Funktionale Textilien dank Nanotechnologie

Funktionale Textilien dank Nanotechnologie Dr. Dirk Hegemann EMPA Materials Science and Technology Lerchenfeldstrasse 5, CH-9014 St.Gallen / Schweiz dirk.hegemann hegemann@empa.ch Nanotechnologie, ihre Produkte und Risiken für den Verbraucher 28. März 2006, BfR, Berlin

EMPA Materials Science & Technology Member of the ETH Domain in Switzerland 820 employees at three sites R&D for SMEs St.Gallen Dübendorf Thun St. Gallen Lake of Konstanz (Bodensee)

Empa Laboratory Functional Fibers and Textiles %Fiber and Textile Chemistry - finishing, wet-chemical treatment %Fiber Development - bi-component fiber spinning device %Plasma-modified Surfaces - cleaning, activation, deposition

Outline Functional Textiles thanks to Nanotechnology %Dimensions d gas dact W/F dep A dep gas in %Nanoscaled coatings %Nanostructuring with particles %Incorporation of nano particles %Applications

Functional Textiles thanks to Nanotechnology Nanostructures and dimensions (<100 nm) 1-dimensional %nanoscaled coatings on fibers and textiles (by plasma coating or wet-chemical grafting) 2-dimensional %nanostructures on fibers and textiles (by etching, embossing or nanoparticle incorporation at the surface) %nanofibers (by electrospinning) 3-dimensional %nanoparticles in fibers and textiles (by incorporation in plasma coatings or during fiber spinning) %nanoporous coatings New material properties of textiles

Nanoscaled Coatings Self-assembled monolayers (SAMs) on ropes Grafting of fluoroalkyltrichlorosilanes uncoated coated? water repellency PA Loss of the performance of wet climbing ropes can be avoided.

Nanoscaled Plasma Coatings Plasma CVD and PVD layer by layer growth plasma polymerization sputtering monomer radicals VUV radiation energetic particles target nano cluster etching surf. diff.

Plasma Polymerization Control of wetting properties by O 2 /HMDSO coatings 120 100 PDMS O 2 /HMDSO CH 3 CH 3 adv. contact angle [ ] 80 60 40 20 0 SiOC:H films quartz 0 10 20 30 40 50 HC 3 Si CH 3 O Si CH 3 CH 3 The residual C concentration also scales with the crosslinking and thus the permeability rel. carbon concentration [at%]

Plasma Sputtering Nanoscaled metallization of fibers Development of electrically conducting, anti-static fibers: - metallization with Ag, Al, Ti etc. - homogeneous coatings - textile properties are unaffected SEM 100 µm SEM medical textiles, occupational safety & health, wellbeing metal-coated multifilament ρ = 10..10 5 Ω/cm (coated) ρ ~ 10 11 Ω/cm (non-coated)

Nanofibers by Electrospinning Influence of solvent and voltage 250 nm 180 nm 2.5% PEO in H 2 O, 15 kv 7 % PEO in H 2 O, 15 kv 7 % PEO in H 2 O, 25 kv Faraday cage syringe pump (ml/h) High voltage DC supply 5-30 kv variable V precursor solution A and B (eg dissolved polymers) metal electrode possible application air filtration Nanofiber nano-fibrous web on fabric Rotating tubular shaped counter electrode for fiber collection (mat)

Nanostructuring of Surfaces Nano particles embedded in wet-chemical coatings SEM pictures 10 µm 5 µm possible application stain repellency 1 µm 0.5 µm

Nanostructuring of Surfaces Coating failure with a high content of nano particles SEM pictures

Nanostructuring of Surfaces Abrasion of nano particle containing coatings SEM pictures

