Brush with Success

Innovation: A paint that absorbs pollution
Available: Near future

For years, the war on city pollution has been fought with bans on car traffic, taxes, and clean-fuel inducements. But at the European Commission's Indoortron labs in Ispra, Italy, Dr. Dimitris Kotzias may have a better solution: a paint that munches up to 90% of the atmosphere's nitrogen oxide and 30% of its nitrogen dioxide.

This is a lot more exciting than watching paint dry: The new coatings contain nanoparticles of titanium dioxide and calcium carbonate (common chalk). The titanium dioxide traps pollutants and, with a little sunlight, converts them to nitric acid. The calcium carbonate then neutralizes the acid, which the next rain washes away.

The big find: polysiloxane, the polymer used as a base material. Previous polymers were overwhelmed by the titanium dioxide, but polysiloxane is proving strangely resistant. One coat of paint should last five years.

Maryland-based Millennium Chemicals already has filed a patent and is, according to New Scientist, bringing an "ecopaint" to market. (The company says it hasn't set a date.) But Kotzias is even more excited about an indoor version that could decompose benzene--a big contributor to leukemia--from carpets and cigarette smoke. "It would be," he says, "a fantastic application."

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