ETHANOL ON GRAPHITE - THE INFLUENCE OF HYDROGEN-BONDING ON SURFACE MELTING

Neutron diffraction demonstrates that ethanol physisorbed on the basal planes of graphite forms a commensurate unit cell with a melting temperature of approximately 205 K for coverages from 0.7 to 1.6 monolayers. This temperature is 46 K above the melting temperature of bulk ethanol, making this system unique among species physisorbed on graphite. A microscopic model of the system has been developed using a molecular dynamics simulation. It predicts a two-step mechanism for melting and demonstrates that hydrogen bonding plays a dominant role in stabilizing the two-dimensional solid.