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Chemistry professor Tim Long’s research group,
students affiliated with the Macromolecule and Interfaces Institute
(MII) at Virginia Tech, and the U.S. Army Research Laboratory created
a block copolymer, where different monomers are linked in a sequential
manner and form a nanostructured film. They used adenine and thymine
nucleotides, two of the four DNA base pairs that recognize each other.
Then the researchers experimented with different kinds of guest
molecules with complementary hydrogen bonding sites (hydrogen has a
low energy attraction to many types of atoms).
The low energy attraction, means the guest
molecules are widely dispersed throughout the membrane, which then
takes on the properties of the guest molecules. “For example,” said
Long, “if the guest molecules have ionic sites (sites with positive
and negative charges), you will be able to transfer water through a
film because you would have ion channels at the nanoscale. It’s
similar to the way a cell membrane works to control the flow of
specific ions into a cell. You can create protective clothing –
against chemicals – that would still allow water vapor through.”
Salts, as ordinary table salt, are hydrophilic (water
loving) and their introduction into a block copolymer template permits
the placement of the salts at the nanometer dimension. One can imagine
forming of channels of salts that are not visible with the human eye,
but act as a roadway for the transport of water molecules.
“The research is synergy at the
nanotechnology-biotechnology interface,” Long said. |
