Percolation, depinning, and avalanches in capillary condensation of gases in disordered porous solids

Laboratoire de Physique Théorique des Liquides, Université Pierre et Marie Curie 4 place Jussieu, 75252 Paris Cedex 05, France

Received: 23 December 2002
Accepted: 7 March 2003

Abstract

We propose a comprehensive theoretical description of hysteresis in capillary condensation of gases in mesoporous disordered materials. Applying mean-field density-functional theory to a coarse-grained lattice-gas model, we show that the morphology of the hysteresis loops is influenced by out-of-equilibrium transitions that are different on filling and on draining. In particular, desorption may be associated to a depinning process and be percolation-like even without explicitly introducing pore-blocking effects.