Tiny tubes, big riddles
Carbon cylinders’ odd traits continue to stump scientists
Moses didn’t need a physics degree to know something was afoot when that woody bush burned and burned but was not consumed. Set fire to carbon — whether shrubbery, paper or charcoal briquettes — and it burns until nothing’s left but carbon dioxide and water vapor. That’s a fundamental of carbon chemistry.
Yet in the tiny world of nano, where objects and distances measure mere billionths of a meter, rules of chemistry and physics that operate at ordinary scales often don’t apply. Scientists recently discovered, for example, that slathering a minuscule tube of carbon in fuel and lighting one end doesn’t destroy the carbon. Flames course down the nanotube, and it gets scorching hot. But the tube remains intact.
“The carbon doesn’t burn up,” says chemist Michael Strano of MIT, who led the research. “What really should happen is oxidation. They should catch fire; there should be nothing left. But the carbon seems to be unscathed. It’s kind of a walking-across-hot-coals type of thing, where you would expect to be scorched but you’re not.”