Byoung Ok Jun, Jae Eun Jang

Daegu Gyeongbuk Institute of Science and Technology (DGIST), Daegu, Korea

junbo@dgist.ac.kr

Today, the wearable and implantable medical devices and sensors have played an important role in modern medicine and continuous health monitoring. In the system, wireless delivery of energy to these devices is desirable. Moreover miniaturization of the system is required to avoid the infection and an inconvenience for patients.

However, current system remains large in scale due to the complex components and unwieldy size of antennas. Wireless thin film transistor (TFT) with micro antenna structure would be an important component, since it could be applied as an important building block in various devices, as an electrical switch, a rectifier or an amplifier, for various electronics with wireless functionality, since it can provide both simplicity and convenience. It will inspire new device concepts, and it is essential to some applications. One side effect of this micro size antenna is the decrease of transmission efficiency that occurs with scaling down the size of antenna. To improve this low efficiency, we have studied a nanostructured magnetic core (MC) system located in center of the micro antenna design to increase the magnetic flux density without changing the size of the antenna structure.

In this study, we investigated an amorphous indium gallium zinc oxide TFT (Îą -IGZO TFT) with a magnetic induction antenna structure. To incorporate a micro antenna structure into a TFT, a magnetic core (MC) of nickel (Ni) coated zinc oxide nano wires (ZnO NWs) was added to the micro antenna structure as shown in Figure 1. This enhanced the power or the delivered signal efficiency as shown in Figure 2, which was reduced as antenna size becomes smaller. The electrical characteristics and the Îą -IGZO TFT structure were optimized to improve the wireless transferred power efficiency, considering the increase of selfresonance frequency produced by the antenna size effect. The suggested wireless TFT structure can be

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a core technology in the field of flexible devices, implantable systems and micro robots, etc.

References [1] Xu, S. et al, Nat. Commun, 4 (2013) 1543.

[2] Mercier, P. P., Lysaght, A. C., Bandyopadhyay, S., Chandrakasan, A. P. & Stankovic, K. M., Nat. Biotechnol, 30 (2012) 1240-1243.

Figures

Figures 1.

Figures 2.

TNT2016 fribourg (switzerland)

Positions-controlled growth of rutile TiO2 nanorods and their optical and electronic properties

Julian Kalb, Johannes Boneberg and Lukas Schmidt-Mende

University of Konstanz, Universitätsstraße 10, 78457 Konstanz, Germany

julian.jalb@uni-konstanz.de

Rutile TiO2 nanorods are semiconducting 1D structures with a band gap of 3.1eV. Beside their high chemical stability, they have beneficial electronic and optoelectronic properties.

Furthermore their fabrication via a hydrothermal growth process is quite simple and inexpensive.

Thus rutile TiO2 nanorod arrays (NRAs) are useful for various applications such as gas sensors [1], supercapacitors [2], photocatalysis devices [3], hybrid solar cells [4], lithium batteries [5], superhydrophobic/superhydrophilic surfaces [6], data storage devices [7] and medical engineering [8]. For many of the listed applications it is advantageous to have positioncontrolled nanorod fabrication techniques available in order to achieve a space-resolved mode of operation. Local gas or molecule sensing, steep gradients on superhydrophobic/superhydrophilic surfaces, local light scattering, high resolution surface roughness gradients or microchannels are important tools for lab-on-achip devices for instance. Here we demonstrate and explain different techniques for the position-controlled growth of rutile TiO2 nanorods on a submicron scale such as advanced optical and electron lithography, focused ion beam milling, advanced scanning probe lithography and a new concept of laser lithography. For all methods we are manipulating the seed layer locally in order to promote or suppress the growth of nanorods.

We developed completely new concepts for scanning probe lithography and laser lithography by inducing either mechanically supported or thermally induced phase transitions in order to get a structured seed layer. We achieved structure sizes with less than 100nm with some of our techniques. Experimental results are shown in the figure below. In the second part the influence of crystal defects and impurities on the optical and electronic properties of rutile TiO2 nanorods is

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shown briefly. Especially the influence on the electrode/TiO2 contact is discussed. Doing so we present the applied measuring techniques as well such as wavelength dependent current over voltage and current over time measurements.

References [1] Tian, W.-C.; Ho, Y.-H.; Chen, C.-H.; Kuo, C.-Y. Sensors, 13 (2013) 865.

[2] Mujawar, S. H.; Ambade, S. B.; Battumur, T.; Ambade, R. B.; Lee, S.-H., Electrochimica Acta, 56 (2011) 4462 – 4466.

[3] Hoffmann, M. R.; Martin, S. T.; Choi, W.; Bahnemann, D.W., Chemical Reviews, 95 (1995) 69–96.

[4] Grätzel, M., Nature, 414 (2001) 338–344.

[5] Natarajan, C.; Setoguchi, K.; Nogami, G., Electrochimica Acta, 43 (1998) 3371 – 3374.

[6] Feng, X.; Zhai, J.; Jiang, L., Angewandte Chemie International Edition, 44 (2005) 5115–5118.

[7] Pickett, M. D.; Strukov, D. B.; Borghetti, J. L.; Yang, J. J.; Snider, G. S.; Stewart, D. R.; Williams, R. S., Journal of Applied Physics, 106 (2009).

[8] Bjursten, L. M.; Rasmusson, L.; Oh, S.; Smith, G. C.; Brammer, K. S.; Jin, S., Journal of Biomedical Materials Research Part A, 92A (2010) 1218–1224.

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Figures

Figure 1. A) About 300nm long TiO2 nanorods grown on 60nm wide linear seeds using electron beam lithography. On the left side the structure is imaged with a reflection electron microscope (REM). On the right side the same structure is imaged with an optical microscope in dark field mode. B) Horizontally grown TiO2 nanorods grown on a sample treated with focused ion beam (FIB) milling. C) About 300nm long rutile TiO2 nanorods grown on a complex structure drawn with a new scanning probe lithography methods on an anatase TiO2 film (top: REM, bottom: optical dark field microscope). D) Microchannel consisting of TiO2 nanorods as side walls on a silicon/TiO2/SiO2 substrate fabricated by laser lithography.

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Electrochemical Properties of TiO2 (Anatase, Rutile) Surfaces: Effects of Flatband Potential

Ladislav Kavan1, Peter Deák2, Jolla Kullgren2, Bálint Aradi2, Thomas Frauenheim2

1

kavan@jh-inst.cas.cz

J. Heyrovsky Institute of Physical Chemistry, v.v.i., Academy of Sciences of the Czech Republic, Dolejskova 3, 18223 Prague 8, Czech Republic 2 Bremen Center for Computational Materials Science, University of Bremen, P.o.B. 330440, D-28334 Bremen, Germany

The electronic band alignment of titania surfaces is of fundamental implication for photocatalysis, solar cells and solar fuel generation (e.g. water splitting).

The position of conduction band (CB) edge controls the reductive photocatalytic reactions, (e.g. hydrogen evolution from water or CO2 reduction), potential of dye-sensitized solar cell (DSC), recombination blocking in perovskite solar cells, etc. However, there is a considerable controversy about the position of CB in TiO2 (anatase, rutile, including the crystals with distinguished facets). [1] Long-time debate concerns the fact that the CB edge of rutile (in contrast to anatase) is not sufficiently upshifted compared to the energy equivalent to the H+/H2 reduction potential. [2] A standard electrochemical tool monitoring the CB edge is the flatband potential. It is measured by Mott-Schottky plots from electrochemical impedance spectroscopy, onset of anodic photocurrent of water oxidation or dark H+ reduction, cyclic voltammetric mapping of DOS including the electron trap states, spectroelectrochemical determination of optical absorbance of CB electrons, etc. The staggered alignment in mixed phases, such as in anatase/rutile, is assumed to enhance photocatalytic activity of titania, but it is widely disputed whether the conduction band edge of rutile or that of anatase is higher. Photoelectron spectroscopy (PES) and most DFT simulations support the former, but the flatband potential measurements provide just opposite results. The controversy can be explained by taking into account the adsorption of OH– and H+ ions from the electrolyte solution on the electrode surface. [3,4] Furthermore, PES indicates that the CB edge of (001)-anatase is upshifted by 0.1 eV referenced to (101)-anatase in agreement with the DFT calculation [5] and with the electrochemical

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flatband potentials [6] (upshift of CB by 60 meV) but there are again some conflicting works claiming the opposite (see Ref. [7] for discussion).

Acknowledgement: This work was supported by the Grant Agency of the Czech Republic (contract No. 13-07724S), by the Grant HHB15 at the Julich Supercomputer Centre (JSC) and HanseWissenschaftskolleg (HWK).

References [1] L. Kavan, Chem. Rec., 12 (2012) 131.

[2] L. Kavan, M. Grätzel, S. E. Gilbert et al., J. Am. Chem. Soc., 118 (1996) 6716.

[3] J. Kullgren, B. Aradi, T. Frauenheim et al., J. Phys. Chem. C, 119 (2015) 21952.

[4] P. Deak, J. Kullgren, B. Aradi et al., Electrochim.

Acta, 199 (2016) 27.

[5] F. De Angelis, G. Vitillaro, L. Kavan et al., J. Phys. Chem. C, 116 (2012) 18124.

[6] R. Hengerer, L. Kavan, P. Krtil et al., J. Electrochem. Soc., 147 (2000) 1467.

[7] B. Laskova, T. Moehl, L. Kavan et al., Electrochim. Acta, 160 (2015) 296.

Figures

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Linear Shear Elasticity and Osmotic Pressure of Concentrated Disordered Ionic Emulsions

Ha Seong Kim1, Frank Scheffold2and Thomas G. Mason1,3

1

hkim@chem.ucla.edu

Department of Chemistry and Biochemistry, University of California- Los Angeles, Los Angeles, CA 90095, USA 2 Physics Department, University of Fribourg, 1700 Fribourg, Switzerland 3 Dep. of Physics and Astronomy. Univ. of California- Los Angeles, CA 90095, USA

We present a free energy model that describes two key thermodynamic properties, the osmotic pressure Π and the linear elastic shear modulus G'p of a disordered system of concentrated deformable emulsion droplets stabilized by ionic surfactants over a range of volume fractions below, near, and above the random jamming point φc. The model unifies existing approaches [1,2,3] by considering entropic, electrostatic, and interfacial (EEI) contributions to a free energy, which depends on the droplet volume fraction φ and the applied shear strain γ. This EEI free energy is minimized with respect to an average deformation parameter that links these three contributions. This minimization reveals that the entropic term is dominant for φ well below φc, the electrostatic term is dominant for φ below φc, and the interfacial term is dominant for φ above φc. The predictions of the model describe measurements of G'p(φ) [4,5] for colloidal emulsions ranging from nanoscale to microscale, and also measurements of Π(φ) for microscale emulsions.

Although emulsions stabilized by ionic surfactants that have been concentrated into disordered structures are technically out-of-equilibrium systems, this nearequilibrium minimization approach nevertheless reasonably predicts the constitutive properties of these systems.

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References [1] Mason TG, Ph.D. Dissertation. Princeton University (1995).

[2] Scheffold F, Wilking JN, Haberko J, Cardinaux F, Mason TG, Soft Matter 10, (2014), 5040-5044.

[3] Mason TG, Scheffold F, Soft Matter, 10, (2014), 7109-7116.

[4] Mason TG, Lacasse MD, Grest GS, Levine D, Bibette J, Weitz DA, Phys Rev E(1997) 56, 3150-3156.

[5] Wilking JN, Mason TG, Phys Rev E, 75, (2007), 041407.

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2D dichalcogenide electronic materials and devices

Andras Kis

Ă&#x2030;cole Polytechnique FĂŠdĂŠrale de Lausanne, Lausanne, Switzerland

andras.kis@epfl.ch

The discovery of graphene marked the start of research in 2D electronic materials which was expanded in new directions with MoS2 and other layered semiconducting materials. They have a wide range of promising potential applications, including those in digital electronics, optoelectronics and flexible devices. Combining 2D materials in heterostructures can increase their reach even further.

I will also update on our efforts to achieve high operation frequencies in scaled TMDC devices.

Next, I will show our work on atomically thin rhenium disulphide (ReS2) liquid-electrolyte gated transistors with atypical behaviour at high charge densities related to the peculiar band structure of this material. Finally, I will present our recent work on electromechanical response of MoS2 and graphene.

In my talk, I will review the status of our research in 2D transition metal dichalcogenides (TMDCs) and present our current level of understanding on the influence of contacts, material quality and the environmental effects on 2D materials, all critical for achieving high performance levels in devices based on 2D semiconductors.

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Highly-Luminescent Colloidal Nanocrystals of Cesium Lead Trihalide Perovskites (CsPbX3, X=Cl, Br, I)

Maksym Kovalenko

ETH Zürich, Department of Chemistry and Applied Biosciences, CH-8093, Zurich, Switzerland and Empa-Swiss Federal Laboratories for Materials Science and Technology, CH-8600, Dübendorf, Switzerland

Chemically synthesized inorganic nanocrystals (NCs) are considered to be promising building blocks for a broad spectrum of applications including electronic, thermoelectric, and photovoltaic devices. We have synthesized monodisperse colloidal nanocubes (415 nm edge lengths) of fully inorganic cesium lead halide perovskites (CsPbX3, X=Cl, Br, and I or mixed halide systems Cl/Br and Br/I) using inexpensive commercial precursors [1]. Their bandgap energies and emission spectra are readily tunable over the entire visible spectral region of 410-700 nm. The photoluminescence of CsPbX3 NCs is characterized by narrow emission line-widths of 12-42 nm, wide color gamut covering up to 140% of the NTSC color standard, high quantum yields of up to 90% and radiative lifetimes in the range of 4- 29 ns.

Post-synthestic chemical transformations of colloidal NCs, such as ion-exchange reactions, provide an avenue to compositional fine tuning or to otherwise inaccessible materials and morphologies. While cation-exchange is facile and commonplace, anion-exchange reactions have not received substantial deployment. Here we present fast, low-temperature, deliberately partial or complete anion-exchange in CsPbX3 NCs. By adjusting the halide ratios in the colloidal NC solution, the bright photoluminescence can be tuned over the entire visible spectral region (410700 nm). Furthermore, fast inter-NC anionexchange is demonstrated as well, leading to uniform CsPb(Cl/Br)3 or CsPb(Br/I)3 compositions simply by mixing CsPbCl3, CsPbBr3 and CsPbI3 NCs in appropriate ratios.

thresholds down to 5±1 µJ cm-2 and high values of modal net gain of at least 450±30 cm-1.Two kinds of lasing modes are successfully realized: whispering gallery mode lasing using silica microspheres as high-finesse resonators, conformally coated with CsPbX3 NCs, and random lasing in films of CsPbX3 NCs.

References [1] L. Protesescu et al. Nano Letters 2015, 15, 3692–3696.

[2] G. Nedelcu et al. Nano Letters 2015, 15, 5635– 5640.

[3] S. Yakunin et al. Nature Communications 2015, 9, 8056.

Figures

We also present low-threshold amplified spontaneous emission and lasing from CsPbX3 NCs [3]. We find that room-temperature optical amplification can be obtained in the entire visible spectral range (440-700 nm) with low pump

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TNT2016 fribourg (switzerland)

Magneto-plasmonic dynamics in gold nanoparticles

Oleksandr Kovalenko, Yu Liu, Mircea Vomir and JeanYves Bigot

Institut de Physique et Chimie des Matériaux de Strasbourg, UMR7504, CNRS, Université de Strasbourg, 23 rue du Loess, BP 43, 67034 Strasbourg, France

bigot@ipcms.u-strasbg.fr

The static magnetic property of plasmonic materials such as gold and silver colloidal nanoparticles has been previously studied with magnetic circular dichroism (MDC) [1] and magnetic Kerr effect [2]. The results show a coupling between the surface plasmons and the external magnetic field. In the present work, using femtosecond optical pulses and a large static magnetic field, we investigate the dynamical properties of the magneto-plasmonic interaction in a single layer of self-organized gold nanoparticles.

Nanoparticles with 10 nm diameter were deposited on a sapphire substrate using the LangmuirBlodgett technique. The strong dipolar interaction between nanoparticles induces a red shift of the surface plasmon resonance (SPR) to 645 nm as compared to the individual one (SPR at 526) [3].

The electron temperature effect the electron damping in the Drude contribution, the occupation state near the Fermi energy and damping of the interband transition [6].

The simulations show a good agreement with the experimental results. Two main mechanisms influence the magneto-plasmon dynamics. First, the coupling between the external magnetic field and free electrons, described with the Voigt model.

Second, a strong coupling between the nanoparticles and the laser field is present when the pump pulses are circularly polarized.

Acknowledgments: This work is supported by the Agence Nationale de la Recherche in France via the project EQUIPEX UNION: # ANR-10-EQPX-52.

References The measurements of the time-resolved reflectivity and magneto-optical Kerr are performed in an external magnetic field of 10 Tesla. The nanoparticles are excited with femtosecond laser pulse with 90 µJ/cm2 and probed with white light continuum pulses generated in a sapphire crystal.

The time dependent magneto-optical response reveals the strong coupling between the pump polarization helicity and the Au nanoparticles both at the interband d→EF transition and at the surface plasmon resonance.

We model these results using two effective medium approximations (Maxwell-Garnet [4] for the short range and Bruggeman [5] for the dipolar interactions) for the reflectivity and in addition the Voigt theory to account for the magnetic response.

[1] M. Artemyev, R. Krutokhvostov, D. Melnikau, V. Oleinikov, A. Sukhanova, I. Nabiev, Plasmonics: Metallic Nanostructures and Their Optical Properties X, 8457 (2010) 10.

[2] B. Sepulveda, J. B. Gonzalez-Diaz, A. GarciaMartin, L. M. Lechuga, G. Armelles, Phys. Rev. Lett., 104 (2010) 4.

[3] Y. Liu, S. Begin-Colin, B. P. Pichon, C. Leuvrey, D. Ihiawakrim, M. Rastei, G. Schmeber, M. Vomir and J.-Y. Bigot, Nanoscale, 6 (2014) 12080–12088.

[4] J. C. M. Garnett, Philos. Trans. R. Soc. Lond., 203 (1904) 385.

[5] D. A. G. Bruggeman, Ann. Phys., 24 (1935) 636.

[6] J.-Y. Bigot, J.-C. Merle, O. C. Régut, A. Daunois, Phys. Rev. Lett., 75 (1995) 4702-4705.

The time dependent dynamics is taken into account via the time-dependent temperatures of the charges and the lattice (two-temperature model).

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Growth of hexagonal gold nanostructures during self-assembling on Ge(001) surface

Franciszek Krok1, N. Gauquelin2, B. R. Jany1, M. Nikiel1, T. Wilhammar2, K. H. W. van den Bos2, A. Janas1, K. Szajna1, D. Wrana1, J. Verbeeck2 and G. van Tendeloo2

1

Jagiellonian University, Institute of Physics, Lojasiewicza 11, PL30384 Krakow, Poland EMAT, University of Antwerp, 171 Groenenborgerlaan, B-2020 Antwerp, Belgium

2

franciszek.krok@uj.edu.pl

Nano sized gold has become an important material in various fields of science and technology such as nanoelectronics, catalysis, nanophotonics and medicine, where control over the size and crystallography of the structures is desired to tailor the functionality. The hexagonal closed packed (hcp) structure of gold is a very unusual form only recently chemically synthesized by Huang et al. [1] in form of graphene-supported thin sheets and nanowires of a few nm in thickness [2] and theoretically studied by Wang et al. [3]. The understanding of electrical as well as physical properties of the system is of great importance and strongly linked to their atomic structure.

temperature. TEM measurements of Au/Ge(001) sample cross sections revealed that the nanoislands created upon annealing at T<640 K are on top of the Ge(001) surface, while for T>640 K part of the island is buried beneath the substrate surface, which confirms the eutectic AuGe melting. The chemical composition of the Au/Ge interface was uncovered using quantitative atomically resolved HAADF-STEM and indicate the absence of alloying.

The crystallographic structure of the Au islands and the presence of hexagonal gold as well as the Au/Ge interface were studied by quantitative atomically resolved HAADF-STEM and their structure was determined.

In the presentation, we will report on studies concerning post-annealing induced nanostructures formation after room temperature deposition of thin film of Au on Ge(001) in UHV. Deposition of 6 ML of Au by MBE resulted in the formation of a continuous Au overlayer as checked by RHEED to be crystalline. Just after deposition, the samples were post-annealed in UHV to temperatures ranging from 473 K to 773 K with different cooling rates.

The self-organized structures, in form of Au nanoislands, were characterized by HR-SEM and HR-STEM methods as well as conductive-AFM and Kelvin Probe Force Microscopy.

References [1] Huang, X., Li, S., Huang, Y., Wu, S., Zhou, X., Li, S., Gan, C. L., Boey, F., Mirkin, C. A. and Zhang, H. Nature Communications 2 (2011). 292.

[2] Fan, Z., Bosman, M., Huang, X., Huang, D., Yu, Y., Ong, K. P., Akimov, Y. A., Wu, L., Li, B., Wu, J., Huang, Y., Liu, Q., Eng Png, C., Lip Gan, C., Yang, P. and Zhang, H. Nat Commun 6 (2015).

[3] Wang, C., Wang, H., Huang, T., Xue, X., Qiu, F. and Jiang, Q. Scientific Reports 5 (2015) 10213.

It has been found that there exists preferential island orientation along crystallographic direction of the substrate surface as provided by diffraction methods (EBSD). For an annealing temperature close to the eutectic temperature of Au/Ge system (640 K), change in size and shape of the Au nanoislands is observed as well as the apparition of the hexagonal phase of gold, indicating eutectic melting of the system. A (011) orientation of the Au islands with respect to the Ge surface was discovered, independently of the annealing

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TNT2016 fribourg (switzerland)

Synthesis and Structural Properties of Magneto-Elastomeric Nanocomposites

Margarita Krutyeva1, Rieke Koll2, Wim PyckhoutHintzen1, Lisa M端ller1, J端rgen Allgaier1, Artur Feld2, Hauke Heller2, Horst Weller2

1

m.krutyeva@fz-juelich.de

J端lich Centre for Neutron Science, Forschungszentrum J端lich GmbH, Germany Intstitute of Physical Chemistry, University of Hamburg, Grindelallee 117, 20146 Hamburg, Germany

2

Recently there is an increasing interest in functional polymer nanocomposites due to emerging novel applications ranging from sensors and plasmonics through stretchable electronics and smart coatings for energy conversion and human health (see e.g.

[1-2]). Further exploitation of the huge potential of functional nanocomposites requires full control of the underlying nanostructure and the interaction between the nanoparticles and the host matrix, e.g. by external fields. The present work is focused on synthesis and consecutive structural investigation of magneto-rheological nanocomposites.

It is known that properties of magneto-rheological nanocomposite materials depend strongly on the distribution of nanoparticles in the nanocomposite and cluster formation. A method to protect those nanoparticles from clustering during the preparation is encapsulation. In this work superparamagnetic iron oxide nanoparticles (SPIONs) [3] encapsulated with a co-polymer embedded in a polymeric matrix were used as nanofiller. For this purpose, a polymer with carbon double bonds (polybutadiene (PB) or polyisoprene (PI)) was used which was cross-linked to stabilize the internal polymer shell surrounding the nanoparticles (see figure 1). For the external polymer shell poly(ethylene oxide) (PEO) was used.

Using scattering methods (SAXS and SANS) and transmission electron microscopy (TEM) we show that the encapsulation of the nanoparticles can be tuned to reach well dispersed SPIONs in polymeric matrix. In addition, the effect of spontaneous chain-like ordering of the nanoparticles without magnetic field was observed (fig.2). In particular, SAXS data analysis using cylinder-sphere model results in about 30% SPIONs participating in chain formation. In average the chains are composed of 3-4 SPIONs.

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These magneto-rheological nanocomposites will be used as a model system for functional nanocomposites based on the magnetic properties of SPIONs and supramolecular polymers [4]. .

References [1] J. Jestin et al., Adv. Mater., 20 (2008) 2533.

[2] A.-S. Robbes et al., Macromolecules 44 (2011) 8858.

[3] C. Chevigny et al., Macromolecules 44 (2011) 122.

[4] http://gepris.dfg.de/gepris/projekt/283337657 ?language=end

Figures

Figure 1. TEM image of encapsulated SPIONs.

Figure 2. SAXS intensity of the nanocomposite based on SPIONs encapsulated in PB-PEO shell. The red line shows a fitting curve with cylinder-sphere model.

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Small is different: emergent paradigms and atomically precise nano stuctures

Uzi Landman

School of Physics, Georgia Institute of Technology, Atlanta, GA 30332-0430, USA

Finite materials systems of reduced sizes exhibit specific forms of aggregation, phases, structures and morphologies, quantized electronic shell structures, dimensionality cross-over, and size-dependent evolutionary patterns, which are manifested in unique, nonscalable, size-dependent physical and chemical properties. Indeed, when the dimensions of materials structures are reduced to the nanoscale, emergent phenomena often occurs, that are not commonly expected, or deduced, from knowledge gained at larger sizes. Discovery, characterization, understanding and possible utilization of such emergent behavior of materials in the nanoscale are among the major challenges of modern materials science. Progress in theses directions is greatly facilitated and enhanced by synthesis, fabrication, separation and measurements of atomically precise nanostructures, and by theoretical investigations of their unique structural, chemical and physical properties. Computer-based quantum computations and simulations are tools of discovery of nanoscale emergent behavior [1]. In this talk we discuss several atomically precise nanostructures, address some of the basic origins that underlie the unique behavior of size-selected materials in the nanoscale, and highlight computational microscopy investigations of nanoscale phenomena in diverse systems. These include: (i) Nanocatalysis by size-selected cluster catalysts of nanometer dimensions [2a] and reassessment of the specific activity and size sensitivity of heterogeneously catalyzed reactions, e.g. ethelene hydrogenation catalyzed by nano-size platinum clusters supported on magnesia or amorphous silica surfaces [2b]; (ii) Monolayer- protected metal nanoclusters [3] and their self-assembled superlattices [3b], exhibiting stabilities and properties originating from superatom electronic shell-closing, atom packing, and interactions between protecting ligands; (iii) The electronic structure and electrical transport characteristics – manifesting Fabry-Pérot interference patterns, described with tight-bonding and a Dirac relativistic formulation with position-dependent mass

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terms – of graphene nanoribbons, GNRs, with atomically precise widths and edges, including segmented GNRs (characterized by width-dependent energy band-gaps) comprised of junctions between nanoribbons of varying width [4]; (vi) Symmetrybreaking and formation of highly-correlated Wigner molecules [5a] in electron quantum dots [5a] and ultracold fermionic atoms, e.g. a few 10-9K 6Li atoms in laser-generated double-well confinements [5b,5c], exhibiting antiferromagnetic ground states modeled with exact numerical solutions of the microscopic Hamiltonian and mapped onto Heisenberg spin-chain and cluster Hamiltonians, as well as the t-J model [5c], suggesting the employment of finite ultracold atom systems in fundamental studies of quantum magnetism and high-Tc superconductivity. *Supported by the Air Force Office of Scientific Research, AFOSR (Grant No. FA9550- 15-1-0519) & the Office Basic Energy Sciences of the US Department of Energy (Grant No. FG05-86ER45234).

References [1] U. Landman, “Materials by Numbers”, Proc. Nat. Acad. Sci. (USA) 102, 6671 (2005).

[2] (a) U. Heiz & U. Landman, Nanocatalysis (Springer, Berlin, 2006). (b) A.S. Crampton, et al.

Nature Comm. 7, Article: 10389 (2016), DOI:10.1038/ncomms10389.

[3] (a) A. Desireddy, et al. Nature, 501, 399 (2013). (b) B.Yoon, et al. Nature Materials, 13, 807 (2014). (c) S. Wickramasinghe, et al., J. Am. Chem. Soc. 119, 10881 (2015).

[4] C. Yannouleas, I. Romanovsky, U. Landman, Sci. Rep. (Nature) 5, 7893DOI: 10.1038/srep07893 (2015).

[5] (a) C. Yannouleas, U. Landman, Rep. Prog. Phys. 70, 206 (2007). (b) B.B. Benedikt, C. Yannouleas, U. Landman, Nano Letters 15, 7105 (2015). (c) C. Yannouleas, B.B. Benedikt, U. Landman, New. J. Phys. 18, 073018 (2016).

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Bio-inspiration of the natural amorphous silica source: the potential use of diatom particles for bone regeneration

Thi Duy Hanh Le 1,2, Antonella Motta 2, Claudio Migliaresi 2

1

Faculty of Materials Technology, Ho Chi Minh of Technology- VNU, 268 Ly Thuong Kiet duyhanhle@hcmut.edu.vn Street, Ho Chi Minh City, Viet Nam 2 Department of Industrial Engineering and Biotech Research Center, University of Trento, Via Sommarive 5, Trento, Italy

Silicon/silicon ion is recognized an essential trace for both bone formation and maintenance. Silicon, in fact, is considered as a nucleation facilitating of the early stage of mineralization as well as an inhibiting factor of bone resorption.

Here we were to take inspiration from the natural source of amorphous silica/silicon, diatomite/diatom skeletons, for the fabrication of bone tissue scaffold containing silicon as bioactive component. Diatom microparticles – DMPs (1 - 10 µm) and nanoparticles DNPs (around 150nm of average particle size) were successfully produced by fragmentation of purified diatom skeletons under the alkaline condition. Both DMPs and DNPs were able to release silicon detected by inductively coupled plasma optical emission spectrometry (ICP/OES); and moreover, these particles showed minimal or non-cytotoxic effects in-vitro as determined by lactate dehydrogenase assays on cell cultures. These results suggest that diatom particlesderived from diatom skeletons could be used as a silicon donor for bone tissue engineering.

To handle this goal, silk fibroin scaffolds loaded diatom particles with different amounts and size of diatom

particles were fabricated by using the salt leaching method. In comparison to the pure silk fibroin scaffold, scaffolds loaded with diatom particles strongly enhanced cell adhesion, cell proliferation as well as the early bone formation in terms of collagen type I synthesis evaluation, osterix expression and alkaline phosphatase induction assessed on human osteosarcoma cell line MG63. These findings provided strong evidence for a potential use of diatom particlesderived from natural diatom skeleton in biological applications, in particular for bone tissue regeneration.

References [1] Beck, G.R; Ha, S.W; Camalier, C. E; Yamaguchi, M; Li, Y; Lee, J. K; Weitzmann, M. N. Nanomedicine: Nanotech. Biol. Med. 2012, 8 (6), pp 793–803.

[2] Mestres, G; Le Van, C; Ginebra, M. P. Acta Biomater. 2012, 8 (3), pp 1169–1179.

[3] Altman, G. H; Diaz, F; Jakuba C, Calabro, T; Horan, R.- L; Chen, J; Lu, H; Richmond, J; Kaplan; D. L. Biomaterials, 2003, 24(3), pp 401–416.

Figures Figure 1. SEM micrographs of diatom frustules (A) and diatom micropartilces -DMPs) - derived from its frustules (B), TEM micrograph diatom nanoparticles DNPs) (C); Confocal scanning laser microscopy of sample stained with specific antibody for collagen type I (red) occurred after 7 days of culture of the pure silk fibroin - SF (D), the SF loaded DMPs (E) and SF loaded DNPs (F) and DAPI for nuclei (blue).

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Carbon nanotubes micromechanical and chemical sensors: Reproducibility, reliability analysis and deployment in real use cases

Bérengère Lebental1,2, Laurence Bodelot3

1

berengere.lebental@polytechnique.edu

Université Paris-Est, IFSTTAR, COSYS, Marne la Vallée, France.

Laboratoire de Physique des Interfaces et Couches Minces (LPICM), UMR 7647, Ecole Polytechnique-CNRS, Palaiseau, France 3 Laboratoire de Mécanique des Solides (LMS), UMR 7649, Ecole Polytechnique-CNRS, Palaiseau, France 2

While today’s galloping urbanization weighs heavily on both People and Environment and while Climate Change increases natural risks worldwide, Internet of Things Technologies stand at the forefront of the efforts toward Greener Cities. Nanosensors fully integrated into wireless sensor node may become instrumental in this field because of their small size, low cost, versatility and low power consumption.

Potential applications are environmental monitoring, structural health monitoring, energy performances monitoring or people exposure monitoring.

Challenges range from the manufacturing of the sensors with high reproducibility to their full integration into communicating devices, including ensuring device reliability in complex and harsh environmental conditions.

Carbon nanotubes (CNT) especially are choice material toward this goal, as they have demonstrated both a very strong sensitivity to a variety of environmental parameters and a strong resilience to chemical and mechanical stress. In the present paper, we present a full proof of concept of the use of carbon nanotubes micromechanical and chemical sensors practical use cases, from the reproducible fabrication of the carbon nanotubes sensors [1] to their practical deployment in real life [2]. Two specific examples are discussed, infrastructure durability monitoring and water quality monitoring. Specific methodologies for reliability analysis of carbon-based nanomaterials are also discussed.

References [1] Michelis et al., Carbon, 2015, 1020-1026.

[2] Michelis et al., IEEE NEMS, 2016.

Figures

Figure 1. Batch fabrication of carbon nanotube sensors by inkjet printing.

Figure 2. Outdoor deployment of CNT sensors in SenseCity demonstrator.

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Towards Adaptive Functional Materials and Nanoarchitectures

Jean-Marie Lehn

ISIS, Université de Strasbourg, France

Supramolecular chemistry is actively exploring systems undergoing self-organization, i.e. systems capable of spontaneously generating well-defined functional supramolecular architectures by selfassembly from their components, on the basis of the molecular information stored in the covalent framework of the components and read out at the supramolecular level through specific interactional algorithms, thus behaving as programmed chemical systems. It allows for the spontaneous but controlled generation of well-defined, functional molecular and supramolecular architectures of nanometric size. It represents a means of performing programmed engineering and processing of functional nanostructures.

Supramolecular entities as well as molecules containing reversible bonds are able to undergo a continuous change in constitution by reorganization and exchange of building blocks.

This capability defines a Constitutional Dynamic Chemistry (CDC) on both the molecular and supramolecular levels. CDC allows for the generation of dynamic materials and nanoarchitectures, which may operate component selection in response to external stimuli or environmental factors and therefore behave as adaptive functional materials and nanoarchitectures of either molecular or supramolecular nature. Applying the previous considerations to polymer chemistry leads to the definition of constitutionally dynamic polymers, DYNAMERS, of both molecular and supramolecular types.

evolutive chemistry, towards systems of increasing complexity.

References [1] Lehn, J.-M., Supramolecular Chemistry: Concepts and Perspectives, VCH Weinheim, 1995.

[2] Lehn, J.-M., Programmed chemical systems : Multiple subprograms and multiple processing/expression of molecular information, Chem. Eur. J., 2000, 6, 2097.

[3] Lehn, J.-M., Toward complex matter: Supramolecular chemistry and selforganization, Proc. Natl. Acad. Sci. USA, 2002, 99, 4763.

[4] Lehn, J.-M., From supramolecular chemistry towards constitutional dynamic chemistry and adaptive chemistry, Chem. Soc. Rev., 2007, 36, 151.

[5] Lehn, J.-M., Chapter 1, in Constitutional Dynamic Chemistry, ed. M. Barboiu, Topics Curr. Chem, 2012, 322, 1-32.

[6] Lehn, J.-M., Perspectives in Chemistry – Steps towards Complex Matter, Angew. Chem. Int. Ed., 2013, 52, 2836-2850.

[7] Lehn, J.-M., Perspectives in Chemistry – Aspects of Adaptive Chemistry and Materials, Angew.

Chem. Int. Ed., 2015, 54, 3276-3289.

These approaches have been implemented in the generation of functional organic and inorganic materials and nanostructures for molecular and supramolecular electronics, optics and mechanics.

They point to the emergence of adaptive and

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Sol-gel synthesis, micro-Raman studies and magnetic characterization of ε-Fe2O3 micro- and nanoparticles embedded in a SiO2 matrix

J. López-Sánchez 1,2, A. Serrano 3, A. Muñoz-Noval 4, L. Pérez 1, M. Abuín 1,5, A. del Campo 6, J. de la Figuera 2,7, J.F. Marco 2,7, N. Carmona 1,2, O. Rodríguez de la Fuente 1,2

1

jesus.lopez@ucm.es

Dpto. de Física de Materiales, Univ. Complutense de Madrid, 28040 Madrid, Spain Unidad Asociada IQFR(CSIC)-UCM, 28040 Madrid, Spain 3 SpLine, Spanish CRG beamline at the ESRF, F-38043 Grenoble, CEDEX09 France and Instituto de Ciencia de Materiales de Madrid, CSIC, Cantoblanco, 28049 Madrid, Spain 4 Department of Applied Chemistry, Hiroshima University, Higashihiroshima, Hiroshima, 739-8527, Japan 5 CEI Campus Moncloa, UCM-UPM, 28040 Madrid, Spain 6 Instituto de Cerámica y Vidrio, CSIC, 28049 Madrid, Spain 7 Instituto de Química-Física “Rocasolano”, CSIC, 28006 Madrid, Spain 2

The ε-polymorph of iron (III) oxide shows very

attractive properties, among them, its giant coercive field (around 2 T at room temperature, RT), its magnetoresistance or its millimeter wave ferromagnetic resonance (FMR) [1]. For these outstanding properties, ε-Fe2O3 nanoparticles are good candidates for the development of applications in fields such as electronics, as well as in a new generation of hard-magnets without rare-earth compounds. In the present work, we describe different synthesis routes in order to obtain εnanoparticles embedded in a SiO2 matrix in powder form and as films deposited on Si(100) [2]. We have been able to fabricate ε-Fe2O3 nano- and microparticles, depending on the sol-gel path followed and the subsequent final thermal treatment chosen. We have investigated the magnetic properties spanning a wide range of temperatures and an extensive structural and morphological characterization of the samples is also carried out by Transmission Electron Microscopy (TEM), Scanning Electron Microscopy (SEM), X-ray Diffraction (XRD) and Confocal Raman Microscopy (CRM) [2,3]. Specially, CRM is employed in order to identify the α-phase from other iron oxides. In this sense, the evolution of the Raman spectra as a function of the temperature is analysed and compared in each case. Nevertheless, other phenomena are also studied, such as the structural transition from α-phase to α-phase varying the output laser power, or the behavior when the material undergoes a Néel transition at 500 K [2].

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References [1] L. Machala, J. Tucek, and R. Zboril, Chem.

Mater., 23, 2011, 3255.

[2] J. López-Sánchez, A. Serrano, A. del Campo, M. Abuín, O. Rodríguez de la Fuente, and N. Carmona, Chem. Mater. 28, 2016, 511.

[3] J. López-Sánchez, A. Muñoz-Noval, A. Serrano, M. Abuín, J. de la Figuera, J. F. Marco, L. Perez, N. Carmona and O. Rodríguez de la Fuente, "accepted in RSC Advances".

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Study of covalent grafting of Fluorescein Isothiocyanate on double-walled carbon nanotubes

Thomas Lorne1,2 Jean-Marc Escudier2 , Mónica Jiménez-Ruiz1 , Pierre Lonchambon2 , Stéphane Rols1 , Cyril Sarrieu2 , Emmanuel Flahaut2

1

lorne@ill.fr

Institut Laue Langevin, Grenoble, France CIRIMAT, UMR CNRS 5085 Université Paul Sabatier, Toulouse, France

2

Over the past decades the popularity of Carbon nanotubes (CNTs) rose drastically and made them the subject of an intense research effort. Nowadays, new applications for CNTs are found each year, leading to foresee an increase of their production and their use for new nanomaterials. Therefore, it became not only legitimate but also necessary to study their toxicity and environmental impact.

happen while the functionalization process. In addition to the combination of those techniques, DFT calculations are performed, expecting deriving quantitative information and distinguish between simple adsorption and covalent grafting for a given molecule.

The use of those CNTs always requires their dispersion which is generally obtained through their functionalization. In the case of covalent grafting, the question of the competition between real grafting and simple adsorption (also likely to happen) is very relevant and has never been really investigated in a rigorous way. This question is however a central one in many current debates, and especially in the field of nanotoxicology and biomedical applications [1a-l] of CNTs, where their functionalization by fluorophores is used to track the latter inside cells. The visualization of the fluorescence is then naturally associated to that of the CNTs. However, fundamental questions are raised as there is no simple evidence that a fluorescent molecule simply adsorbed onto a CNT will indefinitely stay there once inside a cell. In order to answer those questions we chose to deeply investigate the covalent grafting of the Fluorescein Isothiocyanate (FITC, fluorophore commonly used for toxicity studies) onto Double-walled carbon nanotubes (DWCNTs) [2]. The aim of the work presented here is to fully understand the mechanisms involved behind the three steps of the functionalization process (1- Carboxylation of the DWCNTs, 2- Grafting of 1,4-diaminobutane as a linker, 3- Grafting of FITC) [3][4], by using different experimental techniques such as Transmission Electronic Microscopy, Raman spectroscopy, X-ray Photo-electron Spectroscopy and Neutron Vibrational spectroscopy. The preliminary results obtained with XPS and Neutron spectroscopy already seem to indicate that both covalent and non-covalent grafting

[1a] C. Salvador-Morales, E. Flahaut, et al., Molecular Immunology, 43, (3), (2006), 193.

[1b] E. Flahaut, et al., Carbon, 44, (6), (2006), 1093.

[1c] J. Cheng, E. Flahaut, S. H. Cheng, Environmental Toxicology and Chemistry, 26, (4), (2007), 708.

[1d] F. Mouchet, P. Landois, E. Flahautet al., Nanotoxicology, 1, (2), (2007), 149.

[1e] F. Mouchet, et al., Aquatic Toxicology, 87, (2), (2008), 127.

[1f] F. Mouchet, et al., Nanomedicine, 5, (6), (2010), 963.

[1g] K. W. Kwok, et al.,, Nanomedicine, 5, (6), (2010), 951.

[1h] D. Crouzier, et al.,, Toxicology, 272, (1-3), (2010), 39.

[1i] V. Neves, et al., Adv. Funct. Mater., 20, (19), (2010), 3272.

[1j] V. Sanz, et al.,Carbon, 49, (15), (2011), 5348.

[1k] E. Meunier, et al. Nanomedicine, 8, (6), (2012), 987 (DOI:10.1016/j.nano.2011.11.004).

[1l] V. Neves, et al. Nano Research, 5.

[2] E. Flahaut et al., Chem. Commun., (2003), 14421443.

[3] T. Bortolamiol et al. Double-walled carbon nanotubes: Quantitative purification assessment, balance between purification and degradation and solution filling as an evidence of opening.

Carbon 78, 79–90 (2014).

[4] T. Bortolamiol. Nanotubes de carbone biparois : fonctionnalisation et détection in vitro.

(Université Paul Sabatier).

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References

september 05-09, 2016

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Solution-processed nanostructured overcoats for renewable catalysis

Jeremy S. Luterbacher, Florent Héroguel and Benjamin le Monnier

Laboratory of Sustainable and Catalytic Processing, Institute of Chemical Sciences and Engineering, École Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland

Thanks to its wide availability and relatively low cost, lignocellulosic biomass is an attractive source of renewable carbon. However, unlike petroleum, biomass-derived molecules are highly oxygenated, have low volatility, and are often produced in dilute-aqueous streams. Heterogeneous catalysts – the workhorses of the chemical and fuel industries – are often sensitive to water and contain many metals that easily sinter and leach in liquid-phase conditions.

Catalyst overcoating presents a potential solution to this problem. Recent breakthroughs using catalyst overcoating with atomic layer deposition (ALD) showed that base metal catalysts can be stabilized against sintering and leaching in liquid phase conditions. However, ALD is ill suited for commercial catalyst production, creates dramatic drops in activity due to excessive surface coverage and forms an overcoat that is difficult to tune.

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To address these limitations, we are developing layer-by-layer solution-processed catalyst overcoating methods to stabilize heterogeneous catalysts. We achieve the deposition of oxide coatings with nanometer-level control by using subsequent injections of stoechiometically-limited amounts of alkoxide precursors and water. By depositing these solution processed overcoats over Cu/Al2O3, we were able to stabilize this base metal catalysts for use in liquid phase biomass conversion reactions while maintaining a much higher access to the metal sites. Furthermore, liquid phase processing chemistry offers several parameters for controlling the overcoat properties including the chosen solvent, the stoichiometric ratio of precursors, the use of acid catalysts, post synthesis treatments, etc. By tuning synthesis parameters, we hope to both improve stability and introduce shape-selectivity on metal nanoparticle catalysts.

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Nanoscale magnetic imaging with single electronic spins

Patrick Maletinsky

Basel University, Department of Physics, Quantum Sensing Group 4056 Basel, Switzerland

An isolated electronic spin can yield a close-to-ideal magnetometer to investigate magnetic phenomena on the nanoscale [1]. Spins are natural magnetometers by virtue of their Zeeman response to magnetic fields. Additionally, quantum coherence and control can be exploited to tailor their response towards excellent magnetic field sensitivities. Lastly, such spins can be localized to atomic length scales, which enables nanoscale resolution in imaging. The electronic spin of the Nitrogen-Vacancy center in diamond has been identified as a particularly fruitful system to implement these concepts [2]. It combines the above benefits with the ability of optical spin readout and initialization and operates from cryogenic temperatures to ambient conditions, all while maintaining exceptional quantum coherence properties. In the best case, this results in a noninvasive and quantitative magnetometer with single-spin sensitivity and nanoscale spatial resolution - a device with many highly promising applications in science and technology.

In my talk I will present recent activities of the quantum sensing group at the University of Basel in nanoscale NV magnetometry of condensed-matter systems. Specifically, I will describe our experimental approach to realizing such quantum magnetometers and discuss two systems we currently investigate using this technique. I will discuss an experiment where we employ scanning NV magnetometry to image individual vortices in the high-temperature superconductor YBa2Cu3O, [3] and some more recent findings, where we were able to image and study domains in the magnetoelectric antiferromagnet Cr2O3. In both cases, NV magnetometry allowed us to quantitatively determine essential system parameters of the materials under study - the London penetration depth for YBCO and the surface magnetic moment density for Cr2O3. Both

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are central quantities for the understanding of the respective materials, and both have been notoriously hard or impossible to determine using previously existing experimental approaches. Our results therefore illustrate the power of NV magnetometry in exploring local magnetic properties of electronic systems with nanoscale resolution and the promise our technology holds for future exploration of complex, condensed matter systems.

