CSA’19 CSA’19
PRESENTATIONS
PARTNERS
CORK IN SCIENCE AND APPLICATIONS 2019
22nd May
Cork: NEW USES IN ARCHITECTURE
• “Today in addition to the awareness of the limitation of planet reserves, also begins to exist awareness of environmental costs that industrial development has caused on the planet associated with the awareness that the construction is a major source of pollution of the planet" buildings are major contributors indecomposable of toxic waste in the world. • The construction industry uses three billion tons of natural materials on the planet per year Font: Sam Martin, The right stuff, in Mother Earth News, June/July 2000
Planet Natural Resources Awareness
Buoyant
Compressible
Light
Elastic
Poisson's ratio 0
Poisson's ratio is the ratio of the relative contraction strain (or transverse strain) normal to the applied load - to the relative extension strain (or axial strain) in the direction of the applied load Impermeable: - liquids - gases
Insulation: - thermo - acoustic
Resistance: - friction - rot
Slow : - combustion - time
Cork has unique properties that no other product natural or artificial can supersede
CORK :
a
Cork unique natural properties
material
Font: http://www.flickr.com/photos
Use of Cork Through history - architecture Convent of the Capuchos, 1560
Font: Santos,O. Clausters Unidos pela Natureza o mundo do vinho e da Cortiรงa, Amorim, 2008
Use of Cork Through history - architecture Buรงaco Palace was part of a Discalced Carmelite convent , 1628
Arrábida monastery, Setúbal, 1542
http://aladesetubal1.blogspot.ca/2011/10/passeio-ao-convento-daarrabida.html
streets of Monsaraz. XVII-XVIII
http://cebolasdocampinho.blogspot.ca/2013/09/porta-decurtica.html
Use of Cork Through history - architecture
Partition Wallls, Doors, Windows
streets of Monsaraz. XVII-XVIII
http://cebolasdocampinho.blogspot.ca/2013/09/porta-decurtica.html
Use of Cork Through history - architecture
streets of Monsaraz. XVII-XVIII
http://cebolasdocampinho.blogspot.ca/2013/09/porta-decurtica.html
ROOFS
Exterior Walls – Cortiçadas
Use of Cork Through history - architecture
Use of Cork Through history - architecture Chalet of the Countess of Edla, King Ferdinand II, 1870
Use of Cork Through history - architecture Proust cork-lined bedroom, (1871 –1922)
Use of Cork Through history - architecture Tudor House, West Sussex, UK, (18~ )
Cork Today - cork composites Cork and design
Font: http://radardecoracao.com.br/02/corque-design-apresenta-pecas-de-cortica-aos-cariocas/
Cork Today - design Ana Mestre and others
Font: industrie Amorim (2012)
Cork Today - Architecture Thermal, acoustic insulation
Font: industrie Amorim (2012)
Cork Today - Architecture finishing cork flooring
Font: i http://www.grupoamericoamorim.com/xms/files/2011/Arte_Cortica.pdf
Cork Today - Architecture Sagrada Familia Barcelona, Cripta - Jordi Bonet i Armengol
Font: i http://www.grupoamericoamorim.com/xms/files/2011/Arte_Cortica.pdf
Cork Today - Architecture Nezu Museum , Kengo Kuma and Associates
Font: http://cultour.com.pt/tours/coimbra
It is a pre-fabricated and disassemble Pavilion that was later rebuilt in Coimbra. Is formed from a metallic structure, over which walls have been built and covered with around 55 tons of expanded cork agglomerate and also by hand made glazed tiles on the welcome patio. The choice of cork is related to the fact that it is a 100% natural material, isotherm, extremely versatile and totally recyclable and of which Portugal is the main source of production.
Cork Today - Architecture Souto Moura e Siza Vieira, Expo 2000 Hannover Portugal pavilion
Font http://www.archdaily.com/136301/logowines-winery-pmc-arquitectos/
The rhythm given to the facades, with a strong definition of horizontal lines, using various thicknesses of cladding panels of cork, where they fuse the openings for natural lighting inside is reinforced by the natural behavior of the chosen material, causing a set of textures, shades and shadows that mutates over time, in a clear allusion to the maturation of the wine during the period of production.
Cork and the Future - Architecture Logowines Winery / PMC Arquitectos in Évora Pt, 2007
Font:http://www.d10photo.com/davidpereira/portfolio/eco-cabana-barbini-arquitectos-cascais
/
There are endless creativity options which are being explored by new generation designers who are a lot more environment conscious. "The use of biodegradable, ecological and recyclable material such as cork is increasing, especially in the area of product design," he says. In Portugal we regard cork as an iconic material. It has an age-old reputation that dates back to 3,000BC," he says.
