technologyreview.com: By Prachi Patel-Predd

Researchers at Monash University, in Victoria, Australia, have found a way to coat fibers with titanium dioxide nanocrystals, which break down food and dirt in sunlight. The researchers, led by organic chemist and nanomaterials researcher Walid Daoud, have made natural fibers such as wool, silk, and hemp that will automatically remove food, grime, and even red-wine stains when exposed to sunlight.

Daoud and his colleagues coat the fibers with a thin, invisible layer of titanium dioxide nanoparticles. Titanium dioxide, which is used in sunscreens, toothpaste, and paint, is a strong photocatalyst: in the presence of ultraviolet light and water vapor, it forms hydroxyl radicals, which oxidize, or decompose, organic matter. However, says Daoud, “these nanocrystals cannot decompose wool and are harmless to skin.” Moreover, the coating does not change the look and feel of the fabric. [ read more ]