References [1] Chernobrod, B. et al., J. Appl. Phys. 97, 01490.

[2] Taylor J. et al., Nature Phys. 4, 810, Maletinsky P., et al., Nat. Nanotechnology 7, 320.

[3] Thiel L. et al., Nature Nanotechnology, 10.1038/nnano.2016.63.

Figures

Figure 1. a.) Schematic of single spin based quantum sensing: A diamond scanning probe (blue) contains a single nitrogen vacancy (NV) spin and is used for nanoscale magnetic imaging. b.) Stray magnetic field of an isolated vortex in the hightemperature superconductor YBa2Cu3O7 , imaged by scanning NV magnetometry at 4 K. The quantitative image yields a ~10 nm spatial resolution and was obtained at a 0.5 magnetic field sensitivity ~1 ÎźT/Hz .

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Persistence Length of Cationic Dendronized Polymers From AFM Images

Plinio Maroni, Lucie Grebikova, Svilen Kozhuharov, Andrey Mikhaylov, Giovanni Dietler, Dieter SchlĂźter, Magnus Ullner, Michal Borkovec

Department of Inorganic and Analytical Chemistry, University of Geneva, Sciences II, 30 Quai ErnestAnsermet, 1205 Geneva, Switzerland

Plinio.maroni@unige.ch

The persistence length (PL) of dendronized polymers adsorbed on substrates was investigated by atomic force microscopy image analysis. Cationic dendronized polymers from generation 1 to 4 (PG1 - PG4) were prepared in solutions with different electrolyte concentrations and subsequently adsorbed on mica, silica, gold, and highly oriented pyrolytic graphite (HOPG). The adsorbed polymers were imaged in the respective electrolyte solutions with a Cypher AFM in amplitudemodulation (AC) mode. The PL of the adsorbed polymers was determined with an image analysis software, whereby the backbones of the polymeric chains were traced and their lateral coordinates recorded (Figure 1). Our measurements show that the PL increases with increasing polymer generation and decreases when raising the salt concentration (Figure 2). When the polymers are adsorbed on mica, PG1 and PG2 show a stronger variation with ionic strength if compared to PG3 and 4. One can rationalize this behavior by assuming that the efficiency of screening the electrostatic interactions between the charged groups at the polymer backbone might be reduced as the generation is increased and the nature of the surface is changed.

While consistent results are obtained from mica, silica, and gold, noticeable differences are observed when polymers are adsorbed on HOPG. Since this surface is weakly charged and highly hydrophobic, the electrostatic contribution to the persistence length is smaller. On HOPG, specific moleculesurface interactions might play an important role.

Figures

Figure 1. AFM topography of two PG3 molecules adsorbed on mica at pH 4 and at 1 mM KCl concentration. Black lines represent the tracings of the backbones.

Figure 2. PG4 adsorbed at low (left) and high (right) salt levels. At low salt level, the electrostatic repulsion between the charged groups on the dendrons results in a more stretched configuration.

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Graphene Solar Cells fabricated with an Automated Graphene Transfer System 1

Instituto de Sistemas Optoelectrónicos y Microtecnología, UPM, Madrid, Spain Dpto. de Ciencia de Materiales, E.T.S.I de Caminos, Canales y Puertos, Spain 3 Dpto. de Ingeniería Electrónica, E.T.S.I de Telecomunicación, UPM, Madrid, Spain 4 Unidad de Energía Solar Fotovoltaica, CIEMAT, Madrid, 28040, Spain 5 Unidad de Electrónica, CIEMAT, Avda. Complutense 40, Madrid, 28040, Spain 6 Division de Quimica, CIEMAT, Avda. Complutense 40, Madrid, 28040, Spain 2

Although graphene grown by chemical vapor deposition (CVD) has proven to be an excellent material for electronic applications, an inconvenience of this method is the need of transferring the thin graphene layer from the initial metal catalyst to a suitable final substrate. A manual transfer method [1] was developed in order to overcome this issue. It consists of protecting the graphene with a polymer layer, wet-etching the growth substrate, cleaning with deionized water and finally depositing the resulting polymer/graphene membrane onto the desired target substrate. Some drawbacks of this method are that it requires handling skills to perform it, that it is time consuming, and that it is not suitable for an industrial process. An optimized method based on a roll-to-roll system [2] can overcome some of the manual method limitations, but it is mainly focused on flexible, transparent electrodes applications, hence its use for laboratory scale is not convenient due to the initial high investment needed, the typical sample size used or the limitation to flexible substrates.

We report a lab-scale system designed to automatically transfer graphene to arbitrary substrates, but we adapted it for industrial applications like solar cells. The system is composed of several modules that control the process temperature, the liquid flow and the overall system state. A microcontroller is used as the real-time control. The passive components of the system are depicted in Fig. 1. A PTFE tube encloses the graphene sample during the whole process. This enclosing tube has a surface treatment that centers the polymer/graphene membrane that floats inside it. The treatment avoids mechanical stress or induced ripples in the graphene during the process.

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Javier Martinez1, 2, A. Boscá1, 3, J. Pedrós1, 3, S. Fernandez4, J. Carabe4, A. Molinero5, I. Rucandio6, R. Fernandez-Martinez6, A. J. Quejido6, F. Calle1, 3 javier.martinez@isom.upm.es

A fixed platform and a substrate holder ensure a fixed position between the final solar cell and the tube center. All this pieces are immersed in a liquid, starting with an etchant solution and changing gradually into deionized water for the final steps.

Finally, graphene solar cells were processed using a manual method and our automatic method for comparison, showing higher mobilities and less charge impurities for the latter one.

Acknowledgements Supported by MINECO projects RUE (CSD2009-0046) and GRAFAGEN (ENE201347904-C3).

References [1] A. Reina, X. Jia, et al., Nano Lett., vol. 9, 1 (2009), p. 30.

[2] S. Bae, H. Ri Kim, et al., Nat. Nanotechnol., vol.

5, (2010), p. 1.

Figures

Figure 1. Automated transfer system.

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Computational Exfoliation of All Known Inorganic Materials

Nicola Marzari

Theory and Simulation of Materials (THEOS), and National Centre for Computational Design and Discovery of Novel Materials (MARVEL), École Polytechnique Fédérale de Lausanne, CH-1015 Lausanne, Switzerland

nicola.marzari@epfl.ch

We use extensive, high-throughput first-principles calculations to identify novel 2D materials that can be exfoliated from known parent compounds.

Starting from 480,000 non-unique structures harvested from experimental databases of crystal structures (ICSD [1] and COD [2]), we identify first 6400 unique inorganic materials that appear layered according to simple geometric and bonding criteria. Then, quantum simulation based on vander-Waals-corrected density-functional theory are used to assess the metallic, insulating or magnetic character of the 3D parents and of the individual 2D layers, together with their binding energies, leading to the identification of a 2D portfolio of 1800 candidate structures that are layered and weakly, van-der-Waals bound. Full phonon dispersions are computed to assess mechanical or charge-density wave instabilities. This large portfolio of prospective materials can now be explored for optimal properties and performance, or to observe the emergence of exciting physical properties; such work is made possible and straightforward by the

development within the Swiss MARVEL NCCR of the AiiDA materials' informatics platform [3] for computational science – exploiting in this case its automated-workflows engine, database structure, sharing capabilities, and pipelines to and from crystallographic repositories.

Work done in collaboration with Nicolas Mounet, Philippe Schwaller, Andrea Cepellotti, Andrius Merkys, Ivano Eligio Castelli, Marco Gibertini and Giovanni Pizzi.

References [1] http://www.fizkarlsruhe.com/icsd.htm [2] S. Grazulis et al, Nucleic Acids Research, 40, D420 (2012).

[3] G. Pizzi, A. Cepellotti, R. Sabatini, N. Marzari and B. Kozinsky, Comp. Mat. Sci. 111, 218 (2016).

Figures

Figure 1. A few 3D layered materials, and their 2D counterparts, identified with high-throughput first-principles simulations.

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Functional polymer-lipid membranes

Wolfgang Meier

Department of Chemistry, University of Basel, Switzerland

wolfgang.meier@unibas.ch

Similar to conventional surfactants or lipids also suitable amphiphilic block copolymers can selfassemble in aqueous media to micelles or membrane-like superstructures. The physical properties of these membranes can be controlled via the chemical constitution, the molecular weight and the hydrophilic-to-hydrophobic block length ratio of these polymers For that purpose we synthesized and characterized a whole series of related block copolymers [1]. Interestingly such systems offer also the possibility of controlled drug encapsulation and release [2,3]. Compared to conventional low molar mass blocks, membranes based on macromolecular self-assembly, can not only have the advantage of superior stability and toughness, but in addition offer numerous possibilities of tailoring physical, chemical and biological properties since many functions can be implemented simultaneously in one single macromolecule [1].

Interestingly systematic experiments indicate that mixtures of phospholipids and block copolymers or block copolymers with other block copolymers can form membranes in aqueous media consisting of phase separated copolymer domains. Depending on their composition, the thickness of the polymer and/or phospholipid domains and their viscosity, we observed a systematic influence on insertion of proteins into a preferred domain and their local mobility [5].

References [1] C.G. Palivanet al., Chem. Soc. Rev. 2016, 45, 377.

[2] X. Zhanget al. Biomaterials 2016 89, 79.

[3] D. Najer et al. Meier ACS Nano 2014, 8(12), 12560.

[4] F. Itel et al. Macromolecules 2014 47, 7588; F. Itel et al Nano Letters, 2015 15(6), 38718.

[5] J. Kowalet al. Langmuir, 2015, 31, 4868.

Well-defined functions can also be introduced by combining these superstructures with suitable functional units from Nature, e.g., by incorporation of integral membrane proteins. It has to be emphasized many integral membrane proteins can be functionally reconstituted in block copolymer membranes despite the considerable dimensional mismatch between the membranes and the proteins [4].

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Extended and local phonon mode identification in a silicon nanowire by 1/f noise spectroscopy 1

National Institute for Research and Development in Microtechnologies (IMT), 126A, Erou I. Nicolae str., 077190, Bucharest, Romania 2 CEA-LETI, Grenoble, France 3 U. Southampton-UK 4 Honeywell Romania

Current has been injected into a suspended, borondoped silicon nanowire (Fig. 1a, 200nm length and 16.9nm diameter) and the voltage (V) developed across its terminals has been Fourier transformed.

1/f–like noise spectra were found. Since nanowire I-V characteristic is linear (Ohm law valid), the normalized noise intensity (SV/V2) should be independent of voltage. By contrast, we show that local deviations from the Ohm’s law occur in SV/V2 vs. V at voltages corresponding to phonon energies of both silicon and impurities existing in nanowire [1].

M. Mihaila1, C. Dupre2 , E. Ollier2 , Y. Tsuchiya3 , H. Mizuta3 , A. Dinescu1 and C. Cobianu4

Mihai.Mihaila@imt.ro

Acknowledgement: Results obtained in the EU project NEMSIC, Grant agr. No. 224525, 2008-2012.

References [1] [2] [3] [4]

M. Mihaila, US patent, US 7612551 B2 (2009).

A. G. Chynoweth et al., Phys. Rev. 3 (1962) 877.

R. A. Logan et al., Phys. Rev. 6A (1964) 1751.

M. Balkanski and W. Nazarewicz, J. Phys. Chem.

Solids 27 (1966), 671.

Figures The nanowire has been “scanned” in the (0<V<100)mV voltage range, with a ΔV=0.5 mV voltage step, at room temperature. The dependence of SV/V2 vs. V is shown in Fig. 2.

Although the structure in noise is complicated, one can observe the existence of some dominant peaks at 18.54, 57.34, 76.72 and 79.35 mV, respectively. A comparison with the silicon phonon spectrum, measured by inelastic tunneling spectroscopy at 4.2K [2] and 0.8K [3], respectively, revealed that the most intense noise peaks at 18.54 and 57.34 mV correspond to the transversal TA and TO extended phonon modes in silicon, respectively. The noise peaks at 76.7meV and 79.3meV correspond to 76.9meV and 79.9meV local vibration modes of boron in silicon lattice, respectively [4]. The total number of boron atoms in the nanowire was estimated at 3. Apparently, the method is sensitive to a few atoms in the nanowire matrix. Also, the far infrared local modes of the interstitial oxygen were identified at V<7meV (not shown). 14 hours after measurement, the nanowire was broken (Fig. 1b), most probably due to the high current density (>107A/cm2) in it.

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Figure 1. SEM images of the nanowire before (a) and 14 hours (b) after measurements.

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Figure 2. Noise data (a) vs. tunneling spectra at 4.8K [2](b) and 0.8K [3] (c).

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Probing Nanometer-Ranged Attraction between Similar and Dissimilar Surfaces in Presence of Polyamine Cations

Mohsen Moazzami Gudarzi, Gregor Trefalt, Istvan Szilagyi, Plinio Maroni, Michal Borkovec

Department of Inorganic and Analytical Chemistry, University of Geneva, Sciences II, 30 Quai Ernest-Ansermet, 1205 Geneva, Switzerland

mohsen.moazzami@unige.ch

Colloidal probe force microscopy was employed to measure forces between positively charged amidine latex (AL) and negatively charged sulfate latex (SL) particles [1, 2]. Surface forces between all possible pairs, namely AL-AL, AL-SL and SL-SL, are measured in aqueous solutions of an aliphatic hexamines (N6) and KCl. The force profiles can be described by the classical theory of Derjaguin, Landau, Verwey, and Overbeek (DLVO) down to distances of about 7nm, provided that PossionBoltzmann equation is used [3]. However, at interparticle distances below few nanometers, additional attractive non-DLVO forces are observed in all the systems. These forces can be modelled with an exponential force profile. The range of these forces is shorter in the presence of monovalent ions and is about 0.3nm. But, in the presence of N6, the range of this attraction is about 1.0 nm in the SL–SL system, 0.6 nm in the AL–SL system, and 0.3 nm in the AL–AL system.

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References [1] M. Moazzami-Gudarzi, G. Trefalt, I. Szilagyi, P. Maroni, M. Borkovec, Phys. Chem. Chem. Phys., 18 (2016) 8739-8751.

[2] M. Moazzami Gudarzi, G. Trefalt, I. Szilagyi, P. Maroni, M. Borkovec, J. Phys. Chem. C, 119 (2015) 15482-15490.

[3] F. J. Montes Ruiz-Cabello, G. Trefalt, P. Maroni, M. Borkovec, Langmuir, 30 (2014) 4551-4555.

TNT2016 fribourg (switzerland)

How fast can we melt ordered phases in low dimensional materials?

University of ZĂźrich, Department of Physics, 8057 ZĂźrich, Switzerland

Low-dimensional crystalline materials tend to undergo phase transitions to new ground states at low temperature, exhibiting long-range order or exotic properties like a condensate of quasiparticles. Such a new ground state is often accompanied by the opening of a band gap in the electronic structure, like in the case of charge and spin density wave phases or superconductivity.

Angle-resolved photoemission spectroscopy (ARPES) is a method of choice to investigate these materials, as it directly measures their electronic structure in the reciprocal space and therefore gives access to their electronic band gap.

TNT2016 fribourg (switzerland)

Claude Monney

monney@physik.uzh.ch

Here I will address the real-time dynamics after photoexcitation of ordered phase like in charge and spin density wave phases, as well as the case of an exciton condensate. This is experimentally achieved in time-resolved ARPES, for which the investigated sample is perturbed by infrared pump photon pulses and probed subsequently on the femtosecond timescale by ultraviolet probe pulses.

I will discuss how fast the ordered phase can be destroyed by the photoexcitation and how it recovers afterwards. I will also present the case of non-equilibrium phases which can be transiently generated and persist during a few hundreds of femtoseconds.

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Triggering large property changes in stimuli-responsive supramolecular polymers

Lucas Montero de Espinosa1, Luis M. Olaechea1, Rebecca A. Olson2, Diederik W. R. Balkenende1, Sandor Balog1, Christoph Weder1

1

lucas.montero@unifr.ch

Adolphe Merkle Institute, University of Fribourg, Chemin des Verdiers 4, CH-1700 Fribourg, Switzerland.

2 Department of Macromolecular Science and Engineering, Case Western Reserve University, 2100 Adelbert Road, Kent Hale Smith Bldg, Cleveland, OH 44106-7202, USA

Supramolecular polymers are macromolecular assemblies of monomeric units held together via noncovalent interactions such as hydrogen bonding, metal-ligand complexation, host guest interactions or ion pairing. [1] The dynamic nature of supramolecular polymers makes them perfectly suited for the development of materials that enable stimuli-triggered functions including healing, chromism or changes in shape and stiffness. [2] Most supramolecular polymers reported in the literature are phase segregated systems consisting of a low glass transition temperature (Tg) phase and a crystalline hard phase, which physically crosslinks the material and provides mechanical coherence. [3] This design approach provides access to elastomeric stimuli-responsive polymers in which the hard phase dominates the thermomechanical properties. Alternatively, phaseseparation can be prevented if the supramolecular monomers are designed to assemble into amorphous, high-Tg networks, which display a completely different set of properties. [4]

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This contribution will discuss the use of both approaches in the synthesis of several new supramolecular polymer systems with the objective to make new functions accessible. Aspects that will be emphasized in this presentation include the structure-property relationships of the various designs, new materials that permit the in-situ formation of metal nanoparticles and the debonding on demand of supramolecular adhesives.

References [1] Yang, L.; Tan, X.; Wang, Z.; Zhang, X. Chem. Rev. 15 (2015) 7196-7239.

[2] a) Yan, X.; Wang, F.; Zhenga, B.; Huang, F. Chem. Soc. Rev., 41 (2012), 6042-6065. b) Montero de Espinosa, L.; Fiore, G. L.; Weder, C.; Foster, E. J.; Simon, Y. C. Prog. Polym. Sci. 49 (2015), 60-78.

[3] Wojtecki, R. J.; Nelson, A. J. Polym. Sci., Part A: Polym. Chem. 54 (2016), 457-472.

[4] Balkenende, D. W. R.; Olson, R. A.; Balog, S.; Weder, C.; Montero de Espinosa, L. Submitted.

TNT2016 fribourg (switzerland)

Investigation into the Effects of Hydrodynamic Shear Stress on Nanoparticle-Cell Interactions

Thomas L. Moore1, Daniel Hauser1, Ana Belen Garcia Martin2, Barbara Rothen-Rutishauser1, Ruth Lyck2 & Alke Petri-Fink1, *

1

alke.fink@unifr.ch

Adolphe Merkle Institute, University of Fribourg, Chemin des Verdiers 4, 1700 Fribourg, Switzerland 2 Theodor Kocher Institute, University of Bern, Freiestrasse 1, 3012 Bern, Switzerland

While there have been significant advances in the fields of nanotoxicology and nanomedicine in the past decade, there have been relatively few successes translating nanomedicines into the clinic and there still exist significant gaps in our understanding of the phenomena governing nanoparticle-mediated cellular effects (e.g. cytotoxicity). [1,2] In an effort to better understand the fundamental interactions of nanoparticles (NP) with biological systems, some researchers are turning towards more complex in vitro systems. Microfluidics are particularly relevant because they enable the study of NP under hydrodynamic (flow) conditions, a most likely scenario for any systemically administered nanomedicines or NP which are able to enter the blood stream. [3,4] In the presented work, we investigated the effects of hydrodynamic shear forces on NP-cell interactions.

Rhodamine B-labelled silica NP with a diameter of 60 nm (SiNP) were used as a model NP, and a custom built microfluidic cell system [5] was used to study the uptake of SiNP by J774A.1 mouse monocyte/macrophages. J774A.1 were arrested in the flow chamber under low shear stress conditions (0.1 dyn/cm2) on a recombinant intercellular adhesion molecule 1 (rICAM-1)-treated surface or on top of a monolayer of primary mouse lung endothelial cells (pMLEC) treated with tumor necrosis factor alpha (TNFα). Cells were then exposed to SiNP under either static conditions or flow at 1.5 dyn/cm2. Association of SiNP with J774A.1 cells was assessed by measuring fluorescent intensity of individual cells within regions of interest (ROI) over the course of the NP exposure.

Preliminary data showed that more NPs were internalized by cells at the end of the exposure under flow conditions, in addition to exhibiting a higher NP uptake rate. Furthermore, observation of J774A.1 arrested on the pMLEC showed events of macrophage diapedesis, and transport of the internalized SiNP through the endothelial cell monolayer.

TNT2016 fribourg (switzerland)

The preliminary data has significant implications, as static NP-cell interaction studies may not adequately describe the complex physiological environment NP face in the body. Moreover, this system has potential to be expanded to study other important biological phenomena (e.g. transport of NP across biological barriers).

References [1] S Svenson, Curr Opinion Solid State Mat Sci, 16 (2012) 287.

[2] VJ Venditto and F.C. Szoka, Adv Drug Delivery Rev, 65 (2013) 80.

[3] G Fullston, et al. Sci Rep, 5 (2015) 10649.

[4] L Hosta-Rigau and B Städler, Mol Pharm, 10 (2013) 2707.

[5] C Coisne, R Lyck, B Engelhardt, Fluids Barriers CNS, 10 (2013) 7.

Figures

Figure 1. Schematic representation of SiNP uptake by macrophages under (A) static and (B) flow conditions. (C) Transmission electron microscopy images showing SiNP with a diameter of 60 nm. Scale bar represents 100 nm.

(D) Live cell confocal laser scanning microscopy of J774A.1 uptaking SiNP under static conditions after 1 hr of exposure. Scale bar represents 20 µm.

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Development of biomimetic D1 peptides as novel photosynthetic based-biosensors for environmental monitoring

Laura Moro1*, Mehmet Turemis1, Giuseppe Rodio2, Maria Teresa Giardi1,2

1

l.moro@biosensor.it info@biosensor.it

Biosensor Srl, Via Olmetti 44, Formello, Rome, 00060 Italy Institute of Crystallography, CNR Monterotondo, Rome, 00015 Italy

2

Synthetic biomimicry approaches can help to build more robust biorecognition elements for biosensors, overcoming the problem of instability of current biomediators that limits their market applicability. Synthetic peptides that mimic parts of the photosynthetic apparatus as biorecognition elements lead to an increased performance for the detection of environmental contaminants, including pesticides able to bind to D1 protein in the photosystem II and inhibit the photosynthetic process. Thus, the combination of computational analysis, molecular biology and biomimicking tools makes possible the use of more stable, sensitive, selective and specific biomediators for the development of effective biosensors. Based on this approach, this work describes the use of biomimetic peptides of the photosynthetic plastoquinone binding niche of the green alga Chlamydomonas reinhardtii for pesticide measurement in environmental or food samples. In previous studies, we identified point mutations in D1 protein of photosystem II of the alga that increase atrazine binding affinity, particularly the mutant S268C which presents a sensitivity of 1 nM, a 10-fold increase over wild type [1,2]. After identification of key binding residues, biomimetic peptides containing the plastoquinonebinding site in a loop shaped by two alpha-helices were designed and characterized, showing high stability and affinity for the pesticide atrazine (affinity constant 3.52x105 M-1 for the selected peptide D1pepmut) [3]. In further steps, this 70 aminoacid-peptide was modified to increase the solubility in aqueous solvents by adding two histidines in the N- and C-terminus, and three new peptides were selected. A cysteine was included in two of the modified peptides (S264C or

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S268C), peptides were labeled with different types of commercial carboxylated quantum dots (peak emissions from 510 to 710 nm) by carbodiimide reaction coupling and fluorometric detection was performed. The results confirmed that mutation S264C conferred resistance to atrazine and diuron, while the change S268C increased the sensitivity.

The application of new technologies based on quantum dots, nanoparticles and magnetic particles that could lead to improved response of the photosynthetic material and, therefore, to increased biosensor sensitivity -up to the picomolar range- was further explored.

References [1] G. Rea, Protein Sci. 18, 2139â&#x20AC;&#x201C;51, 2009.

[2] M. T. Giardi, Biosens. Bioelectron. 25(2), 294300, 2009.

[3] V. Scognamiglio, Phys. Chem. Chem. Phys. 15, 13108, 2013.

Figures

Figure 1. A- Schematic representation of the 3D structure of Chlamydomonas reinhardtii photosynthetic reaction centre (D1-D2 heterodimer). In green, the region corresponding to synthetic D1 peptide. BStructural model of one of the mutated D1 synthetic peptides. C- Structural simulation of the putative D1 peptide-pesticide complex. D- Quantum dot-labeled D1 peptides for direct fluorescent detection of pesticides using Biosensorâ&#x20AC;&#x2122;s prototype instrument.

TNT2016 fribourg (switzerland)

Exploring and engineering the electronic properties of 2D materials

Alberto Morpurgo

University of Geneva, Italy

Following the discovery of graphene, it has become clear that it is possible to produce, manipulate, and control matter at the ultimate level of atomically thin monolayers. Experiments show not only that when the thickness of materials is reduced to this level new electronic properties emerge, but also that these â&#x20AC;&#x153;2D materialsâ&#x20AC;? can be combined together to produce synthetic media with engineered electronic properties. This level of control would have been simply unimaginable even five years ago, and the field is at its start. In this talk I will use examples from work done in my group on transition metal dichalcogenides, graphene and their interfaces to illustrate how this new field of research is developing extremely rapidly.

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Low temperature PECVD growth of vertically oriented graphene nanowalls for supercapacitor applications

Arevik Musheghyan-Avetisyan, Joan Marti-Gonzalez and Enric Bertran

FEMAN Group, IN2UB, Dep Applied Physics, Universitat de Barcelona, C/ Martí i Franquès, 1, 08028 Barcelona, Spain

amusheghyan91@ub.edu

Graphene nanowalls (GNWs) are networks of “graphitic” sheets that typically appear vertically oriented on a substrate. Low temperature synthesized and vertically oriented GNWs are attractive material with outstanding properties and great potential for various applications like supercapacitors, lithium-ion batteries, solar cells and sensors. For each application, high-quality GNWs should be grown on suitable substrate. For example, GNWs grown on Cu foil becomes an excellent electrode for supercapacitors, meanwhile, GNWs on dielectric (SiO2) substrate could be used to fabricate gas or bio-sensors, also GNWs on semiconductor substrates could be used rather for potential application of solar cells. However, there are still few systematic studies of this promising material. In this study, we have used a RF remote plasma enhanced chemical vapor deposition (PECVD) method for growing the graphene nanowalls on top of Cu foil, c-Si substrate and silica substrate in the temperature range of 600-750⁰C. The morphological and electrical properties of the obtained graphene nanowalls have been tailored by controlling the growth parameters, such as, plasma power, gas flow, temperature, pressure or cooling time. At present, there is no general agreement on an unified theory to unveil the GNW mechanism and to provide guidance for optimum growth condition using different plasma power and temperature. The present results of GNW show new evidences of its morphology, which have allow us to propose an interpretation of its growth mechanism.

References

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[1] Chongyin Yang, Hui Bi, Dongyun Wan, Fuqiang Huang, Xiaoming Xie and Mianheng Jiang, The Royal Society of Chemistry, Direct PECVD growth of vertically erected graphene walls on dielectric substrates as excellent multifunctional electrodes (2013).

[2] Xuefen Song, Jian Liu, Leyong Yu, Jun Yang, Liang Fang, Haofei Shi, Chunlei Du,Dapeng Wei, Materials Letters,Direct versatile PECVD growth of graphene nanowalls on multiple substrates (2014) 25–28.

[3] Yifei Ma, Haegyu Jang, Sun Jung Kim, Changhyun Pang and Heeyeop Chae, Nanoscale. Research Letters a SpringerOpen journal, Copper-Assisted Direct Growth of Vertical Graphene Nanosheets on Glass Substrates by Low-Temperature PlasmaEnhanced Chemical Vapour Deposition Process (2015).

Room temperature manipulation of long lifetime spins in metallic-like carbon nanospheres 1

Institute of Condensed Matter Physics, École Polytechnique Fédérale de Lausanne, Lausanne 1015, Switzerland.

2 School of Chemistry, University of Sydney, Sydney 2006, Australia.

3 Institut für Experimentalphysik, Freie Universität Berlin, Arnimallee 14, Berlin, Germany

The time-window for processing electron spin information (spintronics) in solid-state quantum electronic devices is determined by the spin-lattice (T1) and spin-spin (T2) relaxation times of electrons.

Minimising the effects of spin-orbit coupling and the local magnetic contributions of neighbouring atoms on T1 and T2 at room temperature remain substantial challenges to practical spintronics. Here, we report a record-high conduction electron T1=T2 of 175 ns at 300 K in 37 nm ± 7 nm carbon spheres, which exceeds by far the highest values observed for any conducting solid state material of comparable size. The long T1=T2 is due to quantum confinement effects, to the intrinsically weak spinorbit coupling of carbon, and to the protecting nature of the outer shells of the inner spins from the influences of environmental disturbances.

TNT2016 fribourg (switzerland)

Bálint Náfrádi1, Mohammad Choucair2, KlausPeter Dinse3, László Forró1

nafradi@yahoo.com

Following the observation of spin polarization by electron spin resonance, we controlled the quantum state of the electron spin by applying short bursts of an oscillating magnetic field and observed coherent oscillations of the spin state.

These results demonstrate the feasibility of operating electron spins in conducting carbon nanospheres as quantum bits at room temperature.

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Molecular dynamics simulations of the spherical electrical double layer of a soft nanoparticle

M. Nedyalkova1 and S. Madurga2

1

Faculty of Chemistry, University of Sofia, Blvd. 1 J. Bourchier, 1164 Sofia, Bulgaria Physical Chemistry Department and Research Institute of Theoretical and Computational Chemistry (IQTCUB) of the University of Barcelona (UB), C/Martí i Franquès, 1. Barcelona, 08028, Catalonia, Spain

2

Molecular dynamics simulations were performed to study the ion and water distribution around a spherical charged nanoparticle (Fig.1). A soft nanoparticle model was designed using a set of hydrophobic interaction sites distributed in six concentric spherical layers. To simulate the effect of charged functionalized groups on the nanoparticle surface, a set of charged sites were distributed in the outer layer. Four charged nanoparticle models, from a surface charge value of −0.035 C m−2 to −0.28 C m−2 were studied in NaCl and CaCl2salt solutions at 1 M and 0.1 M concentrations to evaluate the effect of the surface charge, counterion valence, and concentration of added salt.

We obtain that Na+ and Ca2+ ions enter inside the soft nanoparticle. Monovalent ions are more accumulated inside the nanoparticle surface, whereas divalent ions are more accumulated just in the plane of the nanoparticle surface sites. The increasing of the salt concentration has little effect on the internalization of counterions, but significantly reduces the number of water molecules that enter inside the nanoparticle. The manner of distributing the surface charge in the nanoparticle (uniformly over all surface sites or discretely over a limited set of randomly selected sites) considerably affects the distribution of counterions in the proximities of the nanoparticle surface.

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mici345@yahoo.com

Figures

Figure 1. Model of spherical charged soft nanoparticle: + − water layers, Na ions (in blue), and Cl ions (in red) close to 1.0 nm from the nanoparticle surface are displayed.

TNT2016 fribourg (switzerland)

Mechanically-induced protein structural changes in fibrin hydrogels using hyperspectral CARS microscopy

Frederik Fleissner, Mischa Bonn and Sapun H. Parekh

Department of Molecular Spectroscopy, Max Planck Institute for Polymer Research, Ackermannweg 10, 55128 Mainz, Germany

Fibrin is a protein hydrogel material responsible for stabilizing the platelet-rich blood clot over a wound in blood coagulation. Its utilitarian mechanical properties: being stiff or deformable as needed result from the unique hierarchical organization of the polymer network. Experimental and theoretical studies have shown that single filament stretching, network rearrangements, and protein unfolding are responsible for this unique mechanical behavior. In this work, we investigate the biophysics of fibrin unfolding in response to uniaxial stretch in situ using coherent Raman imaging. Fibrin hydrogels are stretched to regime where unfolding transitions of ι-helical structures to β-sheet occur, and spatially resolved broadband coherent anti-Stokes Raman scattering (B-CARS) spectra of fibrin gels are acquired and analyzed.

TNT2016 fribourg (switzerland)

The secondary structure is calculated from spectral analysis of the amide I region, which is sensitive to subtle changes in protein structure via changes in hydrogen bonding along the protein backbone.

Experiments on gels of different polymer concentration and crosslinker density show unfolding transitions that correlate with nonlinear effects seen in shear rheology. Finally, imaging results show an inhomogeneous unfolding distribution near inert beads in the gel, suggesting that local stresses on platelets within biological clots is different from the bulk mechanical response.

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Spintronic and Ionitronic Computing Technologies

Stuart S.P. Parkin

Max Planck Institute for Microstructure Physics, Halle, Germany & IBM Research – Almaden, California 91205, USA

stuart.parkin@mpi-halle.mpg.de

Surface Enhanced Raman Scattering (SERS) has recent advances in manipulating spin-polarized electron currents in atomically engineered magnetic heterostructures make possible entirely new classes of sensor, memory and logic devices - a research field generally referred to as spintronics. A magnetic recording read head, initially formed from a spin-valve, and more recently by a magnetic tunnel junction, has enabled a 1,000-fold increase in the storage capacity of hard disk drives since 1997. The enormous storage capacity of arrays of hard disk drives in the “cloud” has made possible the digital storage and access to all of humankind’s knowledge since the beginning of mankind, thereby ushering in the age of “Big Data” and data analytics.

The creation of unforeseen data-driven businesses and the transformation of entire industries is impacting society in manifold ways. Increasing the performance and reducing the energy consumption of storage and computing technologies will very likely spur yet more innovative applications of such technologies.

Spintronic and ionitronic devices that rely on atomically engineered materials have novel properties that may allow for higher performance, lower energy, and more compact computing devices. The Racetrack Memory is a novel threedimensional technology that stores information as a series of magnetic domain walls in nanowires, manipulated by spin-polarized current. Racetrack Memory, a spintronic technology - combines the best attributes of magnetic disk drives – their very low cost per stored bit - with those of solid-state memories – their high performance and reliability.

Ionitronics allows for the reversible, non-volatile transformation between insulating and metallic states via the flow of tiny currents of ions. Such devices may allow for “plastic” devices that mimic synaptic switches in the brain, thereby allowing for the possibility of very low power computing devices.

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september 05-09, 2016

Mechanical Properties of Ag Nanoparticle Thin Films 1

Katholiek Universitet, Laboratory of Solid state Physics and Magnetism, Dep. of Physics and Astronomy Celestijnenlaan 200D, B-3001, Leuven, Belgium.

2 Interdisciplinary Laboratories for Advanced Materials Physics (I-LAMP) and Dipartimento di Matematica e Fisica, Università Cattolica del Sacro Cuore, Italy 3 Laboratory of Soft Matter and Biophysics, Department of Physics and Astronomy, KU Leuven, Celestijnenlaan 200D, B-3001, Leuven, Belgium 4 Empa, Swiss Federal Laboratories for Materials Science and Technology, Laboratory for Joining and Interface Technology, Überlandstrasse 129, 8600 Dübendorf, Switzerland

Understanding the mechanical properties of nanophase systems constituted by assembled metallic nanoparticles (NPs) will play a key role in biotechnology [1] photocatalysis, energy harvesting [2] and nano-opto-electronics applications. In this context NPs thin films made by Supersonic Cluster Beam Deposition (SCBD) are emerging as a candidate for wide-spread applications because SCBD: (a) is a high throughput technique for the synthesis of NPs thin films on virtually any substrate material; (b) allows to tune the NPs properties/composition; (c) allows synthesizing close to ideal-NPs thin films [3,4].

This work reports on the mechanical properties of Ag NP thin films deposited by SCBD on a sapphire substrate, the film thickness ranging between 15 and 50 nm. On the nanoscale, the samples morphology and composition are inspected via Atomic Force Microscopy and Photoelectron Spectroscopies. On the mesoscale the films mechanical properties are unveiled via Asynchronous Optical Sampling (ASOPS) based ultrafast optoacoustic nanometrology [5,6], see Figure 1.

The films are composed of Ag NP – average diameter in the 6 nm range –, and inter-NPs voids, the filling factor being 0.8. The films behave as high frequency acoustic cavities operating beyond the 100 GHz range, see Figure 2. The acoustic quality factors show a fundamental “quasi-dark” breathing mode whereas the second mode is an acoustically “bright mode”. Rationalizing the physics in terms of an effective homogeneous film, the film’s density and longitudinal sound velocity are found to be 80% that of polycrystalline bulk Ag, whereas the

TNT2016 fribourg (switzerland)

Simone Peli2,*, G. Benetti1,2, E. Cavaliere2, M. Gandolfi2,3, C. Giannetti2, G. Ferrini2, C. Cancellieri4, M. Chiodi4, L. Gavioli2, M. Van Bael1, F. Banfi2 pelisimone@gmail.com

longitudinal elastic stiffness constants amount to only 50% with respect to the Ag bulk.

The mechanical properties here reported are of relevance in view of any application involving Ag NP films and promote SCBD as a cheap, high throughput production technique for optoacoustic transducers in the hypersonic frequency range.

References [1] D. Mrinmoy, Partha, P. S. Ghosh, and V. M. Rotello, Adv. Mater. 2008, 20, 4225.

[2] C. J- Liu; Burghaus, U., F. Besenbacher, Z. L. Wang, ACS Nano 2010, 4, 5517.

[3] E. Cavaliere, S. De Cesari, G. Landini, E. Riccobono, L. Pallecchi, G. M. Rossolini, and Luca Gavioli, Nanomedicine: Nanotechnology, Biology and Medicine 2015, 11, 1417.

[4] Wegner, P. Piseri, H. V. Tafreshi, P. Milani, J. Phys. D Appl. Phys. 2006, 39, R439.

[5] D. Nardi, M. Travagliati, M.M Murnane, H.C Kapteyn, G. Ferrini, C. Giannetti and F. Banfi, Sensors Journal IEEE 2015, 15, 514.

[6] S. Peli, E. Cavaliere, G. Benetti, M. Gandolfi, M. Chiodi, C. Cancellieri, C Giannetti, G. Ferrini, L. Gavioli, and F. Banfi, J. Phys. Chem. C, DOI: 10.1021/acs.jpcc.6b00160 (in press).

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Figures

Figure 1. Schematics of the time-resolved optoacoustic nanometrology technique [5]. The red laser beam is the pump pulse launching the breathing mode in the Ag NPs thin film. The time-delayed probe laser beams detect the filmâ&#x20AC;&#x2122;s breathing mode. The experiment is performed implementing the Asynchronous Optical Sampling technique. Figure adapted from Ref.[6].

Figure 2. Fundamental (n=0) and first (n=1) NPs film acoustic breathing mode oscillation period (left axis) and frequency (right axis) as a function of the film thickness. The full lines are a fit based on an effective homogenous film model based on continuum mechanic.

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TNT2016 fribourg (switzerland)

Dissolving nanocarbons: how to prepare (single layer only) graphene in water

Alain Pénicaud1 , George Bepete1, Kai Huang1, Eric Anglaret2 and Carlos Drummond1

1

penicaud@crpp-bordeaux.cnrs.fr

Centre de recherche Paul Pascal – CNRS, Université de Bordeaux, France Laboratoire Charles Coulomb, Université de Montpellier – CNRS, France

2

(i) Full exfoliation of graphite and graphite nanofibres to form thermodynamically stable, negatively charged, graphene (graphenide) flakes in solution can be achieved by dissolution of graphite intercalation compounds (GICs) in low boiling point aprotic organic solvents under inert atmosphere.

[1,2] Such solutions can be used to reduce metal salts and produce metal nanoparticles directly supported on the graphene substrate. [3] Under certain conditions, graphenide can be transferred to water as single layer graphene only. The Raman spectra of the dispersions themselves show unambiguous signature of single layer graphene. [4] We have thus succeeded in preparing air stable, bulk suspensions of single layer graphene in water.

TNT2016 fribourg (switzerland)

References [1] [2] [3] [4]

A. Catheline et al. Soft Matter, 12, 7882, (2012).

K. Huang et al., Nanoscale, 8, 8810-8818 (2016).

E. Neiva, J. Colloid Interf. Sc. 453, 28-35 (2015).

G. Bepete, C. Drummond, A. Pénicaud, European patent, June 12, 2014, EP14172164.

[5] G. Bepete et al. , arXiv: 1603.05421.

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Influence of phase transformations in metal matrix composites during mechanical alloying on intensification of nanodiamond reinforcing particles agglomerates destruction

Vladimir Popov

National University of Science and Technology “MISIS”, Leninsky prospect, 4, 119049 Moscow, Russia

popov58@inbox.ru

Application of nanodiamonds (ND) for strengthening metal matrix is prospective method of composites improvement [1-4]. Size of nanodiamond particles equals 4-6 nm, but they combine in agglomerates with more big size.

Mechanical alloying (treatment in planetary mill) can destroy agglomerates inside metal matrix effectively. But in aluminum matrix, increasing of treatment time can lead to aluminum carbide formation. Investigation shows that phase transformations in metal matrix during mechanical alloying lead to intensification of nanodiamond agglomerates destruction. Fig.1. demonstrates microagglomerates of nanodiamonds inside matrix from pure technical grade aluminum after 8 hours treatment in planetary mill. And Fig.2 shows nonagglomerated nanodiamond reinforcing particles uniform distribution in matrix from aluminum and copper mixture (equal parts) after mechanical alloying during 6 hours. Images were obtained by high resolution scanning electron microscopy from crosssections of composite granules produced by focused ion beam. It is possible to see that phase transformation (i.e. formation of aluminum-copper intermetallic compounds) lead to completely distraction of smallest nanodiamond agglomerates, because this process connects with changes of lattice parameters and lead to formation of additional internal stresses in nano- and microareas.

References [1] V. A. Popov, B. B. Chernov, A. S. Prosviryakov, V. V. Cheverikin, I. I. Khodos,J. Biskupek, U. Kaiser, J. Alloys Compd., 615 (2014) S433–S436.

[2] V. Popov, Phys. Status Solidi A, 212 (2015) 2722–2726.

[3] V. Popov, D. Toebbens, A. Prosviryakov, Phys.

Status Solidi A, 211 (2014) 2353–2358.

[4] V.Popov, E.Shelekhov, E.Vershinina, Eur J Inorganic Chem 2015; DOI: 10.1002/ejic.201501149.

Figures

Figure 1. Nanodiamond micro-agglomerates inside matrix from technical grade pure aluminum.

The research leading to these results has received funding from the European Union's Seventh Framework Programme (FP7/2007-2013) under the EFEVE project, grant agreement 314582. The author is grateful to A.Prosviryakov and D.Matveev for help with research implementation.

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Figure 2. Uniform distribution of non-agglomerated nanodiamond reinfoircing particles inside matrix fabricated by mechanical alloying from mixture Al and Cu (equalparts).

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Cis-to-Trans Isomerization of Carbon-Carbon Double Bond by Single Molecule Force Spectroscopy 1

Department of Inorganic and Analytic Chemistry, University of Geneva, Sciences II, 30 Quai ErnestAnsermet, 1205 Geneva, Switzerland 2 Department of Chemistry, University of Fribourg, Chemin du MusĂŠe 9, 1700 Fribourg, Switzerland

Milad Radiom1, Phally Kong2, Plinio Maroni1, Andreas F.M. Kilbinger2 and Michal Borkovec1

milad.radiom@unige.ch

There are numerous examples of carbon-carbon double bond containing molecules that are frequently used in chemistry, biology, and medicine. One major attribute of these molecules is that they normally have two isomerization states, namely cis and trans, while each isomer presents specific physical, chemical and pharmacological properties. The isomerization of double bond (cis to trans and the reverse reaction) is induced in nature and technology via irradiation, thermally or by catalysts. The most notable example is the photoinduced cis-to-trans isomerization of 11-cis-retinal to all-trans-retinal and the subsequent reverse reaction that is enzymatic. So far the effect of mechanical force on isomerization of double bond has not been investigated. This is while mechanical force has been used as an alternative trigger to induce transitions in various bonding systems such as coordination, complexation, hydrogen bonding and covalent bonds. Here we present our results on force-induced cis-to-trans isomerization of double bond at the level of single polymer molecules containing cis double bond using atomic force microscopy (AFM). Three double bond containing polymers were used, namely P1, cis-PB and PB. As control, three exclusively single bond containing polymers were investigated, namely P2, PE and PS. The structures of these polymers are shown in figure 1. Upon stretching cis double bond containing polymers to elevated forces, a sudden relaxation in force and increase in elongation of polymer was observed that is attributed to isomerization (figure 2). Investigation of exclusively single bond containing polymers did not show any trace of isomerization. Our results revealed an isomerization force of 800Âą60 pN (figure 3). This force is slightly lower that the force associated with breaking of covalent bonds and rings ~ 1-2 nN [2,3].

Our results show that the mechanical force can be

used to trigger isomerization of double bond. Our results also open the possibility of a new class of force-responsive polymers based on mechanoisomerization of double bond.

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References [1] M. K. Beyer and H. Clausen-Schaumann, Chemical Reviews, 8 (2005) 2921.

[2] J. Wang, et al., Nature Chemistry, 7 (2015) 323.

[3] M. Grandbois, et al., Science, 283 (1999) 1727.

Figures

Figure 1. Structural formulas of the polymers used in this study: synthesized polymers P1 and P2, cis-1,4polybutadiene (cisPB, cis 98%, trans 1%, vinyl 1%), 1,4polybutadiene (PB, cis 36%, trans 55%, vinyl 9%), polyethylene (PE) and polystyrene (PS).

Figure 2. Force versus extension of P1 showing an isomerization event. The onset of isomerization is denoted by force Fct and elongation change Î&#x201D;Xct

Figure 3. The elongation change Î&#x201D;xct x of P1, PB, and cisPB as a function of the isomerization force Fct.

