CAPILLARY CONDENSATION, INVASION PERCOLATION, HYSTERESIS, AND DISCRETE MEMORY

A model of the capillary condensation process, i.e., of adsorption-des orption isotherms, having only pore-pore interactions is constructed. The. model yields (1) hysteretic isotherms, (2) invasion percolation o n desorption and (3) hysteresis with discrete memory for interior chem ical potential loops. All of these features are seen in experiment. Th e model is compared to a model with no pore-pore interactions (the Pre isach model) and iv a related model of interacting pore systems (the r andom field Ising model). The capillary condensation model differs fro m both.