Scattering of water from the glycerol liquid-vacuum interface

Ilan Benjamin

Department of Chemistry, University of California, Santa Cruz, California 95064

Michael A. Wilson and Andrew Pohorille

Department of Pharmaceutical Chemistry, University of California, San Francisco, California 94143 and NASA Ames Research Center, Moffett Field, California 94035

and Gilbert M. Nathanson

Department of Chemistry, University of Wisconsin-Madison, 1101 University Avenue, Madison, Wisconsin 53706-1322

Molecular dynamics calculations of the scattering of D₂O from the glycerol surface at different collision energies are reported. The results for the trapping probabilities and energy transfer are in good agreement with experiments. The calculations demonstrate that the strong attractive forces between these two strongly hydrogen bonding molecules have only a minor effect on the initial collision dynamics. The trapping probability is influenced to a significant extent by the repulsive hard sphere-like initial encounter with the corrugated surface and, only at a later stage, by the efficiency of energy flow in the multiple interactions between the water and the surface molecules.