Capillary waves, slope correlations, and evaporation at the surface of a drop

Numerical calculations, based on a plausible capillary-wave model and assum ing the existence of a local surface of well-defined slope in the neighbour hood of an evaporating molecule, do not yield acceptable distributions of v elocity or angle for molecules leaving the surface. Calculated correlation functions, for the slopes of the surface at two points a short distance apa rt, fall to zero over distances which are comparable with or less than the dimensions of solvent molecules, so the assumption of a surface of well-def ined slope is incorrect. At high energies, where surface motions are effect ively frozen, this assumption remains valid. (C) 2000 Elsevier Science B.V. All rights reserved.