SURFACE MELTING OF ICE INDUCED BY HYDROCARBON FILMS

We apply the continuum theory of van der Waals interactions to a four-component, layered system, composed of a bulk vapor phase, a thin hydrocarbon film, and a water film which is in equilibrium with bulk ice, at the triple point. We rind that for thin hydrocarbon films, these interactions result in a finite film of water at the ice surface with a thickness which increases with the hydrocarbon film thickness, d, reaching a value of about 1000 angstrom for d almost-equal-to 300 angstrom. This corresponds to incomplete surface melting of ice but with a relatively thick wetting layer. However, for larger d, we predict a discontinuous wetting transition as the water film thickness jumps to infinity, indicating complete surface melting of ice.