Comparison of transport characteristics and textural properties of porous material; the role of pore sizes and their distributions

For a set of six porous materials with a range of mean pore radii from 50 to 3000 nm, and mono- or bidisperse pore structure, transport characteristics and textural properties were compared. Two standard methods (mercury porosimetry and helium pycnometry) together with liquid expulsion permporometry (that takes into account only flow-through pores) were used for determination of textural properties. Pore structure characteristics relevant to transport processes were evaluated from multicomponent gas counter-current diffusion and gas permeation. For data analysis the Mean Transport-Pore Model (MTPM) based on Maxwell-Stefan diffusion equation and a simplified form of the Weber permeation equation was used. It appears that for porous solids with monodisperse pore-size distribution the MTPM mean-pore radii and transport-pore distributions agree with the information from standard textural analysis. For porous solids with bidisperse pore-size distribution the MTPM mean-pore radii and transport-pore distributions are close to large pore sizes from standard textural analysis.