Equilibration dynamics of wetting layers

Abstract

A direct and quantitative investigation of the transport kinetics of wetting layers is presented. The temporal decay of pulsed laser induced spatial thickness modulations in liquid ethanol films on a silver surface is monitored by means of optically excited surface plasmons. Our method allows to distinguish between different equilibration mechanisms. Under the conditions in our experiments, the dominant transport process is direct exchange of molecules with the saturated vapor. Contributions from lateral diffusion were found to be less than 10⁻⁸ cm²/s.