Dynamic Properties of the Aqueous Liquid -Vapor Interfacial Region

University Of California-Berkeley, Berkeley CA

Investigators

Abstract

With the support of the Analytical and Surface Chemistry Program, Professor Marcin Majda of the University of California-Berkeley is investigating the viscoelastic properties of water at the air/water interface. Electrochemistry and electron spin resonance (ESR) techniques are being employed with amphiphilic derivatives of TEMPO (2,2,6,6-tetramethyl-1-piperidinyloxy free radical) as probes. By selecting different polar head groups exhibiting progressively greater immersion depth, the lateral diffusion constants obtained by ESR and electrochemistry are being interpreted in terms of the apparent viscosity of the aqueous interfacial region. An area of focus is on the implementation of ESR Heisenberg spin exchange in the study of interfacial processes. The experimental strategies being pursued are enabling new insights into aqueous interfaces, such as those formed by emulsions, water droplets in the atmosphere and phospholipid membranes contacting water.