Adsorption of Gases in Nanomaterials: Theory and Simulations

Abstract

Physical adsorption (physisorption) is the study of atoms or molecules weakly bound to material surfaces. Physisorption-related investigations raise critical questions concerning phase transitions, fractals, wetting transitions, two-dimensional superfluidity, and Van der Waals interactions. This chapter focuses on adsorption of gases (e.g. Ar, Kr, H 2 , CO 2 , and CH 4 ) in nanomaterials, and in particular the authors describe equilibrium properties of the gases adsorbed in carbon nanotubes, graphene and Metal Organic Frameworks (MOFs). The adsorption potential used for developing the theoretical model for studying physisorption involves the summing of two-body interactions, and several important properties of adsorbates can be obtained via simulations, namely equilibrium properties, thermal characteristics, selectivity, wetting features, and structure and phase of the adsorbed monolayer. Applications of physisorption include the separation of cryogenic gases, their storage and their use as a surface characterization tool.