Dewetting on porous media

Removal of a liquid on porous substrates involves two mechanisms: suction a nd dewetting. 1) We study rst the dewetting with no suction of a liquid lm deposited on a porous membrane. We report the rst observation of a finite r eceding angle on a saturated porous surface. Below a critical receding thic kness e(r), the lm dewets by nucleation and growth of a dry patch. 2) To al low for both mechanisms, we study the aspiration of a hole in the liquid lm pumped with a constant current J. Two growth regimes are observed and inte rpreted: i) a suction regime at high J and ii) a dewetting regime at low J.