Imagine
jeans, sweats, or socks that clean and de-odorize themselves when hung
on a clothesline in the sun or draped on a balcony railing. Scientists
are reporting development of a new cotton fabric that does clean itself
of stains and bacteria when exposed to ordinary sunlight. Their report
appears in ACS Applied Materials & Interfaces.
Mingce
Long and Deyong Wu say their fabric uses a coating made from a compound
of titanium dioxide, the white material used in everything from white
paint to foods to sunscreen lotions. Titanium dioxide breaks down dirt
and kills microbes when exposed to some types of light. It already has
found uses in self-cleaning windows, kitchen and bathroom tiles,
odor-free socks, and other products. Self-cleaning cotton fabrics have
been made in the past, the authors note, but they self-clean thoroughly
only when exposed to ultraviolet rays. So they set out to develop a new
cotton fabric that cleans itself when exposed to ordinary sunlight.
Their
report describes cotton fabric coated with nanoparticles made from a
compound of titanium dioxide and nitrogen. They show that fabric coated
with the material removes an orange dye stain when exposed to sunlight.
Further dispersing nanoparticles composed of silver and iodine
accelerates the discoloration process. The coating remains intact after
washing and drying.