Energy implications of 'nano-confined' water

October 07 2008 / by Garry Golden
Category: Science   Year: Beyond   Rating: 5 Hot

Water molecules are central to most energy systems on this planet. Yet when we direct them through tiny nanotubes (a billionth of a meter in diameter) strange things happen to their behavior that might someday have implications for designing new energy systems.

One area deals with the energy intensity of water purification and desalination. Forward looking scientists are turning towards nanoscale engineering to change the cost and energy equation of future water systems.

Last month Indian researchers developed models that applied carbon nanotubes in filtering ‘viruses, bacteria, toxic metal ions, and large noxious organic molecules’. While there is some healthy skepticism over the real world application of nanotubes in water filtration, there is still much that we still do not know about the wide ranging implications of water molecules passing through nanotubes.

Now researchers at the University of North Carolina believe they have found new behavior of water molecules confined to passing through hallow carbon nanotubes made from rolled up graphene or single layer sheets of carbon molecules. One of the key factors of behavior is temperature.

“Normally, graphene is hydrophobic, or ‘water hating’ – it repels water in the same way that drops of dew will roll off a lotus leaf,” said Yue Wu, Ph.D. “But we found that in the extremely limited space inside these tubes, the structure of water changes, and that it’s possible to change the relationship between the graphene and the liquid to hydrophilic or ‘water-liking’.”

This new research area of nano-confined water science could have implications for lower cost water purification and desalination techniques using carbon nanotubes. It might also lead to a better understanding of water molecule behavior inside naturally occurring biological building blocks like proteins which perform key energy conversions.

The Yue Wu Team’s findings were published in the Oct. 3, 2008, issue of the journal Science

Image credit: Ghutchis Flickr CC License