Unified theory of adsorption, pore-filling and wetting

Abstract

Gases adsorb readily on surfaces and inside porous materials when there exists a sufficiently strong attraction provided by these materials. In the extreme opposite situation, little or no adsorption occurs when the attraction is weak. This paper derives a criterion distinguishing which of these two scenarios occurs at zero temperature. The calculations needed to solve these problems employ a set of simple models, adapted to a wide range of geometries. These include cylindrical, spherical, and slit pores, corners formed at the intersection of flat surfaces, interstitial regions within nanotube bundles, and flat surfaces. In each case, the distinguishing criterion is based on a small number of interaction parameters. © 2007 The American Physical Society.