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Sensoresponsive nanomaterials to detect individual circulating tumor cells

Sarah D. Rafiee1, Corine Reis1, Laura RodriguezLorenzo2, Barbara RothenRutishauser2, Alke Petri-Fink2,3, Curzio Ruegg1

1

sarah.rafiee@unifr.ch

Pathology, Department of Medicine, University of Fribourg, Fribourg, Switzerland Adolphe Merkle Institute, Switzerland 3 Chemistry Department, University of Fribourg, Fribourg, Switzerland 2

Breast cancer accounts for about one quarter of women cancers and is a leading cause of cancerrelated mortality in developed countries. [1] Over one third of all breast cancer patients succumb to the disease due to metastasis formation.

Circulating tumor cells (CTCs) in blood play a critical role in initiating metastases. CTCs are indicative of the presence of a disseminated cancer and their determination has been proposed for detection and monitoring of cancers, including breast cancer.

[2] In this project we aim to develop an in vitro diagnostic (IVD) test for one-step detection and characterization of CTCs in blood samples with sensoresponsive nanomaterials. Currently, CTCs detection is a multi-step procedure involving antibody-based immunomagnetic enrichment, followed by immunostaining for additional markers and imaging-based enumeration. [3] Developing a single step test to enumerate and characterize CTCs is a challenge putting us at the forefront of IVD test research. [4] As a first step toward the development of such IVD, we engineered gold nanoparticles (NP1) to target CTCs. Trastuzumab, a humanized anti-HER2 IgG1, was chosen as targeting molecule because it has been proven to be an essential tool in the immunotherapy of beast carcinoma. We have established an in vitro cellular model consisting of HER2 positive and negative cell lines and noncancerous primary cells (fibroblasts and endothelial cells). Different variants of NP1 have been synthesized and their physicochemical behavior under in vitro conditions has been fully characterized. In addition, their ability to specifically target HER2 expressing cancer cells have been characterized by FACS, inductively

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coupled plasma optical emission spectrometry (ICPOES), dark filed optical microscopy with high resolution hyperspectral imaging (DF-HIS) and laser scanning microscopy (LSM). We demonstrated that the conjugation of 5 Trastuzumab molecules per NP1 is sufficient to identify and target HER2 expressing cancer cells. Toxicity study on noncancerous and cancerous cells demonstrated excellent biocompatibility of all NP developed. We have also shown the importance of applying a set of different methods (such as ICP-OES and DF-HSI) to study and evaluate the targeted NPs-cell interactions.

References [1] Malvezzi, M.; Bertuccio, P.; Levi, F.; La Vecchia, C.; Negri, E., European cancer mortality predictions for the year 2012. Ann Oncol 2012, 23 (4), 1044-52.

[2] Pantel, K.; Speicher, M. R., The biology of circulating tumor cells. Oncogene 2015.

[3] Alix-Panabieres, C.; Pantel, K., Technologies for detection of circulating tumor cells: facts and vision. Lab Chip 2014, 14 (1), 57-62.

[4] Ciarloni, L.; Hosseinian, S.; Monnier-Benoit, S.; Imaizumi, N.; Dorta, G.; Ruegg, C.; Group, D.C.-S., Discovery of a 29-gene panel in peripheral blood mononuclear cells for the detection of colorectal cancer and adenomas using high throughput real-time PCR. PLoS One 2015, 10 (4), e0123904.

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A molecular view on supramolecular chain and association dynamics

Dieter Richter

Jülich Centre for Neutron Science (JCNS-2), Forschungszentrum Jülich GmbH

The chain and association dynamics of supramolecular ensembles decisively determines their properties. In this talk I present a combined analysis of small angle neutron scattering, linear rheology, pulsed field gradient nuclear magnetic resonance and neutron spin echo experiments on the structure and dynamics of well-defined telechelically modified poly(ethylene glycol) (PEG) in the bulk. PEG was functionalized with directed hetero complementary hydrogen bonding end groups, thymine (Thy) diaminotriazine (DAT). The polarity of the backbone polymer is comparable to the end groups and avoids clustering of the groups that is often observed in hydrophobic environments. Their linear association behaviour in the melt state was investigated on the microscopic/molecular level as a function of temperature. By means of a selective labelling scheme that should ideally lead to the formation of alternating hydrogenous-deuterated building block sequences, if the hydrogen bonding reaction is exclusively hetero-complementary. I show that the Thy/DAT association is dominant and that Thy/Thy homo-association is approximately three times less probably. From the Q-dependence of a multiblock RPA structure factor, the linear association in the melt is confirmed and quantified. Furthermore, the diffusion and viscosity study reveals simple Rouse dynamics of the supramolecular polymer chains with molecular weight much larger than the entanglement mass Me. The Rouse like dynamics of the long supramolecular chains indicates short lifetime hydrogen-bonds of the end groups. The results are an excellent agreement with the related poly-condensation theory. Using neutron spin echo (NSE) spectroscopy I present further molecular insight in the space-time evolution of this dynamics. I show that the hydrogen bond breaking significantly impacts the mode spectrum of the associates. Their breaking affects the mode

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contributions and not the relaxation times as was assumed previously. The NSE spectra directly reveal the so far intangible H-bond-lifetimes in the supramolecular melt and demonstrate that for both, the microscopic and the macroscopic dynamics of the supramolecular ensemble the instantaneous average of the molecular weight distribution governs the systems response as least as long as the Rouse picture applies.

References [1] Association behaviour, diffusion and viscosity of end-functionalized supramolecular poly(ethylene glycol) in the melt state. M. Krutyeva, A. R. Brás, W. Antonius, C. H. Hövelmann, A. S. Poulos, J. Allgaier, A. Radulescu, P. Lindner, W. Pyckhout-Hintzen, A. Wischnewski and D. Richter. Macromolecules 48, 8933 (2015).

[2] A molecular view on supramolecular chain and association dynamics. M. Monkenbusch, M. Krutyeva, W. Pyckhout-Hintzen, W. Antonius, C. H. Hövelmann, J. Allgaier, A. R. Brás, B. Farago, A. Wischnewski and D. Richter, submitted.

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Impact of trigonal warping on the pseudodiffusive transport in bilayer graphene

Grzegorz Rut, Adam Rycerz

Marian Smoluchowski Institute of Physics, Jagiellonian University, Łojasiewicza 11, PL-30348 Kraków, Poland

grzegorz.rut@uj.edu.pl

A theoretical study of the pseudodiffusive transport in bilayer graphene (BLG) in the Corbino geometry is presented. Using the Landauer-Büttiker formalism together with the transfer matrix approach in the angular momentum space, we investigate the magnetotransport as well as size dependence of conductance [1].

[3] P. M. Ostrovsky, I.V. Gornyi and A.D. Mirlin, Phys. Rev. Lett., 105 036803 (2010), pp. 1-7.

[4] G. Rut and A. Rycerz, Phys. Rev. B 89 (4) 045421 (2014), pp. 1-12.

Figures

The minimal conductivity scales with the system size from σ=8e2/πh up to σ=24e2/ πh (see Fig. 1) [1,2]. Although the considered system is ballistic and interactions are not taken into account, the scaling flow reproduces the behavior expected from disordered systems of Dirac fermions with Coulomb repulsion [3].

The magnetoconductance is enhanced in weak magnetic fields up to a crossover field BL proportional to the next-nearest neighbor intervalley hopping integral t’. For magnetic fields B≳BL the average magnetoconductivity asymptotically drops with increasing magnetic field as 1/B, approaching the pseudodiffusive value σ=8e2/ πh [1,4].

Figure 1. Conductance of an undoped BLG Corbino disk with inner radius Ri and outer radius Ro=2 Ri. The triangles, squares and circles represent the data obtained numerically for t’=0.3 eV, t’= 0.2 eV, and t’= 0.1 eV (respectively), the lines depict the asymptotic behavior (units l depend on t’). The inset presents the scaling function β(σ)=dlog(σ)/dlog(Ro-Ri).

In strong magnetic fields, the conductivity, as well as higher charge-transfer cumulants, show beating patterns with an envelope period proportional to (B/BL)1/2 (see Fig. 2). This provides a qualitative difference between the high-field (B≫BL) magnetotransport in the t’ = 0 and in the t’ ≠ 0 case [1], providing a finite-system analog of the Lifshitz transition.

References [1] G. Rut and A. Rycerz, Phys. Rev. B 93 075419 (2016), pp. 1-12.

[2] G. Rut and A. Rycerz, Europhys. Lett. 107 47005 (2014), pp. 1-5.

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Figure 2. Magnetoconductance of BLG disk with Ri≈26 nm and Ro/Ri = 4.84 for t’=0 eV (dashed blue line) and t’=0.3 eV (solid red line). The vertical line marks the value of BL. The inset presents the period T of the beating envelope. The solid line corresponds to an 1/2 approximate dependence on B proportional to (B/BL) .

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P. Rickhaus1, Ming-Hao Liu2, P. Makk1, R. Maurand1, E. Tovari3, C. Handschin1, S. Zihlmann1, M. Weiss1, K. Richter2 and C. Schönenberger1

PN Junction Based Devices in Ultra-Clean Graphene 1

Dept. of Physics, University of Basel, Klingelbergstr. 81, Basel, CH-4056 Switzerland Institute of Physics, University of Regensburg, Germany 3 Dept of Physics, Budapest University of Technology and Economics, Hungary 2

Encapsulated or suspended graphene offers a promising platform for electron optical devices due the ballistic nature of electron transport. In graphene gapless pn interfaces can be formed by electrostatic gating, showing intriguing effects like a negative index of refraction and tunneling with perfect transmission (Klein tunneling). We have developed a versatile technology that allows to suspend graphene and complement it with arbitrary bottom and top-gate structures. Using current annealing we demonstrate exceptional high nobilities in monolayer graphene approaching 102 m2/Vs. These suspended devices are ballistic over micrometer length scales and display intriguing interference patterns in the electrical conductance when different gate potentials and magnetic fields are applied. Specifically, ballistic electric graphene pn-devices will be discussed, in which one can study electric analogs of a mirror, a guiding fiber, and Fabry-Perot resonators, well known in optics. There are great similarities between the propagation of light in a dielectric and electrons in graphene, but also differences. In particular, a negative refractive index is straightforward to realize in graphene, but hard in optics. The effect of a magnetic field on the electron states in ultraclean pn junctions will also be discussed, where one can monitor the evolution from zero-field cavity standing waves and low field cavity modes to the quasicalassical snake-state and quantum Hall edge state at higher fields. If time permits, we will also discuss recent results on thermoelctric effects and groundstate properties in pn-junction based bilayer graphene.

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References [1] P. Rickhaus, R. Maurand, M. Weiss, C. Schönenberger, Ming-Hao Liu, and K. Richter, Ballistic interferences in suspended graphene, Nature Comm. 4, 2342 (2013).

[2] R. Maurand, P. Rickhaus, P. Makk, S. Hess, E. Tovari, C. Handschin, M. Weiss, and C. Schönenberger, Fabrication of ballistic suspended graphene with local-gating, Carbon 79:486–492 (2014).

[3] P. Rickhaus, Ming-Hao Liu, P. Makk, R. Maurand, S. Hess, S. Zihlmann, M. Weiss, K. Richter, and C. Schönenberger, Guiding of Electrons in a Few-Mode Ballistic Graphene Channel, Nano Lett. 15, 5819 (2015).

[4] Min-Hao Liu, P. Rickhaus, P. Makk, T. Tovari, R. Maurand, F. Tkatschenko, M. Weiss, C. Schönenberger, and K. Richter, Scalable tightbinding model for graphene, Phys. Rev. Lett.

114:036601 (2015) [5] P. Rickhaus, P. Makk, Ming-Hao Liu, E. Tóvári, M. Weiss, R. Maurand, K. Richter and C. Schönenberger, Snake trajectories in ultraclean graphene p–n junctions, Nature Comm. 6, 6470 (2015).

[6] P. Rickhaus, P. Makk, M.-H. Liu et al., Appl.

Phys. Lett. 107, 251901 (2015).

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Figures

Figure 1. Guiding of electrons in graphene in a one-dimensional pnp channel defined by electric potentials alone, see Ref. [1].

Figure 2. Illustration for snake state at a pn interface in graphene, see Ref. [2].

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Hybrids of Reduced Graphene Oxide and Metal Oxides as Catalyst Support in Fuel Cells

Dana Schonvogel1,2, Peter Wagner1, Alexander Dyck1, Carsten Agert1 and Michael Wark2

1

dana.schonvogel@next-energy.de

NEXT ENERGY EWE Research Centre for Energy Technology at the University of Oldenburg, 26129 Oldenburg, Germany 2 Chemical Technology 1, Institute of Chemistry, Carl von Ossietzky University, 26129 Oldenburg, Germany

Degradation of fuel cell components as cause for lifetime limitation is one main challenge in commer-cialisation of fuel cells. [1,2] Especially the corrosion of catalyst supports due to harsh conditions with highly variable potentials results in performance losses. In our recent work, we synthesise nanocompo-sites of reduced graphene oxide (rGO) and indium tin oxide (ITO) as potential cathode support for plati-num nanoparticles in high temperature proton exchange membrane fuel cells (HT-PEMFCs). ITO has already demonstrated high durability in the presence of high cycled potentials.

[3] Furthermore, the appli-cation of graphenebased carbon in low temperature PEMFCs has resulted in higher stabilities than conventional carbon black. [4] The hybrid structure serves for Pt nanoparticle stabilisation at the interface between ITO and rGO and can prevent rGO restacking and corrosion. [5] Reduced graphene oxide was prepared by the use of Hummers method and a following thermal reduc-tion.

Then, the solvothermal ITO nanoparticle precipitation on rGO and finally the Pt deposition via the polyol method have been carried out. After every synthesis step the products were characterised by the use of scanning as well as transmission electron microscopy, EDS, XRD and other techniques. Particularly the precipitation of ITO nanoparticles was studied intensively by variation of synthesis parameters. In order to compare to reference catalyst materials, platinum has been deposited on carbon black as well as on multi-walled carbon nanotubes.

Figure 1b and 1c prove the successful deposition of ITO on rGO by the atomic lattice distance of 0.29 nm, typical for the In2O3 (222) reflex. Furthermore, the determination of the platinum nanoparticle sizes by the use of TEM show diameters of about 2 nm on this alternative catalyst support. Thus, the system represents good conditions as electrocatalyst for the oxygen reduction reaction in fuel cells.

References [1] Y. Shao-Horn, W. C. Sheng, S. Chen, P. J. Ferreira, E. F. Holby, D. Morgan, Top. Catal., 46 (2007) 285-305.

[2] D. Schonvogel, M. Rastedt, P. Wagner, M. Wark, A. Dyck, Fuel Cells (2016), 10.1002/fuce.201500160, accepted.

[3] Y. Liu, W. E. Mustain, Electrochim. Acta, 115 (2014) 116-125.

[4] Y. Shao, S. Zhang, C. Wang, Z. Nie, J. Liu, Y. Wang, Y. Lin, J. Power Sources, 195 (2010) 4600-4605.

[5] R. Kou, Y. Shao, D. Mei, Z. Nie, D. Wang, C. Wang, V. V. Viswanathan, S. Park, I. A. Aksay, Y. Lin, Y. Wang, J. Liu, J. Am. Chem. Soc., 133 (2011) 2541-2547.

The X-ray diffraction pattern of the final platinum catalyst on ITO-rGO in Figure 1a shows the expected In2O3 reflexes (for ITO as Sn-doped In2O3) as well as rGO and Pt reflexes. The TEM images in

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Figures

Figure 1. (a) X-ray diffraction of ITO-rGO and Pt on ITO-rGO, (b) TEM image of ITO-rGO and (c) HR-TEM image of ITOrGO with ITO lattice planes.

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Field-directed assembly of responsive colloids

Peter Schurtenberger

Division of Physical Chemistry, Lund University, Lund, Sweden

peter.schurtenberger@fkem1.lu.se

Field-directed self-assembly (DSA) has recently moved into the focus of the soft-matter and nanotechnology community. It employs the basic principles of self-assembly through carefully chosen building blocks, but the underlying self-assembly process is then aided or modulated using external fields. I will demonstrate how we can apply a combination of responsive nanoparticles and external electromagnetic fields in order to modulate the intrinsic interparticle interactions and tune the subtle balance between thermal motion and the action of interparticle forces, and thus generate novel selfassembled structures. I will show in particular how we can use field-driven selfassembly to induce phase transitions, cycle through various equilibrium and non-equilibrium phases, and study the underlying mechanisms of these phase transitions. Moreover, I will demonstrate the effect of particle anisotropy in field-driven assembly.

References [1] J. J. Crassous, A. M. Mihut, E. Wernersson, P. Pfleiderer, J. Vermant, P. Linse, and P. Schurtenberger, Nature Communications 5 (2014) 5516.

[2] P. S. Mohanty, P. Bagheri, S. Nรถjd, A. Yethiraj and P. Schurtenberger, Phys. Rev. X 5 (2015) 011030.

.

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X-ray Nanotomography for Imaging Nanostructured Materials

Alessandro Sepe

Adolphe Merkle Institute, University of Fribourg, Switzerland

Research on various biological and bio-inspired materials is essential in order to obtain a comprehensive insight into (i) the ultrastructural details of these structures and (ii) on how various processing conditions determine their final assembly. For this, we particularly focus on the structure-function relationship within these materials. The technique of choice is synchrotron scanning coherent diffraction nanotomography, in order to obtain ptychographic nanotomography reconstructions. This X-ray-based technique allows a full 3D insight into the materials and thus exploring, for instance, the molecular assembly occurring within the bio-inspired materials. Such insight allow us to shed light on the morphological properties that might lead to new generations of bio-inspired technologies or further extending the knowledge on the structure-function relationships within these materials.

Biological structures, e.g. photonic structure encountered in numerous animals and plants, can then be used as a model for bio-inspired applications that aim at increasing their efficiency and usability, as well as accurately controlling their assembly pathways through the understanding of the key physical chemistry factors involved within the assembly process. Within our studies natural structures are used as model structures aiming at a deeper understanding on evolutionary optimized structures. Using X-ray nanotomography we are, for instance, able to visualize the three-dimensional chitin network within beetle scales that assembled naturally under ambient conditions. Further insight into this process will enable scientists to adapt assembly pathways from nature and envision novel applications. Our research aims at optimizing the nano-fabrication route of bio-inspired materials in order to achieve the desired morphologies for new generations of bio-technologies.

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Liposomes: Topical and Oral Bioavailability

Julio Cortijo, Patricia Almudéver Folch and Juan Manuel Serrano Núñez

Sesderma Laboratories, Polígono Industrial Rafelbuñol C/Massamagrell 3, Rafelbuñol 46138 (Valencia) Spain

Julio.Cortijo@uv.es, Patricia.Almudever@uv.es, j.serrano@sesderma.com

Liposomes are small vesicles composed of one or more lipid bilayers. The size can go from 30nm up to several microns. Liposomes can encapsulate hydrophilic solutes in the aqueous core and lipophilic solutes in the membrane. These vesicles can be classified according to their size and number of bilayers: Multilamellar (100-10.000nm), Small Unilamellar (less than 100nm), Large Unilamellar (100-500nm).

Sesderma manufactures very uniform, unilamellar liposome populations of between 50-150nm.

The advantages of liposomes are that, the structure is very similar to biological membranes and thus, are biodegradable and non toxic, they can reach the deepest layers of the skin, they provide a sustained release of the active ingredients, they prevent the oxidation and degradation of the ingredients and they show higher efficiencies at lower concentrations.

We have carried out three different experiments on topical bioavailability: liposome penetration through skin, hair follicles and nails.

All the ingredients used to prepare the liposomes are classified as GRAS (generally recognized as safe).

In the first one, we compared the permeation capacity through human skin, using a Franz Diffusion Cell, of two different substances encapsulated and not encapsulated in liposomes: fluorescein and sodium ascorbate. Aliquots were taken from the receptor chamber at different times. The concentration of sodium ascorbate was determined by high performance liquid chromatography with ultraviolet detection (HPLC-UV) and that of fluorescein by spectrofluorimetry. The results were as follows:

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These results might be due to the nature and size of the active ingredients, and the characteristics of the layers of the skin. The epidermis is a stratified layer with plenty of cells, this is why liposomes can get through it easier than the ingredients in solution.

Fluorescein can diffuse faster through the epidermis than sodium ascorbate because fluorescein is more lipophilic than sodium ascorbate. The dermis has less cells and more fibres, and has a greater aqueous volume, so the preparation that permeates faster is that of sodium ascorbate solution due to its hydrophilic nature and small size. Finally, we can confirm that liposomes help substances pass through the skin.

In the second case, liposome ability to go across the follicular canal was assayed with liposomal fluorescein. The skin samples were extracted from human scalp and the equipment used was the same as in the prior experiment: Franz Diffusion Cell.

Pictures were taken at different times with a fluorescence microscope. We concluded that the follicular canal is an excellent penetration enhancer; a liposome reservoir is formed, facilitating its pass through the hair follicle and into the dermis.

In the third experiment, we assessed the penetration capacity of liposomal fluorescein on one hand and a solution of fluorescein on the other hand, through human nails. The equipment utilized was a Franz Diffusion Cell with a coupling device for nails.

Aliquots were taken from the receptor chamber at different times and the concentrations of fluorescein were determined by spectrofluorimetry. Pictures were also taken with a fluorescence microscope.The results showed that the maximum quantity of absorption for both formulations was obtained after 2 days in contact with the products.

The

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concentration of fluorescein (2.96 ±1. 0.2 µg/cm²) for the liposomal formulation was 2.5 times higher than the solution (1.22 ± 0.2 µg/cm²). However, the permeability constant is very similar for both preparations: fluorescein solution (0.006 ± 0.002 cm²/s) and liposomal fluorescein (0.008 ± 0.001 cm²/s). We could also observe that there was an increase in the thickness of the nail treated with liposomal fluorescein whilst there were no changes observed in the nail treated with the solution of fluorescein.

Ascorbic Acid Oral Pharmacokinetics in Rats Aim: Compare the pharmacokinetics of two sodium ascorbate formulations: − Sodium ascorbate solution (extemporaneously prepared). − Sodium ascorbate encapsulated in liposomes.

Method: The day prior to the administration of the formulations, 12 Wistar rats (280-310 g) were cannulated in the jugular vein to allow blood sampling at preset times. A volume of 2.5 mL of each fresh formulation was administered orally as single dose with intraoesophageal cannula. Six replicates were performed for each formulation. 200 µl blood samples were taken at the following times: 0 , 15 , 30, 45 , 60, 90 , 120 minutes and 3, 4 , 5, 6 , 7, 8 , 10, 12 , 23, 26 hours . The samples were centrifuged at 2000g for 5 min to obtain plasma which was immediately deproteinized with icecold MPA 10% (metaphosphoric acid). The samples were filtered through a pore diameter of 0.45µm. The analytical method used to measure vitamin C (sodium ascorbate) was HPLC-UV with UV detection at 254nm.

The mobile phase used consisted of a KH2PO4 (0.1M) solution: ACN (95:5) at a pH of 2. As the stationary phase, the column Sherisorb ODS1 5uM 25x0.4mm was used and the selected flow rate was 1 ml / min.

The injection volume used was 60 µL.

Conclusions: liposomes enable a better control of the release of the drug in plasma and maintains it for a longer period of time. A liposomal formulation of sodium ascorbate requires a smaller dose to reach the desired plasma concentration and, therefore, the desired therapeutic effect.

References [1] Elkeeb, R., Alikhan, A., Elkeeb, L., Hui, X. & Maibach, H. I. 2010. Transungual drug delivery: current status. Int J Pharm, 384, 1-8.

[2] Ishida, A., Otsuka, C., Tani, H. & Kamidate, T. 2005. Fluorescein chemiluminescence method for estimation of membrane permeability of liposomes. Anal Biochem, 342, 338-40.

[3] Karlsen, A., Blomhoff, R. & Gundersen, T. E. 2005. High-throughput analysis of vitamin C in human plasma with the use of HPLC with monolithic column and UV-detection. J Chromatogr B Analyt Technol Biomed Life Sci, 824, 132-8.

[4] Kligman, A. M. & Christophers, E. 1963.

Preparation of Isolated Sheets of Human Stratum Corneum. Arch Dermatol, 88, 702-5.

[5] O'Goshi, K. & Serup, J. 2006. Safety of sodium fluorescein for in vivo study of skin. Skin Res Technol, 12, 155-61.

[6] Sznitowska, M. & Berner, B. 1995. Polar pathway for percutaneous absorption. Curr Probl Dermatol, 22, 164-70.

[7] Torres-Molina, F., Aristorena, J. C., GarciaCarbonell, C., Granero, L., Chesa-Jimenez, J., Pla-Delfina, J. & Peris-Ribera, J. E. 1992.

Influence of permanent cannulation of the jugular vein on pharmacokinetics of amoxycillin and antipyrine in the rat. Pharm Res, 9, 158791.

Results:

Plasma concentration versus time after oral administration of 250 mg of sodium ascorbate formulated in an extemporaneous solution (black line) or in liposomes (green line). Mean ± SEM, n = 6.

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Effect of X-ray irradiation on CoPhthalocyanine thin films studied

by Surface Plasmon Resonance

A. Serrano1,2, O Rodríguez de la Fuente3, C Monton4, A Muñoz-Noval1,2, I Valmianski5, J F Fernández6, Ivan K Schuller5, G R Castro1,2 and M A García6,7

1

SpLine, Spanish CRG Beamline at the ESRF, F-38043 Grenoble, Cedex 09, France Instituto de Ciencia de Materiales de Madrid, (ICMM-CSIC), 28049 Madrid, Spain 3 Dpto. de Física de Materiales, Univ. Complutense de Madrid, 28040 Madrid, Spain 4 Department of Physics and Astronomy, University of Texas at San Antonio, One UTSA Circle, San Antonio, Texas 78249, USA 5 Department of Physics, Center for Advanced Nanoscience, The University of California San Diego, 9500 Gilman Dr., La Jolla, California 92093, USA 6 Instituto de Cerámica y Vidrio, Consejo Superior de Investigaciones Científicas, 28049 Madrid, Spain 7 Instituto de Magnetismo Aplicado ‘Salvador Velayos’, Universidad Complutense de Madrid, 28230 Madrid, Spain 2

We present here, in situ and in real time, the effect of X-ray irradiation (7.7 keV) on Co-Phthalocyanine (CoPc) thin films using Surface Plasmon Resonance (SPR) as a probe. For that, Au/CoPc bilayers were grown in an organic molecular beam epitaxy system. CoPc films with different thickness and growth temperature were analyzed. Simultaneous X-ray irradiation and SPR measurements were performed at the branch A of the BM25 SpLine beamline at The European Synchrotron (ESRF) in Grenoble, France, using a SPR instrument specifically designed for this type of experiments [1]. This set-up follows the Kretschmann–Raether configuration for SPR [2] and its sensitivity allows detecting relative variations in the SPR curve of the order of 10–3 – 10–4 . The very high sensitivity of SPR to slight modifications of the dielectric media allows tracking the small changes of refractive index induced by the irradiation in the organic films.

We have found a small and partially reversible modification of the SPR spectra of CoPc in CoPc/Au bilayers upon irradiation.

TNT2016 fribourg (switzerland)

aida.serrano@esrf.fr

For a beam intensity of ~1011 photons·s−1 mm−2 and an irradiation time of the order of 1 h, we estimate small variations of the order of a few % in the refractive index related to the scattering of the Xrays with the soft matter. A Raman study of the irradiated regions did not show structural modifications, suggesting that the observed variations in the optical properties of the CoPc films are associated with modifications of their electronic configuration.

References [1] A. Serrano, O. Rodríguez de la Fuente, V. Collado, J. Rubio-Zuazo, C. Monton, G. R. Castro and M. A. Garcia, Rev. Sci. Instrum., 83 (2012) 093102.

[2] H. Raether Surface Plasmons on Smooth and Rough Surfaces and on Gratings, (1988) Berlin: Springer.

[3] A. Serrano, O. Rodríguez de la Fuente, C. Monton, A. Muñoz-Noval, I. Valmianski, J. F. Fernández, G. R. Castro, Ivan K. Schuller and M. A. García, J. Phys. D: Appl. Phys., 49 (2016) 125503.

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Nano/Micro-materials for Immunomodulation: A Promising Strategy for Development of Vaccine and Cancer Immunotherapy

Anushree Seth

anushree.seth27@gmail.com

Korea Basic Science Institute, Ochang, Cheongju 28119, South Korea

The immune system is activated when it encounters immunogens such as micro-organisms or cancerous cells. The diversity in the size, shape and surface properties of these disease causing entities influence the type and magnitude of the immune response. Thoughtful engineering of nano/micro-particle systems based on the knowledge of interactions of immunogen and immune system has led to the development of efficient vaccines against infectious diseases and immunotherapeutic regimens for cancer treatment.

These nano/micro-particulate systems impart various advantages such as enhanced cellular uptake, capability to enhance cross-presentation, adjuvanticity, controlled release, polyvalent presentation and co-delivery of adjuvant and/or antigen. [1] Herein, poly-(gamma glutamic acid)(ÎłPGA) based micro-dispersion and poly (lactic acidco-glycolic acid)(PLGA) nanoparticles were explored as delivery agents for combination immunotherapy against cancer. A convenient, reproducible, single step synthesis process using Îł-PGA and water insoluble drugschemotherapeutic agent (paclitaxel) and immune-stimulating agent

imiquimod a toll like receptor 7 (TLR7) agonist was developed. Micro-dispersions formed were stable up to 6 months and the combination treatment illustrated improved tumor inhibition and presence of memory response in mice melanoma model (Fig. A).[2] In another study, PLGA nanoparticles mediated delivery of gardiquimod (TLR7/8 agonist) was used for enhancing activation of dendritic cells and was tested in combination with vasculature disrupting agent DMXAA (5,6-Dimethyl-9-oxo-9Hxanthen-4-yl)-acetic acid) (Fig. B, unpublished data).

The combinations lead to improved tumor regression and survival in mice. Immunostimulation using nano/micro-materials have demonstrated potential for becoming versatile platform for achieving improved therapeutic effect.

References [1] Anushree Seth, Doo-Byoung Oh, Yong Taik Lim, Nanomedicine, 10 (2015), 595 [2] Anushree Seth, Min Beom Heo, Yong Taik Lim, Biomaterials, 35 (2014), 7992

Figures (A)

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(B)

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Formation of normal and reversed nano-sized emulsions in a microfluidic device: insights into the formation mechanism with in-situ SAXS 1

International Iberian Nanotechnology Laboratory (INL), Av. Mestre José Veiga, 4715-330 Braga, Portugal 2 Dep. of Physics, Department of Materials, and Molecular, Cellular & Developmental Biology Department, University of California, Santa Barbara, California 93106, USA 3 Materials Research Lab., University of California, Santa Barbara, California 93106, USA 4 Division of Physical Chemistry, Centre for Chemistry and Chemical Engineering, Lund University, Sweden

Incorporation of in-situ small-angle X-ray scattering (SAXS) onto microfluidic devices allows new interesting possibilities for the study and synthesis of nanomaterials under flow [1-3].

In this work we study the formation of normal oilin-water (o/w) and reversed water-in-oil (w/o) nano-sized microemulsion droplets in the SDSpentanol-water ternary system. A lamellar phase composed by the three components (surfactant, water and pentanol) is flowed in the middle channel of a crossed-microchannel device (figure), and mixed with either water or pentanol flowing from the sides. The addition of water or pentanol induces a transition to normal (o/w) or reversed (w/o) emulsions, respectively. By manipulating the individual flow-rates, one can carefully tune the final system composition (hence, the size and shape of the particles), and furthermore, probe different time-scales of the transition. The ongoing structural evolution is simultaneously monitored in-situ with SAXS. The main findings show that the lamellar to o/w droplets transition (by mixing with water) occurs through a gradual stripping down of bilayers from the lamellar phase, with a microemulsion SAXS signature coexisting with the initial lamellar peak since very early mixing times. Conversely the lamellar to w/o reverse droplets transition (through mixing with pentanol) involves the formation of an intermediate lamellar phase with a smaller spacing before giving place to the reverse droplets.

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Bruno F.B. Silva1,2, Miguel Z. Rosales3, Ulf Olsson4, Youli Li3 and Cyrus R. Safinya2

bruno.silva@inl.int

References [1] J. Polte, R. Erler, A.F. Thunemann, S. Sokolov, T.T. Ahner, K. Rademann, F. Emmerling, R. Kraehnert, ACS Nano, 4 (2010) 1076.

[2] M.E. Brennich, J.-F. Nolting, C. Dammann, B. Nöding, S. Bauch, H. Herrmann, T. Pfohl, S. Köster, Lab Chip, 11 (2011) 708.

[3] B.F.B. Silva, M.Z. Rosales, N. Venkateswaran, B.J. Fletcher, L.G. Carter, T. Matsui, T.M. Weiss, J. Han, Y. Li, U. Olsson, C.R. Safinya, Langmuir, 31 (2015) 4361.

Figures

Figure 1. Schematic of the described experiment. The lamellar phase is flowed in the middle microchannel (100x100 μm cross section), and mixed with either water or pentanol, flowing from the side channels. The three flow rates and their ratios determine the final composition of the system and the observation time.

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Two dimensional copper sheet.

Experimental observation and theoretical investigation

P.B. Sorokin1-3, E. Kano4,5, D.G. Kvashnin1,3, P.V. Avramov6, L.A. Chernozatonskii3, S. Sakai7, A. Hashimoto4,5 and M. Takeguchi4,5

1

National University of Science and Technology MISiS, Moscow, Russia Technological Institute of Superhard and Novel Carbon Materials, Moscow, Russia 3 Emanuel Institute of Biochemical Physics RAS, Moscow, Russia 4 Graduate School of Pure and Applied Sciences, University of Tsukuba, Tsukuba, Japan 5 National Institute for Materials Science, Tsukuba, Japan 6 Kyungpook National University, Daego, South Korea 7 Advanced Science Research Center, Tokai, Japan 2

A The high interest to atomically thin films initiated by investigation of graphene has recently triggered for the study of two-dimensional materials with nonlayered bulk like boron [1], sodium chloride [2] or iron [3]. Among all these materials the latter one attracts special attention because the formation of 2D layered metal is unexpected and controversial.

2D layer with metals is very difficult to form because metallic bonding leads to form 3D structures.

Here we present the report of existence of novel two-dimensional phase of copper studied by experimental and theoretical methods. Using in situ scanning transmission electron microscopy (STEM) it was observed special crystal lattice of 2D Cu on graphene which structure is principally different from the former reports.

Density functional theory allowed to elucidate the nature of the stability of observed Cu nanofilms. It was defined a critical role of the oxygen impurity atoms in the formation of stable 2D Cu cluster with unexpected orthogonal crystal lattice. It was found that the structure and stability of 2D Cu clusters strongly depends on the concentration and relative arrangement of oxygen impurities. Number of oxygen configurations was analyzed and the stable configuration was found corresponded well with experimental data.

PBSorokin@gmail.com

the origin of the 2D phase formation and confirms the experimentally observed structures.

P. B. S. and D. G. K. acknowledge the financial support of the Ministry of Education and Science of the Russian Federation in the framework of Increase Competitiveness Program of NUST "MISiS"(No. К2-2015-033). P. B. S. acknowledges the Grant of President of Russian Federation for government support of young PhD scientists (MK6218.2015.2).

References [1] A. J. Mannix, X.-F. Zhou, B. Kiraly, J.D. Wood, D. Alducin, B.D. Myers, X. Liu, B.L. Fisher, U. Santiago, J.R. Guest, M.J. Yacaman, A. Ponce, A.R. Oganov, M.C. Hersam, N.P. Guisinger, Science 350 (2015) 1513.

[2] J. Zhao, Q. Deng, A. Bachmatiuk, G. Sandeep, A. Popov, J. Eckert, M. H. Rümmeli, Science 343 (2014) 1228.

[3] P. B. Sorokin, A. G. Kvashnin, Z. Zhu, D. Tománek, Nano Lett. 14 (2014) 7126.

Additional to separated clusters, the periodic 2D Cu crystal with embedded oxygen atoms was studied in details. Relative stability, features of elastic, electronic and magnetic properties were investigated. First-principles calculations explained

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Nano-Scale Structural Characterization of Parkinson’s Disease

Henning Stahlberg, Thomas Braun, Paula Perez Navarro, Andreij Bieri, Rosmarie Sütterlin, Stefan Arnold, and Sarah Shamoradian

C-CINA, Biozentrum, University of Basel, Mattenstrasse 26, CH-4058 Basel, Switzerland

Henning.Stahlberg@unibas.ch

Parkinson’s Disease (PD) is the second most common neurodegenerative disease. PD affects ~2% of individuals over 60 years of age. The primary hallmark of PD is a loss of neurons in a central region of the human brain, called substantia nigra, which then leads to tremor and other neuromotor deficits. The affected brain regions show so-called Lewy-bodies, which are dense “blobs” of several tens of micrometers in size that are found in the affected neurons. These Lewybodies are commonly associated with the presence of the protein alpha-synuclein, which is a protein that otherwise is involved in normal neuronal function.

In order to understand the biological processes behind the formation of Lewy bodies, we study the protein alpha-synuclein and its consequences on neurons, using nano-scale tools.

brain samples from deceased PD patients who donated their brain to research. Here, we analyse the cellular ultrastructure of the affected brain tissue [4], and characterize in 3D at the nanometer scale the different processes and mechanisms of disease progression, and their impact on neuronal function.

References [1] Vilar et al., PNAS 105(25), 8637-8642 (2008).

[2] Kemmerling et al., J. Struct. Biol. 183(3), 467473 (2013).

[3] Giss et al., Analytical Chemistry 86(10), 46804687 (2014).

[4] Shahmoradian et al., submitted (2016).

Alpha-synuclein (a-syn) is a small, 14kDa protein, which can be monomeric, form higher-order oligomers, or aggregate into fibrils of various shapes and sizes. Interestingly, the fibril formation is a transmissive process: A certain type of fibril can “seed” the growth of other fibrils of the same type, in a prion-like process. Even though the presence of a-syn fibrils is correlated with PD, it was previously not known, how these fibrils lead to neuronal death. A-syn can also interact with membranes in various forms, such as coating membranes, disrupting membranes, forming pores in membranes, or assisting membrane fusion.

We used biochemical and biophysical methods to produce and characterise a-syn [1], and developed nano-technology tools to study its biophysical behaviour and impact on neurons. We also developed microfluidics-based tools to seed a-syn fibrils into neurons, and then analyse the cytosol of single neurons by microfluidics and transmission electron microscopy [2-3]. We further study human

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Supramolecular association in transiently branched polymer systems

M. Staropoli, C. Hoevelmann, A. Raba, J. Allgaier, W. PyckhoutHintzen, A. Wischnewski and D. Richter

Forschungszentrum Jülich, Leo-Brandt Strasse, Juelich, Germany

m.staropoli@fz-juelich.de

In this contribution, an investigation of the hydrogen bonding mechanism in a transiently branched comb – like polymer system is presented. The system under investigation consists of a polybutylene oxide (PBO) - based backbone, randomly functionalized with thymine (Thy) groups, in combination with shorter PBO graft chains, end-functionalized with Diaminotriazine (DAT) groups. The functional groups are able to associate through hydrogen bonds. The hetero-complementary association of these groups leads to the formation of a transiently branched comb-like polymer system and it is known to be dominant in solution, when compared to the weaker self – association (Thy-Thy; DAT-DAT). In the melt state, often polymer systems based on Thy and Dat, can combine the ability to form supramolecular interaction with a tendency for unspecific aggregation and microphase segregation [1,2]. Only recently, virtually exclusive hetero-complementary association could be observed in the supramolecular association of telechelically-modified oligomeric PEG chains [3]. Here, we aim to extend the linear supramolecular assembly mechanism towards branched structures. The interaction of hydrogen bonding groups in the melt state has been studied on the microscopic level by the Small Angle Neutron Scattering technique (SANS), by means of a selective labeling scheme. A peak observed in the scattering function reveals the formation of a block copolymer, due to the complementary association of the hydrogen bonding groups.

The scattering profile of a block copolymer is

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described by means of the Random Phase Approximation (RPA) formalism through which it is possible to obtain the average aggregation number i.e. comb arm functionality and thus, to evaluate very sensitively the association constant directly in the melt state as a function of temperature. On the other hand, rheological measurements in the melt have been performed in order to study the influence of the reversible bonds on the macroscopic dynamics of the polymer system. The rheology data, in good agreement with the SANS results, confirmed the formation of a responsive material of which the structure and dynamics is affected by the rate of the mechanical activation.

References [1] Cortese J. et al; J.A.C.S 2012, 134, 3671.

[2] Yan T. et al; Macromolecules 2014, 47, 2122.

[3] Krutyeva M. et al; Macromolecules 2015, 48, 8933.

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Additive manufacturing of biologically-inspired composites

AndrĂŠ R. Studart

Complex Materials, Department of Materials, ETH Zurich, 8093 Zurich, Switzerland

Composite materials in nature exhibit heterogeneous architectures that are tuned to fulfill the functional demands of the surrounding environment. Examples range from the cellulosebased organic structure of plants to highly mineralized collagen-based skeletal parts like bone and teeth. Because they are often utilized to combine opposing properties such as strength and low-density or stiffness and wear resistance, the heterogeneous architecture of natural materials can potentially address several of the technical limitations of artificial homogeneous composites.

However, current man-made manufacturing technologies do not allow for the level of composition and fiber orientation control found in natural heterogeneous systems. In this talk, I will show that additive manufacturing (AM) routes might offer a new exciting pathway for the fabrication of biologically-inspired composite materials with unprecedented heterogeneous architectures and functionalities.

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CVD growth of 2 dimensional MoS2 and heterostructures with graphene

Ravi Sundaram, Elisha Mercardo and Jonathan Moffat

Oxford Instruments Plasma Technology, Bristol, UK Oxford Instruments Asylum Research, High Wycombe, UK

Vapour deposition techniques have gained a lot of interest for growth of two dimensional (2D) materials [1-4]. In the recent past there has been a surge in the number of researchers studying atomic planes of other Van der Waals solids and heterostructures created by stacking layers with complementary characteristics to achieve novel functionality [5]. For successful scaling up of prototypical applications demonstrated to date, technologies and processes for large area deposition of these materials need to be developed. Here we present the technology employed and study of the impact of process parameters on a chemical vapour deposition (CVD) process for the production of single-layer MoS2 using a gas-phase S precursor (H2S) and solid Mo precursor (MoCl5). Strategies for optimising crystalline quality via direct control of deposition variables and the impact of process parameters on defect density is analysed qualitatively using Raman spectroscopy [6]. We also present the characteristics of CVD grown MoS2 on different substrates and investigate the use of graphene as a substrate for MoS2 growth which opens an avenue for growth of 2D heterostructures.

[5] Geim, A.K and Grigorieva, I.V., Van der Waals heterostructures, Nature, 499,(2013),419.

[6] Mignuzzi, S. et al., Phys. Rev. B, 91, (2015), 195411.

Figures

Figure 1. (a) Raman spectrum of CVD deposited MoS2 (b) LA(M)/A1g peak ratio of deposited MoS2 on different substrates. (C), (d) AFM analysis of obtained films.

References [1] Li, X et al. Large-area synthesis of high-quality and uniform graphene films on copper foils.

Science 324, (2009), 1312-1314.

[2] Bae, S. et al. Roll-to-roll production of 30-inch graphene films for transparent electrodes. Nat Nanotech. 5, (2010), 574.

[3] Ismach, A. et al. Toward the Controlled Synthesis of Hexagonal Boron Nitride Films. ACS Nano, 6, (2012), 6378.

[4] Zhan, Y et al. Large-Area Vapor-Phase Growth and Characterization of MoS2 Atomic Layers on a SiO2 Substrate. Small, 8 (2012), 966.

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3D structure determination of metals on a TiO2 single crystal surface: Effect of premodification with a mercapto compound on single metal dispersion

Satoru Takakusagi, Kiyotaka Asakura

Institute for Catalysis, Hokkaido University, Sapporo, Japan

takakusa@cat.hokudai.ac.jp

Precise size control of the metal species on oxide surfaces, especially in the range of <1 nm, is now highly important to develop the next-generation catalysts, sensors, and electronic devices. However this is not easy since metal atoms are easily aggregated to form large particles on oxide surfaces. This is due to the small stabilization energy and/or the small activation energy for the metal diffusion. If one can obtain a monatomic metal species on the TiO2(110), it can be a building block of the metal cluster and helps us to control the cluster size in one-atom precision. Our group has developed the “premodified surface method” to obtain a highly dispersed metal species. In the premodified surface method, an oxide surface is precovered with a functional organic molecule possessing a substituent atom which can strongly coordinate to a metal atom before metal deposition. We have determined the precise 3D structures of such metal species by polarizationdependent total reflection fluorescence (PTRF) XAFS technique [1-5].

Figure 1 shows the 3D structure of atomically dispersed Cu species which were prepared by vacuum deposition of Cu metal atoms on a TiO2(110) surface precovered with omercaptobenzoic acid (o-MBA) [2,3]. The 3D structure was determined by fitting the observed PTRF-XAFS spectra with FEFFsimulated spectra. The monomeric Cu species was stabilized by forming chemical bonds with sulfur of the adsorbed o-MBA and oxygen of the substrate TiO2 although in the absence of o-MBA Cu was aggregated to form clusters. The XANES results clearly suggested that the Cu species was monovalent. We also applied the premodified surface method to other metals such as Au, Ni and Pt. Au and Ni were atomically dispersed by bond formation with sulfur and oxygen as similar with Cu in Figure 1, but Pt was

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aggregated to form clusters [1, 4]. We will discuss the factors that govern single metal dispersion based on the energy difference between sulfur−metal−oxygen and metal−metal bond formations.

References [1] S. Takakusagi, A. Kunimoto, N. Sirisit, H. Uehara, T. Ohba, Y. Uemuara, T. Wada, H. Ariga, W.-J. Chun, Y. Iwasawa, K. Asakura, J. Phys. Chem. C, in press (2016) DOI: 10.1021/acs.jpcc.5b11630.

