Sorption and Phase Transitions in Nanopores

Alexander V. Neimark, Peter I. Ravikovitch, Aleksey Vishnyakov Center for Modeling and Characterization of Nanoporous Materials TRI/Princeton, 601 Prospect Avenue, Princeton, NJ 08542, USA E-mail: [email protected] Abstract We present new results on MC simulations and Density Functional Theory modeling of sorption and phase transitions in nanopores. Major attention is paid to the problems of metastability and hysteresis. It is shown that the construction of the full phase diagram, tracing continuously stable, metastable, and unstable states, sheds light on the peculiarities of equilibrium and spontaneous transitions. The proposed methods allow one to predict the adsorption isotherm, the pressure of equilibrium vapor-liquid transition, and the limits of adsorption hysteresis. Simulation and theoretical results are found to be in agreement with reference adsorption measurements.