Nanosized
clusters of
germanium that can be reacted chemically to make useful materials, such as
plastics, have been made by chemists at the University of Wisconsin-Stevens Point and
UC Davis.
nanoparticles, just a few
atoms in size, can have different properties from
bulk materials because of their small size.
germanium nanoparticles can have luminescent properties and could be used, for example, to make highly efficient
lasers or other
light-emitting devices. But these nanoparticles are difficult to work with without a chemical "handle."
Robin Tanke, an assistant professor of
chemistry at UWSP, worked with UC Davis
chemistry professors Susan Kauzlarich and Tim Patten to put useful
coatings on germanium
nanoclusters. Kauzlarich's laboratory has developed methods for making germanium and
silicon nanoclusters, while Patten's research focuses on attaching
polymer coatings to different kinds of nanoparticles.
Using this approach, the researchers grew chains of
polymers from the nanoparticle surfaces. These materials could be made into
plastics that could be cast as
thin films for
displays or other uses.
The strength of the chemical
bonds between the nanoparticle and the coating makes the materials much more stable, Tanke said.
"You can process them as polymers, without losing the nanoparticles," she said.
The ability to put different types of chemical groups on the surface vastly expanded the possible uses of these
semiconductor nanoparticles, Patten said. For example, one could connect a magnetic nanoparticle to a luminescent one to make a tiny building block that could be precisely moved or positioned on a surface, he said.
Katherine Pettigrew from UC Davis, Drew Murphy and Mark Thompson from the University of Southern California and Howard Lee from UltraDots Inc., Fremont, Calif. also contributed to the work, which was published in the journal Chemistry of Materials.