[2] S. Takakusagi, H. Nojima, H. Ariga, H. Uehara, K. Miyazaki, W.-J. Chun, Y. Iwasawa, K. Asakura, Phys. Chem. Chem. Phys., 15 (2013) 14080.

[3] S. Takakusagi, W.-J. Chun, H. Uehara, K. Asakura, Y. Iwasawa., Top. Catal., 56 (2013) 1477.

[4] K. Asakura, S. Takakusagi, H. Ariga, W.-J. Chun, S. Suzuki, Y. Koike, H. Uehara, K. Miyazakia, Y. Iwasawa, Faraday Discuss., 162 (2013) 165.

[5] W.-J. Chun, Y. Koike, K. Ijima, K. Fujikawa, H. Ashima, M. Nomura, Y. Iwasawa, K. Asakura, Chem. Phys. Lett., 433 (2007) 345.

Figures

Figure 1. 3D structure of Cu/o-MBA/TiO2(110). Cu-S and Cu-O bond distances are 0.219 nm and 0.185 nm, respectively.

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Designing and Creating Low-Loss Infrared-Emitting Nanostructured Active Photonic Composites

Mei Chee Tan1, Xinyu Zhao1, Yang Sun2 and Chaobin He2,3

1

meichee.tan@sutd.edu.sg

Engineering Product Development, Singapore University of Technology and Design, Singapore, 8 Somapah Rd, Singapore 487372 2 Department of Materials Science & Engineering, National University of Singapore, 9 Engineering Drive 1, Singapore 117576 3 Institute of Materials Research and Engineering, Agency for Science, Technology and Research (A*STAR), 3 Research Link, Singapore 117602

Infrared-emitting erbium (Er) doped systems are often used to fabricate the active optical components in photonic devices since the radiative transition of Er3+ ions falls within the telecommunication window [1]. In a typical waveguide amplifier, light is guided in a high refractive index core that is surrounded by a lower index cladding material (Fig. 1a). Er-doped inorganic nanocrystals dispersed within polymer matrices to form polymer-based optical waveguide amplifiers offer an attractive low cost versatile solution.

To obtain highly emissive nanocomposites, it is critical to maximize nanoparticle loading in the polymer matrix while minimizing scattering and absorption losses.

Absorption losses are mostly dictated by the optical properties of the polymer matrix, whilst scattering losses are typically affected by the primary particle sizes, agglomerate size and refractive index mismatch between the inorganic particle and polymer. In this presentation, we will discuss the solution-based synthesis of Er-doped nanoparticles of ~20-30 nm with enhanced IR emission efficiency by controlling the nanostructure and dopant chemistry of as-synthesized particles (Fig 1(b) and (c)) [2,3]. We will also present how we have tailored the surface chemistries of our infraredemitting inorganic nanoparticles with a unique amphiphilic POSS-based surfactant which was designed to improve the dispersion behavior of our particles in various polymers. Using our approach, we have demonstrated the successful fabrication of an infrared-emitting nanostructured composite that has exhibits mostly single particle dispersion at high solid loading of up to 10 vol%. The high IRemitting efficiency, small particle sizes and excellent dispersion control of our particles within

various polymer matrices demonstrate the promising potential of our polymeric composites for a myriad of applications, including fiber amplifiers and waveguides.

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References [1] M. C. Tan, D. Naczynski, P. Moghe, R. E. Riman, Australian Journal of Chemistry 66 (2013), 1008-1020.

[2] X. Zhao, M. C. Tan, J. Mater. Chem. C, 3 (2015), 10207-10214.

[3] X. Zhao, M. C. Tan, RSC Adv., 6 (2016), 1834818356.

Figures

Figure 1. (a) Schematic design of polymeric composite waveguide amplifier, (b) Size distribution of assynthesized infrared emitting nanoparticles and (c) Quenched visible and enhanced infrared emissions by optimizing dopant chemistry.

Carbon and Platinum Nanostructured Electrodes on Miniaturized Devices for Biomedical Diagnostics

Irene Taurino

Irene.taurino@gmail.com

Integrated Systems Laboratory, École polytechnique fédérale de Lausanne, Station 14 CH-1015 Lausanne, Switzerland

Monitoring of a set of metabolites (e.g., glucose, lactate) and ions (e.g., potassium) in human fluids is of significant importance in medicine [1].

Instrumentation designed for a timely multi-sensing should be able to do several measurements from a small volume sample. Consequently, the development of a tiny device is a crucial requirement. Electrochemical miniaturized devices are particularly advantageous because of the inexpensive and reproducible fabrication procedures and the simple analytical measurements [2]. A continuing challenge in their fabrication is the detection of metabolites and ions in the physiopathological concentration range. Modifying electrodes with nanostructures can solve this issue as due to their high electrocatalytic activity and large surface-to-volume ratio [3-5].

Tailored nanostructuration methods are extremely important to boost the sensor sensitivity, selectivity and stability over time [3].

In this talk I will illustrate novel protocols to modify electrodes with carbon and metal nanostructures without the use of binders that can mask the nanomaterial promising properties and can compromise the time-stability of the nanostructures in aqueous environment. Carbon nanomaterials were selectively deposited on electrodes by CVD [6,7] and nanoporous metal layers by template-free electrodeposition processes

[8]. Both nanostructuration approaches generated electrodes with significantly enhanced detection performance as compared to the bare counterparts for sensing human metabolites and ions [7-10].

References [1] Moser, I., et al., Biosensors and Bioelectronics, 17.4 (2002) 297-302.

[2] Albery, W. J., et al., Journal of the Chemical Society, Faraday Transactions 1: Physical Chemistry in Condensed Phases, 82.4 (1986) 1033-1050.

[3] Taurino, I., et al., BioNanoScience, 2(4) (2012) 185–195.

[4] Taurino, I., et al., Electrochimica Acta, 93 (2013) 72–79.

[5] Taurino, I., et al.,Thin Solid Films, 548 (2013) 546–550.

[6] Taurino, I, et al., Nanoscale, 5(24) (2013) 12448–12455.

[7] Taurino, I., et al., Nano letters, 14(6) (2014) 3180–3184.

[8] Taurino, I., et al., Scientific Reports, 5 (2015) 15277.

[9] Taurino, I., et al., Talanta, 130 (2014) 423–426.

[10] Sanzó, G. and Taurino, I, et al., Bioelectrochemistry, (2016) In Press.

Figures

Figure 1. Multisite electrochemical sensor including microelectrodes modified with CVD carbon nanomaterials and template-free electrodeposited Pt and Au-Pt nanoporous layers (left). Electrochemical measurements of different concentrations of a metabolite (glucose) and relative calibration curve (right).

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Experiments on triclinic Mn12-acetate mixed with a superconductor: enhanced tunneling, narrow zero-field resonance and Landau-Zener effect

J. Tejada1,2*, R. Zarzuela1,3, A. GarcíaSantiago1,2, N. Statuto1, I. Imaz4, J. Espin4, D. Maspoch4,5 and E. M. Chudnovsky6

1

jtejada@ubxlab.com

Grup de Magnetisme, Dep. de Física de la Matèria Condensada, UB, Spain Institut de Nanociència i Nanotecnologia IN2UB, Universitat de Barcelona, Spain 3 UCLA Physics & Astronomy, 475 Portola Plaza, Los Angeles, CA 90095-1547, USA 4 Institut Català de Nanotecnologia, ICN, Campus UAB, 08193 Bellaterra, Spain 5 Institució Catalana de Recerca i Estudis Avançats (ICREA), 08100 Barcelona, Spain 6 Physics Dep., Lehman College, The City University of New York, USA 2

We report [1,2] characterization and magnetic studies of pure triclinic Mn12-acetate ribbons and mixtures of micrometer-size ribbons of Mn12acetate and micrometer-size particles of YBaCuO superconductor. An extremely narrow zero-field spin-tunneling resonance was observed in both systems, pointing to the absence of the inhomogeneous dipolar broadening. A pronounced magnetic relaxation was measured in the vicinity of zero field and the width of the zero-field resonance reduced to values as low as 50 Oe. By analyzing the tunneling rate from experiments performed by field sweeping near zero field we have been able to get a clear quantitative proof of the Landau-Zener dynamics of the tunneling magnetization. The experimental data for the pure ribbons can be explained by considering that the strong dipolar broadening in the zero-field resonance observed in the conventional tetragonal Mn12- acetate is practically suppressed in the triclinic structure, due

to the fact that the magnetic moments of the molecules do not form chains. On the other hand, the effect in the mixtures was attributed to the screening of the internal magnetic fields in the magnetic particles by Meissner currents flowing between superconducting grains surrounding the particles [3].

References [1] J. Tejada, R. Zarzuela, A. García-Santiago, I. Imaz, J. Espin, D. Maspoch, E. M. Chudnovsky, J. Supercond. Nov. Magn.29 (2016) 1133.

[2] I. Imaz, J. Espin, D. Maspoch, J. Tejada, R. Zarzuela, N. Statuto, E. M. Chudnovsky, arXiv: 1510.08894 (2015).

[3] E. M. Chudnovsky, J. R. Friedman, Phys. Rev. Lett. 85 (2000) 5206.

Figures

Figure 1. Left. Descending branches of magnetization curves of Mn12 ribbons at different temperatures.

Right. Field derivative of the magnetization curve of Mn12 ribbons and their mixture with YBaCuO.

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TNT2016 fribourg (switzerland)

From Superresolution to Fluorescence Enhancement with DNA Origami

Philip Tinnefeld

Institute for Physical & Theoretical Chemistry â&#x20AC;&#x201C; NanoBioScience, and LENA (Laboratory of Emerging Nanometrology), and BRICS (Braunschweig Integrated Center for Systems Biology) Braunschweig University of Technology

In recent years, DNA nanotechnology has matured to enable robust production of complex nanostructures and hybrid materials. We have combined DNA nanotechnology with sensitive optical detection to create functional singlemolecule devices such as nanoscopic rulers for superresolution microscopy and energy transfer switches [1,2]. DNA origamis are also used for single-molecule placement in zeromode waveguides using nanoadapters [3] and for fluorescence enhancement with gold nanoparticles [4].I will discuss DNA origami applications to improve single-molecule detection and how DNA origami in combination with the recently developed superresolution technique DNA PAINT [5] can be used to study the interactions of emitters with metallic nanostructures in a single-molecule mirage. To this end, a method to disentangle the complex factors that influence the fluorescence of single molecules near metallic nanostructures will be presented [6].

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References [1] Schmied, J.J. et al. DNA origami-based standards for quantitative fluorescence microscopy. Nat Protoc 9, 1367-1391 (2014).

[2] Stein, I.H., Steinhauer, C. & Tinnefeld, P. SingleMolecule Four-Color FRET Visualizes EnergyTransfer Paths on DNA Origami. J Am Chem Soc 133, 4193-4195 (2011).

[3] Pibiri, E., Holzmeister, P., Lalkens, B., Acuna, G.P. & Tinnefeld, P. Single-molecule positioning in zeromode waveguides by DNA origami nanoadapters. Nano Lett 14, 3499-3503 (2014).

[4] Acuna, G.P. et al. Fluorescence enhancement at docking sites of DNA-directed self-assembled nanoantennas. Science 338, 506-510 (2012).

[5] Molle, J. et al. Superresolution microscopy with transient binding. Curr Opin Biotechnol 39, 8-16 (2016).

[6] Holzmeister, P. et al. Quantum yield and excitation rate of single molecules close to metallic nanostructures. Nat Commun 5, 5356 (2014).

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Multi-nanostructured autoregenerative sensor for H2O2 quantification with enhanced sensitivity at zero potential

R. M. Trujillo1Ψ, M. L. Zamora1Ψ, F. Ashur1, C. Dore2, C. J. Felice1, A. Cattani-Scholz2 and R.E. Madrid*1

1

rmadrid@herrera.unt.edu.ar

Laboratorio de Medios e Interfases (LAMEIN), DBI, FACET, Universidad Nacional de Tucumán and INSIBIO, CONICET, Av. Independencia 1800, 4000 Tucumán, Argentina.

2 Walter Schottky Institut and Physics Department, Technische Universität München, Am Coulombwall 4, 85748 Garching, Germany

Hydrogen peroxide (H2O2) is a common analyte in sensors area, and of great importance for modern medicine, environmental control, and several branches of industry. Although various techniques have been found to detect H2O2, electrochemical techniques are the preferred methods due to their particular features such as high sensitivity, selectivity, and simplicity. Prussian blue (PB) (Fe 4 III [Fe II (CN) 6] 3) has the peculiar characteristics of its great electrocatalytic activity and selectivity towards the reduction of (H2O2) at low potentials.

In this work we present two nanostructured systems. The first one is a gold disc with drop casted PB nanoparticles (Au + PBNPs), and the second one, a double nanostructured system consisting of a gold disc with electrodeposited nanostructured Iridium Oxide and drop casted PBNPs (Au + EIROF + PBNPs). Both systems are capable to detect very low concentrations of H2O2.

All measurements were carried on in a tripolar cell.

Amperometric measurements were made at 0V DC, by successive addition of low concentrations of H2O2. The Au+PBNPs system responds to concentrations as low as 1 µM, while the Au+EIROF+PBNPs systems responds with concentrations as low as 0.1 µM, one order below.

The system measures at 0V polarization. This feature makes this system almost free of interference and electrochemical degradation. The combination of these two nanostructures (EIROF and PBNPs) improves the sensitivity of the system.

On the other hand, it is well known that oxygen can lower the system sensitivity to H2O2 [1]. This system can respond even in aerobic solutions, so, it can be applied for the evaluation of H2O2 in culture systems without the need to degas with N2.

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Ψ These authors contributed equally

The method employed to synthetize the PBNPs was used for applications in magnetic resonance imaging (MRI) [2], but not used in the development of sensor systems. This procedure allows to obtain NPs, which are very stable and attach strongly to the surfaces by drop casting method, avoiding electrodeposition or other chemical agents such as Nafion® or cross-linking agents to prevent desorption. Another advantage is that both systems have the capacity to regenerate themselves in air, since oxygen re-converts them to its electro-active form.

This results show a promising multi-nanostructured matrix for the development of H2O2 sensors.

Compared to previously reported H2O2 sensor systems, the Au+EIROF+PBNPs one presented here, is an interesting proposal due to its great sensitivity at null polarization and its auto-regenerative capacity.

References [1] Karyakin AA, Karyakina EE, Gorton L. Talanta.

43(9) (1996) 1597–606.

[2] Shokouhimehr M, Soehnlen ES, Hao J, Griswold M, Flask C, Fan X, et al. J Mater Chem. 20(25) (2010) 5251.

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Figures

SEM picture of Au+EIROF+PBNPs

CVs of drop casted PBNPs

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% of Change of Au+EIROF+PBNPs

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The Influence of Thickness, Interpore Distance and Compositional Structure on the Optical Properties of Self-Ordered Anodic Aluminum Oxide Films

C. V. Manzano1, J. P. Best1,‡, J. J. Schwiedrzik1,‡, A. Cantarero2, J. Michler1and L. Philippe1.

1

cristina.vicente@empa.ch

Empa, Swiss Federal Laboratories for Materials Science and Technology, Lab. for Mechanics of Materials and Nanostructures, Feuerwerkerstrasse 39, Switzerland 2 Molecular Science Institute, University of Valencia, P.O. Box 22085, Valencia, Spain

In the last years, the study of structural color obtained from the interaction of light with periodic nanostructures has generated immense interest, as a result of some colors found in nature are based on this interaction. This phenomenon can be applied in relevant scientific areas, such as: optic; photonic; magnetic; sensor; and biologic. Highordered anodic aluminum oxide (AAO) templates are used to different applications and are one of the most studied periodic nanostructures. AAO films were fabricated by two step anodization process and the optical properties of these films were analyzed. The morphological parameters of the AAO films were adjusted in order to study the effect of these parameters on the UV-Vis reflectance properties of these films. These parameters are the thickness, pore diameter, interpore distance, porosity, pore arrangement regularity, and anodization electrolyte. The reflectance was found to depend on the thickness of the AAO films, on the interpore distance, and a strong dependence of the reflectance on the anodization electrolyte was found in the UV region, which was then explained using Raman spectroscopy. A statistical study was made to obtain a relation between the maximum reflectance and the morphological parameters of the AAO films (thickness and interpore distance) as are shown in Figure 1. This study would enable for the first time the unified prediction of porous alumina optical properties based on the morphology, and provides an important understanding of the UV-Vis reflectance properties of AAO films.

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References [1] Manzano, C. V., Martín, J., Martín-González, M. S., Microporous and Mesoporous Materials 184 (2014) 177.

[2] Martín, J., Manzano, C. V., Caballero-Calero, O., Martín-González, M., ACS Applied Materials & Interfaces 5 (2013) 72.

[3] Martín, J., Manzano, C. V., Martín-González, M., Microporous and Mesoporous Materials 151 (2012) 311.

Figures

Figure 1. Reflectance as a function of the thickness and pore diameter of AAO.

TNT2016 fribourg (switzerland)

The force-full fight of immune cells with bacteria

Viola Vogel

Laboratory of Applied Mechanobiology, Department of Health Sciences and Technology, ETH Zurich, Switzerland

viola.vogel@hest.ethz.ch

How do our immune cells fight bacterial infections, particularly in cases where bacteria hold on tightly to surfaces or tissue fibers? The fight of bacteria with immune cells has many mechanical aspects that have found little attention until recently. Cells exploit mechanical forces to sense the physical aspects of their microenvironments and immune cells exploit sophisticated physical mechanisms to pull on bacteria and rupture them off from surfaces. To clear pathogens from host tissues or biomaterial surfaces, macrophages have to first identify their prey, and then firmly hold on to it while they prepare themselves to phagocytize it.

Preceding phagocytosis though, they have to generate sufficient force to break large clusters of adhesive bonds by which bacteria often tightly bind to surfaces or tissue fibers.

TNT2016 fribourg (switzerland)

Even though many strategies have been applied by mankind to fight bacterial infections, primarily designed to either kill bacteria via antibiotics or more recently to prevent their adhesion to surfaces and host tissues, little attention has been given to asking how these pharmaceutical strategies might compromise the efficiency of our own immune cells.

Unexpectedly, novel insights into nanomechanical aspects also revealed some adverse and unanticipated side effects how common antibacterial drugs impair the ability of our immune cells to fight infections.

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Laser induced magnetization precession in cobalt ferrite nano-cubes

M. Vomir1, R. Turnbull2, P. André2 and J.-Y. Bigot1

1

mircea.vomir@ipcms.unistra.fr

Institut de Physique et Chimie des Matériaux de Strasbourg, UMR 7504, CNRS, Université de Strasbourg, BP 43, 23 rue du Loess, 67034 Strasbourg Cedex 02, France.

2 School of Physics and Astronomy, University of St Andrews; St Andrews KY16 9SS, UK

Designing complex nanostructures with controlled magnetic anisotropy is of great importance for innovative information processing technologies as well as for medical applications such as cancer therapy. Simultaneously, a faster manipulation of the magnetization is receiving lots of attention [1].

In that context, emerging technologies aim at combining high temporal and spatial resolutions for the study of structures with reduced dimensionality [2]. Here, we have studied the impact of the time dependent anisotropy of CoxFe3-xO4 crystalline nano-cubes on the laser induced magnetization precession. We show that the phase of the precession, which depends on the orientation of an external static magnetic field, can be π-shifted due to the competition between the time dependent magneto-crystalline and shape anisotropies.

The crystalline 35 nm CoxFe3-xO4 cubes (x = 0, 0.15, 0.30, 0.60, 1.00) are deposited on quartz substrates. They are organized in quasi single layer islands which are influenced by the presence and orientation of an external magnetic field applied during the organization process. The time resolved magneto-optical experiments are performed in Faraday geometry (120 fs, 5 kHz, pump 400 nm, probe 800 nm). In a Cartesian referential (Figure 1a) the sample is placed in the xOy plane and a static magnetic field H can be rotated in the xOz plane.

anisotropy of the individual nanoparticles and the time dependent demagnetizing field modified by the change of the magnetization modulus. Second, the continuous increase of the precession period ΩPrec with decreasing θH indicates the existence of dipolar interactions between nanoparticles.

The magnetization precession is modelled using the Landau-Lifshitz-Gilbert equation taking into account the time dependent electron, spin and lattice temperatures, as well as the temperature dependent anisotropy. The results corresponding to the sample of Co 10% are presented in Fig. 1c.

The good agreement between the simulation and the experimental results is obtained using a simple approximation of the nano-cubes organization on the plane of the substrate i.e. as acting like an average demagnetizing field similar to a thin continuous layer. The competition between the magneto-crystalline and shape anisotropies arises from their different variation with the temperature.

In addition, we have performed a detailed analysis on the influence of the magneto-crystalline anisotropy, the degree of organization of the nanocubes as well as the density of the laser excitation on the phase of the magnetization precession, which brings valuable insights in the control of magnetization in confined nanostructures.

References The variation of the phase and period of the magnetization precession as a function of θH obtained for a Co concentration of 10% is displayed in figure 1b. Two important features can be observed. First, the abrupt change of the precession phase φPrec occurring for θHph ≈ 25° is attributed to the competition between the temperature dependent cubic magneto-crystalline

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[1] E. Beaurepaire, J.-C. Merle, A. Daunois, J.-Y. Bigot, Phys. Rev. Lett., 76 (1996) 4250-4253.

[2] J.-Y. Bigot, M. Vomir, Annalen der Physik, 525, No. 1–2 (2013) 2–30.

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Figures

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The new generation of the hemispherical energy analyser in the novel surface science research

L. Walczak

R&D Department, PREVAC Sp z o.o., Rogow, Poland

l.walczak@prevac.eu

The complexity and the range of materials and their surfaces studied will be expanded across a wide range of topics, including surface science, catalysis, corrosion, semiconductors research, photoelectrochemical energy conversion, battery technology, or energy-saving technologies [1-5]. An unique and exceedingly flexible analysis cluster with a detection system is needed for these fundamental and applied research. Here it will be described a new energy and angle resolved analyser for photoelectron spectroscopy. The analyser has a hemisphere shape with a mean radius of 150 mm and is based on combining an advanced focusing electron lens system, which can be operated in different modes, transmission, spatial resolution or angular resolution. An angular resolution of better than 0.06° and spatial resolution 100 ¾m can be obtained. The spectrometer includes highly stable 6 kV power supply, where each independent voltage module achieves temperature stability below 0.5 ppm of the voltage span per degrees Celsius. The modern 2-D low noise CCD-MCP assembly with a noise level of < 0.01 cps/channel and a 70 fps fast camera are used. Fully automation and environmental software system make it a user-friendly tool for the conducted researches. The combination of the new generation hemispherical energy analyser with a liquid helium/nitrogen manipulators and modular PREVAC surface analysis system as part of multitechnique surface analysis systems will be presented, in order to permit complete characterization of the surface structure via XPS, UPS, ISS and APRES mapping. We will report the first results from this techniques, using analyser and induced by four interaction sources: X-ray, UV, electron or ion impact. Also the results of temperature dependent study on the metallic crystal will be presented. UV excited Xe5p spectra

recorded in the gas phase show that the energy resolution is better than 3 meV at 2eV analyser pass energy. The application of the system will be shown on photovoltaic materials, graphene, or selfassembled organic monolayers of organic molecules. This analyser opens up new possibilities for angular/spatial resolved electron spectroscopy, band-mapping and other applications.

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References [1] S. BengiĂł, et. al, Surf. Sci. 646, 126-131 (2016).

[2] B. Eren el. al, Science 29, 475-478 (2016).

[3] Z. Duan et. al, J. of Solid St. Electrochem. 19, 2265-2273 (2015).

[4] N. Tomaszewska et. al, Surf. Sci. 632, 103-110 (2015).

[5] K. Samson el. al, ACS Catalysis, 4, 373-374 (2014).

[6] Yi-Chun Lu et. al, Sci. Rep. 2, 715 (2012).

Nonthermal symmetry-broken states and nonequilibrium criticality in correlated lattice models

Philipp Werner1, Naoto Tsuji2, Yuta Murakami1, Hugo Strand1, Denis Golez1, Martin Eckstein3

1

philipp.werner@unifr.ch

University of Fribourg, Chemin du Musee 3, 1700 Fribourg, Switzerland RIKEN Center for Emergent Matter Science, Wako 351-0198, Japan 3 University of Hamburg-CFEL, 22761 Hamburg, Germany 2

We study the dynamics of correlated lattice systems, which are driven out of a symmetrybroken phase, using the nonequilibrium generalization of dynamical mean field theory [1].

Trapping in nonthermal ordered states is observed in strongly correlated antiferromagnetic insulators [2] and linked to the long thermalization time of doublons and holes. In the weak-coupling regime, we find clear evidence for a relaxation controlled by a nonthermal fixed point [3]. The universality of the latter concept is further illustrated with results for phonon-mediated superconductors [4] and excitonic insulators [5].

TNT2016 fribourg (switzerland)

References [1] H. Aoki, N. Tsuji, M. Eckstein, M. Kollar, T. Oka, and P. Werner, Rev. Mod. Phys. 86 (2014) 779.

[2] P. Werner, N. Tsuji, and M. Eckstein, Phys. Rev. B 86 (2012) 205101.

[3] N. Tsuji, M. Eckstein, and P. Werner, Phys. Rev. Lett. 110 (2013) 136404.

[4] Y. Murakami, PhD thesis, Tokyo University (2016).

[5] D. Golez, P. Werner, and M. Eckstein, arXiv: 1604.03784 (2016).

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Extreme refractive index wing scale beads cause the bright colors in pierid butterflies

Bodo D. Wilts1, Doekele G. Stavenga2 and Ullrich Steiner1

1

bodo.wilts@unifr.ch

Adolphe Merkle Institute, University of Fribourg, Fribourg, Switzerland Zernike Institute for Advanced Materials, University of Groningen, the Netherlands

2

Despite the limitation to a restricted range of organic materials, evolution has optimized the color response of many organisms to an amazing extent that often appears to surpass the physical limits of the employed organic materials. One such example are the common pierid butterflies which show bright colors ranging from white to red caused by various pterin pigments concentrated in scattering spheroidal beads in the wing scales (Fig. 1, refs. [1-3]). The final coloration arises from the interplay of absorption and scattering of light by these pigment-loaded granules. Given the sparsity of the beads in the wing scales, the high color brightness suggests a scattering strength of the beads that significantly surpasses that of chitin, from which the beads are composed of. To elucidate this apparent contradiction, we have analyzed the optical signature of the pieridsâ&#x20AC;&#x2122; highly saturated pigmentary colors by using JaminLebedeff interference microscopy combined with Kramers-Kronig theory and light scattering modeling [4,5]. Our study shows that both the shape of the beads and the unusually high complex refractive index of these pigmented granules are optimized to give rise to one of the brightest biological materials. Our results present yet another trick of evolution for optimized light scattering that might be useful for bio-inspired applications.

References

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[1] Wilts BD, Wijnen B, Leertouwer HL, Steiner U & Stavenga DG, submitted (2016).

[2] Wijnen B, Leertouwer HL & Stavenga DG, J Insect Physiol, 53 (2007) 1206-1217.

[3] Morehouse NI, Vukusic P & Rutowski R, Proc R Soc B (2007) 359-366.

[4] Stavenga DG, Leertouwer HL & Wilts BD, Light Sci Appl, 2 (2013) e100.

[5] Wilts BD, Michielsen K, De Raedt H & Stavenga DG, PNAS, 111 (2014) 4363-4368.

Figures

Figure 1. Pierid butterfly photonics. (a-d) Investigated Pierid butterflies with various body colors (bars: 1cm). (e) Reflectance spectra. (f,g) Scanning and transmission electron microscopy of a single wing scale showing the arrangement of spheroidal particles attached to the wing scale (bars: 2 Âľm).

Toward atom scale ultra low power electronic circuitry

Robert Wolkow

Department of Physics, University of Alberta and National Institute for Nanotechnology, Edmonton, Alberta, Canada

Decades of academic study of silicon with scanned probe and related techniques have made it possible to now envisage a silicon-based, atom-scale, ultralow power circuitry that merges with and enhances CMOS electronics technology.

The preparation and characteristics of a robust, readily repairable, single atom tip and its varied applications to imaging and fabrication will be described also.

A key step was made in 2008 when single silicon dangling bonds on an otherwise H-terminated surface were shown to behave as ultimate small quantum dots [1]. Because all such dots are identical, and spacing between dots can be identical, and dots can be placed very closely to achieve strong interaction, and because many, many dots can be printed easily there appears to be prospects for interesting circuitry. The same dots can be deployed to make â&#x20AC;&#x153;passiveâ&#x20AC;? elements like wires and to make active elements of diverse kinds including quantum cellular automata with the prospect of room temperature operation, and single electron transistors (SETs) of extremely narrow device to device variation.

References

Among most recently published work I will describe are single-electron, single-atom transport dynamics [2] and the use of multi-probe STM to show surface conduction among collectives of DBs [3]. Just published STM spectral studies of silicon atoms will be shown and the remarkable roles of controlled single atom charge state change and of near surface dopants will be identified [4].

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[1] M. Baseer Haider, Jason L. Pitters, Gino A. DiLabio, Lucian Livadaru, Josh Y. Mutus, and Robert A. Wolkow, Phys.Rev.Lett., 102, 046805 (2009), and patent issued recently.

[2] Marco Taucer, Lucian Livadaru, Paul G. Piva, Roshan Achal, Hatem Labidi, Jason L. Pitters, and Robert A. Wolkow, Phys. Rev. Lett., 112, 256801 (2014).

[3] Bruno V. C. Martins, Manuel Smeu, Lucian Livadaru, Hong Guo, and Robert A. Wolkow, Phys. Rev. Lett., 112, 246802 (2014).

[4] H. Labidi, M.Taucer, M.Rashidi, M.Koleini, L.Livadaru, J.Pitters, M.Cloutier, M.Salomons and Robert A Wolkow, New J. Phys., 17, 073023 (2015).

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FluidFM for single-cell extraction followed by molecular analysis

Tomaso Zambelli1, Orane Guillaume-Gentil2, Jรกnos Vรถrรถs1 and Julia A. Vorhol2

1

ztomaso@ethz.ch

Laboratory of Biosensors and Bioelectronics, D-ITET, ETH Zurich (Switzerland) Institute of Microbiology, D-BIOL, ETH Zurich (Switzerland)

2

The FluidFM is a force-controlled nanopipette, combining AFM technology and nanofluidics [1, 2].

A fluidic channel is incorporated directly in a hollow AFM cantilever. This channel ends in an aperture at the apex of the AFM tip, allowing for local dispensing of soluble molecules in air and in liquid, while retaining the inherent imaging capabilities and force feedback of an AFM system.

Using hollow pyramidal tips with a triangular aperture close to the apex, we have just demonstrated the quantitative and subcompartmental femto-picoliter extraction from single cells in vitro. We showed the integrity of proteins and transcripts as well as versatility of molecular analyses by high-resolution TEM imaging, minute enzyme assays and qPCR of cytoplasmic and nucleoplasmic extracts from distinct or even the same cell [3].

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References [1] A. Meister, M. Gabi, P. Behr, P. Studer, J. Vรถrรถs, P. Niedermann, J. Bitterli, J. Polesel-Maris, M. Liley, H. Heinzelmann, T. Zambelli, Nano Lett.

2009 9:2501.

[2] O. Guillaume-Gentil, E. Potthoff, D. Ossola, C.M. Franz, T. Zambelli, J.A. Vorholt, Trends Biotechnol. 2014 32:381.

[3] O. Guillaume-Gentil, R.V. Grindberg, R. Kooger, L. Dorwling-Carter, V. Martinez, D. Ossola, M. Pilhofer, T. Zambelli, J.A. Vorholt, Cell 2016, just accepted.

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Effect of annealing on magnetic properties and domain wall dynamics of Fe-Ni based magnetic microwires

Arcady Zhukov1,2,3, Juan Maria Blanco2, Galina Abrosimova4, Alexandr Aronin4, Margarita Churyukanova5, Mihail Ipatov1,2, Sergey Kaloshkin5 and Valentina Zhukova1,2 arkadi.joukov@ehu.es

1

Dpto. Física de Materiales, UPV/EHU, 20018, San Sebastián, Spain Dpto. Física Aplicada, EUPDS, UPV/EHU, 20018, San Sebastián, Spain 3 IKERBASQUE, Basque Foundation for Science, 48011 Bilbao, Spain 4 Insituteof Solid State Physics, RAS, Chernogolovka, 142432, Moscow, Russia 5 National University of Science and Technology «MISIS», 119049, Moscow, Russia 2

Glass-coated ferromagnetic microwires intensively studied during last two decades exhibit magnetic properties quite attractive from the point of view of technical applications, such as magnetic bistability, excellent magnetic softness and giant magnetoimpedance, GMI, effect [1,2]. Conventional route for optimization of magnetic properties is related to choosing of adequate chemical composition of the metallic nucleus [1,2]. On the other hand optimization of most interesting magnetic properties, such as velocity of single DW propagation during the magnetization switching is limited by the materials defects and magnetoelastic anisotropy. The DW velocity linearly increases with applied magnetic field, H, until the multiple DW nucleation on defects happens. Therefore the extension of the magnetic field range for single-DW propagation regime limits the DW velocity [3]. This extension is limited by the minimum value of local nucleation field, Hnmin, determining the threshold between single and multiple DW propagation regimes [3]. The local defects are responsible for the spontaneous DW nucleation in different places of the microwire. The origin of these defects is still unclear, although recently we reported that annealing can change the local nucleation fields [3].

We studied the magnetic properties and domain wall (DW) dynamics of Fe47.4Ni26.6Si11B13C2 and Fe77.5Si7.5B15 microwires. Both samples present rectangular hysteresis loop and fast magnetization switching. Domain wall dynamics is considerably affected by the annealing. Linear region on dependence of domain wall velocity on magnetic field in Fe47.4Ni26.6Si11B13C2 sample is considerably shorter. Consequently we studied the structure of

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as-prepared and annealed Fe47.4Ni26.6Si11B13C2 sample using X-ray diffraction and analyzed the effect of annealing on DW dynamics.

References [1] M. Vazquez, H. Chiriac, A. Zhukov, L. Panina and T. Uchiyama, Phys Stat Sol. A 208, (2011) 493.

[2] A. Zhukov, M. Ipatov and V. Zhukova, Advances in Giant Magnetoimpedance of Materials, Handbook of Magnetic Materials, ed. K.H.J. Buschow, Volume 24 (2015) 139.

[3] A. Zhukov, J. M. Blanco, M. Ipatov, and V. Zhukova Sensor Letters 11 (1) (2013) 170.

Figures

Figure 1. Dependences of domain wall velocity, v, on magnetic field, H measured in Fe77.5Si7.5B15 and Fe47.42Ni26.6B12.99Si1.99 microwires.

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Li and Na insertion into TiO2 polymorphs and Li-Ti ternary oxides

M. Zukalova, B. Pitna Laskova and L. Kavan

J. Heyrovský Institute of Physical Chemistry, v.v.i., AS CR, Dolejškova 3, CZ-18223 Prague 8, Czech Republic

marketa.zukalova@jh-inst.cas.cz

Both TiO2 polymorphs (anatase and TiO2 (B)) and LiTi ternary oxides are attractive candidates for anodes in rechargeable Li-ion batteries, due to their low cost, non-toxicity, cycling stability at high charging rate and reasonable capacity. Li insertion into anatase proceeds as a diffusion controlled process, where the peak current scales with square root of the scan rate, whereas Li-insertion electrochemistry of TiO2(B) is basically different.

Zukalova et al found that Li-insertion into TiO2(B) is characterized by unusually large faradaic pseudocapacitance [1] The predominant pseudocapacitive process in TiO2(B) was related to accommodation of Li inside the TiO2(B) open channels in monoclinic lattice.

In parallel with an employment of Li-ion batteries as prominent power sources for many portable devices and their perspectives in large-scale applications more and more research teams realize limited sources of lithium and transition metals. In search for possible alternative a substitution of Li with Na seems to be a feasible solution. Na resources as NaCl in seawater are practically unlimited. However, due to larger radius of Na ion (Na: 1.02 Ǻ, Li: 0.76 Ǻ) there is only limited number of possible Na-ion host materials in contrary to relatively broad variety of materials inserting Li. Recently, lithium titanate spinel (Li4Ti5O12, LTO), used as the negative electrode material in Li-ion batteries, has also been examined for the Na-ion battery. LTO is known as a “high potential” negative electrode material with a formal potential of 1.55 V vs. Li/Li+, whereby one can avoid the dendrite problem. This character should also prevent the Nadendrite deposition. Na insertion in LTO is accompanied with development of extra phase with an about 4-5% larger unit cell volume which co-exists with LTO in a single particle and is identified as a Na-substituted LTO phase [2].

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In our work we studied Li and Na insertion into TiO2(B) and LTO spinel of different particle size and synthetic history, either commercial or laboratory made. The highest capacity and charging rate both for Li and Na insertion exhibited nanocrystalline LTO prepared by sol-gel process pioneered in our laboratory [3].

During testing of Li insertion/extraction by galvanostatic chronopotentiometry at 1C this material exhibited excellent stability over tens of cycles with almost 100% of theoretical capacity (175 mAh/g). In contrary, commercial materials exhibited a capacity drop of about 30% after 50 cycles. In case of Na insertion, the charge capacity of nanocrystalline LTO prepared by sol-gel process was 158mAh/g in the first cycle, however considerable capacity drop of about 40% was observed during cycling. This is obviously the consequence of irreversible structural changes induced by Na accommodation in the Li4Ti5O12 lattice. The best cycling stability for Na insertion exhibited commercial LTO from Altair.

After 50 cycles at 1C the charge capacity of this material (with 20% Super P additive) decreased from initial 105 mAh/g to 85 mAh/g, i. e. of about 20%.

Acknowledgement: This work was supported by the Grant Agency of the Czech Republic (contracts No. 13-07724S and 15-06511S).

References [1] M. Zukalova, M. Kalbac, L. Kavan, I. Exnar, M. Graetzel, Chemistry of Materials, 17 (2005) 1248-1255.

[2] M. Kitta, K. Kuratani, M. Tabuchi, N. Takeichi, T. Akita, T. Kiyobayashi, M. Kohyama, Electrochimica Acta, 148 (2014) 175-179.

[3] L. Kavan, J. Prochazka, T.M. Spitler, M. Kalbac, M.T. Zukalova, T. Drezen, M. Gratzel, Journal of the Electrochemical Society, 150 (2003) A1000A1007.

TNT2016 fribourg (switzerland)

Faceted Vesicles from Interdigitating 1,3-Diamidophospholipids

Andreas Zumbuehl

Department of Chemistry, University of Fribourg, Chemin du Musée 9, 1700 Fribourg, Switzerland

andreas.zumbuehl@unifr.ch

The guided self-assembly of nonspherical phospholipid vesicles or liposomes may lead to interesting applications such as mechanoresponsive drug delivery systems [1]. However, in order to form true facetted vesicles, first the underlying physical forces at play have to be understood.

We approach the problem by organic synthesis of unprecedented phospholipid structures. The highly pure compounds are then submitted to biophysical testing of both their monolayer and bilayer characteristics (surface pressure/molecular area isotherms, gracing incidence angle X-ray diffraction, infrared reflection absorption spectrometry, Brewster-angle microscopy, small-angle X-ray scattering, cryogenic transition electron microscopy, fluorescence release, microfluidics, etc.).

The results from the 1,3-diamidophospholipid PadPC-Pad (1) show a fully interdigitated, flat bilayer membrane at temperatures below the main phase transition of 37 °C. Above the phase transition a cooperative first order transition into a noninterdigitated bilayer Lα phase is observed. This fluid membrane can be extruded into large unilamellar vesicles of 100 nm. Upon cooling to room temperature, various faceted vesicle types form such as lenticular vesicles, or d-form vesicles [2]. The formed membrane defects are attenuated when the system is agitated on a vortex shaker [1].

If no external force is applied, the vesicles retain their cargo. This is unlike natural phospholipid vesicles that either release or do not release their cargo under either conditions.

several new structures that will be discussed, such as 1,2-diamidophospholipids or 1,3-diureaphospholipids.

Overall, the biophysical forces at play will be discussed as well as potential applications for physics-based targeted drug delivery of a vasodilator to the site of an occluded blood artery after a heart attack.

References [1] M. N. Holme, I. A. Fedotenko, D. Abegg, J. Althaus, L. Babel, F. Favarger, R. Reiter, R. Tanasescu, P.-L. Zaffalon, A. Ziegler, B. Müller, T. Saxer, A. Zumbuehl, Nature Nanotechnology, 7 (2012), 536.

[2] R. Tanasescu, M. A. Lanz, D. Mueller, S. Tassler, T. Ishikawa, R. Reiter, G. Brezesinski, A. Zumbuehl, Langmuir, in press.

Figures

Figure 1. Structure of the 1,3-Diamidophospholipid PadPC-Pad (1).

The insights gained from this first generation artificial phospholipid system have flown into

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| 149

Real-time shape approximation and 5-D fingerprinting of single proteins

Michael Mayer

Biophysics, Adolphe Merkle Institute, University of Fribourg, Switzerland

Presentation Summary: This talk describes the use of bilayer-coated, synthetic nanopores to characterize, simultaneously and in real-time, the volume, charge, shape, dipole moment, and rotational diffusion coefficient of single proteins.

This 5-D fingerprint may be used for sensitive biomarker detection and routine protein analysis.

Abstract: Our group is interested in developing novel strategies to explore the structure and function of single proteins in solution. As an example of our advances in this area, this talk describes the use of electrolyte-filled nanopores with self-assembled lipid membrane coatings to determine, simultaneously and in real time, the shape, volume, charge, rotational diffusion coefficient, and dipole moment of individual proteins. It introduces the main concepts for a quantitative understanding and analysis of

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modulations in ionic current that arise from rotational dynamics of single proteins as they move through the electric field inside a nanopore. The resulting multi-parametric information raises the possibility to characterize, identify, and count individual proteins and protein complexes in a mixture. This approach interrogates single proteins and determines parameters such as the shape and dipole, which are excellent protein descriptors and cannot be obtained otherwise from single proteins in solution. Hence, this five-dimensional characterization at the single particle level has the potential for instantaneous protein identification, quantification, and sorting with exciting implications for protein folding studies, structural biology, proteomics, biomarker detection, and routine protein analysis.

TNT2016 fribourg (switzerland)

Stephen Schrettl, Christoph Weder

Calvino, Céline

B. Eydoux, B. Baris, F. Chaumeton, R. Robles, M. Pruneda, N. Lorente, S. Gauthier and D. Martrou

Bouju, Xavier

D. Jacob, et al

Boj, Sylvain

F. Movafagh, S. S. Parhizgar

Beheshtian, Javad

Isa Ravaei

Beheshtian, Javad

Steven B. Fairchild, C. C. Yang

Averett , Kent

Stefan Aeby and Frank Scheffold

Armenta Calderón, Ricardo

Nico Bruns

Apebende, Edward

N. Schuergers and A. A. Boghossian

Antonucci, Alessandra

Andreas A.F.M. Kilbinger

Alizadeh, Mahshid

authors

Switzerland

France

France

Iran

Iran

USA

topic

Nanostructured and nanoparticle based materials

Nanobiotechnologies and Nanomedicine

Nanostructured and nanoparticle based materials

NanoChemistry

Nanostructured and nanoparticle based materials

Graphene and 2D/Carbon nanotubes

NanoChemistry

Low dimensional materials (nanowires, clusters, quantum dots, etc.)

Switzerland Other

Switzerland

Switzerland

Switzerland Other

country

Towards Mechanochromic Materials Based on Non-Covalent Interactions

Atomic structure determination of the (2×2) reconstructions of the polar AlN(0001) surface and atomic metallic deposition

Combining SAXS and DLS for simultaneous measurements & timeresolved monitoring of nanoparticle synthesis

Absorption of iron oxide nano clusters (Fe4O6) on graphene surface: A density functional study

A density functional study of carbon monoxide on pristine and Liencapsulated fullerene-like BeO

Field Emission Behavior of Self-Assembled and Patterned Gallium Nitride Nanowire Arrays

Confinement-induced stable liquid phases mimicking the behavior of lipid bilayers

Synthesis and characterization of stimuli responsive block copolymers for the reversible compatibilization of polymer blends

Interaction of single-walled carbon nanotubes (SWCNTs) with photosynthetic systems

Using Aramid Cis-trans Isomerization as a Model for Auxetic behavior

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Only Posters submitted by registered participants and payment processed are listed below (As of 22/08/2016)

USA

Fabio Donati, Franรงois Patthey and Harald Brune

Fernandes, Edgar

J. N. Gonรงalves, C. O. Amorim, J. G. Correia, K. Johnston, H. Haas, V. S. Amaral, S. Cottenier, L. M. C. Pereira

Fenta, Abel

Mathew Lange, Nathan Lockwood, Daniel Marincel

Fairchild, Steven B.

