It's summer and time to wipe off the lawn furniture. Wouldn't it be great if the dirt on it just disappeared by itself?
At the Fraunhofer institute in Germany, a team has developed something that sounds like an infomercial product: a coating of titanium dioxide-doped polymers that, when exposed to sunlight, kill germs and might get rid of that funky black mold.
It works because when sunlight hits the titanium dioxide, the ultraviolet rays act as a kind of catalyst, triggering an electrochemical reaction that produces free radicals, the molecules that have a single electron on their surfaces. Free radicals destroy cell walls and infiltrate the DNA inside, damaging it and thereby killing bacteria and fungi. Likewise, the grim and goo these organisms create is also eliminated.