Nucleation and Pore Geometry Effects in Capillary Desorption Processes in Porous Media: Topical Report.

摘要

A percolation model previously developed by the authors for adsorption-desorption phenomena in porous solids (J. Colloid Interface Sci. 124, 162 (1988)), is extended to include nucleation effects during desorption, and to general size distributions of pore bodies and pore throats. Conditions under which nucleation is likely to be important are delineated. For such cases, desorption is treated as a growth problem with continuous generation of source sites. Accessibility functions are derived for Bethe lattice representations of the porous medium. Similar calculations are presented for the case when pore bodies and pore throats take arbitrary size distributions. The latter find also applications to other related processes in porous media. In view of the theory presented, the interpretation of experimental sorption isotherms is further discussed. 38 refs., 11 figs.