ABSTRACT
For a thin film of water deposited on a hydrophobic substrate, dry regions appear and grow: this process is called dewetting. It has important practical applications, for example, it governs: - spontaneous drying [1] - the hydroplaning of cars [2] (dewetting between asphalt and rubber) - the operation of 4-color offset printing [3] (dewetting between roller and pa-
per) - the coating of liquid films (for example, the protection of plants by fungicides
in water where dewetting must be blocked). In the last ten years, most studies have focused on dewetting of viscous liquids
on solid substrates. In this case the liquid is collected into a rim around the dry region (the lack of rim formation has been reported on viscoelastic solids [4]). The dynamics which results from a balance between the viscous dissipation in the rim
and the gain in surface energy is now well understood [5, 6]. To be more precise, two regimes have been studied in great details: - metastable regime: below a critical macroscopic thickness the liquid film is
metastable and dewets by nucleation and growth of a dry patch. - spinodal regime: below a microscopic thickness, the film becomes unstable.