Gaining control of pattern formation of dewetting liquid films

Abstract

Thin liquid films on non-wettable solid surfaces are not stable; rather, they are transformed by a symmetry-breaking process termed 'dewetting' into their equilibrium state, a set of droplets. The morphologies observed upon dewetting contain information about the kind of symmetry-breaking process. In this study, we report on experiments on a model system, thin (2-80 nm) polystyrene films dewetting solid substrates, the wettability of which can be varied. We characterize and classify the emerging dewetting patterns. With the help of the effective interface potential, which we determined for our experimental system, we discuss the interplay of short- and long-range forces and the possibilities for influencing the stability of the liquid. Our experimental findings are also in accordance with recent three-dimensional numerical simulations of other groups.