A material originally developed by US chemists for use as a marine "antifouling" coating has now been shown to capture fragrance molecules and release them at room temperature. The research team, led by Karen Wooley and James McDonnellv of Washington University in St. Louis say their polymeric material has a remarkable nanostructure that could be exploited for repelling pests, adding fragrance to the air or even as a nasal spray for administering certain drugs. Wooley fused two normally incompatible polymers - a hyperbranched fluoropolymer and a linear polyethylene glycol - let them phase-separate into distinct domains, one interspersed in the other and then cross-linked them to form the product. The resulting material is a heterogeneous, yet nanoscopically mountainous, coating with hydrophilic and hydrophobic ranges, in which barnacles cannot get a foothold. "We have these channels to serve as capillaries to take in guest molecules and hold them inside the material," explains Wooley, and as such guest fragrance molecules, or other species such as insect repellant or a drug, can be trapped by the materials and released subsequently under the right conditions.