Nano-finishing in fabric

[nawshin farzana]

Nanotechnology has been discovered by the textile industry  – in fact, a new area has developed in the area of textile finishing called "Nanofinishing".   Making fabric with nano-sized particles  creates many desirable properties in the fabrics without a significant increase in weight, thickness or stiffness, as was the case with previously used techniques.    Nanofinishing techniques include: UV blocking, anti-microbial, bacterial and fungal, flame retardant, wrinkle resistant, anti-static, insect and/or water repellant and self-cleaning properties.

One of the most common ways to use nanotechnology in the textile industry is to create stain and water resistance.   To do this, the fabrics are embedded with billions of tiny fibers, called "nanowhiskers" (think of the fuzz on a peach), which are waterproof and increase the density of the fabric.  The Nanowhiskers can repel stains because they form a cushion of air around each cotton fiber. When something is spilled on the surface of the fabric, the miniature whiskers actually cohesively prop up the liquid drops, allowing the liquid drops to roll off.   This treatment lasts, they say, for about 50 home wash cycles before its effectiveness is lost.  A corollary finish is that of using nanoparticles to provide a "lotus plant" effect  which causes dirt to rinse off easily, such as in the rain.

Nanotechnology can also be used in the opposite manner to increase the ability of textiles, particularly synthetics, to absorb dyes. Until now most polypropylenes have resisted dyeing, so they were deemed unsuitable for consumer goods like clothing, table cloths, or floor and window coverings. A new technique being developed is to add nanosized particles of dye friendly clay to raw polypropylene stock before it is extruded into fibres. The resultant composite material can absorb dyes without weakening the fabric.

The other main use of nanoparticles in textiles is that of using silver nanoparticles for antimicrobial, antibacterial effects,  thereby eliminating odors in fabrics.  Nanoparticles of silver are the most widely used form of nanotechnology in use today, says Todd Kuiken, PhD, research associate at the Project on Emerging Nanotechnologies (PEN). "Silver's antimicrobial property is one that suits a lot of different products, and companies pretty much run the gamut of how many consumer products they put it in."