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.
Market drivers
The market for anti-microbial textiles has grown greatly in the last few years, driven by the increased need of consumers for fresh, clean and hygienic clothing.
Nanomaterials also 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.
Performance benefits
Desirable functional properties for the textiles industry afforded by nanomaterials include:
• electroconductive/antistatic (nanomaterials utilized include CNT, Copper, Polypyrrol, graphene and Polyaniline )
• UV protection (Titanium dioxide (rutile), Zinc oxide)
• anti-microbialism (Silver, Chitosan, Silicon dioxide, Titanium dioxide, Zinc oxide)
• gas barrier
• durability (Aluminum oxide, CNT, Polybutyl acrylate , Silicon dioxide, Zinc oxide)
• abrasion resistance (CNT)
• drug/fragrance delivery (Nanostructured hollow bodies (e.g. cyclodextrine-based) , Montmorillonite (nanoscale clay), Silicon dioxide)
• flame retardant (CNT, Boroxosiloxane, Montmorillonite nanoclay, Antimony ash )
• self-cleaning (CNT, Fluoroacrylate, Silicon dioxide , anatase titanium dioxide)
• moisture absorbent (titanium dioxide)
• heat conducting or insulating properties (CNT , Vanadium dioxide)
• EM shielding (Indium tin oxide)
• improved dyeability (nanoporous hydrocarbon-nitrogen coating, Silicon dioxide).
These areas have been commercialized to different degrees of effectiveness and practicality.
Commercialization
At present there are over 100 companies developing nanotechnology enabled textile products. 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.
There are a number of consumer textile products on the market incorporating nanomaterials. Nanosilver is used widely in anti-microbial textiles finishes, including medical textiles.
Products on the market include nanosilver coated socks that kill the bacteria associated with foot odour. Ant-microbial products with nano ZnO, TiO2 and SiO2 Nano-ZnO have also been impregnated onto cotton textiles.
Incorporation of conductive nanocoatings in textiles could lead to improvement in electronic devices and enable the development of next-generation functional fabrics (electronic textiles). Graphene is a leading candidate and recent research has focused on conductive, flexible, and durable reduced coated with graphene oxide. Vorbeck Materials is utilizing graphene conductive inks to produce electronic textile products. Carbon nanotubes are another widely investigated candidate.
Current applications for fibers and textiles incorporating nanomaterials include:
• stain resistant clothing
• anti-odour sportswear
• anti-microbial medical textiles
• conducting cloth
• water repellent fabrics and textiles.
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. Main markets are interior trim and upholstery, sports and leisure, automotive interiors, protective clothing, and medical textiles. In household products, antibacterial textiles are incorporated into kitchen clothes, sponges or towels. In the medical sector, products include antibacterial wound dressings, patient dresses, bed lines or reusable surgical gloves and masks.
