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.

Estimation of adsorption-induced pore pressure and confinement in a nanoscopic slit pore by a density functional theory

“…the least ordered states in non-commensurate pores [20,22] maybe as a result of less complete maps of pore pressure vs pore widths. This emphasizes the usefulness of the calculation speed of DFTs.…”

“…Different authors used Monte Carlo simulation tools to study the pore fluid pressure profiles within nanopores. Do and coworkers performed Grand Canonical Monte Carlo simulations for argon [21,22], methane and methanol [23] in slit-shaped micropores with movable solid layers to compute the pore pressures and corresponding deformations. Kowalczyk and coworkers studied adsorption-induced deformation of microporous carbons filled with carbon dioxide [24,25] and near-critical argon [26].…”

Adsorption-induced deformation of nanoporous materials—A review

“…A number of papers employed molecular modeling techniques for predictions of adsorption-induced strains in various nanoporous materials: Monte Carlo simulations 40,[81][82][83][84][85][86][87][88][89][90][91][92] or classical density functional theory (DFT). [93][94][95][96] At the same time, several purely analytical theories were also proposed.…”

Ti3C2 MXene Paper for the Effective Adsorption and Controllable Release of Aroma Molecules

“…However, the weak original (002) peak is still present in the XRD spectra, which could be attributed to the residual nanosheets that are not intercalated with PA. According to the work of Diao et al on slit pore deformation, the expansion of interlayer space is thought to be induced by the positive solvation pressure before capillary condensation of molecules in the mesopores, thus, leading to the deformation of interlayer space. The graphene paper as a reference material was subjected to the same PA adsorption process for comparison.…”