New nanomaterial freshens air, repels bugs, delivers drugs . . . and removes barnacles

Filed in archive Materials on June 10, 2006

Talk about a product that can do it all . . .

A chemist at Washington University in St. Louis has developed a remarkable nanostructured material that can repel pests, sweeten the air, and some day might even be used as a timed drug delivery system - as a nasal spray, for instance - says a Washington University press release.

Karen L. Wooley, Ph.D., (pictured, left), 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 ship hulls 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

"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."

"This material could be very useful as something to promote the release of a volatile agent," she said, "maybe for some kind of nasal inhalation-based delivery of drugs. Or maybe something as simple as a room-temperature release of a fragrance." (photo David Kilper/WUSTL)