September 17, 2008:By discovering the physical mechanism behind the rapid transport of water in carbon nanotubes, scientists at the U. of Illinois have moved a step closer to ultra-efficient, next-generation nanofluidic devices for drug delivery, water purification, and nano-manufacturing.

“Extraordinarily fast transport of water in carbon nanotubes has generally been attributed to the smoothness of the nanotube walls and their hydrophobic, or water-hating surfaces,” said Narayana R. Aluru, a Willett Faculty Scholar and a professor of mechanical science and engineering at the university. “We can now show that the fast transport can be enhanced by orienting water molecules in a nanotube. Orientation can give rise to a coupling between the water molecules’ rotational and translational motions, resulting in a helical, screw-type motion through the nanotube.”

In addition to explaining recent experimental results obtained by other groups, the researchers’ findings also describe a physical mechanism that could be used to pump water through nanotube membranes in next-generation nanofluidic devices.

Aluru and graduate student Sony Joseph reported their findings in the journal Physical Review Letters.