This document discusses applications of nanotechnology in textiles. It begins by defining nanotechnology as dealing with structures less than 100 nm. It describes how nano materials are used in pigments, computer chips, and surfaces to create properties like self-cleaning. Specific nanomaterials discussed for textiles include silver for antimicrobial effects, silicon dioxide for ceramic coatings, and titanium dioxide for UV protection and photocatalysis. The document also discusses functional materials for properties like waterproofing and breathability, as well as intelligent and smart materials under development. Examples of nanotechnology applications in textiles include antimicrobial silver coatings, ceramic coatings using sol-gel processes, and titanium dioxide coatings to improve ultraviolet protection. The document

1. NanoTECHNOLOGY IN TEXTILES

3. technologies dealing with structures less than 100 nm

4. 1 nm is a trillionth of 1 m (10-9m)

5. surface properties play a more important role compared to

6. the volume properties - therefore:

7. Richard Phillips Feynman “There is plenty of room at the

8. Bottom” is considered to be the “father” of nanotechnolgy

9. interdisciplinary interaction of sciences (physics, chemistry)

10. therefore nanotechnology is called a convergent technology

12. up-to-date computer chips (nano lithography)

14. SOME APPLICATIONS OF NANOTECHNOLOGY IN TEXTILES 1) Ag (antimicrobial activity) 2) SiO2 (sol-gel, ceramic layers) 3) TiO2 (UV-protection, photocatalysis) 4) bionics: shark-skin effect, self-cleaning surfaces

16. EM field protection

18. medical applications

19. silver nanoparticles in the fiber

20. silver nano coating

21. high washing fastness

22. done by electrospinningMicro fiber silver coating braced silver coating on the fiber surface microfiber cross section

24. functional additives- solvent Temp. Lyogel Sol Xerogel textile Properties: mechanical: reinforcing, scratch-resistant, antistatic, anti-adhesive optical: interference colors, UV protection, IR absorption biological: antimicrobial, medical applications

25. How to improve the UPF of Textiles (ultraviolet protection factor) + fabric design + tighter weaving or knitting + higher weight + textile finishing + organic dyes absorbing UV light + optical brighteners (in detergents) + dark coloration + fiber modification + TiO2, ZnOnano pigments for dulling of chemical fibers + coating is essential to prevent photocatalytic reactions

26. Fiber Raw Materials and UV Protection Polyester (PET, PPT, PBT) + terephthalic acid absorbs in the spectral UV range + protection is increased by additional dulling (µ/n-TiO2) + best protection possible Polyamide (PA 6, PA 6,6) - nylon + only „full dull“ types provide good protection natural fibers (cotton, wool, linen)) & regen. cellulose fibers (CV, CLY) + little to no protection at all (especially when wet) + full dull viscose (TiO2) was available a few years ago

27. Application of nano TiO2 on Fibers PA uncoated PA 2 % nano-TiO2 coating

28. UPF after nano TiO2 Coating UPF Rating according to AS/NZS 4399:1996 60 50 50 40 35 30 30 25 20 10 10 5 0 UPF (2 % Nano-TiO2) UPF UPF (uncoated) CO (100 %) 142 g/m2 PES/CO (50/50) 125 g/m2 PA (100 %) 97 g/m2

29. Photocatalytic Degradation of Matter with TiO2 (Anatase Crystal-Modification) + photocatalytic TiO2 nanoparticles in anatase crystal modification in presence with UV-radiation, water and oxygen generate free radicals + radicals destroy organic substances + catalytic process, therefore large and free accessible surface area (e.g. nano) is required

30. Photocatalysis When a semiconductor material is illuminated with ultra band gap light it becomes a powerful redox catalyst capable of killing bacteria, cleaning water, and even splitting water to give hydrogen and oxygen.

31. When photocatalyst titanium dioxide (TiO2) absorbs Ultraviolet (UV)* radiation from sunlight or illuminated light source (fluorescent lamps), it will produce pairs of electrons and holes. The electron of the valence band of titanium dioxide becomes excited when illuminated by light. The excess energy of this excited electron promoted the electron to the conduction band of titanium dioxide therefore creating the negative-electron (e-) and positive-hole (h+) pair. This stage is referred as the semiconductor's 'photo-excitation' state. The energy difference between the valence band and the conduction band is known as the 'Band Gap'. Wavelength of the light necessary for photo-excitation is: 1240 (Planck's constant, h) / 3.2 ev (band gap energy) = 388 nm The positive-hole of titanium dioxide breaks apart the water molecule to form hydrogen gas and hydroxyl radical. The negative-electron reacts with oxygen molecule to form super oxide anion. This cycle continues when light is available.

32. Fiber Degradation (SEM Image of Polyamide)

33. Nature as the Role Model: Shark Skin with minimized Flow Resistance source:

34. Bionics: Swimmsuits with Shark-Skin-Effect + different friction coefficients on the fabric (knitted or printed) + creation of micro vortices

35. Soil Repellence (Lotus Effect®) + nature as the role model (“bionics”) + combination of micro- and nanostructures with low surface energy generated by wax crystals + such high performance is not achieved by common fluorocarbon finish + water, oil and dirt simply roll off + but: structures are sensitive to mechanical stress (scratching, abrasion, washing) + effect is lost if structures are damaged + nature can re-grow these structures - but textiles not (yet)

36. Self-Cleaning Process in Nature (1) hydrophobic surface hydrophilic surface

37. Self-Cleaning Process in Nature (2) nanostructure for small particles microstructure for larger particles

38. Self-Cleaning on Plants (Spiraea)

39. Self-Cleaning on Insects (Rose Beetle) species 1 species 2

40. Self-Cleaning on Insects (Housefly)

41. Self-Cleaning on Plants (Lotus Leaf) source: Schoeller Textiles self-cleaning textile coating with nanostructured surface folien/xxx.ppt/aj Folien Nr. 37; 25.11.2005 © Hohensteiner Institute SEM image (top) and AFM surface topography of a lotus leaf

44. Other Advancements

47. Other Applications SMART TEXTILES Woven optical Woven or Woven or Printed fibers ( screen ) printed Bus Electrodes Circuit on Organza Silk Organza Embroided ( Silk + Gold ) NRIKeypad

48. References Beringer, Dr. Jan (2005). Nanotechnology in Textile Finishing. State of the Art and future Prospects. HohensteinInsitutes. McLaughlin, James (2004). Nanotechnology & Its Applications in Textiles. University of Ulster. Sawhney, P.,Singh, K., Codon, B., Sachinvala, N., and David Hui. Nanotochnology in Modern Textiles http://www.mchnanosolutions.com/mechanism.html