Monte Carlo Simulation of Adsorption-Induced Deformation in Finite Graphitic Slit Pores

Abstract

We present a grand canonical Monte Carlo simulation study of deformation in graphitic slit pores induced by argon adsorption at sub- and supercritical temperatures. We find that solvation pressure is the driving force for the deformation. This is analyzed by studying its spatial distribution across the pore in order to understand the effects of adsorbate location on the deformation. We find that (1) pore width affects the packing of the adsorbate molecules and note that the zero solvation pressure at saturation pressure could be used to distinguish between commensurate and incommensurate pores, and (2) thermal fluctuation increases with temperature meaning that molecular excursions are closer to the pore walls at high temperatures, resulting in greater repulsion compared to that at lower temperatures. Consequently, the pore deformation depends on an intricate interplay between packing and thermal fluctuation.