Cork and the Future - Architecture ECO-CABANAS, Barbini Arquitectos, Cascais, Pt, 2008
Font: http://barrelsecrets.wordpress.com/tag/alvaro-siza-vieira/
The new cellars of Quinta do Portal were built within an already built complex, a unit that dominates and is dominated by the landscape (of vineyards). There is no doubt that in the essential and whenever active, agriculture moulds the landscape. This is the first reason for the beauty of the Douro. It is by nature, a disciplined building. The functional needs, as well as the space, humidity and temperature needs determine its expression.
Cork and the Future - Architecture Quinta do Portal, Alvaro Siza Vieira , Sabrosa, Pt, 2008
Font:http://www.promocork.com/files/cortica-arquitetura.pdf
The first contact with the Centre creates admiration. There is no similar building. The whole coating is made with virgin cork (taken the first time) and Amadia (drawn for the third time in cork over 40 years). And for anyone who doubts the quality of material, the architect Manuel Couceiro ensures that "with careful maintenance, cork is for life."
Cork and the Future - Architecture Observatรณrio do Sobreiro e da Cortiรงa, Manuel Couceiro, Couruche, Pt, 2009
Font:http://www.promocork.com/files/cortica-arquitetura.pdf
The Portuguese architect Carlos Couto created a work 2000 m² coated in pure agglomerated cork as a means to reinforce the concepts of innovation and good environmental practices, integrating them to the concept of sustainability.
Cork and the Future - Architecture Expo 2010 Shanghai Portuguese Pavillion, Carlos Couto, Ch 2010
Font:http://www.promocork.com/files/cortica-arquitetura.pdf
Cork And the Future - Architecture Serpentine Gallery, Herzog & De Murron, UK, 2012
JosĂŠ Pedro Sousa, PhDThesis, TU Lisbon
Cork and CAD/CAM technologies , 2009
Font: http://www.shelterbygg.com/
Cork and the Future - Architecture Shelter ByGG, Hugo Amaral, Guimaraes, PT 2012
i cork
This Research is focussed on the use of cork material in architecture. It provides an environment for researchers, architects, designers as well as those in the industry and other interested parties to meet and develop ideas and experiments using cork.
Cork: NEW USES IN ARCHITECTURE
Gain an appreciation and understanding Cork as a material. • Understanding traditional methods in the use of Cork and learn from that experience. • Conduct explorations with composite cork materials or products to understand its potentialities and possible applications as a building envelop. •
Know the industrial cork processing chain and the composite cork products. • Selection and characterization of cork products and their use changes, i.e. with aging and weathering • Conduct experiences involving the industry, overcoming potentialities of their materials for future applications on building envelop. •
Understanding the architectural practice and foreseeing their future needs. • Selection of new materials and technologies that can, in the future, bring new possibilities of use in architecture and product design. • Understand how research and industry can work together to develop strategies that can be key to the future applications of cork materials in architecture. •
UNIVERSITIES / RESEARCHERS
INSTITUTIONS INDUSTRY
2014
1st. Edition_ Natural Materials
2014
1st. Edition_ Natural Materials
2015
2nd. Edition_ Composite Materials
2015
2nd. Edition_ Composite Materials
2014
1st. Edition_ Natural Materials
Use of textile cork and cork stoppers achieve: cork stoppers became a rigid connection
Phase 1
Phase 1/2 MEMBRANE
Material propertie
2015
2nd. Edition_ Composite Materials
Phase 1/2 MEMBRANE
Phase 1
Material propertie
2015
2nd. Edition_ Composite Materials
Phase 1/2 MEMBRANE
