The thermal roughening of liquid surfaces and its effect on gas–liquid collisions

Abstract

Collisions of inert gases with a perfluorinated liquid over an 85 K range reveal how gas–liquid energy transfer depends on the temperature of the liquid. At higher temperatures, thermal accommodation of impinging Ne, Ar, and Xe atoms grows at the expense of prompt inelastic scattering. The experiments suggest that hotter liquids possess rougher surfaces, which promote multiple collisions that dissipate the atom’s incident energy and which may momentarily trap gases in gaps created by incommensurate packing of the surface molecules. The fraction of energy transferred during a high energy impulsive collision remains almost unaltered by changes in the liquid’s temperature, implying that impulsive encounters within the scattering plane are dominated by single collision events.