( A chemist at Washington University in S...)Triple threat polymer captures and releases

Karen L. Wooley, Ph.D., Washington University James S. McDonnell Distinguished University Professor in Arts & Sciences, has taken the same materials that she developed more than four years ago as marine "antifouling" coatings that inhibit marine organisms such as barnacles from attaching to the hull of ships to now capture fragrance molecules and release them at room temperature.

Wooley mixes two normally incompatible polymers -- a hyperbranched fluoropolymer and a linear polyethylene glycol -- and lets them phase-separate into distinct domains, one interspersed in the other. A chemical process called crosslinking then solidifies the mixture, thus creating a heterogeneous coating that, upon close examination, reveals treacherous nanometer-sized terrain composed of mountains and valleys, ranging from hard to soft, hydrophilic to hydrophobic. The complex surface that is created makes it difficult for marine organisms to establish a toehold. Her laboratory has produced these novel materials and they are being used around the world

Wooley and her collaborators were intrigued by the surface of these nanostructured materials and began to wonder what was beneath the surface. They found that their materials made a perfect host to serve guest molecules.

"We looked at the roughness and complexity of the surface and thought that the surface might provide interesting entrance and exit ports for small molecule guests," Wooley explained."So , our material would be a host that would act like a sponge, because we have this complex subsurface morphology, and we thought of it as being domains that might be like holes in sponges and other domains that might be like sponge material."

Be my guest'"/>

Source:Washington University in St. Louis