Phase 1
Material propertie
2014
1st. Edition_ Natural Materials
2014
1st. Edition_ Natural Materials
2015
2nd. Edition_ Composite Materials
USE OF NATURAL RESINS Problem: to unstable properties mix with cork
Phase 1 CLADDING
Phase 1
LIGHT FILTER Material propertie
2015
2nd. Edition_ Composite Materials
USE OF CNC MACHINE Acoustic characteristics incurve materials using materials in both faces light filter
Phase 1/2 CLADDING
2014
1st. Edition_ Natural Materials
USE OF MDULAR TECHNIQUES in curve surfaces Sound and Thermal characteristics
Phase 1/2 CLADDING
2014
1st. Edition_ Natural Materials
Wall dimensions 3m x 2m
USE OF MDULAR TECHNIQUES
Phase 1 CLADDING
Hexagon dimensions Side: 6.5cm Diameter: 13cm
2014
1st. Edition_ Natural Materials
USE OF MDULAR TECHNIQUES
Phase 1
SELF-SUPPORTING
Phase 1
LIGHT FILTER Material propertie
2015
2nd. Edition_ Composite Materials
2014
1st. Edition_ Natural Materials
UPCYCLE
Phase 1/2
SELF-SUPPORTING
Invited Guest
2015
2nd. Edition_ Composite Materials
2015
2nd. Edition_ Composite Materials
2015
2nd. Edition_ Composite Materials
CORK IN SCIENCE AND APPLICATIONS
Cork’s byproduct used as filter media in a treatment wetland for winery wastewater treatment
Jordi Morató, UPC May 23rd, 2019. 0
Environmental Problem Targeted
Catalunya 39 million of coark oaks Harvest 8.000 ton/year
Most cork unsuitable for cork stoppers 40-70 % sent to landfills 5.000 tonnes year – Catalonia 3
Circular Economy Framework
≈ 60 %
Zero Waste
Save Water
Treatment Wetland
Produce Energy
Gasification pilot plant 4
Ecorkwaste innovative strategy Integrated and sustainable management of cork waste grated and sustainable manageme
generated in the cork industry (LIFE14 ENV/ES/000460)
Diagram of the cork industry
Alternative cork flow– diagram including the ECORKWASTE strategy
Treatment Wetland (TW): Construction, installation, operation and assessment
2 Febrero de 2016
5
Main Objective
Tertiary water treatment to improve the quality of the final winery effluents in the treatment plant located at the Codorniu winery.
CODORNI U
5
Specific Objectives
To minimize landfilling of by-products by means of turning it into value. To demonstrate at pilot scale the feasibility of an innovative hybrid constructed wetland (CW) for the treatment of winery wastewaters, using cork waste as granular media. To reduce water consumption in the winery industry by an onsite wastewater reuse application (water & cork on site circular economy)
6
Analysis of Winery Wastewater
Seasonal variation of temperature, pH, COD and TSS, and Water Flow in CODORNIU WWTP effluent
110 m3/d
Harvesting 250 m3/d
150 m3/d
Data provided by CODORNIU. 7
Analysis of Winery Wastewater
Seasonal variation of Polyphenols, Zn, Ni, Cu and Pesticides in CODORNIU WWTP influent and effluent.
Samples from Nov. 2015 to Oct. 16. 8
Analysis of Winery Wastewater Codorniu WWTP – Low reduction for some Nutrients
8
Pilot Treatment Wetland Tertiary water treatment – Shipping Containers (mobile TW)
Project indicators 200m3
ECORK
year
-Winery Wastewater treated. 95% - Pesticides removal 90% - COD removal 80% - NO3-N removal
9
Pilot Treatment Wetland Open Top Shipping container 20 ft
10
Pilot Treatment Wetland Wetland – Shipping Container 20ft Open Top Waterprofing
11
Pilot Treatment Wetland Control Room – Shipping Container 20ft
12
Pilot Treatment Wetland Control Room – Shipping Container 20ft
ECORK
13
Pilot Treatment Wetland Functional Scheme
Discharge Vertical Flow 2 m3/d Area 14 m2 Irrigation Saturated Intermittent Aeration 27.000 l/d – 4 phases (Air - 25 min each, followed by 35 min w/o) Pump Electrovalve Flowmeter Level and Temp. Sensor
Multiparameter Quality Water Meter
Sedimentation Tank
Wastewater
Inlet Tank
VF
HF
TW Aer.
