Long-time evolution of interfacial structure in dewetting*

When a solid plate is withdrawn from a partially wetting liquid, a liquid layer dewets the moving substrate. High-speed imaging reveals alternating thin and thick regions in the entrained layer in the transverse direction at steady state. To quantify the absolute thickness of these steady-state structures precisely, I have developed an interferometric technique taking advantage of a varying angle of incidence. This method allows us to measure the absolute thickness as well as the local slope of the thin film. A new technique of likelihood maximization is applied to detect interference fringes. The result shows that the thicknesses of both regions of the film scale with the capillary number, Ca. In addition, a new region is observed during onset which differs from the behavior predicted by previous models.