Capillary condensation in one-dimensional irregular confinement

Abstract

A lattice-gas model with heterogeneity is developed for the description of fluid condensation in finite sized one-dimensional pores of arbitrary shape. Mapping to the random-field Ising model allows an exact solution of the model to be obtained at zero-temperature, reproducing the experimentally observed dependence of the amount of fluid adsorbed in the pore on external pressure. It is demonstrated that the disorder controls the sorption for long pores and can result in H2-type hysteresis. Finite-temperature Metropolis dynamics simulations support analytical findings in the limit of low temperatures. The proposed framework is viewed as a fundamental building block of the theory of capillary condensation necessary for reliable structural analysis of complex porous media from adsorption-desorption data.

Impact of Geometrical Disorder on Phase Equilibria of Fluids and Solids Confined in Mesoporous Materials

“…Despite many relevant studies − over many years, geometric disorder has remained neglected in the quantitative analysis of the experimental findings and was mainly the focus of fundamental research mostly addressed in computer modeling studies. − Physical aspects accompanying phase transitions in disordered environments have been thoroughly studied using various realizations of the random-field Ising model, − quenched-annealed lattice gas model, , or its mean-field realizations − by using random quenched porous solids. − These studies have provided deeper insight into many experimental findings such as the return point memory or slow relaxation dynamics. , In the recent decade, this topic has been reiterated in the context of gas–liquid and solid–liquid equilibria in random pores. − …”

A single-walker approach for studying quasi-nonergodic systems

“…it takes place at a lower pressure (or chemical potential) compared to the bulk saturation value 61,62 . While studies of fluids confined in single pores of simple geometry have clarified the mechanism for such shifted transitions [62][63][64][65][66] , the situation in real materials such as mesoporous glasses and silica gels, that consist of an interconnected network of pores of various shape and size, is still under active investigation [67][68][69][70][71][72][73][74] .…”

Modelling Avalanches in Martensites

“…The zero-temperature Random-Field Ising Model (RFIM) is a prototype model for avalanche dynamics that has been applied to study a wide range of phenomena including magnetisation reversal [47,62], fluid invasion [46,63], capillary condensation in porous media [64,65] and even opinion shifts [66]. The RFIM is defined as a set of N spin variables {s i = ±1; i = 1, 2, .…”