Outlet Tank
Aerated System 14
Winery Wastewater Treated
Int. Aerated Saturated Vertical TW 665 m3 from Mar-17 until Oct-31 70,000
Treated Water
50,000 40,000 30,000 20,000 10,000
r (2
01
7) Ap r Ma y Ju n Ju l Au g Se p Oc t No v Ja D n ( ec 20 18 ) Fe b Ma r Ap r Ma y Ju n Ju l Au g Se p Oc t
0
Ma
Liters per Mon nth
60,000
2,500 L
500 L
1,000 L
2,000 L
15
28 22:00
20:00
18:00
16:00
1st aeration phase
15 22:00
Environment 20:00
17
18:00
19
16:00
2nd 22:00
20:00
18:00
16:00
14:00
12:00
10:00
8.2
14:00
Temperature TW - July 8ht 08:00
3rd
12:00
3rd 35
06:00
8.1
10:00
4th 8.0
08:00
1st aeration phase
06:00
2nd
04:00
1.0
04:00
2.0
02:00
8.5
02:00
DO TW - July 8ht
00:00
4th
pH
3.0
00:00
30
Temperature(ºC)
22:00
20:00
18:00
16:00
14:00
1.5
14:00
29 12:00
10:00
08:00
06:00
04:00
0.5
12:00
10:00
08:00
06:00
04:00
02:00
DO (mgl-1) 2.5
02:00
31 00:00
0.0
00:00
Temperature(ºC)
Aeration 27.000 l/d – 4 Phases 8.6
pH TW - July 8th
8.4
8.3 4th
3rd
2nd 1st aeration phase
33
31
29
27
25
23
21
Temperature - July 8th TW
16
Increase in Aeration - 27.000 l/d –to 43.000 l/d 8.6
3.5
pH - July
DO - July
3.0
25' aeration phase 40'
25' aeration phase 40' 8.4
2.0
pH
DO (mg l-1)
2.5
1.5
8.2
1.0 0.5
8.0
0.0 6
7
8
9
10
11
12
13
14
15
16
17
18
19
7
8
9
10
11
12
13
14
15
16
17
18
19
Day
Day
Aerated – 4 Phases
31.0 30.5
Temperature (ºC)
6
From July 6th to 15th
30.0
27.000 l/d – 25’ per phase
29.5 29.0
From July 15th to 19th
25' aeration phase 40'
28.5
Temperature - July 28.0 6
7
8
9
10
11
12
13
14
15
16
17
18
19
43.000 l/d – 40’ per phase
Day
17
Pilot Treatment Wetland COD and BOD5 Removal Efficiency First months of operation (new cork) Higher values at the effluent
A
30 20
30 20
Ma y2 2 Jun 19 Jul 25 (17 ) Se p2 8
3 t0 Oc
5 l2 Ju
3 y2
Ma
Ma
p2 Se
) 17 5(
Ju
l2
n1 Ju
17 2(
r7
0 8
0 9
10
y2
A
40
10
Ma
nA
BOD
Oc t 03
40
)
COD (g/m m 2 d)
nA
50
VF_Out
Jul 25
COD
50
Sed_Out
Ma y2 3
VF_Out
Ma r7
Sed_Out
60
BOD ((g/m 2 d)
60
18
Pilot Treatment Wetland NT, NO3-N, NH4-N & N02-N Removal Efficiency 45
40
NT
NT (g/m2 d)
35 30
nA
A
25 20 15 10
15 10
0
40
40
30
nA
A
A
NH4-N
25 20 15 10
30
nA
A
25 20 15 10 5
0
0
Outlet
NO2-N
35
5
Inlet
A
20
0
nA
nA
25
5
NO2-N (g/m2 d)
NH4-N (g/m2 d)
30
5
35
NO3-N
35
NO3-N (g/m2 d)
40
Inlet
Outlet
19
Pilot Treatment Wetland 100
Removal Efficiency %
80 60 40 %
20 COD BOD5
0 -20
TSS
TN
NO3- NO2- NH4- PO43-
TP
Ni
Cu
-40 -60 -80
New cork
Removal Efficiency %
-100
Parameter / No Aerated
- Aerated
21
Molecular Microbiology Analysis Quantitative PCR real time (nirS and nosZ genes, biological markers of denitrification process) and 16S rRNA (general bacteria marker)
Relative abundance of denitrifying genes Relative abundance nosZ/16s 2017 Jan Mar Ap May Jun 0,21 Jul 0,03 Aug 0,03
(%) 2018 0,0005 0,0001 0,0000 0,0004 0,0003 0,0012 0,0000
Rel abund (%) of dry cork nosZ/16s nir/16s 0,0001 0,0049
Relative abundance nir/16s 2017 Jan Mar Ap May Jun 16,29 Jul 0,88 Aug 0,71
(%) 2018 0,003 0,004 0,020 0,033 0,170 0,000 0,001
Chon et al. 2009 ďƒ 0-0.1%
Denitrification scheme
23
Evolution of microbial communities Subsurface cork
No aeration
Aeration
24
Evolution of microbial communities Genes -vs- Sampling site 3 sampling sites on the Constructed Wetland Surface (P1,P3, P6) ďƒ
Kruskal-Wallis Test; p-value: 0,970
Kruskal-Wallis Test; p-value: 0,978
Kruskal-Wallis Test; p-value: 0,776
There are no statistically significant differences between the 3 sampling sites for the data analyzed. 25
Evolution of microbial communities Quantification of GC/g of biofilm in depth cork
26
Evolution of microbial communities Genes -vs- Depth No significant differences for denitrifying genes.
