The researchers described their work on the
so-called self-cleaning coating last week during the 56th Southeast
Regional Meeting of the American Chemical Society, the worlds largest
scientific society, held in Research Triangle Park, N.C.
The coating doesnt actually clean itself, but it
does resist dirt much better than other fabric treatments, explains
research team member Phil Brown, Ph.D., a textile chemist with Clemson
University in Clemson, S.C. The concept is based on the lotus plant,
whose leaves are well-known for their ability to self-clean by
repelling water and dirt. Likewise, when water is exposed to the
treated fabric, the dirt will be carried away more easily. You will
still need some water to rinse away dirt and stains, but cleaning will
be quicker and less frequent.
Unlike conventional water-repellant coatings, the
new coating, which doesnt yet have an official name, is permanently
bonded onto the fibers of the fabric and will not wash off, Brown says.
In addition, no fluorine-based chemical finishes are used so there are
potential environmental advantages, according to the researcher. The
research team is also trying to engineer antimicrobial particles into
the coating, which could help repel strong odors such as body odor and
even cigarette smoke, they say.
Dirt adheres to the fibers of most fabrics. To
clean the fabrics, people typically put them in the washer or send
them to the dry cleaners. But the water-repellency of fabrics made
with the new coating is superior and makes it easier to keep dirt from
accumulating, Brown says, because water that is applied to the garment
rolls off and takes the dirt with it. Suits made with the new coating
could simply be sprayed clean or wiped with a damp cloth to remove the
dirt, the researcher says. If desired, the fabric can still be cleaned
by conventional means, including washing as well as dry cleaning,
without harming the coating, he notes.
In addition to suits, the new coating could be
applied to hospital garments, sportswear, military uniforms and rain
coats. Other possible applications include awning material for outdoor
campers, fabrics for lawn furniture and convertible tops for cars. The
coating could appear in consumer products within five years, the
Prices of clothing and other products treated with
the new coating will initially be a bit more expensive than other
water-repellant garments, Brown predicts. But he and his associates
are currently working on ways to make the coating cheaper.
Self-cleaning fabrics can be made in any color,
according to Brown, since the treatment is applied after the fabric
has been dyed. If youre concerned that clothes coated with the silver
nanoparticles will activate an alarm at an airport security stop,
dont worry. The material is unlikely to be detected by conventional
metal detectors, he says.
Other researchers involved in the project include
team leader Igor Luzinov, Ph.D., a polymer scientist, and George
Chumanov, Ph.D., a physical chemist, of Clemson; and Sergiy Minko,
Ph.D., a polymer scientist with Clarkson University in Potsdam, N.Y.
The National Textile Center, a research consortium
of eight universities, provided funding for this study from a grant
administered by the U.S. Department of Commerce.