SPECIAL
CaSTL SEMINAR
HOSTED
BY THE CHEMICAL BONDING CENTER (CBC)
Professor
Maxim S. Pshenichnikov
Rijksuniversiteit
Groningen, the Netherlands
Tuesday,
April 15, 2008
1:00
PM
2201
Natural Sciences II
Title:
"Water Dynamics near Lipid Interfaces"
Abstract: Water layers in proximity of biological
interfaces are strongly influenced by their properties due to specific
water-surface interactions and the truncation of the hydrogen bond network. One
of the efficient approaches to design a model system for such a system is to
use reverse micelles - the nanosize water droplets surrounded by a monolayer of
AOT amphiphilic surfactant. We investigate the dynamics of water in the
reversed micelles of various sizes with two-dimensional infrared correlation
spectroscopy in the OH stretching mode region. For large micelles extremely
fast 200 fs dynamics are observed which are comparable to those for the bulk
water. In contrast, water dynamics in small micelles decelerate to 10Ős of ps.
That is a clear signature of markedly different water properties near the lipid
surface where the relaxation processes and environmental changes are
considerably frozen as compared to bulk state.