16S
ANOVA; p-value: 0,018
nirS
ANOVA; p-value: 0,904
nosZ
ANOVA; p-value: 0,2
Significant differences for 16s gene) with the lower parts being the least abundant. 27
Evolution of microbial communities
Existing relationship between NT with the molecular results
PRINCIPAL COMPONENT ANALYSIS
nosZ
16S nirS
T-test; p-value: 0,024
MKO; p-value: 0,4 Bartlett; p-value: 0,024
28
Pesticides Removal Inlet and outlet wetland concentrations
20-25% reduction in TW No pesticides on Cork!!
30
Cork Granulates Structure Inner structure of cork granulate in the wetland after 1,5 year of operation
A
B
C
D
Fig. 4 SEM micrographs of wetland cork granulate after 1,5 year of operation ; (A) surface of cork granules in 250 magnifications; (B) surface of cork granules in 1000 magnifications; (C) inner and otter cork granules in 500 magnifications; (D) inner cork granules in 500 magnifications. 32
Conclusions 1. Vertical flow treatment wetland with induced aeration and cork as a filter medium showed a greater removal of NO3-N (81-99%), which suggests that cork could be an alternative material to remove TN (25-90%). 2. Aerated process showed higher removal efficiency for all parameters (TSS, TN, NH4-N, NO2-N, NO3-N, TP, PO4 and Cu). 3. The studied pesticides had not been detected in the cork samples, so the cork treatment wetland has not got over its useful life (1.5 years).
33
CORK IN SCIENCE AND APPLICATIONS
Thank You!!!
Jordi Moratรณ, UPC May 23rd, 2019. 32
Two Cork Houses Emiliano López & Monica Rivera Architects Palafrugell, Girona
STUDY ON CORK APPLICATIONS IN THE CONSTRUCTION SECTOR María Pilar Giraldo PhD Architect pilar.giraldo@incafust.cat
Introduction Cork is an ideal material to meet of the Green Buildings demands due to its properties combined with a favourable ecological footprint.
RENEWABLE RESOURCE
ANTIMICROBIAL
Some by-products BIODEGRADABLE ECO FRIENDLY
NO CHEMICALS / TOXINS EXCEPTIONAL PERFORMANCE
Introduction According to the ranking of FM Cork is a gold material in terms of health above other insulation materials.
Sustainability The environmental impact of its extraction and transformation processes is very low compared to other construction materials.
The cork oak tree sequesters CO2 during its whole life The harvest period is every 9 years (stripping)
Sustainability
The harvesting process is traditionally done by hand, so the only generated carbon is transporting the cork till factory. The transformation processes do not require large consumption of embodied energy.
Sustainability Cork’s extraction and transformation process suppose a carbon footprint much lower than that of other synthetic construction materials with similar thermal properties like polyurethane foam sheets (PU) and expanded polystyrene (EPS).
Material & processes Stoppers
+
Ecological value
-
plastic, petroleum products Compression Moulding
Expanded Cork board Natural cork
+PU Binder Agglomerated Cork
Granules Cork Composites Natural cork Blocks & rolls
Veneers
Floor and coverings
Backing
Cork fabrics Composite panels
+Rubber
Corkrubber
+Thermo plastic
CPC Pellets
Rolls Blocks
Injection Moulding
Material properties Cork has unique properties which give it an unrivalled character. It is light, impermeable to liquids and gases, elastic and compressible, provides thermal and acoustic insulation, it has a certain fire retardant capacity and is highly abrasion-resistant. Furthermore, it is completely biodegradable, renewable and recyclable.
Material properties Cork is combustible but has a certain fire retardant capacity.
Reaction to fire Classification of Cork
E
Which indicates that it is a combustible and flammable material. However, due to its physicochemical properties, the surface forms a carbonized layer that slows down the combustion process. But it does not make it a fireproof material Ongoing research carried out by INCAFUST in collaboration with the Fire Lab of EPSEB - UPC
Material properties The physical properties of cork are due to its cellular structure and its chemical composition. Cork consists of suberin cells in the shape of tiny pentagonal or hexagonal honeycombs, a complex fatty acid and filled with an air-like gas, which makes up 90% of its volume. It possesses an average density of around 200 kg/m3 and low thermal conductivity.
