Surface interactions of graphitic sheets and water: A study of the hydrophobic effect

PHYS 464

Estelle M. Huff, emhuff@uark.edu, Department of Chemistry and Biochemistry, University of Arkansas, Chem 101, Fayetteville, AR 72701 and Peter Pulay, pulay@uark.edu, Department of Chemistry and Biochemistry, University of Arkansas, Chemistry Building, Fayetteville, AR 72701.
The interaction energy between a coronene molecule as a model for a graphitic sheet and a water molecule above it have been calculated at the DFT and MP2 levels using a modified 6-311++G** basis set. The two methods give similar results, showing that dispersion plays only a minor role, unlike in the interaction between two graphitic sheets. The lowest energy orientation has both hydrogen atoms of the water pointed down symmetrically towards the graphitic surface. This is different from the lowest energy orientation of the water-benzene system where one hydrogen points toward the center of the ring. The data were parametrized as a function of the water position and orientation. The calculations are being extended to water clusters, with the goal of supplying data for molecular dynamics simulation of the interaction between water and a hydrophobic surface.
 

Poster Session
7:30 PM-10:00 PM, Wednesday, 13 September 2006 Moscone Center -- Hall D, Poster

Sci-Mix
8:00 PM-10:00 PM, Monday, 11 September 2006 Moscone Center -- Hall D, Sci-Mix

Division of Physical Chemistry

The 232nd ACS National Meeting, San Francisco, CA, September 10-14, 2006