Coating self-cleans glass and paints.

A deliverance for moms who must continually wipe tiny hand prints off white walls? An end to insect-smeared windshields?

Adam Heller and Yaron Paz, chemical engineers at the University of Texas at Austin, have devised a chemical coating for glass surfaces that automatically clears away most types of dirt and grime. The thin-film titanium dioxide coating functions as a photocatalyst. Reacting with sunlight, it breaks down and strips away deposits of organic debris. It's an adaptation of the catalyst-coated glass beads that Heller developed to break down spilled crude oil (SN:5/22/93, p.322).

Working with 1-inch squares of glass in the laboratory, the researchers have found that the "self-cleaning" coating rids itself of just the kind of organic scum that tends to accumulate on walls and car windows. In a distinctly nonscientific test, Heller said that he has been driving around town with coated glass squares pasted onto his car windows--just to see what happens. "It works," he says. "The dirt comes off."

Because the coating works as effectively on painted surfaces as on glass, Heller envisions new kinds of latex paints for household walls that would clean themselves of fingerprints and food stains when illuminated.