Material properties The chemical composition of cork includes several types of compounds, which are traditionally divided into five groups: • Suberin (45%) - main component of the cell walls, responsible for the elasticity of the cork; • Lignin (27%) - insulating compound; • Polysaccharides (12%) components of the cell walls that help define the texture of the cork; • Tannins (6%) - polyphenolic compounds responsible for the colour; • Wax (6%) - hydrophobic compounds that guarantee the impermeability of the cork. • Ash (4%) - hydrophobic compounds that guarantee the impermeability of the cork.
wax
4%
Ash
Outdoor applications Expanded insulation corkboard for faรงade systems
Corkboard for roof and faรงade claddings
Projected cork for roofs
1B
Vipeq
1A
Ventilated faรงade corktherm.com/
2C
1A Amorim
Projected cork for faรงades
ETICS
1B 2B
Granulated cork for insufflation
Terra.org
Indoor applications
Rolled cork liner Cork ceiling panels
Expanded insulation corkboard for walls and roofs
2A corktherm.com/
1C Acoustic corrector boards
5A
2A
3B
4A Corkcoustic
Cork flooring 1D
composites panels for indoor applications
6B
6A
3C
3A
Anti-vibration and acoustic boards
Amorim
Partition walls
Some applications of cork in construction
MarĂa Pilar Giraldo PhD Architect pilar.giraldo@incafust.cat
Thanks for your attention!
Production of Cork hollow pieces by an innovate process based on rotational moulding
O PROBLEMA (The Problem)
Líder (leader)
Empresa Corticeira (Cork Industry)
Parceiros (Partners)
Empresa de Plásticos Instituições de I&D (R&D Organizations)
• Characterization of cork powder and granulates. • Characterization of micronized polyolefins.
•
The introduction of cork softens the thermoplastic.
•
Cork incorporation increases the creep compliance of the composite.
•
Creep recovery depends on the amplitude of the compression force. cork cells crushing Middle range high amplitudes
low amplitude Non-linear behaviour Cell walls buckling linear behaviour
Manuela Mendes
Luís Miranda Sérgio Miranda Andreia C Lopes Sara V Lucas Telma Anágua
A. C. Diogo J. M. Bordado
Isabel Tinoco Abel Rodrigues Miguel Pestana
Instituto Nacional de Investigação Agrária e Veterinária, I.P. Av. da República, Quinta do Marquês, 2780-157 Oeiras, Portugal Tel : (+ 351) 21 440 3500 | Fax : (+ 351) 21 440 3666 www.iniav.pt
Pyrolysed cork wastes used for ultra-light-weight microwave absorbers, EMI shielding or RAM materials Robert C. Pullar a
rpullar@ua.pt
Rui M. Novais a, Ana A. P. Caetano a, K. A. Krishnakumar and Kuzhichalil P. Surendran b a
b
Dept. Eng. Materials and Ceramics/CICECO – Aveiro Materials Institute, University of Aveiro, Aveiro, Portugal
Materials Science and Technology Division, CSIR-NIIST, Industrial Estate, Trivandrum 695019, India
b
Microwave absorbers – 0.3-300 GHz ď Ž
There is a great deal of interest in microwave (MW) absorbing materials, for EMI shielding and military/ stealth technology as radar absorbing materials (RAM) at GHz frequencies Stealth aircraft, ships & vehicles with RAM material incorporated Blocking of radar & military comms EMI shielding for testing, standards, security & health applications
The X-Band (8-12 GHz) of Great Interest ď Ž
X-band (wavelength ~2.5-3.7 cm) is used for military radar and communications, some commercial and civil wireless and satellite communications, motion sensors and speed detection
Carbon (graphite) is a well known GHz / MW Absorbing Material
Has been used as powder (carbon black, charcoal), carbon fibre, carbon nanotubes (CNTs) and graphene
Carbon powder used in commercial absorbing materials, usually in composites with densities of ≥ 1 g cm-3
PMMA composite with 7 wt% CNTs added, d = 1.2 g cm-3
