DYNAMICS OF DEWETTING

Films of silicone oils (or alkanes) deposited on low-energy surfaces (grafted silicon wafers) are metastable. We nucleate a dry spot at the center of the wafer and observe the rate of growth V = dR/dt of the dry patch of radius R. We find that V is (a) independent of R, (b) independent of the film thickness, (c) inversely proportional to the oil viscosity, and (d) very sensitive to the value of theta-e, the equilibrium contact angle between oil and wafer. At small theta-e, V almost-equal-to theta-e3. All these features are in agreement with a recent hydrodynamic theory.