Dynamics of dewetting at the nanoscale

Abstract

We use large-scale molecular dynamics simulations to model the dewetting of solid surfaces by partially wetting thin liquid films. As observed experimentally and in previous simulations, the films recede at an initially constant speed, creating a growing rim of liquid with a constant receding dynamic contact angle. Film recession is faster on the more poorly wetted surface to an extent that cannot be explained solely by the increase in the surface tension driving force. Furthermore, the rates of recession of the thinnest films are found to increase with decreasing film thickness. These results suggest not only that the mobility of the liquid molecules adjacent to the solid increases with decreasing solid-liquid interactions, but also that the mobility adjacent to the free surface of the film is higher than in the bulk, so that the average viscosity of the film decreases with thickness. Recent simulations of films with a wide range of solid-liquid interactions lend support to this view.