Pande et al, DOI 10.1007/s11671-008-9246-x
Carbon fibre/CNT/Ni powder composites, d = ~0.9 g cm-3
Liu et al, DOI 10.1016/j.carbon.2013.11.027
Specific Shielding Effectiveness, SSE
Most papers talk of Shielding Effectiveness, SE, in dB – a value greater than -30 dB is generally considered to be very good
However, another useful value is Specific Shielding Effectiveness, SSE, in dB g-1 cm3, considering the density
This is very important if lightweight materials are required, e.g. stealth coatings for aircraft or vehicles, or portable equipment Cork would seem an obvious choice of material Made of 20 mm wide hexagonal cells, a very light material, d = ~0.24 g cm-3 Can be pyrolysed to form carbon BUT LITTLE WORK ON CORK
Cork is the Bark of a Slow Growing Oak (Quercus Suber Suber)) from the Mediterranean
50% of all cork comes from Portugal
Bark is harvested every 9-13 years, but tree lives on unharmed as carbon sink for >200 years
Cork is a Renewable Resource, with a Natural 33-DOM Microstructure Wine Corks
a) Hexagonal Radial section b) Rectangular Tangential or Axial section
~50,000 t per year of waste cork powder & granules are generated by the cork industry – currently most is burnt to generate energy
We Valorise Waste Cork Products ď Ž
Powder called MF5, made by Amorim in Portugal, as well as waste cork discs, winestoppers, granules and other wastes
ď Ž
MF5 = 300300-500 mm particles, but bulk density much less than cork wood, at 0.050.05-0.07 g cm-3
We also used samples of Solid Cork from Recycled Cork Wine Stoppers ď Ž
Before pyrolysis, d ~0.16 g cm-3, lower than 0.24 of fresh bark
ď Ž
Solid cork expands during pyrolysis. Afterwards, volume = 134 %, weight = 28 %, d ~0.034 g cm-3, similar to the powder
We also pyrolysed cork sheets
Pyrolysed Cork Biomimetic Carbon
Graphite furnace at 900 ºC in Ar or N2 cork carbon
The pyrolysed cork loses >70% weight, but maintains the same cellular microstructure as the original cork, but thinner walls
>70wt% loss
In the pyrolysed cork, structure still like cork, but made of pure carbon, and is nanoporous
Pyrolysed at 900 ºC
Wood
Carbon
This means it is much lighter – d now 0.031 g cm-3, 1/8 of cork wood, & ½ that of the MF5 cork waste powder
TGA/DSC of Cork Pyrolysis in N2
Water loss below 100 ºC, then volatile organics at 200-250 ºC, and suberin, etc., at 550-600 ºC – no further weight loss Even in air, cork can withstand >500 ºC before losing structure
SEM Images of Pyrolysed Waste Cork Powder (pure carbon, d = 0.03 g cm-3)
Shielding Measurements in the XX-Band • The studies were done in a vector network analyser using the wave guide method. SER, SEA and SET (= R+A, Reflection + Absorption) were calculated • Solid Cork samples were made into a rectangular shape of 10.1 x 22.86 mm, with varying thickness, through grinding using sand-coated polishing paper. Samples with thicknesses of 3, 5, 7 and 8.6 mm were prepared • Cork Powder samples were suspended in paraffin wax in the ratio (powder to wax) of 1:4 by mass. The composite was then hot pressed to form 10.1 x 22.86 mm rectangles • SSE (Specific Shielding Effectiveness) calculated from density • For comparison, we also measured un-pyrolysed cork samples
MW Measurements of Un-Pyrolysed Cork We did not expect the unpyrolysed cork to be very good, and indeed this proved to be the case All had very poor SE throughout the X-band
Cork powder Thickness(mm) 1.78
SER (dB) 0.1-1.2
SEA (dB) 0.01-0.3
SET (dB) 0.2-1.3
Finely powdered cork (>100 mm) Thickness(mm) SER (dB) 1.60 0.1-1.1
SEA (dB) 0.01-0.2
SET (dB) 0.1-1.2
Solid cork A Thickness(mm) 5.7
SER (dB) 0.1-0.8
SEA (dB) 0.01-0.4
SET (dB) 0.1-1.1
Solid cork B Thickness(mm) 5.9
SER (dB) 0.1-0.8
SEA (dB) 0.01-0.4
SET (dB) 0.1-1.1
