Nanotube membranes are created

LIVERMORE, Calif., May 25 (UPI) -- U.S. scientists say they've created a nanotube membrane on a silicon chip the size of a quarter that might offer a cheaper way to remove salt from water.

The researchers at the U.S. Department of Energy's Lawrence Livermore National Laboratory say the nanotubes are hollow and more than 50,000 times thinner than a human hair, with billions of the tubes acting as the pores in the membrane.

Scientists said the super smooth interior of the nanotubes allow liquids and gases to rapidly flow, while the tiny pore size can block larger molecules.

The membrane is created by filling the gaps between aligned carbon nanotubes with a ceramic matrix material. The pores are so small only six water molecules could fit across their diameter.

"The gas and water flows that we measured are 100 to 10,000 times faster than what classical models predict," said Olgica Bakajin, a Livermore scientist who led the research. "This is like having a garden hose that can deliver as much water in the same amount of time as fire hose that is 10 times larger."

The research appeared in the May 19 edition of the journal Science.