Interfacial Compositions and Polypeptide Topologies in Surfactant Assemblies: New Applications of the Chemical Trapping Method

With this renewal award, the Organic and Macromolecular Chemistry Program is continuing support for the work of Dr. Laurence S. Romsted in the Department of Chemistry at Rutgers University in New Brunswick, NJ. Dr. Romsted's work is focused on understanding the species concentrations and chemical reactions that take place at the oil-water interface of micelles, microemulsions, and vesicles. Part of the rationale for doing the work is to understand the behavior of antioxidants at interfaces of this type. Lipid peroxidation, which is decreased by the presence of antioxidants, takes place in a number of diseases and is also involved in the formation of off-flavors and odors in foods as they spoil.

Dr. Romsted has developed a method for studying the concentrations and orientations of molecules at oil-water interfaces using aggregate bound arenediazonium ion as a trap for weakly basic nucleophiles, such as water, hydroxyl group, halide and carboxylate ions, the N and O atoms of peptides, and the head groups of ionic and nonionic surfactants. He has used a variety of methods to probe the interfacial region, including NMR, UV/Vis spectroscopy, fluorescence, IR, and EPR, and shown that his trapping method gives complementary and sometimes unique information not available by the other methods.