Phally Kong, Sandor Balog, Andreas F. M. Kilbinger

Drechsler, Susanne

O. Kovalenko, V. Shokeen, Z. Raolison, G. Pourroy, J.-Y. Bigot

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Sandor Balog, Christoph Weder, Lucas Montero de Espinosa

del Prado Abellรกn, Anselmo

Daniel Midtvedt

Croy, Alexander

D. Burnand, B. Goris, S. Bals, A.M. Hirt, M. Lattuada, L. Haeni, B. RothenRutishauser and A. Petri-Fink

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Ji Young Bae and Ha-Jin Lee

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Chih-Peng Liu and Hsiang-Wen Tseng

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Tai-ju Hsieh, Chun-Min Liu, Ya-Chin Lo, Taiwan

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Chi Tso Chang

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Experimental Determination of the Adsorption Sites of Individual Metal Atoms on MgO(100) Thin Films

Graphene and adatoms: ab initio calculations and hyperfine interactions

Carbon Nanotube Fiber Array Field Emission Cathodes

Aromatic amides and their use for self-assembly

Investigation of dynamics of Permalloy-Molybdenum flakes by magneto-optical time-resolved spectroscopy

Towards high performance supramolecular materials

Valence-force model and nanomechanics of single-layer phosphorene

Influence of ligand exchange on crystallography, magnetic and thermal behavior of iron oxide nanoparticles for hyperthermia

Portable Polyelectrolyte Brush-Coated Sponge Composites for Environmental Remediation

Sensitive Electrodes of Azulene-Based Complexing Polymer Films for Heavy Metal Ions Detection

Anti-tumor and Anti-metastasis Activities of Dichloro (1, 2diaminocyclohexane) Platinum (II) (DACHPt)-Incorporated Hyaluronic Acid Nanoparticles in Colon Cancer and Melanoma Model in vivo

Self-Aligned Carbon Nanotube Formation for Next Generation Transistor

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Benjamin Le Monnier, Jeremy S. Luterbacher

Héroguel, Florent

Adrien Spaggiari

Hengsberger, Stefan

J. Bourquin, C. A. Monnier, A. PetriFink, V. Ball and B. Rothen-Rutishauser

Hauser, Daniel

Ali Maleki

Hatefi Chaharborj, Mohammad

N. Muller, L. Froufe, F. Scheffold

Haberko, Jakub

Yucheng Zhang, Meng Li, Rolf Erni, Hyung Gyu Park and Ivo Utke

Guerra, Carlos

Tobias Kuhnt, Worarin Meesorn, Lucas Montero de Espinosa, Christoph Weder

Graterol, Sandra

N. Muthuchamy, K-P. Lee

Gopalan, Anantha Iyengar

Nicolas Muller, Frank Scheffold, Olimpia Onelli & Silvia Vignolini

Fuchs, Nathan

N. de Sousa, J.J. Saenz, F. Scheffold, and A. García-Martín

Froufe-Pérez, Luis S.

N. de Sousa, J. J. Saenz and A. García-Martín

Froufe-Pérez, Luis S.

R. Paniagua-Domínguez, J. J. Sáenz and J. A. Sánchez-Gil

Froufe-Pérez, Luis S.

Asiye A. Avan

Filik, Hayati

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Korea

Switzerland

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Switzerland

Turkey

Nanostructured and nanoparticle based materials

Nanostructured and nanoparticle based materials

Nanobiotechnologies and Nanomedicine

Graphene & 2D / Carbon nanotubes

NanoOptics/NanoPhotonics/Pla smonics/Nanophononics

Graphene and 2D/Carbon nanotubes

Nanostructured and nanoparticle based materials

Nanomaterials for Energy

NanoOptics/NanoPhotonics/Pla smonics/Nanophononics

NanoOptics/NanoPhotonics/Pla smonics/Nanophononics

NanoOptics/NanoPhotonics/Pla smonics/Nanophononics

NanoOptics/NanoPhotonics/Pla smonics/Nanophononics

NanoChemistry

Chemical layer deposition of porous alumina overcoats increases activity and stability in liquid phase catalytic conversion of biomassderived chemicals

Optimisation of the demoulding properties of plastic parts with micro/nano surface treatments: an eurostars project

Stimuli-responsive polydopamine/protein nanoparticles can target cancer cells and induce cell death

Dielectric properties of nematic liquid crystal doped with Graphene nanoplates

Three-dimensional networks derived from hyperuniform point patterns and their optical properties

Surface and interface engineering of TiO2 thin films deposited on carbon nanotubes by Atomic Layer Deposition

One-component nanocomposites based on polymer-grafted cellulose nanocrystals

Novel Manganese oxide-Titanium dioxide-Graphene Based Tetranary Nanohybrids for High-Performance Supercapacitor

Biotemplating white beetle scales for isotropic high index photonic materials

Light Emission Statistics as a Local Probe for Structural Phase Switching

Magneto-optical activity in high-index dielectric materials

Localized magnetic plasmons in all-dielectric structures

Simultaneous electrochemical determination of ascorbic acid, dopamine, uric acid and tryptophan with azure A-interlinked multi-walled carbon nanotube/gold nanoparticle composite modified electrode

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Natalia Rosiak, Andrzej Bogucki, Roman Świetlik

Lewadnowska, Kornelia

A-I. Gopalan, N. Muthuchamy

Lee, Kwang-Pill

Md. Shahinul Islam, Won San Choi

Lee, Ha-Jin

Florent Héroguel, Jeremy S. Luterbacher

Le Monnier, Benjamin P.

Susanne Drechsler, Sandor Balog, Andreas F. M. Kilbinger

Kong, Phally

Hyun Kyung Kim, Myung Seong Kim, Young Hwan Kim, Yeon Jun Choi, Jun Hui Jeong and Seok Woo Lee

Kim, Kwang-Bum

Gülşen Akın Evingür, Semira Bener, Hakan Kaygusuz, F. Bedia Erim

Kahya, Nilay

Do Rim Kim, Kiwan Jang, Ho Sueb Lee, Dong Soo Shin

Jeong, Jung Hyun

Yue Guo, Kiwan Jang, Ho Sueb Lee, Dong Soo Shin

Jeong, Jung Hyun

Kaori Sugihara

Jajcevic, Kristina

M. Jafari, A. Goodarzi, M. Asadpour

Jafari, Maryam

M. S. Mazloum, S. J. Azimi, R. Jafari

Jafari, Mahmoud

Shou-Yi Kuo

Hsieh, Ming-Yang

Diederik W. R. Balkenende, Lucas Montero de Espinosa, Christoph Weder

Hohl, Diana Kay

Nanomaterials for Energy

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Spectroscopic properties of the complexes formed by graphene oxide and porphyrins substituted with aryl group

Silica Micelles (Hydrophilic Core@Amphiprotic Shell) for Multiple Applications A Green One-step Approach for the Synthesis of Graphene Included Bismuth Oxychloride Nanosheets and Photoelectrochemical Sensing

Chemical Layer Deposition of metal oxide overcoats with targeted porosity by Stoichiometric and Kinetic control

Synthesis of aramide rod-like molecules and re-entrant honeycomb structure for the investigation of auxetic polymers

Physical and Chemical Modification of Graphene for Electrochemical Energy Storage Applications

Optical Properties and Characterization of Graphene OxideChitosan Composites through Tensile Testing, TGA/FTIR Analysis

Crystal structure and upconversion luminescence properties of Er3+

Fluorescence properties with redshift of Eu2+ emission in novel phosphor-silicate apatite Sr3LaNa(PO4)2SiO4 phosphors

Gold nanowire fabrication with lipid nanotubes

Magnetic properties of interstitial Fe in graphene nanosheet

Optimization of a broadband and omnidirectional anti-reflection layer for Cu2ZnSnS4 solar cells Electronic and Optical properties of interstitial Fe in graphene nanosheet

Hyperbranched, surpramolecular polymer adhesives exhibiting high toughness and stiffness

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D. W. R. Balkenende, S. Coulibaly, S. Schrettl, B. Wilts, Y. Simon, C. Weder

Neumann, Laura

H.Ghorbanfekr and F. M. Peeters

Neek-Amal, Mehdi

Trappe V.

Nazzani, Francesco

Janak Sapkota, Christoph Weder

Natterodt, Jens

K. V. Bukhryakov, O. Bertrand, K. B. Vu, J.-F. Gohy, N. Hadjichristidis and V. O. Rodionov

Mugemana, Clément

M. Pivetta, S. Rusponi and H. Brune

Mousadakos, Dimitrios

Jonathan Brignoli, Thierry Moser, Patrick A. Rühs, André R. Studart

Moore, David G.

Parsa Haji Adineh, Ali Maleki, Hossein Jamali

Molaei, Amir Hossein

Anuja Shirole, Dimitri Vanhecke, Lucas Montero de Espinosa and Christoph Weder

Meesorn, Worarin

F. Crippa, C. A. Monier, A. M. Hirt, A. P. Fink and M. Lattuada

Martinez Garcia, Julio Cesar

J. Rubio-Zuazo, I. Arnay, A. MuñozNoval, A. Serrano, N. Carmona, O. Rodríguez de la Fuente and G. R. Castro

López-Sánchez, Jesús

Ahmed Ali, Hyunki Kang and Eun Young Hwang

Lim, Dong Woo

NanoOptics/NanoPhotonics/Pla smonics/Nanophononics

Nanostructured and nanoparticle based materials

Nanostructured and nanoparticle based materials

Nanomagnetism and Spintronics

Nanobiotechnologies and Nanomedicine

Graphene and 2D/Carbon nanotubes

Nanostructured and nanoparticle based materials

Switzerland

Iran

Nanostructured and nanoparticle based materials

Theory and modelling at the nanoscale

Switzerland Other

Switzerland

Switzerland Other

Switzerland

Switzerland Other

Iran

Switzerland

Switzerland

Spain

Korea

The Mechanoresponsive Nature of Metallosupramolecular Polymers

N-doped graphene: polarization effects and structural properties

Characteristics of strong glass formers in charged microgel systems

Polymer nanocomposites with cellulose nanocrystals functionalised with 2-ureido-4[1H]pyri¬midinone

Ring Opening Metathesis Polymerization of Cyclopentene Using a Ruthenium Catalyst Confined by a Branched Polymer Architecture

Nucleation of Sm and Dy on graphene on Ir(111)

Functional microcapsules with inorganic-organic thick shells using sol-gel chemistry

Optical characterization of graphene doped liquid crystalline matrix using z-scan technique

Improving the Filler Dispersion in Polymer Nanocomposites with Cellulose Nanocrystals

Evaluating the magnetic anisotropy temperature dependence of (SPIONs) system

Temperature dependence on the magnetic, morphological and structural properties of Fe3O4(111)/SrTiO3(111) thin films grown by PLD

Electric Field-responsive Anisotropic Nano-architectures for Dual Drug Delivery Systems

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Janak Sapkota, E. Johan Foster and Christoph Weder

Shirole, Anuja

O Rodríguez de la Fuente, V. Collado, J. Rubio-Zuazo, C. Monton, G R Castro and M A García

Serrano, Aida

Chi Zhang, Frank Scheffold

Şenbil, Nesrin

Dimitri Kokkinis and André R. Studart

Schaffner, Manuel

Sandor Balog, Lucas Montero de Espinosa, Christoph Weder

Sautaux, Julien

Marko Pavlovic, Istvan Szilagyi

Rouster, Paul

Amir Hosein Molaee, Ali Maleki, Dariush Jahani

Rashedi, Ali

Miriam Unger, Honghua Yang, Eoghan Dillon, Kevin Kjoller and Craig Prater

Rascher, Daniela

Popov, Vladimir A.

A. Iqbal, J. S. Cha, and J. Kim

Park, Kyeongsoon

Lucas Montero de Espinosa, Christoph Weder

Olaechea, Luis

D. G Moore, P. Schwendimann, M. L Eggersdorfer, E. Amstad, D. A Weitz and A. R Studart

Ofner, Alessandro

Nanostructured and nanoparticle based materials

Nanostructured and nanoparticle based materials

NanoOptics/NanoPhotonics/Pla smonics/Nanophononics

Graphene and 2D/Carbon nanotubes

NanoChemistry

Nanomaterials for Energy

Nanostructured and nanoparticle based materials

Switzerland

France

Nanostructured and nanoparticle based materials

Other

Switzerland Other

Switzerland Other

Switzerland

Switzerland

Iran

Germany

Russia

Korea

Switzerland

Switzerland Other

Shape Memory Composites Based on Electrospun Poly(vinyl alcohol) Fibers and a Thermoplastic Polyether Block Amide Elastomer

Combination of surface plasmon resonance and X-ray absorption spectroscopy: SPR-XAS setup

Active microrheology in an emulsion glass

Multimaterial magnetically assisted 3D printing of composite materials

Supramolecular polymer solids with orthogonal binding motifs

Functionalization of titanate nanostructures for bioapplications

The role of hopping energy of electrons in graphene on bangap of a periodic graphehe-dielectric structure

Amplitude- and Phase-Resolved Infrared Imaging of 2D Materials

Thermoelectric Properties of Ca2.9M0.1Co4O9 (M = Li, Na, and K) and Ca3Co3.9N0.1O9 (N = Li, Na, and K) Fabricated by Spark Plasma Sintering Process “In-situ” synthesis of TiC reinforcing nanoparticles inside aluminium matrix from nanodiamond and titanium precursors during mechanical alloying

Stimuli-responsive Pt(0) containing metallosupramolecular polymers

High throughput microfluidic glass devices to form functional materials

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Benjamin Lambert, Esra Ahunbay, Nils SchĂźrgers, Ardemis Boghossian

Zubkovs, Vitalijs

J. Mino, J. J. Del Val, J. M. Blanco, J. Gonzalez, M. Baibich, G. Martinez, M. Ipatov, R. Varga, V. Zhukova

Zhukov, Arcady

N. Gnan, T. G. Mason, E. Zaccarelli and F. Scheffold

Zhang, Chi

C. Rawlings, S. Bonanni, M. Spieser, P. Mensch, S. Karg, P. Paul, H. Wolf, U. Duerig, A. Knoll and F. Holzner

Wu, ZhengMing

Roland Widmer

Stolz, Samuel

Nanofabrication tools and nanoscale integration

High spatial resolution spectroscopies under SPM probe

Switzerland

Spain

Nanobiotechnologies and Nanomedicine

Nanomagnetism and Spintronics

Switzerland Other

Switzerland

Switzerland

Single-walled carbon nanotube-based optical sensors for continuous glucose monitoring

GMR Effect in Co-Cu Microwires Microwires

Structural signatures of the glass transition in emulsions

Sub-20 nm lift-off techniques without charged particle damage using Thermal Scanning Probe Lithography

Formation of enantioselective molecular structures on the PdGa:A(1-1-1)Pd3 surface

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Using Aramid Cis-trans Isomerization as a Model for Auxetic behavior Mahshid Alizadeh 1* , Andreas A.F.M. Kilbinger 1University of Fribourg, Faculty of science, Chemistry Department, Chemin du Musée 9, CH-1700 Fribourg ‫כ‬mahshid.alizadeh@unifr.ch Unlike conventional material, auxetic materials show a negative poisson ratio.1 They expand perpendicular to the direction in which they are stretched. Several molecular polymeric structures have been proposed as being potentially auxetic.2,3 The proposed approach to auxetic materials is based on aramide oligomers. N-substituted (cis-trans) benzanilides might be useful in designing re-entrant structures for auxetic materials.

This project deals with the question whether the cis-trans isomerization of amides can be exploited in the synthesis of auxetic polymeric materials. The following isomerization unit containing polymers were designed for single molecule stretching experiments via AFM. These should serve as models to relate molecular changes to macroscopic movements.To synthesize the polymers shown in figure 1, we designed an isomerizable central unit as a macro-initiator. The approach to synthesize such an ATRP initiator from aramides is shown below. The included cis-segment serves as the mechano-responsive element.

References [1] Kenneth, E.; Li P.; Griffin, A.; Smith, C. Macromol. Chem. Phys. 2005, 206, 233±239.

[2] Mir M.; Najabat Ali M.; Sami J.; Ansari U. Adv.Mater 2014.

[3] Liu Y.; Hong, Hu;. Sci. Res. Essays. 2010, 5, 1052-1063.

Figures

Figure 1: Models for AFM experiments Figure 2: Synthetic route for the ATRP-initiator in cis configuration

Interaction of single-walled carbon nanotubes (SWCNTs) with photosynthetic systems A. Antonucci, N. Schuergers, and A. A. Boghossian

Institute of Chemical Sciences and Engineering (ISIC) Ecole Polytechnique FĂŠdĂŠrale de Lausanne (EPFL), 1015-Lausanne, Switzerland alessandra.antonucci@epfl.ch For years, the distinctive optical and structural properties of single-walled carbon nanotubes (SWCNTs) have inspired the development of promising applications in the field of cell nanobiotechnology[1], [2]. In particular, the synergistic interaction with photosynthetic organisms has attracted an increasing level of attention due to the potential of engineered nanoparticles to enhance the native performance of biological systems, paving the way for novel, renewable, and low cost solutions for light-harvesting, energy conversion and subcellular sensing[3], [4].

So far, major studies have largely focused on enabling cellular uptake of SWCNTs by engineering the SWCNT surface through non-covalent side-wall functionalizations. Non-covalent functionalization with a rich variety of biomolecules and polymers has been shown to potentially increase SWCNT solubility and membrane translocation while endowing these nanostructures with enhanced biocompatibility[5].

Most recently, this platform has been successfully applied to intact chloroplasts to augment their photosynthetic capability and improve stability against reactive oxygen species[6]. Our work builds on these empirical findings to gain an in-depth understanding of the dynamics of the underlying interaction on a molecular level. We performed a systematic investigation of the effect of SWCNT functionalization on membrane penetration properties using a novel biological host. The results of this study offer great promise for the development of a new generation of light-harvesting nanobionic devices.

References: [1] [2] [3] [4] [5] [6]

A. a. Boghossian, J. Zhang, P. W. Barone, N. F. Reuel, J. H. Kim, D. a. Heller, J. H. Ahn, A. J. Hilmer, A. Rwei, J. R. Arkalgud, C. T. Zhang, and M. S. Strano, ChemSusChem, vol. 4, no. 7 (2011) pp. 848Âą863.

S. F. Oliveira, G. Bisker, N. a. Bakh, S. L. Gibbs, M. P. Landry, and M. S. Strano, Carbon 95, (2015) p. 767-779.

M. F. Serag, N. Kaji, S. Habuchi, A. Bianco, and Y. Baba, RSC Adv., vol. 3, no. 15 (2013) p.

4856.

M. D. Lambreva, T. Lavecchia, E. Tyystjärvi, T. K. Antal, S. Orlanducci, A. Margonelli, and G. Rea, Photosynth. Res., vol. 125, no. 3 (2015) pp. 451¹471.

6 9DUGKDUDMXOD 6 = $OL 3 0 7LZDUL ( (URáOX . 9LJ 9 D 'HQQLV DQG 6 5 6LQJK Int. J. Nanomedicine, vol. 7 (2012) pp. 5361¹74.

J. P. Giraldo, M. P. Landry, S. M. Faltermeier, T. P. McNicholas, N. M. Iverson, A. a Boghossian, N. F. Reuel, A. J. Hilmer, F. Sen, J. a Brew, and M. S. Strano, Nat. Mater., vol. 13, no. 4 (2014) pp. 400Âą8.

Synthesis and characterization of stimuli-responsive block copolymers for the reversible compatibilization of polymer blends

Edward Apebende, Nico Bruns Adolphe Merkle Institute, University of Fribourg, Switzerland

edward.apebende@unifr.ch Abstract It is often necessary to blend polymers in order to introduce or improve certain useful properties.

However, not all polymers are miscible. Several polymers phase separate when blended with other 1 2 ones . This set back is often overcome by adding block copolymers as compatibilizers to the blends .

Although the addition of block copolymer stabilizes the blends, it also makes it impossible to recover the different homopolymers by recycling the material. We envisioned that a stimuli responsive compatibilizer would perform the dual function of stabilizing the blend in the first instance and subsequently cleave when stimulated to allow the material to be recycled. Therefore, temperatureresponsive block copolymers bearing a stimuli-responsive molecular switch between their blocks were synthesized and their response to thermal stimuli was studied. Several polystyrene-block-poly(lactic acid) block copolymers were synthesized via sequential Atom Transfer Radical Polymerization (ATRP) and Ring Opening Polymerization (ROP) from a bifunctional but asymmetrical initiator based on an 3 anthracence-maleimide diels-alder adduct. Such adducts can be cleaved by temperature and by 4 mechanical forces . In order to show that the block copolymer can be cleaved by heat, the block copolymer was refluxed in THF and the products were analyzed by gel permeation chromatography (GPC). A reduction in molecular mass and an increase in dispersity were observed. This is consistent ZLWK WKH LGHD WKDW WKH ³WKHUPRSKRUH´ FOHDYHV LQ UHVSRQGV WR KHDW 7KH WKHUPDO UHVSRQVH RI WKH SRO\PHU follows a retro [4+2] cycloaddition mechanism.

The block copolymers were used as a compatibilizer in blends of the homopolymers of polystyrene and poly(lactic acid). 10%wt of the block copolymer led to smaller domain sizes in the blend, as observed on atomic force microscopy (AFM) images. Above 110°C the block copolymer cleaves and the two homopolymers phase separate into large domain sizes. This allows for the recycling (recovery) of the different homopolymers from the blend.

References (1) Leung, B. O.; Hitchcock, A. P.; Brash, J. L.; Scholl, A.; Doran, A. Macromolecules 2009, 42, 1679.

(2) Li, T.; Topolkaraev, V. A.; Hiltner, A.; Baer, E.; Ji, X. Z.; Quirk, R. P. Journal of Polymer Science Part B: Polymer Physics 1995, 33, 667.

(3) Syrett, J. A.; Mantovani, G.; Barton, W. R. S.; Price, D.; Haddleton, D. M. Polymer Chemistry 2010, 1, 102.

(4) Li, J.; Shiraki, T.; Hu, B.; Wright, R. A. E.; Zhao, B.; Moore, J. S. Journal of the American Chemical Society 2014, 136, 15925.

Confinement-induced stable liquid phases mimicking the behavior of lipid bilayers

Ricardo Armenta-Calderón, Stefan Aeby, Frank Scheffold Physics Department, University of Fribourg Ch. Du Musée 3, 1700 Fribourg ricardo.armenta@unifr.ch

Model colloid-polymer mixtures have been extensively studied since the decade of 1990s. It has been shown that the presence of random polymer coils induces an effective attraction between colloidal 1 particles, commonly referred to as depletion forces . This attraction interaction leads the system to undergo phase separation under appropriate conditions of concentration and polymer-to-colloid size ratio.

We study dense assemblies of 410nm PMMA spheres and monitor their phase behavior and dynamics combining confocal microscopy and direct observation. Having characterized the system in bulk, we observe its phase separation in confined environments of high complexity, such as periodically or randomly distributed immobile obstacles (quenched disorder). We compare our results with theoretical 2 predictions .

[1] Ilett, S. M., Orrock, A., Poon, W. C. K., & Pusey, P. N., Phase behavior of a model colloid-polymer mixture. Physical Review E 51, 1344 (1995) [2] Fischer T.; Vink R.L.C.; Domain formation in membranes with quenched protein obstacles: Lateral heterogeneity and the connection to universality classes; J.Chem.Phys. (2011), 134, 055106

A

B

Figure: Cylindrical obstacles, diameter 5µm, average center-to-center distance 9µm were prepared by two-photon lithography. A concentrated colloid-polymer mixture of PMMA particles and polystyrene (Mw= 15MDa, Rg=108nm) is added to a substrate with the obstacles arranged periodically (A) or randomly (B).

Field Emission Behavior of Self-Assembled and Patterned Gallium Nitride Nanowire Arrays 1

1

K.L. Averett , S.B. Fairchild , C.C. Yang

2

1

Materials and Manufacturing Directorate, Air Force Research Laboratory, Wright-Patterson AFB, OH USA 2 National Taiwan University, Institute of Photonics and Optoelectronics, Taipei Taiwan Kent.Averett@us.af.mil or Kent.Averett@gmail.com Field emission nano-structures for high performance applications require: 1) Low turn-on threshold fields, 2) Chemical stability, 3) High current density capability, and 4) Modulation capability.

1 Gallium Nitride (GaN) is well-known for its high current density, chemical and radiation stability , and high 2 frequency operation through its work with high electron mobility transistors (HEMT) . Epitaxial growth of GaN nanostructures can produce high quality, single crystal GaN nanowires (NW) without damage induced through dry etching processes. Molecular beam epitaxy (MBE) and metal-organic chemical vapor 3 deposition (MOCVD) on sapphire (0001), Si(111) , and Si(100) substrates is demonstrated. The majority of nanowire epitaxy is through the self-assembly process, which randomizes the aerial density, diameter, and relative heights between nanowires in the array. We demonstrate the ability to grow nanowire arrays using patterning techniques to uniformly control all three parameters.

Field emission measurements of self-assembled and patterned GaN nanowire arrays will be presented, investigating field thresholds for emission current, NW emission behavior and examining the geometrical enhancement factor by comparing field emission behavior as a function of NW diameter.

REFERENCES 1. - 9DLWNXV ( *DXEDV 9 .D]XNDXVNDV HW DO ³$ 1HZ 5DGLDWLRQ +DUG 6HPLFRQGXFWRU ¹ Semi,QVXODWLQJ *D1 3KRWRHOHFWULF 3URSHUWLHV´ $,3 &RQI 3URF 772, pp. 207-8 (2005).

2. 8 0LVKUD 3 3DULNK < :X ³$O*D1 *D1 +(07V ¹ An Overview of Device Operation and $SSOLFDWLRQV´ 3URF 2I WKH ,((( 90, pp. 1022-31 (2002).

3. - ( 9DQ 1RVWUDQG . / $YHUHWW 5 &RUWH] HW DO ³0ROHFXODU %HDP (SLWD[LDO *URZWK RI +LJK 4XDOLW\ *D1 1DQRFROXPQV´ - &U\VW *URZWK 287, pp. 500-3 (2006).

4. ' . 7 1J 0 + +RQJ / 6 7DQ < : =KX & + 6RZ ³)LHOG HPLVVLRQ HQKDQFHPHQW IURP SDWWHUQHG JDOOLXP QLWULGH QDQRZLUHV´ 1DQRWHFKQRORJ\ 18, p.

375707 (2007).

a

b

c

Figure 1. GaN NW arrays: (a) Self-assembled, (b) Tapered tip, (c) Tapered wire. NW diameters are ~ 100 nm.

Figure 2. Field emission behavior of self-assembled GaN NW array in Figure 1 (a).

Absorption of iron oxide nano clusters (Fe4O6) on graphene surface: A density functional study 1

2

2

Javad Beheshtian , F. Movafagh , S. S. Parhizgar Chemistry Department, Faculty of Sciences, Shahid Rajaee Teacher Training University, Tehran, Iran 2 Department of Physics, Islamic Azad University, Science and Research Branch, Tehran j.beheshtian@srttu.edu Abstract 1

Nanocluster iron oxides in the form of clusters and nanoparticles find a number of applications owing to their unique magnetic, biochemical and catalytic properties. These include applications in catalysis, biomedical uses like magnetic hyperthermia in cancer treatment, targeted drug release, magnetic 1Âą6 resonance imaging and immunoassays as well as magnetic data storage. In this study, the number of iron oxide nano-clusters optimized energy The electronic properties of clusters and interaction with graphene surface were studied. The functional PBE of density functional theory are used. Relative stability, features of electronic and magnetic properties were investigated.

The results show that the three nano clusters (Fe4O6) are stable and relatively strong interaction with graphene have led to significant changes in the band structure. Their interaction energy has been reported. Our results show significant chemical interactions between the clusters and graphene.

References [1] K. Ogawa, T. Vogt, M. Ullmann, S. Johnson and S. K. Friedlander, J. Appl. Phys. 87(2000) 63Âą73 [2] S. Laurent, D. Forge, M. Port, A. Roch, C. Robic, L. V. Elst and R. N. Muller, Chem. Rev. 108(2008) 2064Âą2110 [3] A. S. Teja and P. Y. Koh, Prog. Cryst. Growth Charact. Mater. 55(2009) 22Âą45.

[4] A. Scha¨tz, O. Reiser and W. J. Stark, Chem. Âą Eur. J., 16(2010) 8950Âą8967. > @ / 0DFKDOD - 7XFĂ&#x;HN DQG 5 =ERUĂ&#x;LO &KHP 0DWHU (2011) 3255Âą3272.

[6] D. Li, W. Y. Teoh, C. Selomulya, R. C. Woodward, P. Munroe and R. Amal, J. Mater. Chem. 17 (2007) 4876Âą4884.

Figures (a)Structure of optimized models for stable adsorption of Fe4O6 cluster on the graphene, and their band strctuer plot. Bonds are in Ă&#x2026;

A density functional study of carbon monoxide on pristine and Li-encapsulated fullerene-like BeO

Javad Beheshtian, Isa Ravaei Chemistry Department, Faculty of Sciences, Shahid Rajaee Teacher Training University, Tehran, Iran j.beheshtian@srttu.edu Abstract We report adsorption energies, structures, energy gap (Eg), charge transfer and electronic properties of carbon monoxide (CO) on primary, Li-encapsulated fullerene-like beryllium oxide (Be16O16, + Li @Be16O16, Li@Be16O16, respectively) for several adsorption states. The results have been interpreted

by DFT calculations. The presented evidence is that shows that the CO molecule is not strongly adsorbed on the fullerene-like Be16O16 on, leading to energy release of -0.17 to -0.4 eV while its + electronic properties is not significantly changed. Li @Be16O16, Li@Be16O16, can adsorb carbon monoxide more strongly than their pristine fullerene-like Be16O16. The energy gap (Eg) of the Li@Be16O16 is significantly decreased from 3.51 to 2.88 eV upon the CO adsorption corresponding to the most stable configurations, respectively. It was shown that the electrical conductance of the Li@Be16O16 may be increased after the CO adsorption. It was found that the electronic properties of Li@Be16O16 are sensitive to the presence of CO molecule.

References [1] K. Joshi. R. Jain. R. Pandya. B. Ahuja, B. Sharma, J. Chem. Phys. 111 (1999) 163.

[2] L. Ren. L. Cheng. Y. Feng, X. Wang, The Journal of chemical phys 137 (2012) 014309.

[3] M. Zhou. Z. Yi. K. Li. J. Zhang, W. Wu, Nan.Res. lett. 6 (2011) 1.

[4] D.-Y. Hwang, A. M. Mebel, Chem. Phys lett. 348 (2001), 303.

[5] M. Noei. V. ZareÇŚShahabadi, S. N. Razi, Chin. J. Chem. Phys. 26 (2013) 612.

[6] R. Shinde, M. Tayade, J. Phys. Chem. C 118 (2014) 17200.

Figures (a)Structure of optimized Li into Be16O16 fullerene-like (endohedral), (b) Models for stable adsorption of CO on the Li@Be16O16 fullerene-like, and their density of states (DOS) plot. Bonds are in Ă&#x2026;

Combining SAXS and DLS for simultaneous measurements & time-resolved monitoring of nanoparticle synthesis D. Jacob, et al., presented by Sylvain Boj Cordouan Technologies, Cité de la Photonique, 11 Avenue Canteranne, 33600 Pessac, France sylvain.boj@cordouan-tech.com Abstract Time-resolved characterization of nano-particle (NP) synthesis is a promising mean to produce NPs under controlled conditions. Here, an innovative experimental demonstration of a NP characterization tool which combines a laboratory Small Angle X-ray Scattering (SAXS) instrument, a new Dynamic Light Scattering (DLS) device and a microflow reactor is shown. The complementary SAXS and DLS techniques were designed and optimized to meet the ambitious requirements of time-resolved monitoring of NP suspensions while ongoing synthesis. For this purpose, SAXS instrument performance was enhanced by the implementation and optimization of a unique X-ray metal jet source. In parallel, an innovative DLS fiber remote probe head was developed specifically for in situ measurements. DLS measurements were performed directly inside a 2.0 mm diameter glass capillary located inside the SAXS vacuum sample chamber. The combined SAXS and DLS devices were tested separately on commercially available gold NP suspensions of known size. Furthermore, simultaneous SAXS and DLS measurements were performed during the synthesis of silica NPs. References [1] J. Wang, D. Ye, G. Liang, J. Chang, J. Kong, J. Chen, J. Mater. Chem. B 2 (2014) 4338±4345.

[2] X. Zhou, Y. Yin, L. Wan, Y. Guo, Chem. Commun. 48 (2012) 2198±2200.

[3] J. Zhou, J. Ralston, R. Sedev, D.A. Beattie, J. Colloid Interface Sci. 331 (2009) 251±262.

[4] B.R. Cuenya, Thin Solid Films 518 (2010) 3127±3150.

[5] M. Ahameda, M.S. AlSalhia, M.K.J. Siddiqui, Clin. Chim. Acta 411 (2010) 1841± 1848.

[6] B. Chu, T. Liu, J. Nanopart. Res. 2 (2000) 29±41.

[7] H. Boukari, J.S. Lin, M.T. Harris, J. Colloid Interface Sci. 194 (1997) 311±318.

[8] J. Eyssautier, D. Frot, L. Barre, Lagmuir 22 (2012) 11997±12004.

[9] D.J. Tobler, L.G. Benning, Geochim. Cosmochim. Acta 114 (2013) 156±168.

[10] B. Chu, T. Liu, J. Nanopart. Res. 2 (2000) 29±41.

[11] O. Hemberg, M. Otendal, H.M. Hertz, Appl. Phys. Lett. 83 (2003) 1483±1485.

[12] D.H. Larsson, U. Lundström, U.K. Westermark, M.A. Henriksson, A. Burvall,H.M. Hertz, Med. Phys.

40 (2013) 021909.

[13] <https://www.excillum.com>.

[14] A. Kleine, SCATEX The new scatterfree pinholes, <www.incoatec.de>.

[15] J.S. Pedersen, Appl. Crystallogr. 37 (2004) 369±380.

[16] W. Stober, A. Fink, E. Bohn, J. Colloid Interface Sci. 26 (1968) 62±69.

[17] D.L. Green, S. Jayasundara, Y. Lam, M.T. Harris, J. Non-Cryst. Solids 315 (2003) 166±179.

[18] J.S. Pedersen, in: P. Lindner, Th. Zemb (Eds.), Neutrons, X-Rays and Light,Elsevier Science B.V., 2002. p. 391.

[19] M. Kotlarchyk, S. Chen, J. Chem. Phys. 79 (1983) 2461.

[20] B.J. Berne, R. Pecora, Dynamic Light Scattering with Applications to Chemistry, Biology and Physics, Dover Publications Inc., 2000.

Figures Fig. 1. X-ray beam collimation with two SCATEX pinholes.

Fig. 2. Schematic drawing of the OFRH. It incorporates the optics for the main laser and the scattered light. The optics are coupled to optical fibers.

Fig. 3. Optical Fiber Remote Head (top) integrated into the SAXS sample chamber (bottom) with a temperature sensor (1), capillary holder (2) the DLS head (3) and the optical fibers (4).

Fig. 4. Schematic drawing of the production and characterization line of a NP suspension.

Fig. 5. Flow-through capillary holder inside the SAXS sample chamber. The X-ray and laser beam hit the flow-through capillary at the same position Fig. 6. SAXS measurements (top) and DLS measurements (bottom) on standard gold NPs with radii of 5 nm, 7.5 nm and 10 nm. The SAXS curves were fitted assuming a Schulz-Zimm (solid line) and a Gaussian (red dashed line) size distribution, respectively.

Fig. 7. TEM images of standard gold NPs with diameters of 10 nm, 15 nm and 20 nm.

Fig. 8. Evolution of the mean radius Rm and r during the monitoring experiment Fig. 9 Representative SAXS curves of SAXS measurements taken from each section. The black lines are the fitted curves.

Fig. 10. TEM images of NPs synthesized in Sections 1,2,4 and 5. For Section 3 no proper images could be made due to agglomeration of the NPs.

Atomic structure determination of the (2×2) reconstructions of the polar AlN(0001) surface and atomic metallic deposition 1

1

1

2

Benoit EYDOUX , Bulent Baris , Florian CHAUMETON , Roberto ROBLES , Miguel PRUNEDA 2 , Nicolás LORENTE 2 , 3 , Sébastien GAUTHIER 1 , Xavier BOUJU 1 , David 1 MARTROU 1 NanoSciences Group, CEMES, CNRS UPR 8011, 29 rue J. Marvig, F-31055 Toulouse, France 2 ICN2 – Institut Catala de Nanosciencia i Nanotecnologia, Campus UAB, 08193 Bellatera (Barcelona), Spain 3 Centro de Física de Materiales CFM/MPC (CSIC-UPV/EHU), Paseo Manuel de Lardizabal 5, 20018 Donostia-San Sebastiá́n, Spain, and Donostia International Physics Center (DIPC), Paseo Manuel de Lardizabal 4, 20018 Donostia-San Sebastián, Spain

Group-III nitride semiconductors are ideal candidates for high-power electronic applications. Among these materials, aluminium nitride (AlN) has the largest band gap. It also has unique properties such as small density, large stiffness, large piezoelectric constant, large fracture resistivity and chemical inertness. Unfortunately, defects and interface states seriously compromise devices based on these materials and there is an urgent need for high-quality interfaces and surfaces. For these reasons, its surface reconstructions have received a lot of attention theoretically.

Furthermore, due to its high ionicity, AlN crystallizes in the wurtzite structure and its (0001) growth surface is polar, like other zinc blende (001) semiconductor surfaces. The consequence of this polarity is that the crystal should be stabilized by the apparition of surface charges that can be generated by different mechanisms like surface reconstructions. Experimentally, due to the large gap of AlN (6.2 eV) it is not possible to observe its surface by scanning tunneling microscopy (STM) except for the Al rich phase. One effective way to get information at the atomic scale is to use atomic-force microscopy in the non-contact mode (NC-AFM) under UHV. The growth of AlN samples was carried out in a MBE chamber equipped with a RHEED gun working at 15 keV. The AlN layer is grown on a 4H-SiC(0001) substrate following a recipe described elsewhere [1]. With the help of density functional studies, we determine new protocols for growing the technologically interesting N-rich AlN surfaces. This is achieved by dosing the precursor gases at unusually low rates. The measured surface reconstructions are in good agreement with our calculated structures [2]. Our protocols permit us to access the surface based on one additional N atom in a (2×2) cell. These N-rich AlN surfaces could open new routes to dope AlN layers with important implications in high- power and temperature technological applications.

Additionally, we have studied the adsorption of metallic components with the perspective of fabrication of planar atomic nanopads on AlN. Examples with Mg, Ag, and Au metallic deposition will be shown both experimentally and theoretically.

Figure 1 : NC-AFM topography image of AlN(0001) surface after growth of 200 nm thick sample at Tsubstrate = 950°C, BEPNH3 = 10 Torr and a growth rate of 100 nm/h (a) and 5 nm thick at 10 nm/h (b). (c) Cross section along the dashed line in (b).

−5

This work has been supported by the ICT-FET European Union Integrated projects AtMol (www.atmol.eu) and PAMS (www.pams-project.eu).

References [1] [2]

Chaumeton, F.; Gauthier, S.; Martrou, D. AIP Advances 2015, 5, 067108.

Chaumeton, F.; Robles, R.; Pruneda, M.; Lorente, N.; Eydoux, B.; Bouju, X.; Gauthier, S.; Martrou, D. Physical Review B Letters 2016, 2016 soumis.

Towards Mechanochromic Materials Based on Non-Covalent Interactions 1

1

CĂŠline Calvino , Stephen Schrettl , Christoph Weder

1

1

Adolphe Merkle Institute, Chemin des Verdiers 4, 1700 Fribourg, Switzerland celine.calvinocarneiro@unifr.ch

Abstract Materials found in nature have unique properties that remain challenging to replicate artificially. Thus, mechanosensory neurons or color changing chromatophores can translate mechanical stimuli into a 1 materials response. The development of mechanoresponsive materials is inspired by such examples and several chemical motifs UHIHUUHG WR DV ³mechanophores´ have been identified that respond to 2 mechanical activation through the scission of covalent bonds. More recently, non-covalent interactions have been considered as potentially useful mechanoresponsive moieties that offer dynamic interactions, 3 tunable interaction strengths, and a reversible process as additional benefits. In this context, we aim to exploit supramolecular interactions to prepare materials which, upon mechanical activation, exhibit a macroscopic response such as a change of color.

Here we present the preparation of supramolecular polymers that relies on the reversible coordination to naphthalimide-based chromophores with conjugated thiourea moieties as the binding motif (Figure 1).

The versatile nature of the latter allowed for the coordination of anions such as carboxylates or bases 4,5 such as amines. In both cases, the formation of the coordination complex was found to induce charges into the conjugated chromophores and resulted in a substantial red-shift of their absorption. In the solid state, the complex formation of the prepared chromophores with carboxylate-based polymers was hampered by the competing counter ions. By contrast, amine-based polymers coordinated to the chromophores and supramolecular polymers were successfully obtained in solution as well as in the solid state. The response of these materials to mechanical stimuli is the subject of our investigations and chromogenic effects may act as an internal probe that facilitates the detection and analysis of wear.

References [1] J. B. Messenger, Biol. Rev. 76 (2001) 473Âą528.

[2] M. M. Caruso, D. A. Davis, Q. Shen, S. A. Odom, N. R. Sottos, S. R. White, J. S. Moore, Chem. Rev. 109 (2009) 5755Âą5798.

[3] L. Brunsveld, B. J. B. Folmer, E. W. Meijer, R. P. Sijbesma, Chem. Rev. 101 (2001) 4071Âą4098.

[4] H. D. P. Ali, P. E. Kruger, T. Gunnlaugsson, New J. Chem. 32 (2008) 1153Âą1161.

[5] O. Azzaroni, B. Trappmann, P. van Rijn, F. Zhou, B. Kong, W. T. S. Huck, Angew. Chem. Int. Ed. 45 (2006) 7440Âą7443.

Figures

Figure 1: The thiourea-based naphthalimide chromophore can be activated through hydrogen bonding with carboxylates or through ionic interactions with amines. On this basis, the preparation of responsive supramolecular polymer films is investigated.

Self-Aligned Carbon Nanotube Formation for Next Generation Transistor H. L. Chang and C. T. Chang Department of Material Science and Engineering of National Chiao Tung University Technology Research Department, Samsung Electronics Beyond Si CMOS technology is the current challenging for next generation transistor. As demand for nano-scaled devices increase, the ability to manipulate the building blocks of electronic is essential. Catalytic-assisted CNTs are integrated into trenches and holes under CH4/H2 gases by microwave plasma chemical vapor deposition, the trench and hole are used to fabricate for gate electrodes and interconnections, respectively. Results indicate the orientation of grown CNTs is dominated by pattern geometry. The field emission results show that the CNTs exhibit robust 2 electronic properties with emission densities of over 1mA/cm at 3.97 and 6.30 9 Č?P indicating the high electron emission efficiency as the CNT field effect transistor application. The growth models of Fe and CoSi2 and application for nanoelectronics are purposed. Figure 1(a)-(c) depicts the CNTs that were selectively deposited vertically on patterned Fe trench arrays. When Fe catalysts are used with a SiO2 interfacial layer, the catalyst is on the top of the tubes for a brief period, in which hydrogen reduction time is Â&#x201D; 5 min. A longer reduction time (10 min) forms chemical bonds between Fe and the SiO2 film, causing the base growth of CNTs owing to strong Fe and SiO2 adhesion.

Using Fe catalysts with the SiO2 interfacial layer, cause Fe catalyst to be present on the top of the tubes for only a brief deposition time. A longer deposition time is suggested to cause bonding between Fe and the SiO2 film, resulting in the base growth of CNTs. According to the Fe-Si phase diagram, two phases, FeSi and FeSi2, are present at process temperature. The FeSi2 formed at long processing time is bound tightly to the substrate, resulting to base growth otherwise the top growth. For both top and base CNTs growth, the CNTs are constrained in the patterned Fe catalysts trench, indicating high deposition selectivity. The introduction of H2 plasma pretreatment is considered to active catalyst. When SiO2 is inserted, highly oriented CNTs are formed via catalyst films rather than catalytic particles. This process yields CNTs with a conformal diameter and length that is as determined from the TEM image shown in Fig. 1 (d-e). Fig, 2 presents the schematic diagram as interconnect of CNTs on Cu/CoSix process.This work studies the synthesis of selective deposition of CNTs on patterned trenches and holes using Fe and CoSi2 catalysts. The results show that well-aligned CNTs are obtained using an Fe catalytic film and that the hydrogen pretreatment time dominates whether the catalytic film is located on the base or on the top. Wrapped CNTs are successfully formed in the CoSi2 hole arrays. This study supports CNTs growth methods applied in the gate electrode and interconnection for next generation of nanaoelectronics.

Fig. 1 Fe assisted CNTs deposition (a) trench arrays (b) and (c) high Fig. 2 Schematic diagram of magnification, base and top growth for H2 reduction time in 10 min Cu Damascene and CNTs and 5 min, respectively integration

References [1] V. V. Mitin, V. A. Kochelap and M. A. Stroscio, Introduction to nanoelectronics (Cambridge, 2008), p10.

[2] S.Iijima, Nature (Lond.) 354, 56 (1991).

[3] T. W. Ebbseen, H. J. Lezec, H. Hiura, J. W. Bennett, H. F. Ghaemi, and T. Thio, Nature 382, 54 (1996).

[4] W. A. de Heer, W. A. Chatelain, and D. A. Ugarte, Science 270, 1179 (1995).

[5] G. S. Duesberg, A. P. Graham, F. Kreupl, M. Liebau, R. Seidel, E. Unger, and W. Hoenlein, Dia. Relat. Mar. 13, 354 (2004) [6] B. Q. Wei, R. Vajtai, P. M . Ajayan, Appl. Phys. Lett. 79, 1172 (2001).

[7] P. Avouris, Acc. Chem. Res. 35, 1026 (2002) 1

Anti-tumor and Anti-metastasis Activities of Dichloro (1, 2-diaminocyclohexane) Platinum (II) (DACHPt)-Incorporated Hyaluronic Acid Nanoparticles (DACHPt/HANPs) in Colon Cancer and Melanoma Model in vivo

Shih-Ta Chen, Tai-ju Hsieh, Chun-Min Liu, Ya-Chin Lo, Chih-Peng Liu, and Hsiang-Wen Tseng Biomedical Technology and Device Research Laboratories, Industrial Technology Research Institute, Hsinchu, Taiwan, ROC

godzilla@itri.org.tw Abstract Nanotechnology provides many potential benefits to cross the hurdle of cancer therapy, such as delivering drugs to cancer cells, or reducing adverse side effects of toxicity.

