Nanotechnology is allowing for textiles with ground breaking new properties from UV-protection to drug delivery.
The application of nanomaterials to textiles involves the modification of existing textile materials using electrostatic self-assembly and atomic layer deposition techniques to create novel and customizable surfaces on conventional textile substrates with an emphasis on natural fibers. Textiles modified with nanomaterials display huge advantages as conventional methods used to impart different properties to fabrics often do not lead to permanent effects, and will lose their functions after laundering or wearing. Nanomaterials allow for increased durability for fabrics, as nanoparticles have a huge surface area-to-volume ratio and high surface energy. This allows for better affinity for fabrics and an increase in durability, without affecting the breathability or hand feel.
Desirable functional properties for the textiles industry afforded by nanomaterials include soil repellence, UV protection, anti-bacterialism, abrasion resistance and drug delivery, and these areas have been commercialized to different degrees of effectiveness and practicality. Current applications for fibers and textiles incorporating nanomaterials include stain resistant clothing, anti-odor sportswear, anti-microbial medical textiles, conducting cloth, and water repellent fabrics and textiles or a combination of these. Nanomaterials are also being developed for protective clothing for firefighters, emergency responders, and military personnel that selectively blocks hazardous gases and minuscule contaminants but allows air and moisture to flow through.
Stain repellent fabrics and textiles are already on the market incorporating nanomaterials, as are nanocrystalline based wound dressings and patches for delivery of anti-microbials and aromatherapeutics. Brand owners who utilise the coatings in products include New Balance, Gap, Old Navy, Target, Smith and Nephew, Hugo Boss, Paul Stuart, Rene Lezard, Lee, Nike, Champion, Levi and Simmons. For imparting anti-bacterial properties, nano-sized silver, titanium dioxide and zinc oxide are routinely used as they have a sterilising effect. Nano-silver is currently being applied in applications such as anti-bacterial sportswear and medical dressings. Water and oil repellence is extremely desirable in textiles, and the so-called lotus effect, a biomimetic approach for fabrication of ultra hydrophobic fibers with repellency and self-cleaning ability, is one that has received a great deal of coverage over the past decade, without a huge degree of commercial success. Other nanomaterials employed in textiles include silicon oxide, nanoclays, nanotubes and nanofibers. BASF produces a lotus-effect aerosol spray that combines nanoparticles with hydrophobic polymers such as polypropylene, polyethylene and waxes. Mincor TX TT is a composite material consisting of nanoparticles embedded in a carrier matrix. This finish may provide solution for the fabrics like polyester awning, sunshades, flags and sails that are generally required to remain continuously in outdoor environment; therefore these can not be cleaned in washing machine. Other applications in textiles include sweat-resistant anti-staining fiber products, self-cleaning household goods and clothing and waterproof clothing.
The UV-blocking property of a fabric is enhanced when a dye, pigment, delustrant, or ultraviolet absorber finish is present that absorbs ultraviolet radiation and blocks its transmission through a fabric to the skin. Organic compounds that absorb in the UV range or inorganic metal oxides such as TiO2 are being applied for UV protection in textiles. Products on the market include Belfasun from Pulcra Chemicals (www.pulcra-chemicals.com), which contains nanoparticulate zinc oxide and UV cotton textiles with nanosilver coatings from JR Nanotech (www.jrnanotech.com).
Alexium International (http://alexiuminternational.com) has recently announced a commercial agreement with Duro Textiles, LLC (www.duroindustries.com) to apply Alexium’s novel, environmentally friendly, bromine and halogen free, flame retardant (FR) treatment for commercial and military customers in North America. Duro and Alexium are targeting a North American current market opportunity in excess of 4 million linear yards of nylon. The company’s Reactive Surface Treatment process is a low energy process that can be applied to a variety of materials and surfaces. Alexium has also been awarded a $200,000 contract with the US Air Force Research Laboratory to demonstrate Cleanshell® CB treatments for chemical and biological protection applications. An estimated 200,000 chemical and biological protection suits are purchased annually by the US military.
Alexium’s Cleanshell® CB repellency treatment is targeted specifically to the treatment of the outershell fabric of CB protection ensembles. Alexium’s Cleanshell® CB treatment has been optimized to provide excellent water and oil repellency, but has also shown dramatically increased repellency of Chemical Warfare Agent simulants.
At present there are over 100 companies developing nanotechnology enabled textile products.Vestagen Technical Textiles (http://www.vestagen.com) produces Vestex nanocoatings that can help prevent the formation of potentially dangerous microorganisms on hospital and healthcare textiles, such as scrubs, uniforms, laboratory coats, privacy curtains and gowns. Clariant (http://www.clariant.com) and Schoeller Technologies AG (http://www.schoeller-tech.com) develop textile materials finished with Nanosphere repel liquids, dirt and stains. Japanese company Toray (http://www.toray.com) produces ‘Nano-Plem’ technology that imparts water- repellant characteristics and color resilience to nylon and polyester fabrics, and Terylene/ wool blends. Nano-Tex (http://www.nano-tex.com) is a leading producer of nanocoated textile finishes for increasing durability, water and oil repellency, and stain resistance. Their chemical formulation and application technology is easily adopted by existing textile mills and embeds textiles with “nanowhiskers” that make the fabric dense, increasing the surface tension so drops of liquid can’t soak through.
Other companies in the market include Advanced Nano Products, Inc., ARC Technologies, Asahi Kasei, Beijing ChamGo Nano-Tech Co, CC-NanoChem, Ciba Specialty Chemicals, Industrial Nanotech, Inc, Innotech Textile Co. Ltd, J2LFA Co. Ltd, NanoHorizons, Nano-Care AG, NanoSonic Inc.,, nCoat, Inc, iFyber, LLC, De Cie GmbH, Eeonyx Corporation, HeiQ Materials AG and iFyber, LLC. A comprehensive list and market study will be publised by Future Markets, Inc. in late 2012.
The Main Players…
1 Nano-Tex
www.nano-tex.com
Develops SiO2 coatings for textiles. Products include Resists Spills, Coolest Comfort , Resists Static and Repels and Releases Stains.
2 P2i Ltd.
www.p2i.com
P2i’s plasma technology enables the surfaces of textiles be enhanced with a super oleophobic and hydrophobic treatment while leaving the other properties of the product unchanged.
3 Schoeller
www.schoeller-tech.com
Schoeller eveloped the NanoSphere technology to make water-repellent fabrics. NanoSphere impregnation involves a three-dimensional surface structure with gel-forming additives which repel water and prevent dirt particles from attaching themselves. The mechanism is similar to the lotus effect.
