The Experimental Physical Chemistry program of the Division of Chemistry supports the research of Professor Boris Akhremitchev of the Department of Chemistry, Duke University. Akhremitchev and his students will investigate hydrophobic interactions at a single-molecule level by applying new approaches to atomic force microscopy and single-molecule force spectroscopy. These measurements will probe the interactions between individual hydrophobic molecules in aqueous environments on a nanometer scale. Interacting hydrocarbon molecules will be tethered to a substrate and probe via flexible hydrophilic linkers to avoid surface artifacts. These experiments will explore the dependence of hydrophobic interactions on the size of interacting species and on temperature. This research will test the "dewetting hypothesis," which suggests that for nanometer size hydrophobic solutes a depletion of water density occurs at the surface of the solute. Specific goals of the proposed work include the development of measurement and data analysis procedures to accurately determine activation barrier widths and dissociation rates of single-molecule interactions between hydrocarbons of different sizes.
These studies aim to clarify our molecular level understanding of hydrophobicity in interactions between non-polar molecules in aqueous environments. Hydrophobic interactions are critical for many biological and technological processes and are of fundamental importance in biochemistry, biomedicine, and biotechnology. The research project will train undergraduates and graduate students, as well as minority high school students, in fundamental research in nanoscience. Akhremitchev also will develop a graduate level course in the technical aspects and contemporary applications of atomic force microscopy and single-molecule force spectroscopy.
