Impact of noise on spinodal dewetting of liquid-liquid films

The dewetting processes that occur between moving interfaces have been studied extensively but the dynamics of liquid bilayer systems still pose a number of open questions. Here, the authors combine experimental and theoretical results of spinodal dewetting of one liquid from another to suggest it is necessary to develop new strategies for incorporating thermal fluctuations into the modelling of such systems. Spinodal dewetting provides fundamental insights into the physics at interfaces, such as van der Waals forces driving dewetting, dissipation processes or thermal fluctuations. The dewetting process of liquid bilayer systems still raises open problems involving two coupled moving interfaces. Comparison of experimental results of spinodally dewetting liquid polystyrene films from liquid polymethylmethacrylate substrates, with predictions from linear stability analysis, we demonstrate that both the spinodal wavelength and the rupture times show significant differences. Key for this discrepancy is the altered mode selection process due to the initial surface roughness of the liquid-air and liquid-liquid interfaces, which is perturbed by partially correlated colored noise in the linearly unstable region. The strong effect of noise on mode selection and rupture time is confirmed by comparing experimental results with numerical solutions of the full dynamic nonlinear model and suggest new strategies to include thermal fluctuations into modeling these processes.