Flat cork sheet Thickness(mm) 5.75
SER (dB) 0.1-0.2
SEA (dB) 0.2-0.3
SET (dB) 0.3-0.6
Partially combusted cork Thickness(mm) SER (dB) 8.05 0.01-0.7
SEA (dB) 0.01-0.2
SET (dB) 0.01-0.8
X-Band MW Measurements of Pyrolysed Cork Powder in Wax Composite • The pyrolysed cork waste powder is VERY fine and light, and had to be mixed in a composite to be handled and measured Thickness(mm) 1.65
SER (dB) 3.0-7.9
SEA (dB) 8.9-11.6
SET (dB) 14.4-18.1
Density of the wax composite is 0.946 g cm-3 Not very high SE values, but this composite is only 20% pyrolysed cork – the rest is wax In all these samples, SER contributes much less than SEA to the total SET
X-Band MW Measurements of Pyrolysed Solid Cork of Various Thicknesses Thickness(mm) 2.96 4.98 6.95 8.6
SER (dB) 3.7-8.7 3.8-8.5 3.8-7.4 3.9-7.6
SEA (dB) 12.3-17.7 14.1-18.5 22.9-27.7 27.5-34.0
SET (dB) 19.8-23.3 20.4-24.5 28.5-32.7 34.0-38.3
Values increase with thickness, to over -30 dB for 7 & 8.6 mm Not surprisingly, we can see that it is the absorption SEA which increases with thickness The reflectance SER remains constant, as the surface microstructure is constant
What is REALLY Exciting is the SSE Thickness (mm)
SSE (dB g-1 cm3)
Pyrolysed Solid Cork
2.96 4.98 6.95 8.6
SET (dB) 19.8-23.3
20.4-24.5 28.5-32.7 34.0-38.3
Density (g cm-3) 0.031
SSE (dB g-1 cm3) 638.7-751.6 658.0-790.3 919.4-1054.8 1096.8-1235.5
As pyrolysed cork is so light (0.03 g cm-3), SSE is VERY HIGH 1200 dB g-1 cm3 is the highest reported SSE These are solid pyrolysed cork, so no polymer binder or composite to increase density of material Sustainable material!
Cork structure enhances MW absorption due to internal reflection within the cells
How does this compare to Carbon Foams Using GRAFOAM® FPA-20 and GRAFOAM® FPA 10, 1-4 mm high Foam densities = 0.324 & 0.166 g cm-3, cells are 100’s of mm 1 & 4mm = GRAFOAM FPA-20, 2 mm = GRAFOAM FPA-10 SSE values ~125-155 g-1 cm3 for 4 mm GRAFOAM FPA-20, ~195-250 g-1 cm3 for 2 mm GRAFOAM FPA-10 Only 1-4 GHz
Compared to PF/CNT/Fe3O4 Foams Carbonised phenolic foam/2 wt% MWCNT/1-7 wt% Fe3O4 foam composites, d = 0.103-0.130 g cm-3, PF foam SSE ~ 120 g-1 cm3 CNTs only: SSE with 1 wt% CNT ~184 g-1 cm3, for 5 wt% CNTs SSE ~330 g-1 cm3
10.1016/j.carbon.2016.03.055
Compared to PF/CNT/Fe3O4 Foams PF/2wt% MWCNT/1-7 wt% Fe3O4 foams, d = 0.121-0.130 g cm-3 Left: thickness effect; Right: all 3 mm thick SSE with 1 wt% Fe3O4 ~315 g-1 cm3, for 7 wt% Fe3O4 SSE ~517 g-1 cm3
10.1016/j.carbon.2016.03.055
Conclusions: We have made MW Absorbers with the Highest Reported SSE values in the X-Band from Pyrolysed Waste Cork Material
Density (g cm-3)
SSE (-dB g-1 cm3) F (GHz)
3 mm pyrolysed cork
0.031
660-780
8-12
7 mm pyrolysed cork
0.031
950-1055
8-12
8.6 mm pyrolysed cork
0.031
1100-1235
8-12
3 mm PF/2% CNT /1% Fe3O4
0.127
~315
8-12
5 mm PF/2% CNT /7% Fe3O4
0.127
~555
8-12
3 mm PF/5% CNT
0.106
~330
8-12
3 mm carbon PF foam
0.104
~120
8-12
2 mm GF FPA-10
0.166
195-250
1-4
Thank you for your attention Acknowledgements: This work was carried out under the H2CORK project, FCT grant no. PTDC/CTMPTDC/CTMENE/6762/2014, as well as POCIPOCI-0101-01450145-FEDERFEDER-016862. Thanks are also due to Amorim Cork Composites, S.A. for donating the cork samples. RCP wishes to thank FCT grant IF/00681/2015 for supporting this work. This work was developed within the scope of the project CICECOCICECO-Aveiro Institute of Materials, POCIPOCI-0101-01450145-FEDERFEDER007679 (FCT UID/CTM /50011/2013), financed by national funds through the FCT/MEC and coco-financed by the EU with FEDER funds under the PT2020 Partnership Agreement.
www.ciceco.ua.pt/RobPullar
Our other work on pyrolysed cork materials with incredibly high surface areas = 1670 m2 g-1