Nanoparticles can passively accumulate in the tumor through the leakage of endothelium by the enhanced permeability and retention (EPR) effect, or further actively target the specific cancer cells via various receptors expressing on the cell surface of cancers. Hyaluronic acids (HA) are high biocompatible macromolecules, suited to application in biomedicine, and as ligands binding to many receptors (CD44, ICAM etc.). Here, we investigated a novel type of HA polymer based delivery system, the dichloro (1, 2- diaminocyclohexane) platinum (II) (DACHPt)- incorporated HA comb-like polymer (DACHPt/HANPs) with anti-tumor and anti-metastasis effects in colon cancer and melanoma. We used HA-Boc-His polymer to play a role in the particle release and stabilization, providing the hydrophobicity as a driving force for the metal-polymer ionic complex formation between the platinum of DACHPt and the carboxyl group on the HA. In the present study, in vivo experiments of anti-tumor activity were performed on human colon cancer cell line, HT29 xenograft tumor model. Intravenously administered DACHPt/HANPs suppressed tumor growth significantly than free oxaliplatin, the standard chemotherapy of colon cancer. The tumor growth inhibition (TGI) of HT29 tumor treated by oxaliplatin or DACHPt/HANPs was 2±14 % or 60±8 %. DACHPt/HANPs not only demonstrated effective tumor growth inhibition of colon cancer, but also inhibited melanoma lymphatic metastasis. The volume of lymph nodes in mice subcutaneous injected of DACHPt/HANPs or intravenous injected of oxaliplatin were 34±20 or 73±46 mm3 in the murine melanoma cell line, B16-F10-luc2 spontaneous lymphatic metastasis model. Our study showed that DACHPt/HANPs considerably increased the anti-tumor and anti-metastasis activities, and the HA based DACHPt ionic nanoparticles are promising for the drug delivery system.

References [1] Cabral H, ACS Nano. 2015 May 26;9(5):4957-67 [2] Endo K, Cancer Sci. 2013 Mar;104(3):369-74.

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Sensitive Electrodes of Azulene-Based Complexing Polymer Films for Heavy Metal Ions Detection 1

2

2

2

2

1

I. Chilibon , E.-M. Ungureanu , G. Buica , M. Mihai , R. Isopescu , C. Vasiliu , R. Iordanescu

1

1

National Institute of Research and Development for Optoelectronics, INOE-2000, 409 Atomistilor Street, P.O. Box MG-5, Bucharest-Magurele, 077125, Romania, qilib@yahoo.com 2

University Politehnica of Bucharest, Faculty of Applied Chemistry and Materials Science, 1-7 Gheorghe Polizu, 011061, Bucharest, Romania

Abstract Electrochemical sensors are important to detect the excess of toxic heavy metals, like lead and cadmium in the liquid medium [1]. Sensitive electrodes of azulene-based complexing polymer films were made by using the method of electrochemical deposition on carbon vitreous. The electrochemical characterization and polymerization were performed in a three electrode cell on glassy carbon disk ±2 + working electrodes with a platinum wire counter electrode and Ag| 10 M Ag in CH3CN + 0.1 M TBAP as reference electrode, according to similar procedures [2]. The characterization was done by cyclic voltammetry (CV) and differential pulse voltammetry (DPV). The support of samples was vitreous carbon disk (ø 6 mm diameter), that were deposited thin films by electropolymerization, with potential and charges for EPC as variables. Different azulene-thiourea-like monomers were tested. Investigation and morphological characterization of samples were performed using Scanning Electron Microscope (SEM) and dispersive X-ray spectrometer in energy (EDS).

Acknowledgements The authors are grateful for the financial support from ANCSI - NUCLEU Programme, Contract code PN 09 27 / 2016 and from UEFISCDI Project ID PN-II-PT-PCCA-2013-4-2151, Contract nr. 236/2014.

References [1] M.B. Gumpu, S. Sethuraman, U.M. Krishnan and J.B.B. Rayappan, Sensors and Actuators B, 213, (2015) 515 [2] G.-O. Buica, E.-M. Ungureanu, L.Birzan, A.C. Razus, L.-R. Mandoc, Journal of Electroanalytical Chemistry, 693, (2013) 67 ± 72 Figures

a) +1.45 V potential and 3.32 mC charge b) +1 V potential and 1.61 mC charge Fig. SEM images for chemically modified electrodes functionalized by CPE

Portable Polyelectrolyte Brush-Coated Sponge Composites for Environmental Remediation

Ji Young Bae, Ha-Jin Lee, and Won San Choi* Department of Chemical and Biological Engineering, Hanbat National University, 125 Dongseodaero, Yuseong-gu, Daejeon, 34158, Republic of Korea E-mail: choiws@hanbat.ac.kr; Fax: +82-42-821-1692; Tel: +82-42-821-1540

Abstract

Due to advancement of industrial development, heavy metal ions in waste water are daily flowing into ground surface and water resources. Cases of serious side effects have been reported since they are accumulated in the human body along the food chain. Because of effectiveness of adsorption process, numerous adsorbents have been proposed for efficient removal of heavy metal ions or organic pollutants in waste water. However, previously reported adsorbents and adsorption process are not suitable for small scale enterprise and individual user. Development of a portable heavy metal ion remover which can be used even by untrained user is highly demanded. Sponge is portable, easy to use, and ubiquitous materials. Polymer brushes possess advantages of numerous reaction sites and pH-responsive behaviors for control of adsorption/desorption. Thus, highly porous VSRQJH FRPSRVLWHV GHFRUDWHG ZLWK SRO\PHU EUXVKHV YLD ³JUDIWLQJ-IURP´ RU ³JUDIWLQJ-WR´ SRO\PHUL]DWLRQ ZDV developed for fast and efficient removal of heavy metal ions in waste water or drinkable water.

References [1] Aleeza Farrukh, Attia Akram, Abdul Ghaffar, Sara Hanif, Almas Hamid, Hatice Duran, and Basit Yameen, Design of Polymer-Brush-Grafted Magnetic Nanoparticles for Highly Efficient Water Remediation, ACS Appl.

Mater. Interfaces 2013, 5, 3784í3793.

[2] Yongfang Yang, Yulei Xie, Lichuan Pang, Mao Li, Xiaohui Song, Jianguo Wen, and Hanying Zhao, Preparation of Reduced Graphene Oxide/Poly(acrylamide) Nanocomposite and Its Adsorption of Pb(II) and Methylene Blue, Langmuir 2013, 29, 10727í10736.

Influence of ligand exchange on crystallography, magnetic and thermal behavior of iron oxide nanoparticles for hyperthermia 1

4

2

2

3

1

1

F. Crippa , D. Burnand , B. Goris , S. Bals , A.M. Hirt , M. Lattuada , L. Haeni , B. Rothen-Rutishauser 1,4 and A. Petri-Fink .

1

1

Adolphe Merkle Institute, University of Fribourg, Chemin des Verdiers 4, 1700 Fribourg, Switzerland, 2 EMAT, University of Antwerp, Groenenborgerlaan 171, 2020 Antwerp, Belgium, 3 Institute of Geophysics, ETH Zurich, Sonneggstrasse 5, 8092 Zurich, Switzerland, 4 Chemistry Department, University of Fribourg, Chemin du Musée 8, 1700 Fribourg, Switzerland federica.crippa@unifr.ch

Abstract The thermal decomposition of iron oleate complexes in organic solvent is a robust and popular route to 1 synthesize highly monodisperse superparamagnetic iron oxide nanoparticles (SPIONs) . However, the resulting oleic acid coated nanoparticles are not stable in polar solvents and therefore unsuitable for biomedical applications. To overcome this limitation, these synthesized SPIONs are commonly 2 subjected to a phase transfer step prior to any subsequent surface functionalization or application .

Here, we investigate how ligand exchange procedures may affect the magnetic and thermal properties of SPIONs, subsequently making them attractive candidates for magnetic hyperthermia.

Large-scale synthesis of oleic acid coated SPIONs (core diameter = 20 nm) is achieved by thermal decomposition of the iron oleate complex in an automated reactor that controls crucial reaction parameters. High Resolution Scanning Transmission Electron Microscopy and X-Ray Diffraction studies of oleic acid coated SPIONs show a wüstite (FeO)/magnetite (Fe3O4) core/shell structure (Figure 1).

This observation is in agreement with magnetic measurements and hyperthermia tests that highlight weak superparamagnetism and poor thermal properties. However, when the particles are transferred to water with a high temperature ligand exchange procedure, the wüstite core is oxidized to a single crystal of magnetite. In particular, we observe that the magneto-thermal properties of functionalized SPIONs are significantly enhanced by the thermal annealing process that occurs during ligand exchange. The nanoparticles show a pronounced superparamagnetic behavior, and their thermal signature is increased by more than ten times.

The possibility for large-scale synthesis is given by thermal decomposition and post-processing treatments. Consequently, the altering of the crystalline structure renders the SPIONs more efficient for magnetic hyperthermia.

References [1] Park J. et al., Nature Materials, 3 (2004) 891-895.

[2] Lattuada M. and Hatton T.A., Langmuir, 23 (2007) 2158-2168.

Figures

Count frequency (-)

1

0.08 SPIONs distribution Gaussian fit

2

0.06

0.04

0.02

0.00 10

20

30

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Figure 1: TEM size distribution (1), high angle annular dark field-STEM (2) and STEM- electron energy loss spectroscopy (3) measurements of 20 nm oleic acid coated SPIONs revealing a core/shell crystalline structure.

3

Valence-force model and nanomechanics of single-layer phosphorene Alexander Croy1,2 and Daniel Midtvedt3

2

1 Max-Planck-Institute for the Physics of Complex Systems, Dresden, Germany Institute for Materials Science and Max Bergman Center of Biomaterials, TU Dresden, Dresden, Germany 3 Department of Physics, Chalmers University of Technology, Gothenburg, Sweden

Email: alexcroy@gmail.com Abstract In order to understand the relation of strain and material properties, both a microscopic model connecting a given strain to the displacement of atoms, and a macroscopic model relating applied stress to induced strain, are required. Starting from a valence-force model for black phosphorous (phosphorene) [1] we use recent experimental and computational results to obtain an improved set of valence-force parameters. From the model we calculate the phonon dispersion and the elastic properties of single-layer phosphorene [2]. Finally, we use these results to derive a complete continuum model, including the bending rigidities, valid for longwavelength deformations of phosphorene. This continuum model is then used to study the properties of pressurized suspended phosphorene sheets.

References [1] C. Kaneta, H. Katayama-Yoshida, A. Morita, Solid State Communications 44, 613 (1982).

[2] D. Midtvedt, C. H. Lewenkopf, A. Croy, 2D Materials 3, 011005 (2016).

[3] R. Fei and L. Yang, Appl. Phys. Lett. 105, 083120 (2014).

Figures

Figure: Phonon dispersion of phosphorene numerically calculated from the VFM is indicated by solid lines.

The dashed lines show the behavior of the acoustic branches according to the continuum model.

Filled circles are ab initio data from [3].

TOWARDS HIGH PERFORMANCE SUPRAMOLECULAR MATERIALS Anselmo del Prado, Sandor Balog, Christoph Weder, Lucas Montero de Espinosa Adolphe Merkle Institute, University of Fribourg, Chemin del Verdiers 4, 1700, Fribourg, Switzerland anselmodelpradoabellan@unifr.ch

Abstract Thermosetting materials consist of covalently cross-linked macromolecular chains with high temperature and chemical resistance, as well as good mechanical properties. However, these materials cannot be reprocessed and recycled as they directly degrade at high temperatures. On the other hand, thermoplastics show melt processability and a broad range of properties in the solid state, depending on their composition, but the high melt viscosity of many engineering thermoplastics such as polyamides often limits their applications. Supramolecular polymers are a promising alternative to overcome these disadvantages, as their monomeric units are linked by non-covalent bonds that 1 undergo reversible dissociation at high temperatures. As a result, supramolecular polymers form very low viscosity, reprocessable melts as opposed to high molecular weight thermoplastics, which suffer from extensive entanglement. Therefore, to some extent, it should be possible to prepare new supramolecular polymers with similar properties to thermoplastic and thermosetting materials, but enhanced processability and recyclability, in addition to stimuli-responsiveness, as non-covalent bonds 2 are more susceptible to small changes or external stimuli such as temperature or UV-light.

Previous work in our group focused on the synthesis and characterization of Bisphenol A-coepichlorohydrin-based supramolecular networks displaying hydrogen bonding interactions between 3 carboxylic acid and pyridine groups. These materials presented high stiffness and low melt viscosity, but were also brittle. In this contribution, we will present different strategies used to render these materials tougher, including the use of a plasticizing supramolecular chain stopper, and the introduction of low-glass-transition 4-vinylpyridine/acrylate copolymers to induce the formation of soft nanodomains and stop crack propagation (Fig. 1).

References [1] Yang, L.; Tan, X.; Wang, Z.; Zhang, X. Chemical Reviews, 2015, 115, 7196-7239.

[2] Montero de Espinosa, L.; Fiore, G. L.; Weder, C.; Johan Foster, E; Simon, Y. C. Prog. Polym. Sci. 2015, 49, 60-78.

[3] Balkenende, D. W.R.; Olson, R. A.; Balog, S.; Weder, C.; Montero de Espinosa, L. Submitted.

Figure

Fig.1: Proposed approach to stop crack propagation in high-Tg supramolecular networks.

Investigation of dynamics of Permalloy-Molybdenum flakes by magneto-optical time-resolved spectroscopy A. Demchenko, O. Kovalenko, V. Shokeen, Z. Raolison, G. Pourroy, J.-Y. Bigot Institut de Physique et Chimie des Matériaux de Strasbourg, UMR 7504, Université de Strasbourg, BP 43, 23 rue du Loess, 67034 Strasbourg Cedex 02, France.

CNRS,

We report on a study of the static and dynamic magnetic properties of Permalloy-Molybdenum (PyMb) flakes using magneto-optical time-resolved spectroscopy performed with femtosecond laser pulses. A detailed investigation of the spatial magnetization in the PyMb flakes has been performed using a magneto-optical Kerr microscope designed to provide simultaneously sub-micron spatial and ~100 femtoseconds temporal resolutions. The pump-probe configuration provides information on the demagnetization and re-magnetization times as well as on the local ferromagnetic resonance modes.

It is found that the frequency P and damping of the magnetization precession varies spatially from =156-180 ps. We attribute this effect to a local change of the effective field P = 7-8 GHz and associated to the shape and magneto-crystalline anisotropies GXH WR WKH ³OHDI-OLNH´ VKDSH RI WKH IODNHV. Further work is under progress to investigate the presence of resonant modes associated to vortices.

7KLV ZRUN KDV EHHQ FDUULHG RXW ZLWKLQ WKH UHVHDUFK SURJUDP ³(TXLSH[ 81,21´ ILQDQFHG E\ WKH $JHQFH Nationale de la Recherche (ANR-10-EQPX-52).

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1

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Susanne Drechsler , Phally Kong , Sandor Balog , Andreas F. M. Kilbinger

1

1

University of Fribourg, Faculty of science, Chemistry Department, Chemin du Musée 9, CH-1700 Fribourg 2

∗

Adolphe Merkle Institute, Chemin des Verdiers 4, CH-1700 Fribourg

susanne.drechsler@unifr.ch

Structures of aromatic amides (aramides), as it is known from Kevlar for instance, show high shape persistence on a molecular level. Due to their aromatic backbone, preferred trans-conformation of the amide bonds and its double-bond character, they are constituted as very rigid rods. Using different non-covalent interactions, such as hydrophilic/ hydrophobic ones, hydrogen bonding or π-π stacking, oligomers of these compounds are expected to self-assemble in a well-defined and therefore controllable manner. This makes them interesting candidates for supramolecular materials within the field of soft matter.

[1]

So far research concentrated mainly on organo-solubility and only few groups addressed the issue of [2] water solubility or the synthesis of amphiphilic aramides. This project focuses on unusual geometrical structures synthesized from para-aminobenzoic acid building blocks, which are commonly used for aramides. For more complex structures (such as in figure 1) self-assembly of these compounds is no longer trivial. Herein we present the synthesis of two unusual geometries, consisting of hydrophobic and hydrophilic p-aminobenzoic acid derivatives. These structures only differ in one functional group, but already exhibit different self-assembly into nano-scopic objects as investigated via transmission electron microscopy (TEM) and dynamic light scattering (DLS).

Figures

hydrogel formation

Figure 1 Oligomers showing different self-assembly: TEM images (scale bar 2µm) and DLS measurements

References !"#$%&’(&)*$+,-$./(0/12&)*$3,$4,$! " #$%&%’( #) ’( *+! " " #*$, - 5667*$8"9":8"9;,$ !6#$<=>?@)A*$B,$C ,-$D@=*$E,$3,-$E=F /GH*$I,$%,$./++0&/+12( &/+3%#/$! " " $% $4- 556J7*$K6K6:K6KJ,$

Carbon Nanotube Fiber Array Field Emission Cathodes Steven B. Fairchild, Mathew A. Lange, Materials and Manufacturing Directorate, Air Force Research Laboratory, Wright-Patterson Air Force Base, OH 45433 Nathan P. Lockwood Directed Energy Directorate, Air Force Research Laboratory, Kirtland Air Force Base, NM 87117 Daniel Marincel Department of Chemical and Biomolecular Engineering and Department of Chemistry, Rice University, Houston, TX 77005 Field emission (FE) cathodes made from carbon nanotube (CNT) fibers have demonstrated high emission currents, low turn-on voltages, long lifetimes and offer considerable potential for use as electron sources for vacuum electronic devices. CNT fibers were fabricated by wet-spinning of pre-made CNTs1 and consist of CNT fibrils held together by van der Waals forces. The fibers were 50 m in diameter and their morphology was controlled by fabrication method, processing conditions, as well as purity, size, and type of the CNT starting material. These fibers have demonstrated stable field emission currents exceeding 1 mA for 10 hours2. Cathode arrays were made by weaving the CNT fiber into carbon cloth which is then mounted to a graphite block. All fibers were cut to uniform height by holding the fibers between 2 glass slides and cutting with a razor blade across the top. A 5x5 array consisting of 5mm long fibers spaced 5mm apart was fabricated. The array was tested in a diode configuration test stand with DC emission current reaching 17mA for an applied field strength of 0.39V/ m. The cathode array demonstrated stable emission at ~9mA for 1 hour of operation. A 10x10 array consisting of 1mm length fibers spaced 1mm apart has been fabricated and the results will be presented.

1 %HKDEWX HW DO ³6WURQJ /LJKW 0XOWLIXQFWLRQDl Fibers of Carbon Nanotubes with Ultrahigh Conductivity´ Science 2013, 339, 182.

2. S. Fairchild et al., ³Morphology dependent field emission of acid-spun carbon nanotube fibers´, Nanotechnology 2015, 26, 105706

________________________________ * Work supported by a Government Agency

GRAPHENE AND ADATOMS: AB INITIO CALCULATIONS AND HYPERFINE INTERACTIONS

A. S. Fenta1,2,3*, J. N. Gonçalves1, C. O. Amorim1, J. G. Correia3,4, K. Johnston3, H. Haas2, V. S. Amaral1, S. Cottenier 5, L. M. C. Pereira2 1

Department of Physics and CICECO, University of Aveiro, 3810-193 Aveiro, Portugal Leuven, Instituut voor Kern- en Stralingsfysica, Celestijnenlaan 200 D, 3001 Leuven, Belgium 3 CERN, EP Division, 1211 Geneva 23, Switzerland 4 Centro de Ciências e Tecnologias Nucleares (C2TN), Instituto Superior Técnico, Universidade de Lisboa, 2686953 Sacavém, Portugal 5 Department of Materials Science and Engineering, Ghent University, Technologiepark 903, BE-9052 Zwijnaarde, Belgium 2 KU

*fenta@ua.pt

Abstract From the moment it was isolated as a 2-dimensional material, graphene has become a remarkable subject of research, exhibiting novel phenomena that extend to virtually every domain of solid state physics and applications [1,2]. A particularly active domain of graphene research deals with its interaction with atoms which are adsorbed on its surface (adatoms) [3,4].

We present density functional theory (DFT) calculations of the interaction between graphene and adatoms: atomic positions, binding energies, electronic structure, and hyperfine parameters. While DFT calculations (arguably) lack absolute predictive power in this context, they can provide great insight when combined with experimental studies. Our work is based on the combination of DFT calculations and experimental hyperfine techniques: perturbed angular correlation (PAC) spectroscopy and Mössbauer Spectroscopy (MS). Experimental hyperfine parameters ± electric field gradient (EFG) and hyperfine magnetic field (HMF) ± are measured using PAC and MS, and compared to the EFG and HMG values calculated for various structural/electronic/magnetic configurations. The EFG carries the signature of the atomic position with respect to the graphene host, charge state, and type of bonding (ionic, covalent, van der Waals). The HMF provides information on the electronic (and spin) configuration and, in appropriate cases, magnetic phenomena (paramagnetism, magnetic inteUDFWLRQV« . As representative examples, we present calculations for Fe, Ta and Hg adatoms, which have suitable MS (Fe) and PAC (Ta, Hg) isotopes and decay schemes.

These calculations form the basis for the experiments which are currently being prepared at the ISOLDE facility at CERN, using ASPIC (Apparatus for Surface Physics and Interfaces at CERN) [5].

References [1]A. K. Geim, Science, 324, 1530-1534, 2009.

[2] K. S. Novoselov et al., Nature 490, 192 (2012).

[3] Chenfang Lin et al., Nano Lett., 15 (2), 903±908, (2015).

[4] A. D. Güçlü et al., Phys. Rev. B 91, 125403, (2015).

[5] K. Potzger et al., Phys. Rev. Lett., 88, 24, (2002).

Experimental Determination of the Adsorption Sites of Individual Metal Atoms on MgO(100) Thin Films Edgar Fernandes, Fabio Donati, François Patthey and Harald Brune Institute of Physics (IPHYS), Ecole Polytechnique FÊdÊrale de Lausanne (EPFL), Station 3, CH-1015 Lausanne, Switzerland edgar.fernandes@epfl.ch Magnetic properties of surface-adsorbed atoms are intimately related to the symmetry of the adsorption site. A recent example is given by single Ho atoms adsorbed on MgO(100) thin films grown on Ag(100).

These atoms show long magnetic relaxation times due to a ground state that is protected from quantum fluctuations by the symmetry of the adsorption site [1]. For surfaces made of a single element, the adsorption site of adatoms can be determined by means of atomically resolved scanning tunnelling microscopy (STM) images. However, on MgO the atomic protrusions cannot unequivocally be attributed to either of the two atomic species. In addition, the tunnel parameters required for atomic resolution on MgO imply small tip-sample distances where the adatoms are frequently displaced, thus preventing a clear identification of their adsorption site. Hereafter we present a method that solves these issues.

We grow MgO thin films on Ag(100) and use 0.5% doping with Ca, which substitutes Mg. Ca has different STM contrast than Mg and thereby serves as marker for the Mg positions. The adsorption sites of adsorbed Ho atoms, and of any other atom, are determined by extrapolating the MgO lattice from images with atomic resolution of an adsorbate-free surface spot onto an area where the adsorbates are.

After Ho deposition, we observe that two species, with two different apparent heights, coexist on 1 and 2 ML MgO. Using the method described above, we observe that Ho atoms occupy two adsorption sites.

They are on-top of O atoms or on bridge sites between two O atoms. We can reversibly switch between these two sites by STM manipulation. In addition, a third Ho species, adsorbed on top of the Mg atom, can be created. This species does not naturally exist upon Ho evaporation and is purely artificial.

Finally we probed the thermal stability of the two species of Ho/MgO that form spontaneously by gently warming up the sample surface up to 50 K. This showed that both species do not diffuse up to this temperature, hence allowing the measurement of the magnetic properties of Ho atoms on a wide range of temperatures.

References [1] F. Donati, S. Rusponi, S. Stepanow, C. Wäckerlin, A. Singha, L. Persichetti, R. Baltic, K. Diller, F. 3DWWKH\ ( )HUQDQGHV - 'UHLVHU ä âOMLYDQÞDQLQ . .XPPHU & 1LVWRU 3 *DPEDUGHOOD + %UXQH Science, 352 (2016) 318.

Simultaneous electrochemical determination of ascorbic acid, dopamine, uric acid and tryptophan with azure A-interlinked multi-walled carbon nanotube/gold nanoparticle composite modified electrode Hayati Filik, Asiye A. Avan

Istanbul University, Faculty of Engineering, Department of Chemistry, 34320 AvcĂ&#x2022;ODU ,VWDQEXO Turkey filik@istanbul.edu.tr Ascorbic acid (AA), dopamine (DA), uric acid (UA) and tryptophan (TRP) are considered as crucial small biomolecules for physiological processes in human metabolism. It is well known that AA, DA, UA and TRP usually coexist in biological matrixes. Abnormal levels of these species will lead to several diseases and disorders. Tryptophan is an important amino acid owing to its crucial roles in biological systems. It is a vital constituent of proteins and indispensable in human nutrition for establishing and maintaining a positive nitrogen balance. Therefore, the determination of their concentration is important not only for biomedical chemistry and neurochemistry but also for diagnostic and pathological research. Multi-walled carbon nanotube/Azure A/gold nanoparticle composites (AuNPs/MWCNTs/AA) were prepared by binding gold nanoparticles to the surfaces of azure A-coated carbon nanotubes. AuNPs/MWCNTs/AA based electrochemical sensor was fabricated (Fig. 1) for the simultaneous determination of ascorbic acid, dopamine, uric acid, and tryptophan. Cyclic voltametry and electrochemical impedance spectroscopy were used to characterize the electrochemical properties of the modified electrodes. The modified electrode showed excellent electrocatalytic activity toward ascorbic acid, dopamine, uric acid, and tryptophan (pH 7.0) (Fig. 2). The experiment results showed that the linear response range for simultaneous detection of AA, DA, UA and TRP were 300 Âą10000 ÂľM, 0.5Âą50 ÂľM, 0.5Âą50 ÂľM and 1.0Âą100 ÂľM, respectively, and the detection limits were 16 ÂľM, 0.014 ÂľM, 0.028 ÂľM and 0.56 ÂľM (S/N=3). The proposed method offers promise for simple, rapid, selective and cost-effective analysis of small biomolecules. The procedure was also applied to the determination of tryptophan in spiked milk samples.

Fig. 1. Schematic diagram of fabrication method.

Fig. 2. CVs of the GCE (a), Nafion/MWCNTs/ AuNPs (b), Nafion/AzA/MWCNTs/ AuNPs /GCE(c) and AzA/MWCNT/Nafion/ AuNPs /GCE(d)

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Biotemplating white beetle scales for isotropic high index photonic materials Nathan Fuchs, Nicolas Muller, Frank Scheffold, Olimpia Onelli & Silvia Vignolini University of Fribourg, Department of Physics, Chemin du Musée 3, 1700 Fribourg, Switzerland nathan.fuchs@unifr.ch Abstract Nanostructured dielectrics are omnipresent in nature and display magnificent permanent colors in addition to multi-functionality. Natural photonic nanostructures alter the spectral composition of impinging light, leading to enhanced photonic properties such as brilliant colors and strong light-matter interactions in particular manner for efficient light diffusers and reflectors [1]. In our experiments we study the white Cyphochilus spp. beetle as a biotemplate for optical materials design. The whole beetle body is covered with imbricated scales which exhibit an extremely efficient broadband reflectance [2].

The scale¶V structure is only 5-7um thin and is composed of a three-dimensional disordered assembly of highly intricated, low refractive index (n~1.55), chitin network rods. This remarkably optimized network acts as dense scattering media and is at the origin of its optical properties [3]. The replication of white beetle scales into TiO2 (n~2.45) or Si (n~3.6) can be performed by means of a double inversion procedure. This process consists of a combination of atomic layer deposition, calcination and chemical vapor deposition to reproduce the white beetle polymer network. We expect that, upon replication of the structure into a material of higher refractive index, extremely efficient white optical diffusers can be realized approaching the regime of non-classical light transport or Anderson localization.

a. White beetles Cyphochilus spp. generally occurring in south-east Asia. b. Scanning electron microscopy of the internal chitin network. Scale bar 5µm.

References [1] N. Muller et al. Advanced Optical Materials, 2 (2014) 115-119 [2] M. Burresi et al. Scientific Reports, 4 (2014) 6075 [3] L. Cortese et al. Advanced Optical Materials, 3 (2015) 1337-1341

Novel Manganese oxide-Titanium dioxide-Graphene Based Tetranary Nanohybrids for HighPerformance Supercapacitor 1

N. Muthuchamy , K-P. Lee

1,2,3,

A-I. Gopalan

2.3

1

Department of Chemistry Education, Kyungpook National University, Daegu, S.Korea

2

Research Institute of Advanced Energy Technology, Kyungpook National University, Daegu, S.Korea 3

Department of Nanoscience and Nanotechnology, Kyungpook National University, Daegu, S.Korea Presenting author: A-I. Gopalan (algopal99@gmail.com)

This research reports the first synthesis of manganese oxide-titanium dioxide-graphene ternary nanohybrids (MnO2@TiO2(G)-TNH) and demonstrates their excellent performances as supercapacitor electrode materials. The morphologies, microstructures, compositions and optical properties of the MnO2@TiO2(G)-TNH were characterized by field emission scanning electron microscopy equipped with an energy dispersive X-ray spectrometer, X-ray diffraction, X-ray photoelectron spectroscopy, UV-visible and diffuse reflectance spectroscopy. The MnO2@TiO2(G)-TNH offered high electrode/electrolyte interfacial contact areas, rapid charge/discharges and fast electron transfer pathways for supercapacitor applications. Due to the synergistic effect of MnO 2, TiO2 and G in their nanostructured forms, the supercapacitor electrode with the as prepared MnO2@TiO2(G)-TNH existed significantly enhanced -1

specific capacitance at a current density of 3 A g , excellent rate capability and remarkable cycling stability (after 350 cycles). And, the present strategy offers a promising design and synthetic protocol of electrode materials for future supercapacitor applications

One-component nanocomposites based on polymer-grafted cellulose nanocrystals Sandra Graterol, Tobias Kuhnt, Worarin Meesorn, Lucas Montero de Espinosa, Christoph Weder Adolphe Merkle Institute, University of Fribourg, Chemin de Verdiers 4, 1700 Fribourg, Switzerland sandra.graterol@unifr.ch Abstract One-component nanocomposites (OCNs) are a class of materials resulting from the assembly of hairy [1] nanoparticles (NPs) in the solid state . In contrast to traditional polymer nanocomposites, which often suffer from macrophase separation at high filler contents, OCNs cannot undergo phase separation of their components as these are covalently linked. As a result, the composition of OCNs can be tuned through a wider range of filler-to-polymer ratios. Additionally, the processing of OCNs is straightforward either via solvent casting of the NPs dispersion or by melt processing the dried material at a temperature above the glass or the melting transition of the grafted polymer.

While the synthesis of cotton cellulose nanocrystal (cCNC)-based hairy NPs has been extensively [2] [3] reported in the context of filler-matrix compatibility , the solid state properties of such hairy NPs are virtually unexplored. Moreover, most works in the field employ complex controlled polymerization [4] methodologies to graft polymer chains from the surface of CNCs , which limits the upscaling potential of such routes. We present here the synthesis of cCNC-based OCNs displaying poly(hexyl methacrylate) or poly(methyl methacrylate) grafts through a synthetically undemanding protocol, which involves the surface functionalization of cCNCs with benzophenone moieties as radical photoinitiators (Figure 1), and the subsequent acrylate polymerization upon irradiation with 365 nm UV light. We show that this enables the synthesis of cCNC-based OCNs with cCNC contents of up to 40% and report the mechanical properties of these materials, which strongly depend on the nature of the grafted polymers.

References [1] N. J. Fernandes, H. Koerner, E. P. Giannelis, R. A. Vaia, MRS Commun., 3 (2013) 13-29.

[2] S. J. Eichhorn, A. Dufresne, M. Aranguren, N. E. Marcovich, J. R. Capadona, S. J. Rowan, C. Weder, W. Thielemans, M. Roman, S. Renneckar, W. Gindl, S. Veigel, J. Keckes, H. Yano, K. Abe, M. Nogi, A. N. Nakagaito, A. Mangalam, J. Simonsen, A. S. Benight, A. Bismarck, L. A. Berglund, T. Peijs, J. Mater Sci, 45 (2010) 1-33.

[3] M. N. Belgacem, A. Gandini, Composite Interfaces, 1-2 (2005) 41Âą75.

[4] H. Kang, R. Liu, Y. Huang, Polymer, 70 (2015) A1-A16.

Figure 1. PHMA-OCN containing 20 wt. % of cCNCs.

Surface and interface engineering of TiO2 thin films deposited on carbon nanotubes by Atomic Layer Deposition 1

2

3

2

3

1

Carlos Guerra , Yucheng Zhang , Meng Li , Rolf Erni , Hyung Gyu Park and Ivo Utke 1) EMPA, Swiss Federal Laboratories for Materials Science and Technology, Thun, Switzerland.

2) EMPA, Swiss Federal Laboratories for Materials Science and Technology, Dübendorf, Switzerland.

3) ETH Zürich, Nanoscience for Energy Technology and Sustainability, Zürich, Switzerland. carlos.guerra-nunez@empa.ch In this work we studied the nucleation and growth mechanisms of ALD TiO 2 on vertically aligned carbon nanotubes (CNTs) using TTIP and H2O. The use of CNTs as a model substrate to deposit metal oxides offers several advantages to study the interface, nucleation and growth of ultrathin films compared to the traditional flat substrates. The versatility of CNTs to be dispersed on a TEM grid allows for direct observation of the nucleation density, thickness, and morphology of the TiO 2 film [1]. The large surface area of the CNTs and thus of the deposited metal oxide, greatly enhances the signal of many characterization methods (i.e. Raman, XPS, XRD) to study crystallization, stresses, chemical bonding 2 3 and oxidation states even with only ~1-nm-thick film. Additionally, we can monitor the sp -to-sp transition of the surface carbon atoms as a function of the number of cycles to elucidate surface coverage [2]. These studies have revealed a temperature dependence in the nucleation density (surface coverage), which consequently influences the growth behaviour and surface characteristics. We will present this work and discuss the approach of using nanostructures as a model substrate to study thin films deposited by ALD.

1 µm

Figure 1. SEM image of vertically aligned carbon nanotubes conformally coated with 10 nm of TiO2.

References [1] Y. Zhang, C. Guerra-Nuñez, I. Utke, J. Michler and R. Erni, J. Phys. Chem. C, 6 (2015) 119.

[2] C. Guerra-Nuñez, Y. Zhang, M. Li. V. Chawla, R. Erni, J. Michler, H. G. Park and I. Utke, Nanoscale 7 (2015) 10622.

Three-dimensional networks derived from hyperuniform point patterns and their optical properties 2

1

2

2

J. Haberko , N. Muller , L. Froufe , F. Scheffold 1

Faculty of Physics and Applied Computer Science, AGH University of Science and Technology, al. Mickiewicza 30, 30-059 Krakow, Poland 2 Department of Physics and Fribourg Center for Nanomaterials, University of Fribourg, Chemin du Musée 3, CH-1700 Fribourg, Switzerland

haberko@fis.agh.edu.pl Abstract Amorphous photonic materials derived from hyperuniform point patterns [1] (strictly or in approximation) have drawn a lot of attention recently. It has been claimed, both theoretically and experimentally [2-4], that if reproduced in a dielectic material with a sufficiently large refractive index contrast substantial photonic bandgap (PBG) emerges both in two and three dimensions [5-6].

However, for the case of three dimensional materials evidence for the existence of a full photonic gap is still scarce. Moreover, the robustness of such a gap in the presence of imperfections or deviations from the desired geometry is largely unknown. The latter will be crucial however for any possible experimental realization of this new type of materials.

In the present work we numerically analyze light transport through hyperuniform dielectric networks with a high refractive index n>2.5 in air. We show how the transmission spectrum is affected by structural parameters of the network including the filling fraction of the dielectric phase, the shape and aspect ratio of dielectric rods. From our Finite Difference Time Domain (FDTD) computer simulations we extract parameters describing light transport inside our material, such as light scattering attenuation length and study how they are influenced by the geometrical parameters of the network.

Furthermore, we compare these results with FTIR measurements of such structures, which we have manufactured by means of the two-photon laser nanolithography combined with ZnO and TiO2 infiltration followed by a silicon double inversion process.

References [1] [2] [3] [4] [5]

Florescu, M., Torquato, S., Steinhardt, P. J., PNAS, Vol. 106 (2009) 20658–20663 Haberko, J. and Scheffold, F., Opt. Ex. 21 (2013) 1057–1065 Haberko, J., Muller, N., and Scheffold, F., Phys. Rev. A, 88 (2013) 043822 Muller, N., Haberko, J., Marichy, C., and Scheffold, F., Adv. Opt. Mat, 2 (2014) 115–119 Froufe-Pérez, L. S., Engel, M., Damasceno, P. F., Muller, N., Haberko, J., Glotzer, S.C. and Scheffold, F., submitted, http://arxiv.org/abs/1602.01002 [6] Liew, S. F., Yang, J. K., Noh, H., Schreck, C. F., Dufresne, E. R., O’Hern, C. S. and Cao, H. Phys.

Rev. A 84 (2011) 063818

Figures

Fig. 1: An SEM micrograph of a 3D hyperuniform all-dielectric network. Scale bar is 30 ȝm

Fig. 2: Light transport through a 3D hyperuniform dielectric network (cross-section). Electric field intensity map for a wavelength outside (a) and inside (b) the PBG.

Dielectric properties of nematic liquid crystal doped with Graphene nanoplates 1 2 Mohammad Hatefi Chaharborj , Ali Maleki 1

2

Shahid mostafa khomeini School, Urmia, Iran; Kharazmi University, Iran std_maleki@khu.ac.ir

Abstract In this paper, the influence of Graphene nanoplates on dielectric properties of planar and homeotropic oriented nematic liquid crystals (NLCs) were studied during the temperature interval of 298 - Ă&#x203A;. ,W ZDV IRXQG WKDW WKH GLHOHFWULF SHUPLWLYLW\ ZDV FRQVLGHUDEO\ LQFUHDVHG E\ Ddding Graphene mass percentages. The obtained dielectric anisotropy ( ) have shown an immense increment in the value of 10% wt. graphene doped NLCs. These results were assigned to the strong dipole-dipole interaction between the graphene nano plates and the surrounding LC molecules.

References [1] Ghanadzadeh Gilani A, Moghadam M, Zakerhamidi MS, Moradi E., J. Dye. Pigment. Elsevier, 92, 2012 [2] .RSĂžDQVNĂŞ 3 7RPDĂŁRYLĂžRYiV 1 .RQHUDFNi 0 7LPNR 0 =iYLĂŁRYi 9 (EHU 1 )RGRU-Csorba K, TĂłth-Katona T, Vajda A, Jadzyn J, Beaugnon E, Chaud X., J. Magn. Magn. Mater., 322, 2010

Figures

Stimuli-responsive polydopamine/protein nanoparticles can target cancer cells and induce cell death Daniel Hauser, Joël Bourquin, Christophe A. Monnier, Alke Petri-Fink, Vincent Ball and Barbara Rothen-Rutishauser Adolphe Merkle Institute, University of Fribourg, Chemin des Verdiers 4, 1700 Fribourg, Switzerland daniel.hauser@unifr.ch Abstract Polydopamine is a major pigment of naturally occurring melanin. In relation to this material, nanoparticles made of polydopamine (PDA NPs) exhibit peculiar physicochemical properties, such as heat induction upon exposure to UV light. In return, these features make them particularly attractive for 1 the theranostic field.

Depending on the intended application, any protein can be combined with these PDA NPs to adapt the surface by conducting a relatively simple synthesis. In this context, we have designed and produced PDA NPs containing human serum albumin (HSA), a readily available and biocompatible protein, and 2,3 transferrin (Tf), a widely used epitope to target cancer cells. In vitro studies demonstrated that these NPs are readily taken up by mouse macrophages (J774A.1 cells) and lead to apoptosis when irradiated with a UV laser (Ȝ = 405 nm). Moreover, mouse melanoma (B16 F10) cells subjected to UV irradiation exhibited an enhanced cell death rate with PDA/Tf NPs in comparison to PDA/HSA NPs. These findings indicate that the proteins on the PDA NP surface retain their active nature and effectively convert UV irradiation into heat.

References 1.

2.

3.

Liu, F. et al. Facile preparation of doxorubicin-loaded upconversion@polydopamine nanoplatforms for simultaneous in vivo multimodality imaging and chemophotothermal synergistic therapy. Adv. Healthc. Mater. 4, 559±568 (2015).

Singh, R. et al. Dose-Dependent Therapeutic Distinction between Active and Passive Targeting Revealed Using Transferrin-Coated PGMA Nanoparticles. Small (2015). doi:10.1002/smll.201502730 van der Meel, R., Vehmeijer, L. J. C., Kok, R. J., Storm, G. & van Gaal, E. V. B. Ligand-targeted particulate nanomedicines undergoing clinical evaluation: Current status. Adv. Drug Deliv. Rev. 65, 1284±1298 (2013).

OPTIMISATION OF THE DEMOULDING PROPERTIES OF PLASTIC PARTS WITH MICRO/NANO SURFACE TREATMENTS: AN EUROSTARS PROJECT Stefan Hengsberger, Adrien Spaggiari Haute école d’ingénierie et d’architecture de Fribourg, HESͲSO/FR

In the frame of the Eurostars project Superslip E!7412 six partners out of three European countries collaborated around the optimization of the release properties of plastic objects during the injection process. At the institute of applied Plastics research at the College of Engineering in Fribourg (Switzerland) systematic tests of the influence of surface coatings in combination with surface finishes like microblowing and nano Laser texturing have been performed. Several main plastic materials were employed that are in use by the partner companies in this project consortium: out of these materials results for Polypropylene (PP), POM and ABS are presented.

In this project a new test mould has been developed that allows for fixing cylindrical inserts with different surface treatments. The force that arises during the ejection phase was analyzed and the maximum force and the impulse (integral of the force versus time signal) were determined.

Figure 1: left: Cylindrical insert that has been surface treated and tested in an injection mould right: Test piece. Several polymers that are commonly in use in plasturgie have been tested.

The results have demonstrated that the optimal surface treatment depends on the applied polymer (see Figure 2). The injection tests have demonstrated a significant effect of the superslip coating (CrN & N2 ions) on the ejection force for PP. In fact a reduction of the demoulding force of 20% was detected for this material. It is supposed that the additional N2 dose makes the surface coating chemically more inert (see Figure 3). A CrN coating with HiPiMS (High power impulse magnetron sputtering) has shown a 30% reduction for POM and a laser nano texturing with Ra=0.57 um has led to a 28% decrease of the ejection force for ABS. The test protocol that has been developed in the frame of this project has allowed for quantifying the absolute effect of each mould surface treatment step. These promising results have been thoroughly checked in terms of reproducibility. The project outcome has furthermore been validated under production conditions by two Danish industrial partners of the consortium, i.e. Proinyec and Novo Nordisk.

160 140

relative ejection force (%)

120 100 POM

80

ABS PP

60 40 20 0 no treatment

CrNͲSD

CrN & N2 ions

CrN HiPiMS

TiAlN

Laser texture

DLC

Figure 2 : Relative change of ejection force for different surface treated cores. The optimal surface treatment depends on the applied polymer. The Superslip coating based on CrN & N2 ions has shown a 20% reduction for PP while Laser texture has shown a reduction of 28% for ABS. The CrN coated with HiPiMS (high power impulse magnetron sputtering) has shown a 30% decrease for POM.

Figure 3: CrN coating with additional N2 ion sputtering. The depth of penetration of the ions can be tuned with the kinetic energy. The superficiel deposition of additional ions makes the CrN coating chemically more inert.

Chemical layer deposition of porous alumina overcoats increases activity and stability in liquid phase catalytic conversion of biomass-derived chemicals Florent HĂŠroguel, Benjamin Le Monnier, Jeremy S. Luterbacher Laboratory of Sustainable and Catalytic Processing, EPFL, Lausanne, Switzerland Florent.heroguel@epfl.ch Biomass-derived chemicals represent an attractive sustainable alternative to petrochemicals.

However, the competitiveness of these processes has been limited by the low stability of metal catalysts under the severe conditions used during biomass upgrading. In order to prevent metal leaching and sintering, we developed a chemical layer deposition (CLD) overcoating technique based on the control over aluminum alkoxide surface reactions kinetics and stoichiometry. After deposition of 30 cycles of an alumina overcoat onto alumina supported copper nanoparticles, imaging using high angle annular dark field scanning transmission electron microscopy (HAADF STEM) revealed a conformal porous overcoat.

This porosity was was characterized and quantified by nitrogen physisorption. The overcoat suppressed irreversible catalyst deactivation during the liquid-phase hydrogenation of furfural. While a significant loss of activity due to mass transfer limitations and metal coverage by the overcoat was observed by 2 2Âś1HLOO et al. when using atomic layer deposition (ALD), most of the surface metal sites remained accessible with CLD as confirmed by chemisorption, illustrating the benefits of overcoats porosity that can be targeted by tuning synthesis parameters. Current work is focused on tuning this porosity for the synthesis of shape selective catalyst overcoats. [ @ +pURJXHO ) 5R]P\VĂĄRZLF] % /XWHUEDFKHU - 6 , Chim. Int. J. Chem. 10 (2015), 582-591. > @ 2Âś1HLOO % - -DFNVRQ ' + . &ULVFL $ - )DUEHURZ & $ 6KL ) $OED-Rubio, A. C.; Lu, J.; Dietrich, P. J.; Gu, X.; Marshall, C. L.; Stair, P. C.; Elam, J. W.; Miller, J. T.; Ribeiro, F. H.; Voyles, P. M.; Greeley, J.; Mavrikakis, M.; Scott, S. L.; Kuech, T. F.; Dumesic, J. A. Angew. Chem., 51 (2013), 1405314057.

