Cotton and Clay Make a "Hot" Pair
April 6, 2004
Service scientists have merged two natural products, each with unique
qualities, to create a brand-new material that offers both heat tolerance and
toughness. Chemist Leslie A. White and mechanical engineer Christopher D.
Delhom have accomplished this by joining cotton fibers with particles of clay.
The resultant material--boasting cotton's softness and clay's
durability--could someday be used as fabric for protective apparel and as
insulation that protects against fire in homes.
Readily available in a pure and usable form, clay minerals can
enhance the flame-retardant properties of a textile. They also give it
strength. Scientists have known this for some time, but they've never before
tried pairing clay with a plant material, such as cotton.
Compared to unbleached cotton, the combination cotton-and-clay
product has an increased heat tolerance of 70 to 85 degrees Fahrenheit.
White, who's located in the ARS
Chemistry Research Unit of the
Southern Regional Research
Center in New Orleans, La., was able to create the novel fibers by
dissolving cotton fibers with a solvent and then mixing in clay particles on a
Montmorillonite clay particles, the same type used in some cat
litters, are incorporated into the cotton fibers as microscopic-sized
particles. Once the mixture is dried and the solvent removed, the tiny clay
particles become dispersed and embedded throughout the cotton matrix.
Not only is this cotton-clay "nanocomposite" natural, but the
process by which the two components are joined is considered environmentally
friendly. The solvent used to dissolve the cotton fibers is recyclable and is
applied in a closed system.
White and Delhom are investigating a range of cellulosic fibers,
including those of wood, grass, leaves and even recycled newspaper, to see if
they can be beneficially transformed with the addition of different types of
about the research in the April issue of Agricultural Research
ARS is the U.S. Department of
Agriculture's chief scientific research agency.