Fluids Confined in Porous Materials: Towards a Unified Understanding of Thermodynamics and Dynamics

Abstract

AbstractA recently developed theoretical approach to understand the relaxation processes for fluids confined in mesoporous materials, especially in adsorption/desorption from bulk gases, is discussed. The theory is based on a lattice gas formulation of the molecular interactions in the system and is referred to as dynamic mean field theory. The theory has the important property that the limiting behavior at long times is consistent with the results from mean field theory (or density functional theory) for the model. In this sense it provides a unified picture of thermodynamics and relaxation dynamics for the system. Two illustrative applications are presented. The first is to the dynamics of capillary condensation in a finite length slit pore in contact with a bulk gas. The second application is to the dynamics of cavitation during desorption from an inkbottle pore in contact with the bulk gas. The outlook for future developments and applications of the approach is also discussed.