Hyperbranched, surpramolecular polymer adhesives exhibiting high toughness and stiffness Diana Kay Hohl, Diederik W. R. Balkenende, Lucas Montero de Espinosa, Christoph Weder Adolphe Merkle Institute, University of Fribourg, Chemin des Verdiers 4, 1700, Fribourg, Switzerland diana.hohl@unifr.ch Abstract In a supramolecular polymer, monomeric units are assembled via directed, secondary interactions such as hydrogen bonding or electrostatic interactions.[1] The dynamic, reversible nature of these noncovalent bonds renders these materials susceptible to a range of stimuli so that depending on the nature of the bonds, the equilibrium of the assembled state can be tuned by triggers such as temperature or light. While the temporary disassembly of the polymer can, for example, result in improved melt processability, the development of supramolecular materials exhibiting superior mechanical properties remains a challenge and generally limits their industrial applicability. A supramolecular material of high mechanical strength and good melt processability has yet to be developed.

Our group has recently reported a trifunctional monomer unit carrying three quadruple hydrogenbonding ureido-4-pyrimidinone (UPy) groups that assembles into a disordered glass of high stiffness and promising adhesive properties.[2] However, limited toughness and high brittleness were identified as the limiting material properties. Building on this work, this contribution will discuss the synthesis of a hyperbranched macromonomer displaying UPy end groups and its solid-state assembly into a supramolecular network through UPy-UPy interactions. The hyperbranched macromonomer was synthesized via branching of trifunctional amine-terminated polypropylene oxide (PPO) units with molecular weights of ca. 440 g/mol and 3000 g/mol with hexamethylene diisocyanate and by end capping of the remaining amine groups with UPy and 2-ethylhexyl groups. The one-pot synthesis results in materials exhibiting two coexisting, amorphous domains: a low glass transition (Tg) domain offering high toughness and a high T g domain providing stiffness. The combination of these characteristics and the low melt viscosity induced through the supramolecular motif afford a promising material of unprecedented mechanical performance. In addition, promising adhesive properties were observed and the temperature-induced bonding and debonding on demand present an interesting opportunity for a broad range of applications.

References [1] Yang, L.; Tan, X.; Wang, Z.; Zhang, X., Chemical Reviews, 115 (2015) 7196Âą7239.

[2] Balkenende, D. W. R.; Monnier, C. A.; Fiore, G. L.; Weder, C., Nat. Commun., 7 (2016) 1Âą9.

Figures

Figure 1. (a) Picture of a stainless steel lap joint bonded with the supramolecular adhesive. (b) Schematic representation of the hyperbranched, supramolecular network.

Optimization of a broadband and omnidirectional anti-reflection layer for Cu2ZnSnS4 solar cells Ming-Yang Hsieh and Shou-Yi Kuo* Department of Electronic Engineering, Chang Gung University, No.259, Wenhua 1st Rd., Guishan Dist., Taoyuan City 33302, Taiwan sykuo@mail.cgu.edu.tw Abstract Anti-reflection coatings (ARCs) play an important role in the performance of optoelectronic devices because of their ability to minimize Fresnel reflection loss at the interface between air and semiconductor materials [1-2]. In this article, a study is presented of aluminum-doped zinc oxide (AZO) sub-wavelength grating (SWG) nanostructures for broadband and omni-directional anti-reflection coatings (ARCs) on Cu2ZnSnS4 (CZTS) solar cells using the rigorous coupled-wave analysis (RCWA) method. Various SWG nanostructures of different shapes and periodic AZO on CZTS solar cells are discussed in detail. The optimized reflectance decreased from 9.9% to 1.67%, and efficiency increased from 12.56% to 13.74%, accordingly. The omni-directional and broadband antireflections of the AZO SWG nanostructures are also investigated. This considerable enhancement in light harvesting is attributed to the linearly graded effective refractive index profile from the air to the device surface.

References [1] M.-A. Tsai, P.-C. Tseng, H.-C. Chen, H.-C. Kuo, and P. Yu, Opt. Express, 19, (2011) A28-A34.

[2] J. Zhu, Z. F. Yu, G. F. Burkhard, C. M. Hsu, S. T. Connor, Y. Q. Xu, Q. Wang, M. McGehee, S. H. Fan, and Y. Cui, Nano Lett. 9, (2009) 279Âą282.

Figures

(a) The geometry of AZO SWGs expressed by the equation of the parabola-shaped, (b) the geometries of AZO SWGs at OT = 3, 2, 1.6, 1 and 0.5, (c) calculated effective refractive index profiles of the AZO SWGs with R=150 nm and H=300 nm at OT = 3, 1.6, 2, 1 and 0.5. (d) Contour plots of the calculated reflectance variation as a function of wavelength at different OT for AZO SWG nanostructures on CZTS solar cell. (e) The simulation angular reflectance spectra for solar cell with (top) bare and (bottom) with AZO SWGs solar cells. (f) The weighted reflectance of the cells.

Electronic and Optical properties of interstitial Fe in graphene nanosheet

1

1

1

2

M. Jafari , M. S. Mazloum , S. J. Azimi , R. Jafari 1Department of physics, K. N. Toosi University of Technology, Tehran, Iran 2Department of civil engineering, K. N. Toosi University of Technology, Tehran, Iran jafari@kntu.ac.ir Abstract In this paper electronic and optical properties of interstitial Fe in graphene nanosheet have been studied. The calculations have been performed using pseudo-potential method in the framework of perturbation density functional theory and the LDA approximations within Quantum Espresso package.

Our results show the gap energy become zero and the graphene nanosheet display metallic properties.

Furthermore, the optical properties have been presented in terms of the real and imaginary parts of dielectric function.

Magnetic properties of interstitial Fe in graphene nanosheet

1

1

1

2

M. Jafari , A. Goodarzi , M. Asadpour , M. Jafari 1Department of physics, K. N. Toosi University of Technology, Tehran, Iran 2Department of industrial engineering, Faculty of engineering (Farabi), University of Tehran, Iran jafarifr@yahoo.fr

Abstract In this paper electrical and magnetic properties of interstitial Fe in graphene nanosheet have been investigated. The calculations have been performed in the framework of density functional theory and the GGA approximations within Quantum Espresso package. The band structure calculation show that direct band gap of graphene nanosheet along M direction. According to this calculation, the electronic and magnetic properties of this structure depend to the Fe atom, which will be attained the magnetic metal or magnetic semiconductors.

Gold nanowire fabrication with lipid nanotubes Kristina Jajcevic, Kaori Sugihara Department of Physical Chemistry, University of Geneva, Switzerland

The fabrication of conductive nanostructures is the key technology in semiconductor industry and has gained importance in biology for applications such as biosensors and drug delivery.

We have demonstrated a high-throughput approach to fabricate gold nanowires on surfaces with a lipid nanotube template. Biotin-tagged lipid nanotubes are formed from lipid blocks in inverted hexagonal phase adsorbed on polymer-coated surfaces upon application of shear force. Streptavidin-coated gold nanoparticles were attached to the biotin-tagged lipid nanotubes and gold nanoparticle-encapsulated LNTs were crosslinked by chemical fixation. Samples were dried and treated with oxygen plasma to remove the organic template and connect the particles. The created nanowires were characterized by cryo-transmission electron microscopy, atomic force microscopy and electrical measurements.

Crystal structure and upconversion luminescence properties of Er 1,*

1

2

3+

2

Jung Hyun Jeong , Do Rim Kim , Kiwan Jang , Ho Sueb Lee , Dong Soo Shin

3

1

Department of Physics, Pukyong National University, Busan 608-737, South Korea Department of Physics, Changwon National University, Changwon 641-773, South Korea 3 Department of Chemistry, Changwon National University, Changwon 641-773, South Korea *jhjeong@pknu.ac.kr 2

Abstract This paper gives the properties of upconversion photoluminescence (UCPL) on SrLaMgTaO 6 crystal doped with trivalent erbium at concentrations of 1 ~ 20 mol% were prepared by a solid state reaction process from powder based precursors. The crystal structure, electronic structure, and optical 3+ properties of SrLa(1-x)MgTaO6:Er x were studied by using X-ray diffraction (XRD), field-emission scanning electron microscopy (FE-SEM), UV-visible spectrophotometer, DFT (density functional theory) calculations and photoluminescence (PL) spectra. Under the excitation of a 975 nm laser diode, the 2 4 2 4 2 3+ phosphors emitted green ( H11/2, S3/2ĺ I15/2) and red ( F9/2ĺ I15/2) UCPL[1]. Under the Er 3+ concentration of 10 mol %, the intensity of the green UCPL was increased in linear proportion to Er 3+ concentration, which was attributed that the UCPL of low concentration of Er in SrLaMgTaO6 was 3+ mostly generated from ESA process. From higher Er concentration above 10 mol%, however, the ETU process had additionally participated to UCPL, the intensity of UCPL was decreased. It was attributed 3+ that the concentration quenching was more active than ETU process at high concentration of Er in SrLaMgTaO6.

References [1] Li Y H, Hong G Y, Zhang Y M, et al, J. Alloys and Compounds, 456(2008), 247±250.

Figures

Fluorescence properties with redshift of Eu

2+

emission in novel phosphor-silicate apatite

Sr3LaNa(PO4)2SiO4 phosphors

1,*

1

2

2

Jung Hyun Jeong , Yue Guo , Kiwan Jang , Ho Sueb Lee , Dong Soo Shin

3

1

Department of Physics, Pukyong National University, Busan 608-737, South Korea Department of Physics, Changwon National University, Changwon 641-773, South Korea 3 Department of Chemistry, Changwon National University, Changwon 641-773, South Korea *jhjeong@pknu.ac.kr 2

Abstract The apatite like-compounds Sr10(PO4)6F2 can easily modified by various anionic and cationic substitutions with different ion sizes due to the flexibility of the apatite structure. One category is a 34silicate-substituted apatite following the pattern: (PO4) + F = (SiO4) . Huang et al.[1] have reported 2+ 3that the emission spectra of Eu ions shows red shift after the replacement of (PO 4) by the more 4covalent (SiO4) group in apatite. Another separate category is two divalent alkaline earth cations replaced by one trivalent rare earth ion and one monovalent alkaline earth cations, following the pattern 2+ 3+ + as: 2Sr = La + Na . The La-Na combination reduces the symmetry of the atomic arrangement from P63/m to P3 [2]. Follow these ideas, we generate the new phosphor-silicate apatite Sr3LaNa(PO4)2SiO4.

2+ In this study, a serious of Eu -activated novel phosphor-silicate apatite Sr3LaNa(PO4)2SiO4 phosphors were synthesized via a conventional high temperature solid-state reaction. The XRD results 2+ revealed that the phosphors possessed single-phase and the incorporation of small amount Eu ions did not induce any significant changes in the crystal structure. The reflectance spectra showed an 2+ overall red shift of the wavelength to 700 nm. The two different crystallographic sites of Eu ions had 2+ been confirmed by their lifetimes. Energy transfer of two kinds Eu centers were demonstrated both from dipole-dipole interaction. All of the phosphors exhibited strong broad absorption bands in the near ultraviolet (near-UV) range, revealing the phosphor-silicate phosphor interesting for application in the output wavelength of the near-UV used phosphor-converted LED chips.

References [1] X. Wang, J. Gan, Y. Huang, H.J. Seo, The doping concentration dependent tunable yellow 2+ luminescence of Sr5(PO4)2(SiO4):Eu , Ceramics International, 38 (2012) 701-706.

[2] J.F. Rakovan, J.M. Hughes, Strontium in the apatite structure: strontian fluorapatite and belovite(Ce), The Canadian Mineralogist, 38 (2000) 839-845.

Figures

Optical Properties and Characterization of Graphene Oxide-Chitosan Composites through Tensile Testing, TGA/FTIR Analysis 2

3

1

Nilay Kahya , *Â OĂşHQ $NĂ&#x2022;Q (YLQJÂ U , Semira Bener , Hakan Kaygusuz , F. Bedia Erim 1

1

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øVWDQEXO 7HFKQLFDO 8QLYHUVLW\ Department of Chemistry, Maslak, øVWDQEXO 7XUNH\ Piri Reis University, Department of Electrical and Electronics Engineering, Tuzla, øVWDQEXO 7XUNH\ 3 Kultur University, Department of Civil Engineering, %DNĂ&#x2022;UN|\ Istanbul, Turkey kahyan@itu.edu.tr

2

&KLWRVDQ LV D QDWXUDO SRO\VDFFKDULGH FRPSRVHG RI UDQGRPO\ GLVWULEXWHG Č&#x2022;-(1-4)-linked D-glucosamine and N-acetyl-D-glucosamine units. Chitosan is obtained by partial deacetylation of chitin in basic media.

Chitin, a well-known polysaccharide, forms structural components of many animals, such as exoskeletons. In the present study, we investigated physical, chemical and mechanical properties of graphene oxide-chitosan (GO/Ch) hydrogel films. Nowadays, graphene based biocomposites have generated a huge interest in the field of materials science, physics, chemistry and biotechnology. The oxidized form of graphene is graphene oxide and it easily disperses in organic solvents and water with the help of its functional groups [1]. In order to prepare GO/Ch films, graphene oxide was added to 1% (v/v) acetic acid solution having a concentration of 80 Âľg/mL in 1% (w/v) chitosan solution. After continuously mixing, these chitosan solutions were poured into petri dishes and dried in a laboratory refrigerator until they become a thin film. Chitosan films were dipped into 1% or 20% (w/v) sodium sulfate crosslinking solutions and ionically crosslinked at room temperature for one hour. Thermal stability of chitosan and GO/Ch films were studied by thermogravimetric analysis (Figure 1) and were characterized using FTIR spectroscopy. In order to evaluate mechanical properties, tensile test was applied to the films. Tensile modulus and resilience parameters were calculated from linear elastic regions of stress-strain curves of films. Optical properties of both chitosan and GO/Ch films were determined from the transmission measurement in the range of 200-800 nm. The effect of graphene oxide dopant on energy gap has been examined for chitosan films. In conclusion, chitosan and GO/Ch films were doped with graphene oxide and then these biomaterials were characterized by various methods.

References [1] Dimitrios Konios et al., Journal of Colloid and Interface Science, 430 (2014) 108-112.

Figure 1: TG curves of GO/Ch, GO/Ch/Na2SO4 (1%) and GO/Ch/Na2SO4 (20%) films.

Physical and Chemical Modification of Graphene for Electrochemical Energy Storage Applications Kwang-Bum Kim, Hyun Kyung Kim, Myung Seong Kim, Young Hwan Kim, Yeon Jun Choi, Jun Hui Jeong and Seok Woo Lee Department of Material Science and Engineering, Yonsei University, 134 Shinchon-dong, Seodaemoon-gu, 120-749, Seoul, Republic of Korea * kbkim@yonsei.ac.kr Abstract Graphene, a one-atom-thick, two-dimensional (2D) sp2 carbon structure, has attracted considerable interest as a next-generation electrode material for electrochemical energy storage devices.This can be attributed to a number of interesting properties of graphene, such as chemical stability, high electrical conductivity, high concentration of edge sites and a large surface area. The combination of these unique physical and chemical properties means that graphene has significant potential to act as either an electrochemically active material for use in electrochemical capacitor applications.[1-3] At the same time, graphene nanomesh exhibits quantum confinement, enriched edge and localization effects, combined with the inherent properties of graphene, and thus, they have great potential applications in the fields such as energy storage, gas separation/storage.[4-7] In this study, we report on the synthesis and electrochemical characterization of graphene nanomesh as an electrode material for energy storage applications.

References [1] H.K. Kim, A.R. Kamali, K.C. Roh, K.B. Kim and D.J. Fray Energy Environ. Sci., 2016, Advance Article DOI: 10.1039/C6EE00815A [2] S.H. Park, H.K. Kim, S.B. Yoon, C.W. Lee, D.J. Ahn, S.I. Lee, K.C. Roh and K.B. Kim, Chem. Mater., 2015, 27 (2), pp 457±465 [3] H.C Youn, S.M. Bak, M.S. Kim, C. Jaye, D.A. Fischer, C.W. Lee, X.Q. Yang, K.C Roh, and K.B. Kim, ChemSusChem 2015 8(11) 1875 DOI: 10.1002/cssc.201500122 [4] H.K Kim, K.C Roh, and K.B Kim, Energy Environ. Sci 2016,9, 1270-1281 [5] 4 V. H. Nguyen, F. Mazzamuto, J. Saint-Martin, A. Bournel and P. Dollfus, Nanotechnology, 2012, 23, 289502.

[6] J. Yang, et al., Nanoscale, 2014, 6, 13301±13313.

[7] D. P. Yang, et al., J. Phys. Chem. C, 2014, 118, 725±731.

[8] O. Akhavan, ACS Nano, 2010, 4, 4174±4180.

Synthesis of aramide rod-like molecules and re-entrant honeycomb structure for the investigation of auxetic polymers Phally Kong1, Susanne Drechsler1, Sandor Balog2, Andreas F. M. Kilbinger1 1

Department of Chemistry, University of Fribourg,Switzerland, 2Adolphe Merkle Institute, University of Fribourg, Switzerland Phally.kong@unifr.ch

Auxetic materials are characterized by a negative Poisson’s ratio (NPR), which means they tend to expand perpendicularly to the applied force when stretched, unlike non-auxetic materials, which would shrink under same conditions. Auxetic behavior can be achieved with different architecture and shows to be scale independent1. Auxetic polymeric materials are of interest since they are expected to have mechanical properties such as a higher shock absorption and greater fracture resistance due to their intrinsic molecular structure compared to their nonauxetic counterparts. So far, a series of these materials have been produced in the form of foams, fibers and composites. Some molecular-level auxetic polymers have been theoretically designed, but they have not been synthesized yet. That is why this project is focused on auxetic polymeric materials on the molecular level.

In this study the exploration of polymeric molecular auxeticity of rod-containing polymers2 and re-entrant honeycomb structure3, 4 were designed and investigated. The molecular geometric shapes were synthetically achieved via shape persistent aromatic amide oligomers for the rodcontaining polymers and their aggregation was studied. Several rod-containing polymers were synthetized containing different percentage of rods, see figure 1. Gel permeation chromatography (GPC) and dynamic light scattering (DLS) experiments indicate an increasing size particles according to the increasing rod percentage. A synthetic route for the polymer with re-entrant honeycomb shape via Sonogashira cross-coupling metathesis and coupling of an amine with acyl chloride is proposed. A designed re-entrant honeycomb structure is shown in the figure 2.

References: [1] [2] [3] "#$!

Liu, Y., Hu, H., A review on auxetic structures and polymeric materials, Scientific Research and Essays, 2010, Vol. 5 (10), pp. 1052-1063, 18 May He,C. ; Liu,P. ; Griffin,A. ; Smith,C .; Evans,K. Macromol. Chem. Phys. 2005, 206, 233 Evans, K.E.; Design of doubly-curved sandwich panels with honeycomb cores; Compos. Struct.

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Chemical Layer Deposition of metal oxide overcoats with targeted porosity by Stoichiometric and Kinetic control Benjamin P. Le Monnier, Florent HĂŠroguel, Jeremy S. Luterbacher Laboratory of sustainable and catalytic processing / Ecole FĂŠdĂŠrale Polytechnique de Lausanne, Lausanne, Switzerland Benjaminpierre.lemonnier@epfl.ch Abstract Catalyst overcoating could become an important strategy in catalyst synthesis due to the possibility of tuning surface reactivity, active site stability and general physicochemical properties of the materials.

It has been demonstrated that overcoating via Atomic Layer Deposition (ALD) and subsequent calcination to induce porosity in the overcoat is an effective catalyst stabilization technique [1]. However, this process is known to be expensive and difficult to apply to powders. Using sol-gel chemistry could be an attractive approach but batch deposition approaches often suffer from poor control of the resulting nanomaterial especially in the case of highly reactive oxide precursors such as aluminum alkoxides..

We report a strategy that combines the advantages of ALD and sol-gel chemistry techniques by applying a solution-phase layer-by-layer technique controlled by the stoichiometry and kinetics of precursor deposition. Our procedure allows for the synthesis of overcoats with targeted thickness and porosity by judiciously choosing synthesis parameters such as water/alkoxide ratio, solvent choice or material aging conditions. Our initial study focused on the overcoating of an alumina supported copper catalyst (Fig. 1). The texture of the overcoats was analyzed by N2-physisorption and copper accessibility was measured by N2O titration and the shape of the coating was imaged by STEM-HAADF. Because this layer-by-layer coating method is performed in solution, a vast number of parameters can be controlled compared to gas phase deposition potentially leading to the formation of several novel nanoenvironments.

Fig. 1: Steps of catalyst preparation: (1) Impregnation, (2) overcoating, (3) thermal treatment

References [1] %UDQGRQ - 2Âś1HLOO 'DYLG + . -DFNVRQ -HFKDQ /HH &KULVWLDQ &DQODV 3HWHU & 6WDLU &KULVWRSKHU / Marshall, Jeffrey W. Elam, Thomas F. Kuech, James A. Dumesic, and George W. Huber, ACS Catal. 5, 2015, 1804Ă­1825 [2] Rachel A. Caruso and Markus Antonietti, Chem. Matter. 13 (2001), 3272-3282

Silica Micelles (Hydrophilic Core@Amphiprotic Shell) for Multiple Applications 1

2

1,3

Md. Shahinul Islam, Won San Choi, and Ha-Jin Lee * 1

Western Seoul Center, Korea Basic Science Institute, Seoul, 03759, Korea Department of Chemical and Biological Engineering, Hanbat Nat¶l University, Daejeon, 34101, Korea 3 Department of Chemistry and Nano Science, Ewha Womans University, Seoul, 03760, Korea hajinlee@kbsi.re.kr

2

Abstract We present the preparation and multiple applications of superhydrophobic hollow SiO2 micelles (SHSMs) with hydrophilic cores and amphiprotic (superhydrophobic/hydrophilic) shell structures that act as ³all-in-one´ smart nanomaterials. Our SHSMs are better than hydrophilic@hydrophobic micelles prepared using previously reported methods for several reasons: (i) the polyallylamine hydrochloride (PAH) chains were extended and survived from the core to the shell even after octadecyltrimethoxysilane (OTMS) treatment, meaning that hydrophilic groups (PAH) exist inside and outside of the SHSMs. In other words, hydrophilic PAH coexists with hydrophobic OTMS outside of the SHSMs. (ii) The SHSMs simultaneously showed hydrophilic (surface charge, +31.27 mV) as well as hydrophobic o (superhydrophobicity, CA=163 ) properties due to their unique structures consisting of hydrophilic cores and amphiprotic shells. Therefore, amphiprotic shells and active amine groups made the SHSMs to use as catalysts for hydrophilic and hydrophobic environments. We demonstrate multiple applications of SHSMs: (a) inorganic catalysts for micelle catalytic reactions in organic or aqueous solutions, (b) superhydrophobic coating of sponges or metal meshes for oil/water separation and pollutant purification, and (c) hydrophobic carriers for ultrahigh loading of enzymes with significant stability and efficient recyclability.

References [1] Md. Shahinul Islam, Won San Choi, Sun Ha Kim, Oc Hee Han, Ha-Jin Lee, Adv. Funct. Mater. 25 (2015) 6061-6070.

[2] Md. Sahinul Islam, Won San Choi, Ha-Jin Lee, ACS Appl. Mater. Interfaces 6 (2014) 9563-9571.

[3] Md. Shahinul Islam, Ha Neul Choi, Won San Choi, Ha-Jin Lee, J. Mater. Chem. B 3 (2015) 1001-1009.

Figure. (a) A schematic representation for the synthesis of silica micelles (Hydrophilic Core @Amphiprotic Shell: SHSM) and (b) UHR-SEM images of the AuNP-embedded SHSM.

A Green One-step Approach for the Synthesis of Graphene Included Bismuth Oxychloride Nanosheets and Photoelectrochemical Sensing 1,2

A-I. Gopalan

3

1,2,3,

N. Muthuchamy , K-P. Lee

1

Research Institute of Advanced Energy Technology, Kyungpook National University, Daegu, S.Korea 2

Department of Nanoscience and Nanotechnology, Kyungpook National University, Daegu, S.Korea 3

Department of Chemistry Education, Kyungpook National University, Daegu, S.Korea Presenting author: K-P Lee (kplee@knu.ac.kr)

We have utilized a simple and green approach for the preparation of graphene included bismuth oxychloride nanosheets (BiOCl(G)-NS). The approach involves the hydrothermal method, eco-friendly chemicals and short reaction time. The as prepared BiOCl(G)-NSs were characterized by field emission scanning electron microscopy, energy dispersive electron X-ray spectroscopy, Fourier transform infrared sprctroscopy, X-ray diffraction studies, electrochemical impedance spectroscopy and cyclic voltammetry.

The photoelectrochemical properties of BiOCl(G)-NS were evaluated in a redox electrolyte and also in the presence of glucose and compared with BiOCl-NS by cyclic voltammetry and amperometry under light irradiation. Results from cyclic voltammetric and deferential pulse voltammetric measurements revealed that the BiOCl(G)-NS electrode is capable of generating photocurrent for glucose when its surface is irradiated with visible light. The inclusion of G in BiOCl-NS increases the photocurrent responses to glucose. The photocurrents produced for the oxidation of glucose through photoamperometry at +0.50 V were linearly correlated to the glucose concentration in the range of 0.5 to 10 mM with a detection limit of 0.22 mM. The BiOCl(G)-NS based non-enzymatic glucose sensor exhibited good performances with high -1

-2

sensitivity (1.878 and 127.2 µM mM cm ), wide concentration range (500 µM ± 10 mM), good selectivity, reproducibility (RSD=2.4%) and applicability to real sample (human serum).

Spectroscopic properties of the complexes formed by graphene oxide and porphyrins substituted with aryl group 2

1

Kornelia Lewandowska , Natalia Rosiak , Andrzej Bogucki 5RPDQ Ä?ZLHWOLN 1

1

1

Polish Academy of Science, Institute of Molecular Physics, ul. Smoluchowskiego 17, 60- 3R]QDÄ&#x201D; Poland 2 Faculty of Technical Physics, Poznan University of Technology, ul. Piotrowo 3, 60- 3R]QDÄ&#x201D;, Poland kornelia.lewandowska@ifmpan.poznan.pl

Abstract Nowadays, research of graphite oxide (GO) modified by donor or acceptor organic molecules is a hot topic because these materials exhibit novel and unique properties. Recent studies show that this type of structures have really interesting photoelectrochemical properties and can be practically used in optoelectronics or molecular photovoltaics (field-effect transistors, photovoltaic devices, nonlinear optics applications) [1,2].

The aim was to create new hybrid systems with donor-acceptor properties, consisting of graphite oxide and porphyrins substituted with different aryl derivatives.

Hybrid systems based on GO and porphyrin derivatives (eg. 5,10,15,20 - Tetrakis (4-hydroxy-xyphenyl) -21H, 23H-porphine) were obtained by simple sonication. In the studied systems we observed the similar interaction between GO and porphyrin as in other GO complexes obtained by complicated method. The detailed spectroscopic properties of these composites were investigated by using UV-Vis, fluorescence, IR absorption spectroscopy, and Raman scattering technique. The study shows that the electrostatic and Ę&#x152;-Ę&#x152; stacking and H-bonding cooperative interactions between GO and pophyrin are probably the main driving forces for complexation.

The changes in IR absorption and Raman spectra, and fluorescence quenching with increasing concentrations of GO may be associated with charge transfer and/or energy between the hybrid structures, which was also indicated by Geng and Shu [2,3].

References [1] Y. Xu, Z. Liu, X. Zhang, Y. Wang, J. Tian, Y. Huang, Y. Ma, X. Zhang, Y. Chen, Adv. Mater., 21 (2009) 1275.

[2] M. Bala Murali Krishna, N. Venkatramaiah, R. Venkatesan, D. Narayana Rao, J. Mater. Chem., 22 (2012) 3059.

[3] J. Geng, H.-T. Jung, J. Phys. Chem. 114 (2010) 8227-8234.

[4] J. Shu, Z. Qiu, Q. Wei, J. Zhuang, D. Tang, 5 (2015) 15113. a

b

Figure 1. The fluorescence emission spectra of Porphyrin-GO hybride (a) and IR absorption spectra (b) of Porphyrin, Go and Porphyrin-GO hybride Acknowledgments The scientific work funded by the Ministry of Science and Higher Education under the programme Âł,XYHQWXV 3OXV LQ WKH \HDUV -2017 (project no. 0256/IP2/2015/73)

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Temperature dependence on the magnetic, morphological and structural properties of Fe3O4(111)/SrTiO3(111) thin films grown by PLD 1,2

J. López-Sánchez,

3,4

3,4

5

J. Rubio-Zuazo, I. Arnay, A. Muñoz-Noval, A. Serrano, 1,2 3,4 O. Rodríguez de la Fuente and G. R. Castro

3,4

1,2

N. Carmona, ,

1 Departamento de Física de Materiales, Universidad Complutense de Madrid, 28040 Madrid, Spain.

2 Unidad Asociada IQFR (CSIC)-UCM, 28040 Madrid, Spain.

3 Spanish CRG, Spline, The European Synchrotron (ESRF), 38000 Grenoble, France.

4 Instituto de Ciencia de Materiales, Consejo Superior de Investigaciones Científicas (ICMM-CSIC), Madrid, Spain.

5 Department of Applied Chemistry, Hiroshima University, Hiroshima, 739-8527, Japan.

jesus.lopez@ucm.es Abstract Despite the immense scientific literature regarding the oldest known magnetic material, magnetite has magnetic and structural properties still unveiled. Specifically, in the nanometric scale, many efforts are being developed in order to obtain high quality thin film layers with a preferred crystalline orientation [1].

This aspect is crucial for spintronic devices for optimal spin-polarized current in a metal/semiconductor heterojunction. In this sense, a positive spin polarization at the (111) surface of magnetite has been recently observed [2]. The chemically layered polar nature of the junction Fe3O4(111)/SrTiO3(111) might be employed as a scenario for studying spin injection from half metals into semiconductor materials.

Therefore, aiming to discover the possible spin-polarized current effects, high quality Fe3O4(111) epitaxial thin films (~30 nm) are grown on SrTiO3 substrates by Pulsed Laser Deposition (PLD) as a function of temperature deposition (300-900 ºC). Depending on the different temperature stages, a homogeneous thin film or triangular Fe3O4 terraces as a single phase are formed. The structural properties and chemical composition of the epitaxial thin films are characterized by surface X-ray diffraction (SXRD), X-ray photoelectron spectroscopy (XPS) and confocal Raman microscopy (CRM). Apart from this, the magnetic properties of the samples are examined by a magneto-optic Kerr effect (MOKE) system in ultra-high vacuum (UHV). With this study we present not only a broad characterization of these epitaxial Fe3O4 samples, but also investigate the correlation between magnetic, morphological and structural properties as a function of the temperature deposition and how this could affect for the progress of future spintronic devices.

References [1] A. Muñoz-Noval, J. Rubio-Zuazo, E. Salas-Colera, A. Serrano, F. Rubio-Marcos, G. R. Castro, Appl.

Surf. Sci., 355, (2015), 698-701.

[2] A. Pratt, M. Kurahashi, X. Sun, D. Gilks, and Y. Yamauchi, Phys. Rev. B, 85, (2012) 180409.

Figures

Figure 1. (a) Optical images of the sample grown at 900 °C; (b) In-plane Raman intensity image obtained from mapping the region marked with a red square in Figure A, measuring different single Raman spectra taken each 100 nm with an integration time of 0.5 s.

Spectral ranges from 629 to 742 cm-1 for Fe3O4 triangular terraces (red color) and from 195 to 486 cm-1 for SrTiO3(111) contribution (soft blue color) were integrated to obtain the Raman intensity image; (c) Average Raman spectra obtained from in-plane Raman image; (d) Reciprocal space map evidencing an incommensurable growth along (111).

Improving the Filler Dispersion in Polymer Nanocomposites with Cellulose Nanocrystals Worarin Meesorn, Anuja Shirole, Dimitri Vanhecke, Lucas Montero de Espinosa and Christoph Weder Adolphe Merkle Institute, University of Fribourg, Chemin des Verdiers 4, 1700 Fribourg, Switzerland worarin.meesorn@unifr.ch Abstract Cellulose nanocrystals (CNCs) have been widely used as a reinforcing component in polymer [1, 2] nanocomposites due to their ability to form percolation networks within a variety of matrices . Above the percolation threshold, the stress-transfer process is thought to be facilitated by CNC-CNC interactions resulting from hydrogen bonding between their surface hydroxyl groups. However, CNC aggregation can take place at high concentrations, which limits the amount of CNCs that can be added to a polymer and the potential reinforcement. With the aim of tackling this problem, we sought to explore the possibility of including a third component in polymer/CNC nanocomposites with the goal to improve the dispersion of CNCs at high filler contents.

Taking a well-known poly(ethyleneoxide-co-epichlorohydrin) (EO-EPI)/CNC nanocomposite as a model, we explored the effect that small amounts of poly(vinyl alcohol) (PVA) have on the mechanical properties of the composites. This design was based on the assumption that PVA would interact with the CNCs through hydrogen bonding and prevent their aggregation and possibly also act as a hydrogen bonding binder, enhancing CNC-CNC stress-transfer. Indeed, the incorporation of small amounts (1 Âą 5% w/w) of PVA into the EO-EPI/CNC nanocomposites produced a significant enhancement of the mechanical properties for compositions with a CNC concentration above 10% w/w, i.e., above the percolation threshold, in comparison with the EO-EPI/CNC nanocomposite made without PVA. The highest strength and stiffness were obtained for composites with a PVA content of 5% w/w. Laser scanning microscopy (LSM) was used to probe the mechanistic hypothesis by labelling PVA and CNCs with fluorophores known to be capable of fluorescence resonance energy transfer (FRET) and analyzing the resulting EO-EPI/CNC nanocomposites with and without PVA. The LSM data suggest that PVA and CNCs are indeed co-localized and that this results in CNCs being more evenly distributed within the polymer matrix.

References [1] J.R. Capadona, K. Shanmuganathan, D. Tyler, S.J. Rowan, C. Weder, Science. 2008, 319, 13701374.

[2] K. Shanmuganathan, J.R. Capadona, S.J. Rowan, C. Weder, Prog. Polym. Sci. 2010, 35, 212-222.

Figures

Schematic representation of the proposed system for PVA-enhanced mechanical properties of EOEPI/CNC nanocomposite.

Optical characterization of graphene doped liquid crystalline matrix using z-scan technique 1 2 1 Parsa Haji Adineh Ali Maleki , Hossein Jamali 1

2

The educational center for exceptional talentes, Iran; Kharazmi University, Iran maleki.ali20@gmail.com

Abstract The nonlinear optical properties of a liquid crystal mixture doped with different concentration of graphene nanoplates has been studied. The nonlinear refractive index (n 2) of guest-host system has been obtained by using Z-scan technique with continuous wave, He:Ne laser beam at 632.8 nm. The experimental results of the optical experiments have been shown that Graphene doped the liquid crystal includes the positive sign for n2 which presents self-focusing optical nonlinearity. Also, the results have -5 been revealed the striking values for different mass percentages of guest materials in order of 10 2 cm /w.

References [1] Saievar Iranizad E, Dehghani Z and Nadafan M, J. Mol. Liq. 190, 2014 [2] Imran A, Badran H and Hassan Q, J. Eng. 04 , 2014 [3] Neeraj and Raina K K, J.Opt. Mater. (Amst). 35, 2013

Figures

Functional microcapsules with inorganic-organic thick shells using sol-gel chemistry David G. Moore, Jonathan Brignoli, Thierry Moser, Patrick A. RĂźhs, AndrĂŠ R. Studart ETH ZĂźrich, Vladimir-Prelog-Weg 5, ZĂźrich, Switzerland david.moore@mat.ethz.ch Abstract One of the challenges in encapsulation is to independently control the chemical and mechanical properties of the microcapsule shells. For instance, for some encapsulations it may be desirable to achieve chemical protection of the encapsulant from oxidative [1] or irradiative stresses [2] via the addition of protective agents to the shell. But, the addition of such materials often affects the mechanical properties of the shell as well as the rheological and interfacial properties of the shell precursor, and therefore the encapsulation process. Through a sol-gel method, we propose a technique for forming microcapsules with inorganic-organic hybrid shells, which can be independently tuned for mechanical and chemical properties by adjusting the organic and inorganic precursors, respectively.

A silane-functionalized poly(propylene) glycol macromonomer was selected due to its optical transparency, wide range of solubility, low cost, and biodegradability/biocompatibility. For bulk tests the macromonomer was simply cast as a film and exposed to humidity for several hours. By varying the molecular weight or degree of functionalization, one can achieve two orders of magnitude variation in WHQVLOH VWUHQJWK DQG <RXQJÂśV PRGXOXV 0HDQZKLOH WKH DGGLWLRQ RI LQRUJDQLF sol-gel precursors such as tetraethyl orthosilicate (TEOS) or titanium (IV) isopropoxide (TIP) had no effect on mechanical properties. Additionally, because the polymer mesh size is defined by the molecular weight of the macromonomer, the gel has predictable permeability for encapsulants of known hydrodynamic radius.

It was also found that these sol-gel precursors could gel in-situ using oil-templated techniques. A capillary microfluidic approach was used to form w/o/w double emulsion templates that are in turn converted into mirocapsules [3]. Macromonomer was dissolved in oils that may diffuse through water, such as dichloromethane, chloroform, or toluene. After 24 hours of exposure to water, the polymers have gelled and the oil has diffused away leaving behind a transparent, inorganic-organic hybrid shell microcapsule. Addition of inorganic precursors such as TEOS or TIP was investigated for the addition of chemical functionality to the shell. The wide range of sol-gel chemistries and silane-functionalized poly(propylene) glycol monomers available makes the proposed method a powerful route for the preparation of microcapsules with tunable chemical and mechanical properties.

References [1] M.K. Reddy et al., Appl. Biochem. Biotechnol., 151 (2008), 565Âą577.

[2] Z.Z. Li et al., J. of Controlled Release, 111 (2006), 81-88.

[3] A.S. Utada et al., Science, 308 (2005), 537-541.

Figures

Figure 1. Siloxane-crosslinked poly(propylene glycol) gels produce flexible, optically transparent elastomers. These gels form in the presence of water through a hydrolysis/condensation reaction. a) synthesis of macromonomer, b) gelation reaction, c) a transparent flexible elastomer is formed.

Nucleation of Sm and Dy on graphene on Ir(111) D. Mousadakos∗ , M. Pivetta, S. Rusponi and H. Brune Institute of Physics, Ecole Polytechnique Fédérale de Lausanne,1015 Lausanne, Switzerland ∗ dimitris.mousadakos@epfl.ch

Abstract The fabrication of cluster arrays has drawn a lot of attention the last decades. Clusters, due to their reduced size, display unique properties unseen in the atomic scale or in the bulk state [1]. In nanotechnology, cluster arrays have become very popular because of their potential in the magnetic storage media, catalysis and bio-sensing applications. One way of fabricating cluster arrays with bottom-up approach is to deposit atoms from gas phase onto a template, where the particles diffuse and aggregate on specific sites, forming a periodic array. The graphene (Gr) moiré pattern [2], arising from the lattice mismatch between Gr and single crystal surfaces, represents one of the densest templates for this purpose. Here we use this template to grow cluster superlattices of rare earths. Our work is focused on the nucleation of Samarium (Sm) and Dysprosium (Dy) on Gr/Ir(111). For Sm we obtain ordered superlattices for deposition temperatures between 90 K and 110 K, while Dy clusters never form periodic arrays.

References [1] K.-H. Meiwes-Broer, “Metal clusters at surfaces: Structure, quantum properties, physical chemistry,” (Springer Berlin Heidelberg, Berlin, Heidelberg, 2000) Chap. Electronic Level Structure of Metal Clusters at Surfaces, pp. 151–173.

[2] J. Coraux, A. T. N’Diaye, C. Busse, and T. Michely, Nano Lett. 8, 565 (2008).

Ring Opening Metathesis Polymerization of Cyclopentene Using a Ruthenium Catalyst Confined by a Branched Polymer Architecture Clément Mugemana a

a&b

a

c

a

, Konstantin V. Bukhryakov , Olivier Bertrand , Khanh B. Vu , Jean-François c a a Gohy , Nikos Hadjichristidis and Valentin O. Rodionov

Kaust Catalysis Center and Division of Physical Sciences and Engineering, King Abdullah University of Science and Technology, Thuwal, 23955-6900, Kingdom of Saudi Arabia b Adolphe Merkle Institute, Macromolecular Chemistry, Chemin des Verdiers 4, 1700 Fribourg, Switzerland c Université Catholique de Louvain, Institute of Condensed Matter and Nanosciences (IMCN), Bio and Soft Matter (BSMA), Place Louis Pasteur 1bte L4.01.01-1348, Louvain-la-Neuve, Belgium clement.mugemana@unifr.ch Abstract

Multi-arm polystyrene stars functionalized with Grubbs-type catalysts in their cores were synthesized and used for the ring-opening metathesis polymerization (ROMP) of cyclopentene. [1-2] The spatial confinement of the catalytic sites and the nanoscale phase separation between polystyrene and the growing polypentenamer chains lead to a dramatic inhibition of the ROMP termination and chain transfer steps (Figure 1). Consequently, cyclopentene polymerizations proceeded fast and with a high degree of conversion even in air. The Grubbs second generation catalyst was oxidatively inactivated under the same conditions. In contrast to conventional small molecule catalysts, the ultimate degree of conversion of the cyclopentene monomer and the polydispersity of the product polypentenamer are not affected by the temperature. This indicates that spatial confinement of the catalyst results in a significant change in the activation parameters for the alkene metathesis ring opening.

Figure 1. Representative scheme of the polymerization of cyclopentene using the star polymer functionalized with Grubbs Catalyst. [1] References [1] C. Mugemana, K.V. Bukhryakov, O. Bertrand, K.B. Vu, J.F. Gohy, N. Hadjichristidis and V.O. Rodionov, Polym. Chem. 7 (2016) 2923.

[2] K.V. Bukhryakov, C. Mugemana, K.B. Vu and V.O. Rodionov, Org. Letter. 17 (2015) 4826.

Polymer nanocomposites with cellulose nanocrystals functionalised with 2-ureido-4[1H]pyrimidinone

Jens Natterodt, Janak Sapkota, Christoph Weder Adolphe Merkle Institute, University of Fribourg, Chemin des Verdiers 4, 1700, Fribourg, Switzerland jens.natterodt@unifr.ch Cellulose nanocrystals (CNCs) are mechanically rigid, toxicologically benign, fiber-like nanoparticles, which can easily be extracted from renewable bio-sources and have attracted significant interest as a reinforcing filler in industrially produced polymers [1]. The polar nature of CNCs makes it however difficult to compound these particles with nonpolar polymers; indeed the thermodynamic immiscibility promotes the formation of micro- or macro-phase separated mixtures, unless very particular processing approaches are employed to circumvent this problem [2]. Alternative solutions include the functionalization of CNCs with non-polar surface groups [3], or decorating them with compatibilizing surfactants or polymers [3]. However, neither of these methods is universal, usually the reinforcing capability is reduced, and additional and sometimes complex and non-scalable processing steps are required. We have explored the use of the 2-ureido4[1H]pyrimidinone (UPy PRWLI DV ³XQLYHUVDO´ FRPpatibilizer for CNCs. Indeed, we show that UPy-modified CNCs [4] can be readily dispersed in nonpolar (toluene) as well as polar (dimethyl formamide) solvents, on account of morphing interactions: in the former solvent, the UPy motifs appear to form intra-CNC dimers, and LQ WKLV VWDWH WKH SDUWLFOHV DSSHDU WR E\ ³K\GURSKREL]HG´ DQG ZHOO-dispersible in a nonpolar environment. By contrast, the UPy motifs appear to dissociate in DMF and promote dispersibility through interactions with this polar solvent. We have exploited this feature to integrate UPy-modified CNCs into various host polymers and report on the mechanical properties of these materials.

References [1] Moon, R. J.; Youngblodd, J.; Chem. Soc. Rev. 2011, 40, 3941.

[2] Sapkota, J.; Jorfi, M.; Weder, C.; Foster, J. Macromol. Rapid Comm. 2014, 35, 1747.

[3] de Menezes, A. J. ; Siqueira, G.; Curvelo, A. A. S.; Dufresne, A. Polymer 2009, 50, 4552.

[4] Biyani, M.; Foster, J.; Weder, C. ACS Macro Lett. 2013, 2, 236.

Characteristics of strong glass formers in charged microgel systems Nazzani F., Trappe V. University of Fribourg, Department of Physics, Chemin du MusĂŠe 3, Fribourg, Switzerland veronique.trappe@unifr.ch For molecular glass formers the dependence of the structural relaxation time on temperature strongly depends on the type of material used, which has led to the classification of strong and fragile deviates from a glasses. Fragility expresses here by how much the temperature dependence classical Arrhenius behavior. In strong glasses the system exhibits typical Arrhenius behavior, i.e increases exponentially upon approach of the glass transition temperature Tg. By contrast, in fragile diverges critically at Tg. Hard sphere colloidal systems are typical examples of fragile glasses glasses, the parameter governing the glass transition being here the particle concentration. In this contribution we show that charged permeable colloids can exhibit the characteristics of strong glass formers. This is, however, not due to attractive trapping like in molecular systems, but rather to a repulsive particle interaction that decreases with increasing particle concentration.

N-doped graphene: polarization effects and structural properties 1

2

Mehdi Neek-Amal , H. Ghorbanfekr , F. M. Peeters

2

1

Department of Physics, Shahid Rajaee Teacher Training University, 16875-163, Lavizan, Tehran, Iran.

2

Department of Physics, Universiteit Antwerpen, Groenenborgerlaan 171, B-2020 Antwerpen, Belgium.

Structural and mechanical properties of N-doped graphene (NG) are investigated using ReaxFF potentials in large scale molecular dynamics simulations. We found that ripples, which are induced by the dopants, changes the roughness of NG which depend on the number of dopants and their local arrangement. For any doping ratio N/C the NG becomes ferroelectric with a net dipole moment. The formation energy increases non-linearly with N/C ratio, while the Young's modulus, tensile strength and intrinsic strain decreases with the number of dopants. Our results for the structural deformation and the thermo-electricity of the NG sheet are in good agreement with recent experiments and ab-initio calculations.

