Modelling diffusion from simulated porous structures

An algorithm has been developed for the simulation of liquid diffusion from a porous material in the presence of a concentration gradient. A network model, Pore-Cor, was used to create simulated porous networks. These structures comprised cubic pores connected by cylindrical throats each centred on the coordinates of a three-dimensional 10 × 10 × 10 Cartesian matrix of positions. The simulated structure was then saturated with a mixture of benzene and cyclohexane and immersed in static pure cyclohexane. The algorithm then simulated the diffusion of benzene from the porous structure into the surrounding cyclohexane. The effects on the diffusion process of the geometries of the simulated structures were investigated by generating predefined structures and isolating the effect of each geometric parameter. The method presented in this study should lead to a predictive tool for studying the diffusion processes within real samples, as the pore network model can generate void structures which have porosity and percolation properties that closely match experimental mercury intrusion porosimetry data of real porous materials.