Nanostructuring of Surfaces Abrasion of nano particle containing coatings 170 CA H 2 O 160 150 140 130 120 without NP high content of NP low content of NP A suitable content of nano particle incorporation can enhance the abrasion resistance of water repellent coatings. 110 100 0 2000 4000 6000 8000 10000 abrasion cycles Martindale test

schoeller Switzerland Patented technology NanoSphere it s naturally selfcleaning

Incorporation of Nano Particles into Fibers Handling of nano particles + dispersion granulate NP e.g. flame synthesis compound granulate melt spinning + drawing SiO 2 : stiffness ZnO: UV blocking agent TiO 2 : photocatalysis Ag: anti-odor, antimicrobial agent nano clay: FR CNT: strength, FR

Bi-component Fiber Spinning Core/sheath structures loaded with nano particles nano particle degradable polymer durable polymer possible applications Drug release; Flame retardancy

Ag Nano Particles and Coatings Wound dressings, socks, underwear etc.

Nano Particle Containing Plasma Coatings Combination of plasma CVD and PVD plasma polymerization + sputtering monomer etching radicals VUV radiation energetic particles surf. diff. target nano cluster? in-situ incorporation of nano particles (10..100 nm)

Ag/PEO-like Coatings Anti-microbial treatment 10 µm 10 µm adhesion of P. aeruginosa on native PVC non-fouling Ag/PEO-like surface D.J. Balazs et al., in: Plasma Processes and Polymers, ed. R. d Agostino et al., Wiley-VCH, Weinheim, 2005, p. 351.

Ag/PEO-like Coatings Incorporation of silver nanoparticles plasma copolymerization: embedding of Ag particles (by sputtering) into a plasmapolymerized PEO-like matrix germicidal properties of Ag + ions in swollen state Ag-S- HS- inhibition hydrogenof hydrogen transfer transfer Ag-S- HS- D.J. Balazs et al., in: Plasma Processes and Polymers, ed. R. d Agostino et al., Wiley-VCH, Weinheim, 2005, p. 351.

Functionalized Coatings Retention of functional groups during plasma deposition C O OH N H H O C CH 2 H C OH CH 2 CH 2 O specific functionalization nanoscaled coatings with accessible functional groups within nano-porous structure

Deposition of Nano Porous Coatings Functionalized coatings amino-functionalized (65 nm thick) carboxy-functionalized (45 nm thick)? nano porous structure (<30 nm)

Functionalized Coatings Dyeing of plasma coatings on textile fabrics untreated plasma activated plasma coating 50 nm PET Stability: >50 000 cycles in Martindale test dyestuff: Sandolan walk blue N-GLN 180

Functionalized Coatings Substrate independent dyeing plasma-treated untreated CA PP cotton PA PET acid wool dye cationic dye

Plasma Reactors Continuous reactors @ Empa St.Gallen demonstration of industrial scale-up Web coater width = 65 cm velocity = 0.1..100 m/min RF + MW, magnetron sputtering one-step processing (of 3 processes) Fiber coater mono- and multifil fibers (0.01..2 mm) velocity = 0.1..100 m/min RF, magnetron sputtering one-step processing (of 2 processes)

Applications dyeability reinforced composites hydrophobicity metallizations biocompatibility moisture/heat management D. Hegemann, A. Fischer, D.J. Balazs, Textilveredlung 3/4, 2005, 14.

Outlook Functional Textiles thanks to Nanotechnology %Nano particles in use: SiO 2 : nano structuring? stain repellence Ag: incorporation? anti-bacterial treatment nano clay: incorporation? flame retardance %Nanoscaled coatings %Nanoporous coatings? container systems

Acknowledgment Laboratory for Functional Fibers and Textiles %Group Plasma-modified Surfaces contact dirk.hegemann@empa.ch dawn.balazs@empa.ch Dawn Balazs, Ratnesh Thapliyal, Martin Amberg, Armin Fischer, Mokbul Hossain, Michael Keller, Dirk Hegemann %M. Heuberger, R. Hufenus, A. Ritter, G. Fortunato, J. Lübben, P. Furrer, M. Halbeisen, F. Reifler %CTI Bern for funding