The Mechanoresponsive Nature of Metallosupramolecular Polymers 1

1

1

1

1

1,2

L. Neumann , D. W. R. Balkenende , S. Coulibaly , S. Schrettl , B. Wilts , Y. Simon , C. Weder

1

1

Adolphe Merkle Institute, University of Fribourg, Chemin des Verdiers 4, 1700 Fribourg, Switzerland 2 Polymer Science Research Center, University of Southern Mississippi, USA laura.neumann@unifr.ch

Abstract The design principles of natural materials are frequently exploited to furnish artificial materials with tailored properties such as a responsiveness to mechanical stimuli. In these mechanoresponsive materials, a macroscopic mechanical force is translated into a chemical change on the molecular 1 level. Metallosupramolecular polymers are attractive candidates as mechanoresponsive materials, due to their reversible assembly into dynamic structures and the tunable interaction strength of the 2 binding motif that can be adjusted through a variation of the metal or ligand. We aim to prepare mechanically responsive materials based on metallosupramolecular polymers and investigate their behavior under stress from the macroscopic down to the molecular level.

Thus, polymeric networks were made by the coordination of metal ions to a telechelic poly(ethylene2,3 co-butylene) that was end-capped with methylbenzimidazolyl pyridine ligands.

Europium- and terbium-based supramolecular polymer films were successfully welded by ultrasonication as a means of mechanical stimulation and the interface of joined pieces was investigated by energy-dispersive Xray spectroscopy to elucidate the diffusion of metals (Figure 1A). Moreover, telechelic polymers carrying ligands with extended were prepared to allow better analysis of the (dis)assembly of the metal-ligand complexes upon application of mechanical forces. Upon addition of europium the bright blue fluorescence of the unbound ligands is replaced by the red fluorescence of the europium-based metal-ligand complexes in solution as well as the solid state (Figure 1B). Application of ultrasound to solutions of the metallosupramolecular polymers resulted in a temporary decrease of the europium fluorescence, indicating the transient disassembly of the metal-ligand complexes. Investigating how these supramolecular polymers respond to mechanical stimuli in solution and in the solid state is envisioned to provide a detailed understanding of their mechanochemistry.

References [1] J. Li, C. Nagamani, J.S. Moore, Acc. Chem. Res. 48, (2015) 2181.

[2] D.W.R. Balkenende, S. Coulibaly, S. Balog, Y.C. Simon, G.L. Fiore, C. Weder, J. Am. Chem. Soc. 136 (2014) 10493.

[3] M. Burnworth, L. Tang, J.R. Kumpfer, A.J. Duncan, F.L. Beyer, G.L. Fiore, S.J. Rowan, C. Weder, Nature, 472 (2011), 334.

Figure

Figure 1: (A) Mechanochemical welding of europium- and terbium-lap joints and investigation of the welded interface. (B) Fluorescence of a Ę&#x152;-extended ligand in solution, the solid state, and upon application of ultrasound.

High throughput microfluidic glass devices to form functional materials 1

1

1

2

Alessandro Ofner , David G. Moore , Pascal Schwendimann , Maximilian L. Eggersdorfer , Esther 3 2 1 1 Amstad , David A. Weitz , Patrick A. Rühs , André R. Studart 1

2

Complex Materials, Department of Materials, ETH Zurich, 8093 Zurich, Switzerland School of Engineering and Applied Sciences, Harvard University, Cambridge MA 02138, USA 3 Institute of Materials, EPF Lausanne, 1015 Lausanne, Switzerland alessandro.ofner@mat.ethz.ch

High-throughput production of monodisperse droplets is essential for industrial and scientific applications, such as in the fields of diagnostics, pharmaceutics, cosmetics, materials, and food science. In order to increase the throughput of microfluidic devices, parallelization of a large number of droplet makers is needed. However, up to now, such parallelized devices are limited by either their complicated channel geometry or by their chemically or thermally unstable embedding material.

Here we show a novel, scalable microfluidic step emulsification chip in glass with 364 linearly parallelized droplet makers. The geometry of this device consists of two 120 µm deep channels, which are connected through an array of linearly-ordered 20 µm high nozzles with wedge-shaped droplet makers (Fig. 1) [1]. In this design, the droplets are formed at the step between each nozzle and the continuous phase channel [2-3]. Our microfluidic glass devices are produced using a simple and efficient technique comprising photolithographic, etching, and bonding steps.

The device enables the production of emulsions at a throughput of up to 25 ml/h with a coefficient of variation lower than 3 %. The chemical stability of glass as embedding material allows for the production of a broad variety of functional materials by using any desired solvent together with nanoparticles, polymers, and hydrogels. In addition, the thermal stability of glass enables emulsification at higher temperatures, which opens the possibility to produce microparticles of materials that are solid at room temperature or to increase the throughput by lowering the viscosity (Fig. 2). Moreover, the microfluidic device can be stringently cleaned and recycled through chemical treatment or by heating of the glass chip to 600 °C. This provides the ability to renew our microfluidic device for nearly unlimited use. All in all, the combined benefits of our microfluidic chip facilitate the production of a broad variety of new materials at high throughput.

[1] Amstad E. et al., Patent WO2014186440-A2 - WO2014186440-A3 (2015) [2] Dangla R. et al., Journal of Physics D: Applied Physics, 46 (2013), 114003 [3] Sugiura S. et al., Langmuir 17 (2001), 5562

Fig. 1 (left): Schematic of a step emulsification channel arranged with parallelized droplet makers (a) and an actually working device producing monodisperse oil-in-water droplets (b).

Fig. 2 (right): Functional emulsions and microparticles generated in chemically (a,b) and thermally (c,d) compatible microfluidic glass chips.

Stimuli-responsive Pt

(0)

containing metallosupramolecular polymers

Luis Olaechea, Lucas Montero de Espinosa, Christoph Weder Adolphe Merkle Institute, University of Fribourg, Chemin des Verdiers 4 Fribourg, Switzerland, luismiguel.olaechea@unifr.ch Supramolecular polymers (SPs) are macromolecules formed by self-assembly of monomeric units via [1] non-covalent interactions such as H-bonding, metal-ligand complexation or ion pairing. SPs combine the physical properties of polymers and the advantages of dynamic supramolecular interactions, which also can impart stimuli-responsive behavior. Metallosupramolecular polymers (MSPs) represent a subclass of this materials family, in which chain extension takes place through coordination of multifunctional macroligands with metal salts.

(0)

[2]

Building on previous work on cross-linked Pt -containing MSPs, we have recently developed a synthetic framework for the synthesis of MSPs in which chain extension takes places through (0) (0) Pt (alkyne)2 complexes. These materials are prepared by fast ligand exchange between Pt (styrene)3 and a diphenyl acetylene-terminated telechelic core; for this study the low-glass-transition cores poly(ethylene-co-butylene) and poly(tetrahydrofuran) were selected.

Homogeneous films of the new polymer were solvent cast and characterized by transmission electron microscopy (TEM), small angle X-ray scattering (SAXS) and Fourier transform infrared spectroscopy (FTIR). Collectively, the techniques revealed nanophase segregation with no long range order and adequate stability under ambient conditions. Heating these materials over a characteristic threshold (0) (0) temperature causes the dissociation of the Pt (alkyne)2 complex, which leads to the formation of Pt nanoparticles in the polymer matrix as confirmed by TEM. The decomplexation kinetics were studied (0) using a model compound that mimics the thermally labile polymeric Pt (alkyne)2 complexes and it was observed that the threshold temperature for thermal decomplexation depends strongly on the ligand structure. Overall, this procedure presents a new approach to the preparation of Pt nanoparticles, which has significant practical advantages over previous protocols that involve the in situ reduction of a metal [3] salt.

[1] L. Yang, X. Tan, Z. Wang, X. Zhang, Chem. Rev., 115 (15) (2015), 7196Âą7239.

[2] A. Kokil, C. Huber, W. R. Caseri, C. Weder, Macromol. Chem. Phys., 204 (2003), 40-45.

[3] S.W. Lee, J.R. Kumpfer, P.A. Lin, G. Li, X.P.A. Gao, S.J. Rowan, R.M. Sankaran, Macromolecules, 45 Ă­

Heat

Thermoelectric Properties of Ca2.9M0.1Co4O9 (M = Li, Na, and K) and Ca3Co3.9N0.1O9 (N = Li, Na, and K) Fabricated by Spark Plasma Sintering Process 1

1

1

K. Park , A. Iqbal , J. S. Cha , and J. Kim

2

1

Faculty of Nanotechnology and Advanced Materials Engineering, Sejong University, Seoul 143-747, Korea 2

Department of Advanced Materials Engineering, Hoseo University, Asan 336-795, Korea Contact@E-mail: kspark@sejong.ac.kr

Abstract Thermoelectric modules are solid-state devices that directly convert thermal energy into electrical energy, based on the Seebeck effect. The key issue in thermoelectric modules is to develop materials whose thermoelectric properties are highly stable at high temperatures. Oxide based materials have attracted a significant attention for high-temperature thermoelectric applications, due to their high thermal and chemical stability [1]. In particular, Ca3Co4O9 has been recognized as a good candidate for high-temperature thermoelectric applications. The Ca3Co4O9 has a layered structure consisting of two monoclinic subsystems, CaO±CoO±CaO rock salt-type layer and CdI2-type CoO2 layer, stacked along the c-axis direction [2]. In this study, polycrystalline Ca2.9M0.1Co4O9 (M = Li, Na, and K) and Ca3Co3.9N0.1O9 (N = Li, Na, and K) samples were fabricated by spark plasma sintering process using the Ca2.9M0.1Co4O9 and Ca3Co3.9N0.1O9 powders prepared by sol±gel method. XRD patterns were in good accordance with Ca3Co4O9 (JCPDS card No. 21-0139), indicating that the prepared samples are in Ca3Co4O9 type symmetry. The electrical conductivity increased with increasing temperature in the whole temperature range, indicating the semiconducting behavior. The sign of the Seebeck coefficient was positive for the entire measured temperature range, indicating that the major conductivity carriers are holes. The Seebeck coefficient increased with an increase in temperature. The power factor and figureof-merit of the Ca2.9M0.1Co4O9 and Ca3Co3.9N0.1O9 increased with an increase in temperature, implying high thermal stability at high temperatures. The effects of substitution of alkali metal elements (Li, Na, and K) for Ca and Co on the thermoelectric properties were systematically investigated in an attempt to achieve a further improvement in the thermoelectric performance of the material.

References [1] Rezaul Kabir, Tianshu Zhang, Danyang Wang, Richard Donelson, Ruoming Tian, Thiam Teck Tan, and Sean Li, J. Mater. Sci., 49 (2014) 7522±7528.

[2] S. Pinitsoontorn, N. Lerssongkram, A. Harnwunggmoung, K. Kurosaki, S. Yamanaka, J. Alloys Compd. 503 (2010) 431±435

³,Q-VLWX´ V\QWKHVLV RI 7L& UHLQIRUFLQJ QDQRSDUWLFOHV LQVLGH DOXPLQLXP PDWUL[ IURP QDQRGLDPRQG and titanium precursors during mechanical alloying V.A.Popov 1DWLRQDO 8QLYHUVLW\ RI 6FLHQFH DQG 7HFKQRORJ\ ³0,6,6´ /HQLQVN\ SURVSHFW 0RVFRZ 5XVVLD Popov58@inbox.ru Abstract The development of new, advanced materials, including metal matrix composites with reinforcing nanoparticles, has been a focus of ongoing research to increasing the quality and the service life of various products. However, one of the problems impeding the wide application of these materials is the presence of foreign inclusions and contaminants on the nanoparticle surface because the surface corresponds to the interface between the reinforcing particles and the metal matrix. Despite their low levels, these contaminants can significantly decrease the adhesive strength between the composite components. Casting technologies lead to the absence of wettability, preventing the regularly spaced distribution of the reinforcing particles during melting, ultimately leading to their removal from the alloy.

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nanoparticles inside an aluminium matrix by mechanical alloying was examined. Commercially available nanodiamonds [1-3] produced by detonation synthesis and titanium powder served as the starting materials for the nano-carbides synthesis. Commercially available aluminium powder was used to generate the matrix. Mechanical alloying was carried out in Retsch PM400 planetary mills in an argon atmosphere, without using surfactants, in sealed steel grinding jars of 500-ml nominal volume. The initial materials were treated using chromium steel milling balls 12 mm in diameter. The ratio of the weight of the balls to that of the treated mixture (charge ratio) was 7:1. The rotational speed of the carrier was 300 rpm. The grinding jars were air-cooled during the operation. To prevent strong overheating, the mill was stopped for 5 min for each 10 min of operation. The real time, without accounting for stops, was considered to be the treatment time. The duration of treatment was 8 h. The mechanically alloyed granules were investigated by X-ray diffractometry (XRD), scanning electron microscopy (SEM) and differential scanning calorimetry (DSC). The DSC was carried out at a Netzsch 404 C instrument in platinum crucibles; a dynamic inert atmosphere (argon; blowdown rate, 70 ml/min) was maintained. The XRD was performed on a Bruker D8 ADVANCE diffractometer in PRQRFKURPDWL]HG &X.ÄŽ UDdiation (with the diffracted-beam monochromator). Morphology of composite granules surface was investigated with Zeiss Supra 25 scanning electron microscope.

The investigations indicated that the synthesis of the nanoparticles proceeded to completion. The XRD patterns showed only aluminium and titanium carbide peaks. No peaks from residual titanium were observed; in addition, no products from an aluminium-titanium reaction and no other compounds were observed. Therefore, the obtained composite granules consist of the aluminium matrix and reinforcing titanium carbide particles. The results of the granule structure investigation using SEM reveal that the titanium carbide particles have a regularly spaced distribution in the aluminium matrix, and their sizes range from 10 to 30 nm. Thus, they can be classified as nanoparticles. The DSC curve shows that chemical reactions between the titanium carbide nanoparticles and the aluminium alloy begin at temperatures higher than 750 Â&#x192;É&#x2039; ,Q FRQFOXVLRQ PHFKDQLFDO DOOR\LQJ DOORZV H[HFXWLQJ ÂłLQ-VLWX´ V\QWKHVLV RI WLWDQLXP FDUELGH QDQRSDUWLFOHV LQVLGH DOXPLQLXP PDWUL[ DQG GHYHORSLQJ Âł$O QDQR-7L&´ FRPSRVLWH PDWHULDO ZLWKRXW WKH occurrence of unwanted chemicDO UHDFWLRQV DV PLQLPXP XS WR Â&#x192;É&#x2039; The research leading to these results has received funding from the Ministry of Education and Science of Russian Federation under the project number 14.587.21.0030 (identifier RFMEFI58716X0030).

References [1] V.A.Popov, E.V.Shelekhov, E.V.Vershinina. European Journal of Inorganic Chemistry, 2016, V.2016, Is.13-14, pp. 2122-2124.

[2] 9ODGLPLU 3RSRY 'DQLHO 7|EEHQV $OH[H\ 3URVYLU\DNRY Phys. Status Solidi A 211, No. 10, 2353Âą 2358 (2014) / DOI 10.1002/pssa.201330662 [3] V. A. Popov, A. V. Egorov, S. V. Savilov, V. V. Lunin, A. N. Kirichenko, V. N. Denisov, V. D. Blank, O. M. Vyaselev, and T. B. Sagalova. Journal of Surface Investigation. X-ray, Synchrotron and Neutron Techniques, 2013, No.6 1034-1043

Amplitude- and Phase-Resolved Infrared Imaging of 2D Materials Miriam Unger1,2, Honghua Yang1, Eoghan Dillon1, Kevin Kjoller1 and Craig Prater1 1 2

Anasys Instruments, Santa Barbara, California 93101, USA Physical Electronics GmbH, 85737 Ismaning, Germany munger@phi-europe.com

Surface plasmon polaritons (SPPs) and surface phonon polaritons (SPhPs) in 2D materials, with their high spatial confinement, can open up new opportunities for enhanced light-matter interaction, super lenses, subwavelength metamaterials, and novel photonic devices. In situ characterization of these polaritonic excitations in different applications requires a versatile optical imaging and spectroscopy tool with nanometer spatial resolution.

Through a non-invasive near-field light-matter interaction, scattering-type scanning near-field optical microscopy (s-SNOM) provides a unique way to selectively excite and locally detect electronic and vibrational resonances in real space. By collecting scattered light from the area underneath the atomic force microscope (AFM) tip, local optical properties of the sample can be measured with spatial resolution limited by the tip radius of ~20nm. The full near-field optical response of the polaritonic resonances can be measured with phase resolved detection, providing both amplitude and phase information.

Here we demonstrate the technique by imaging both SPhPs on hexagonal boron nitride (hBN) and SPPs on graphene with tunable QCL and CO2 laser sources. Amplitude and phase near-field optical images provide complementary information for characterizing the complete polaritonic resonances.

Phase shifts >90° for SPhPs are observed on hBN, indicating strong light-matter coupling.

By integrating with broadband and ultrafast light sources, sSNOM can be further used to study nonlinear properties associated with these polaritonic resonances.

The role of hopping energy of electrons in graphene on bangap of a periodic graphehedielectric structure Ali Rashedi, , Amir Hosein Molaee, Ali Maleki, Dariush Jahani Photonics Lab, Kharazmi University, Tehran, Iran dariush110@gmail.coml Abstract The effect of hoping energy on the electromagnetic wave propagation of 1D photonic structure which is formed by embedding alternative graphene layers, a 2D carbonic material with a honeycomb lattice, into a dielectric background is investigated. By using the complete expression of the tight-binding Hamiltonian of graphene layer, we numerically show that the hopping parameter can significantly affect the corresponding bandgap of the structure. Our study could be extend to different frequency region of electromagnetic spectrum.

Noticeable effects also due to the changing the amount of doping which in turn leads to changing the amount of chemical potential are obtained in the numerical part. It is clear that increasing the amount of chemical potential leads to creating wider bandgap. The other aspect of our research is finding out the effect of enhancing hopping energy which gives wider bandgap which by shrinking the layers of SiO_{2} as a dielectric background, the location of the bandgap will be in the upper part of the spectrum range of light.

Noticing the feasibility of various graphene applications in high-frequency range devices besides lack of the acceptable number of the performed research on the optical conductivity of the above mentioned type of photonic crystal beyond the Dirac approximation in graphene, motivate us to take step in this way. Below, just for abstract reviewing, we show two figures in this regards which shows bandgabs as a function of wavelength of electromagnetic waves.

References [1] E. Yablonovitch, Phys. Rev. Lett. 58 (1987) 2059.

[2] S. John, Phys. Rev. Lett. 58 (1987) 2486.

[3] J.D. Joannopoulos, S.G. Johnson, J.N. Winn, R.D. Meade, Photonic Crystals: Molding the Flow of Light, second ed., Princeton University Press, Princeton, NJ, 2008.

[4] T. Stauber, N.M.R. Peres, A.K. Geim, Phys. Rev. B 78 (2008) 085432.

Figures

left: the effect of decreasing the hopping. Right:The effect of increasing the amount of chemical potential with the same Hoping t = 2.7 eV on the temperature range related to altering the sign of Im(KB) is depicted

Functionalization of titanate nanostructures for bioapplications Paul Rouster, Marko Pavlovic, Istvan Szilagyi Department of Inorganic and Analytical Chemistry, University of Geneva, 30 quai Ernest Ansermet, CH-1205, Geneva, Switzerland paul.rouster@unige.ch Over the past decades, titania has been widely used in many applications namely implants, SKRWRFDWDO\VLV GUXJ GHOLYHU\ HWFÂŤ It has actually demonstrated to be useful for bioapplications as titania is biocompatible and after surface modification, it can present specific bioactivity. However, until now, titania has mostly been used as nanoparticles whereas only little attention has been paid to other structures (i.e. nanowires, nanosheetsÂŤ). More interestingly, in some cases, the use of titania nanosheets (TNS) instead of titania nanoparticles even led to an improvement of the materials properties[1]. For example, in drug delivery, the colloidal stability of the TNS is an important issue[2].

Indeed, the suspension must be stable (and the particles should not aggregate) in order to allow the TNS to act as nanocarriers.

Here we synthesized TNS (Figure 1) using a hydrothermal treatment. The chemical structure and properties of the synthesized TNS were characterized to ensure the formation of anatase. The adsorption of polyelectrolytes on the TNS (Figure 1) allowed to tune and tailor their properties (charge, PRELOLW\ DJJUHJDWLRQ UDWHÂŤ Electrophoretic mobility and colloidal stability measurements were performed to determine the appropriate dose of polyelectrolytes needed to functionalize the TNS as well as the conditions under which the colloidal suspension is stable. Moreover, the polyelectrolyte coating led to a charge reversal of the nanosheets and to the enhancement of their stability. Therefore, polyelectrolyte functionalized TNS appear to be a method of choice to obtain stable TNS suspensions prior to their use as nanocarriers.

References [1] Wang, Z.; Lv, K.; Wang, G.; Deng, K.; Tang, D. Applied Catalysis B-Environmental 2010, 100, 378.

[2] Pavlovic, M.; Adok-Sipiczki, M.; Horvath, E.; Szabo, T.; Forro, L.; Szilagyi, I. Journal of Physical Chemistry C 2015, 119, 24919.

(a)

1000

(b)

TNS-PDADMAC TNS-P(AAm-co-DADMAC)

Stability ratio

100

10

1

0.001

0.01

0.1

1

10

100

1000

Polyelectrolyte dose (mg/g)

Figure 1. Transmission electron microscope image of a TNS (a) and stability ratio of PDADMAC and P(AAm-co-DADMAC) coated TNS (b). Please note that the values close to one correspond to fast aggregation of the particles while higher values indicate more stable systems.

Supramolecular polymer solids with orthogonal binding motifs Julien Sautaux, Sandor Balog, Lucas Montero de Espinosa, Christoph Weder Adolphe Merkle Institute, University of Fribourg, Chemin des Verdiers 4, 1700, Fribourg, Switzerland julien.sautaux@unifr.ch Abstract Supramolecular polymers (SPs) are formed by self-assembly of monomeric units that are connected by dynamic non-covalent interactions such as hydrogen bonding, metal-ligand coordination, ionic interactions, ʌ-ʌ stacking, or host guest interactions. The reversibility of these bonds can be exploited to disassemble SPs back into their monomeric species, which can be achieved in a controlled manner by the application of specific stimuli including temperature, light or mechanical force. Most stimuliresponsive materials are based on a single type of supramolecular interaction; however, the combination of multiple (orthogonal) supramolecular interactions in one material in principle allows creating multi-responsive polymers, i.e., materials that respond to different stimuli with different property changes. While the orthogonality of a number of supramolecular binding motifs has been already demonstrated for several polymeric systems in solution,[1] very few reports have explored the potential of such interactions to create multi-responsive solid polymeric material.

Building on our group’s recent work on supramolecular polymers with orthogonal functionalities,[2] we have synthesized two supramolecular macromonomers based on a telechelic trifunctional polypropylene oxide (PPO) core displaying either metal-coordinating 2,6-bis(1’-methylbenzimidazolyl)pyridine (Mebip) ligands or hydrogen-bonding ureipyrimidinone (UPy) units as end groups. This contribution will discuss the properties of the supramolecular networks obtained by assembly of the individual macromonomers 2+ via (Mebip)2Zn or UPy-UPy interactions and compare them with those of the mixed material (Figure 1), which can be regarded as two interpenetrated supramolecular networks. The orthogonality of the supramolecular interactions in the blended system will be discussed on the basis of UV-Vis analysis, small-angle X-ray scattering (SAXS) and dynamic mechanical thermal analysis (DMTA). The results show that the thermoresponsive behavior of these materials is driven mainly by the phase segregation of the binding motifs into well-defined hard phases that introduce physical cross-links. The two supramolecular networks appear to be co-continuous and can be sequentially and selectively disassembled upon increasing the temperature.

References [1] Li, S.-L.; Xiao T.; Lin, C.; Wang, L. Chem. Soc. Rev., 41 (2012) 5950-5968.

[2] Coulibaly, S.; Heinzmann, C.; Beyer, F. L.; Balog, S.; Weder, C.; Fiore, G. L. Macromolecules, 47 (2014) 8487-8496.

Figure

Figure 1. Schematic representation of orthogonal supramolecular binding upon mixing of two supramolecular macromonomers.

Multimaterial magnetically assisted 3D printing of composite materials 1

1

Manuel Schaffner , Dimitri Kokkinis and AndrĂŠ R. Studart

1

1

Complex Materials, Department of Materials, ETH ZĂźrich, 8093 ZĂźrich, Switzerland

3D printing allows creating objects with unusual geometries. Recent developments demonstrate printing of multiple materials and indicate that the technology can potentially offer a much wider design space beyond unusual shapes. We show that a new dimension in the design space can be exploited through the control of the orientation of anisotropic particles used as building blocks during a direct ink-writing process. Low magnetic fields can be used to orient magnetized stiff platelets in the deposited inks. Multimaterial dispensers and a two-component mixing unit provide additional control over the relative composition (+1D) and spatial distribution (+1D) of building blocks in the printed layers. This five-dimensional design space covered by the proposed multimaterial magnetically assisted 3D printing platform (MM-3D printing) opens the way towards the manufacturing of functional heterogeneous materials with exquisite microstructural features thus far only accessible by biological materials grown in nature.

Reference [1] D. Kokkinis, M. Schaffner, A. R. Studart (2015), Nature communications, 6, 8643.

Active microrheology in an emulsion glass Nesrin ĂšHQELO, Chi Zhang, Frank Scheffold University of Fribourg, Department of Physics, Fribourg,Switzerland nesrin.senbil@unifr.ch Abstract

Active microrheology is an important phenomenon to understand the rheological properties of complex fluids. In our experiments we use a laser tweezer to drag a tracer particle through a dense oil-in-water emulsion. Emulsion particles with diameter of 2 micron and 10% polydispersity are prepared applying shear using a homemade couette cell[1]. The refractive index and density of the emulsion droplets are matched to the solvent, and tracer particles, the same size as emulsion particles, are added to the sample.

Using centrifugation the sample is quenched slightly above jamming transition. By careful dilution the experiments are then run at a point right below jamming transition, i.e. in the glass. To this end the sample is diluted in small steps to determine where the jamming transition occurs using dynamic light scattering. Applying constant force with optical tweezer we determine probability distribution of the tracer particle position and compare it to the theoretical model of Fuchs et al[2]. Our results are important to understand non-equilibrium systems and useful for transport phenomena in biological systems.

References

[1] [2]

Zhang, C., et al., Structure of marginally jammed polydisperse packings of frictionless spheres.

Physical Review E, 2015. 91(3): p. 6.

Gazuz, I., et al., Active and Nonlinear Microrheology in Dense Colloidal Suspensions. Physical Review Letters, 2009. 102(24): p. 4.

Combination of surface plasmon resonance and X-ray absorption spectroscopy: SPR-XAS setup A Serrano1,2, O RodrĂ­guez de la Fuente3, V. Collado1,2, J. Rubio-Zuazo1,2, C. Monton4, G R Castro1,2 and M A GarcĂ­a5,6 1 2

SpLine, Spanish CRG Beamline at the ESRF, F-38043 Grenoble, Cedex 09, France

Instituto de Ciencia de Materiales de Madrid, (ICMM-CSIC), Cantoblanco, 28049 Madrid, Spain 3

Dpto. de FĂ­sica de Materiales, Universidad Complutense de Madrid, 28040 Madrid, Spain

4 Department of Physics and Astronomy, University of Texas at San Antonio, One UTSA Circle, San Antonio, Texas 78249, USA 5 Instituto de CerĂĄmica y Vidrio, Consejo Superior de Investigaciones CientĂ­ficas, 28049 Madrid, Spain 6

,QVWLWXWR GH 0DJQHWLVPR $SOLFDGR Âľ6DOYDGRU 9HOD\RVÂś 8QLYHUVLGDG &RPplutense de Madrid, 28230 Madrid, Spain aida.serrano@esrf.fr

Abstract We present an experimental system to combine surface plasmon resonance and X-ray absorption spectroscopy: SPR-XAS setup [1,2]. The system allows the study of the interaction between electromagnetic radiation and matter using one type of radiation to modify the material and the other one as a probe, performing the study in real time and in situ. The surface plasmons, measured under the Kretschmann-Raether configuration [3], can be used to monitor in situ changes induced by the Xrays in the metallic film, the substrate and the top dielectric medium [4,5]. Similarly, the changes in the electronic configuration of the material when surface plasmons are excited can be measured by X-ray absorption spectroscopy [1]. The resolution of the system allows observing changes in the signals of the order of 10-3 to 10-5 depending on the particular experiment and used configuration. The device has been mounted at the SpLine BM25 beamline at ESRF in Grenoble, France, and it is currently available for experiments.

References [1] A. Serrano, O. RodrĂ­guez de la Fuente, V. Collado, J. Rubio-Zuazo, C. Monton , G. R. Castro and M. A. Garcia, Rev. Sci. Instrum., 83 (2012) 093102.

[2] A. Serrano, Modified Au-Based Nanomaterials Studied by Surface Plasmon Resonance Spectroscopy, Springer Theses (2015).

[3] H. Raether Surface Plasmons on Smooth and Rough Surfaces and on Gratings, (1988) Berlin: Springer.

[4] A. Serrano A, F. GĂĄlvez, O. RodrĂ­guez de la Fuente and M.A. Garcia, J. Appl. Phys. 113 (2013) 113104.

[5] A. Serrano, O. RodrĂ­guez de la Fuente, C. Monton, A. MuĂąoz-Noval, I. Valmianski, J. F. FernĂĄndez, G. R. Castro, Ivan K. Schuller and M. A. GarcĂ­a, J. Phys. D: Appl. Phys., 49 (2016) 125503.

Shape Memory Composites Based on Electrospun Poly(vinyl alcohol) Fibers and a Thermoplastic Polyether Block Amide Elastomer Anuja Shirole, Janak Sapkota, E. Johan Foster, and Christoph Weder Adolphe Merkle Institute, University of Fribourg, Chemin des Verdiers 4, 1700 Fribourg, Switzerland anuja.shirole@unifr.ch Abstract Shape memory polymers, which have the ability to return from a deformed state to their original shape through application of pre-defined stimulus (such as exposure to heat, chemicals, electrical current, and others) in a highly selective and reversible manner are generating great interest. Many design principles have been proposed and demonstrated to be useful to create such materials. One attractive approach is the exploitation of shape-memory composites that consist of two components in a co-continuous architecture. They typically include an elastic polymeric phase and a filler that is responsible for fixing the temporary shape, either due to a phase transition or the formation / break-up of a mechanically reinforcing network induced by the stimulus. One intriguing feature of shape-memory composites is that they display emergent properties, i.e., a characteristic behavior that is not found in either of the components alone. From an application point of view, the possibility to create novel materials with new properties from readily available components without the new chemistry is particularly attractive.

In this study, we report the fabrication of new thermally responsive shape-memory composites employing two widely used commercially available polymers and fabricated by a simple melt compaction process (Figure). Electrospun fibers mats of poly(vinyl alcohol) (PVA) were used as the switching element and thermoplastic polyether block amide elastomer (PEBA) were used as the rubbery matrix. Upon introduction of 10-20% w/w PVA fibers, the room-WHPSHUDWXUH VWRUDJH PRGXOXV (ƍ RI composites increased by a factor of 4-5 in comparison to the neat PEBA, and they reveal a stepwise UHGXFWLRQ RI (ƍ DURXQG WKH glass transition temperature of PVA. This transition was further utilized to demonstrate in both qualitative and quantitative manner, the emergent shape memory characteristics of the obtained composites.

References [1] Shirole,A.; Sapkota, J.; Foster, E. J; and Weder, C. Shape Memory Composites Based on Electrospun Poly(vinyl alcohol) Fibers and a Thermoplastic Polyether Block Amide Elastomer, ACS Appl. Mater. Interfaces, 2016, 8 (10), 6701±6708 [2] Hager, M. D.; Bode, S.; Weber, C.; Schubert, U. S.Shape Memory Polymers: Past, Present and Future Developments Prog. Polym. Sci. 2015, 49±50, 3± 33 [3] Robertson, J. M.; Birjandi Nejad, H.; Mather, P. T.Dual-Spun Shape Memory Elastomeric Composites ACS Macro Lett. 2015, 4, 436± 440

Figures

Electrospinning

PVA mat

Melt compaction

Composite

Schematic representation of the fabrication process of PVA fibers and PEBA/PVA composites.

Formation of enantioselective molecular structures on the PdGa:A(-1-1-1)Pd3 surface Stolz Samuel, Widmer Roland EMPA, nanotech@surface, Überlandstrasse 191, 8600 Dübendorf, Switzerland samuel.stolz@empa.ch.

Abstract Intermetallic PdGa has recently attracted considerable interest because of its high activity, selectivity, and stability in the catalytic semi-hydrogenation of ethyne [1], being an important step in the polyethylene production. Owing to its non-centrosymmetric bulk structure of the space group P213, PdGa exists in two enantiomeric forms A and B [2]. Investigating PdGa{111} surfaces, the stacking sequence in the [111] direction involves four nonequivalent atomic planes. As a consequence, the top and bottom surfaces are different: PdGa:A(111) is terminated by an atomic layer containing one isolated Pd atom per surface unit cell and accordingly this termination is denoted as Pd1, on the other side, PdGa:A(-1-1-1) reveals isolated Pd trimers and is thus denoted as Pd3 [3].

To probe the chirality of the Pd1 and Pd3 surfaces, 9-Ethynylphenanthrene (9-EP) which is a prochiral molecule is adsorbed on both surfaces. For the Pd1 surface a highly enantioselective adsorption with an enantiomeric excess of 98% is reported upon 9-EP evaporation at room temperature (RT) [4].

Adsorbing 9-EP at RT on Pd3 yields in a 1:1 ratio of left and right oriented molecules, thus no enantiomeric excess is observed. However, post-annealing to 500 K of the 9-EP on Pd3 results in the formation of new structures consisting of three 9-EP molecules in a propeller-like shape. 99.8% of the 9EP molecules forming the propellers are of the same enantiomeric form, thus 99.3% of all propellers are homochiral with an enantiomeric excess of 98.6%.

Further analysis of these propellers by STM reveal a voltage dependent protrusion in the center of the propeller, which might be explained by a sp2 hybridisation of the C=C-H bonds or by an electronic effect. Therefore, nc-AFM investigations with a CO functionalized tip were performed and will be compared to STM (see Fig. 1) and discussed.

References [1] Marc Armbrüster, Kirill Kovnir, Malte Behrens, Detre Teschner, Yuri Grin and Robert Schlögl, J. Am. Chem. Soc., 132 (2010) 14745-14747.

[2] Dirk Rosenthal, Roland Widmer, Ronald Wagner, Peter Gille, Marc Armbrüster, Yuri Grin, Robert Schlögl, and Oliver Gröning, Langmuir, 28 (2012), 6848-6856 [3] Jan Prinz, Roberto Gaspari, Carlo A. Pignedoli, Jochen Vogt, Peter Gille, Marc Armbrüster, Harald Brune, Oliver Gröning, Daniele Passerone and Roland Widmer, Angew. Chem. Int. Ed., 51 (2012), 9339-9343.

[4] Jan Prinz, Oliver Gröning, Harald Brune and Roland Widmer, Angew. Chem. 127 (2015), 3974-3978.

Figure 1: Comparison of 9-EP propellers on Pd3 between STM and nc-AFM STM

Nc-AFM

Sub-20 nm lift-off techniques without charged particle damage using Thermal Scanning Probe Lithography 2

1

2

2

1

1

ZhengMing Wu , Colin Rawlings , Simon Bonanni , Martin Spieser , Philipp Mensch , Siegfried Karg , Philip 2 1 1 1 2 Paul , Heiko Wolf , Urs Duerig , Armin Knoll , Felix Holzner 1 2 ,%0 5HVHDUFK Ă­ Zurich, 8803 Rueschlikon, Switzerland, SwissLitho AG, 8005 Zurich, Switzerland wu@swisslitho.com Abstract Charged particle beams for the fabrication of devices comprising sensitive nanowires or 2D materials can lead to unwanted influence or damage of electronic properties of the device [1, 2]. Still, electron beam lithography (EBL) in combination with lift-off is the most commonly used method to fabricate prototypes of such devices.

Thermal Scanning Probe Lithography (t-SPL) is an alternative mask-less lithography technique with similar speed (up to 20 mm/s) and resolution (10 nm half-pitch) as EBL, but without charged particles involved [3, 4].

In this poster, we present two recently developed lift-off techniques for t-SPL that have enabled the creation of sub-20 nm Au, Pt and Ni structures and devices without the usage of high energy charged particle beams.

Thermal Scanning Probe Lithography (t-SPL) uses a heated silicon tip to locally decompose and evaporate a thermally responsive resist, usually PPA (polyphthalaldehye). PPA has been proven to be a suitable mask for pattern transfer into Si with sub-20 nm half-pitch using a hard mask stack [5].

A similar approach using a tri-layer stack was used to enable high resolution lift-off with metals. Figure 1a illustrates this lift-off method using a stack consisting of PPA, SiO 2 and PMMA. RIE is used to precisely define the undercut in PMMA for the subsequent lift-off. Figure 2 shows an InAs nanowire device, where top gate electrodes have been fabricated with 50 nm half-pitch using t-SPL and the lift-off method. The top gate electrodes have been overlaid on top of the InAs nanowire using the in-situ topography imaging method of tSPL, which has been shown to be capable of sub-5 nm overlay accuracy [6]. No significant damage on the electrical properties of the InAs nanowire could be seen in such devices. Figure 3 and 4 show further examples with sub-20 nm features and gaps using t-SPL and this lift-off method.

The second lift-off method uses PMGI as under-layer and wet development to create the undercut (see Figure 1b). Parallel Pt lines with a half-pitch of 70 nm have been successfully fabricated (see Figure 5). We further demonstrate that smaller gaps can be created if the under-etched PPA is stable enough to remain free standing. The first test results demonstrate that it is possible to fabricate sub-20 nm metal gaps (see Figure 6).

REFERENCES [1] S. F. Karg, V. Troncale, U. Drechsler, P. Mensch, ÂŤ, and B. Gotsmann, Nanotech., 25, (2014) 305702.

[2] M. Puster, J. A. RodrĂ­guez-0DQ]R $ %DODQ 0 'UQGLĂź ACS Nano, Vol. 7, no. 12, (2013) 11283.

[3] D. 3LUHV - / +HGULFN ÂŤ 0 'HVSRQW 8 'XHULJ DQG $ W. Knoll, Science, 328, (2010) 732-735.

[4] P.C. Paul, A.W. Knoll, F. Holzner, M. Despont and U. Duerig, Nanotech., 22, (2011) 275306.

[5] H. Wolf, C. Rawlings, P. Mensch, ÂŤ and A. Knoll, J. Vac. Sci. Technol. B, 33, (2015) 02B102.

[6] C. Rawlings, U. Duerig, J. Hedrick, D. Coady, A. Knoll, IEEE Trans. on Nanotech., 13, (2014) 6.

Figure 1

Figure 5

Figure 2

Figure 6

Figure 3

Figure 4

Figure 7

Structural signatures of the glass transition in emulsions Chi Zhang1,* , Nicoletta Gnan2,3 , Thomas G. Mason2,3 , Emanuela Zaccarelli4,5 , and Frank Scheffold1 1

Department of Physics, Universite´ de Fribourg, CH-1700 Fribourg, Switzerland.

2 CNR-ISC, UOS Sapienza, P.le A. Moro 2, Roma I-00185, Italy.

3 Dipartimento di Fisica, Sapienza Universita` di Roma, P.le A. Moro 2, Roma I-00185, Italy.

4 Department of Chemistry and Biochemistry, University of California Los Angeles, Los Angeles,CA 90095, USA. 5 Department of Physics and Astronomy, University of California Los Angeles, Los Angeles, CA 90095, USA. * chi.zhang2@unifr.ch

The nature of colloidal glasses and the glass transition remains a topic of scientific interest. Scientists often focus on the study of dynamical properties since major structural changes have not been found to date in the vicinity of the glass transition. In this work we investigate structural and dynamical properties of moderately polydisperse emulsions across an extended range of droplet volume fractions φ, encompassing fluid and glassy states up to jamming. Combining experiments and simulations, we show that when φ approaches the glass transition volume fraction φg , dynamical heterogeneities and amorphous order arise within the emulsion. In particular, we find an increasing number of clusters of particles having five-fold symmetry (i.e. the so-called locally favoured structures, LFS) as φ approaches φg , saturating to a roughly constant value in the glassy regime. However, contrary to previous studies, we do not observe a corresponding growth of medium-range crystalline order; instead, the emergence of LFS is decoupled from the appearance of more ordered regions in our system. We also find that the static correlation lengths associated with the LFS and with the fastest particles can be successfully related to the relaxation time of the system. By contrast, this does not hold for the length associated with the orientational order. Our study reveals the existence of a link between dynamics and structure close to the glass transition even in the absence of crystalline precursors or crystallization.

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GMR Effect in Co-Cu Microwires Microwires

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Arcady Zhukov , Jakub Mino , Juan Jose Del Val , Juan Maria Blanco , Julian Gonzalez , Mario 5 5 1,2 4 1,2 Baibich , Gerardo Martinez , Mihail Ipatov , Rastislav Varga , Valentina Zhukova , 1 Dpto. Física de Materiales, UPV/EHU, 20018, San Sebastián, Spain 2 Dpto. Física Aplicada, EUPDS, UPV/EHU, 20018, San Sebastián, Spain 3 IKERBASQUE, Basque Foundation for Science, 48011 Bilbao, Spain 4 Institute of Physics, Faculty of Science, UPJS, Park Angelinum 9, 041 54 Kosice, Slovakia 5 Instituto de Física, UFRGS, C.P. 15051, 91501-970 Porto Alegre, RS, Brazil arkadi.joukov@ehu.es Abstract After discovery of giant magnetoresistance (GMR) in 1988 in magnetic multilayered films [1] many new materials with GMR have been developed. In particularly GMR effect was found in granular materials consisting of small grains distributed inside a non-magnetic matrix [2,3]. Cosequently granular materials usually formed by immiscible elements (Co, Fe, Ni)-(Cu, Pt, Au, Ag) attracted considerable attention since beginning of 1990-th [2,3]. Like in the case of multilayered thin films, GMR effect has been attributed to spin-dependent scattering of conduction electrons within the magnetic granules as well as at the interfaces between magnetic and nonmagnetic regions [2,3].

We prepared Cu100-xCox (x=5,10,20) glass-coated microwires using Taylor-Ulitovsky technique and studied the influence of annealing on structure and giant magnetoresistance (GMR) effect. We observed a significant increasing of the GMR effect in the samples annealed at 400 °C with long enough annealing time. Considerable enhancement of the GMR effect are related to structural changes of the studied samples after annealing and quite promising for technical applications.

References [1]. M. Vazquez, H. Chiriac, A. Zhukov, L. Panina and T. Uchiyama, Phys Stat Sol. A 208, (2011) 493.

[2] A. Zhukov, M. Ipatov and V. Zhukova, Advances in Giant Magnetoimpedance of Materials, Handbook of Magnetic Materials, ed. K.H.J. Buschow, Volume 24 (2015) 139 [3] A. Zhukov, J. M. Blanco, M. Ipatov, and V. Zhukova Sensor Letters 11 (1) (2013) 170.

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tann(min) Dependences of GMR ratio, 'R/R, on annealing time measured in Cu80Co20 microwires.

Single-walled carbon nanotube-based optical sensors for continuous glucose monitoring Vitalijs Zubkovs, Benjamin Lambert, Esra Ahunbay, Nils

rgers, Ardemis Boghossian

Laboratory of NanoBiotechnolgy (LNB), Institute of Chemical Sciences and Engineering (ISIC), School of Basic Sciences (BS), Ă&#x2030;cole Polytechnique FĂŠdĂŠrale de Lausanne (EPFL), Lausanne, Switzerland ardemis.boghossian@epfl.ch Abstract st

One of the major threats to public health in the 21 century is diabetes mellitus, which is on the rise worldwide causing more than 3.7 million deaths per year [1]. In the absence of a cure it is essential for patients with diabetes to continuously monitor their blood glucose levels to minimize the risk of complications. This leads to an increasing demand for accurate, cost-effective and convenient glucose monitoring devices.

Semiconducting single-walled carbon nanotube (SWCNT)-based sensors are promising candidates DPRQJ WKH ³QHZ JHQHUDWLRQ´ RI ELRVHQVRUs for glucose monitoring [2]. SWCNTs fluoresce in the range between 900 and 1300 nm and this near infrared emission is highly sensitive to the surrounding environment. Due to the low absorbance of near infrared light by tissue the signal that is emitted from the SWCNT can be continuously recorded through the skin, Moreover, when the surface of the SWCNT is decorated with proteins that have high affinity for glucose we can design a saccharide-specific, implantable near infrared sensor.

In the scope of this work we will design and study optical properties of SWCNT-based glucose sensors (Figure 1, a). The protein candidate that we have chosen for this study is glucose oxidase (GOx) because it not only selectively binds to glucose, but also changes its redox potential in its catalytic cycle (Figure 1, b). [3]. We believe that modulation of the redox state alters fluorescence response of the SWCNT, enabling us to design a continuous monitoring sensor (Figure 1, c).

References [1] World Health OrganizatLRQ ³*OREal Report on Diabetes´ (2016) p. 6 [2] Veiseh, O., Tang, B. C., Whitehead, K. A., Anderson, D. G., Langer, R., Nature Reviews Drug Discovery, 14 (2015) p. 45 [3] Vogt, S., Schneider, M., Schäfer-Eberwein, H., NÜll, G., Analytical Chemistry, 15 (2014) p. 7530 Figures

Figure 1: (a) Cartoon representing the working principle of the SWCNT-GOx sensor. (b) Change of GOx redox potential during glucose oxidation correlates with changes in SWCNT-GOx fluorescence intensity. (c) Fluorescence intensity of the SWCNT-GOx sensor after 30 mM glucose solution in phosphate-buffered saline (PBS) and PBS were sequentially administrated to the sensor.

Edited By Alfonso GĂłmez 17 28037 Madrid â&#x20AC;&#x201C; Spain info@phantomsnet.net www.phantomsnet.net