Estimating models for predicting effective permeability of mixed matrix membranes

Mixed matrix membranes have become a highly potential unique materials in many engineering application to overcome limitations presented by other products. In this contribution, an improved form of Maxwell's equation (the extended Maxwell equation) based on the hard-sphere model fluid proposed by Chiew and Glandt [Y.C. Chiew, E.D. Glandt, The effect of structure on the conductivity of a dispersion, J. Colloid Interface Sci. 94 (1983) 90-104] is evolved. The resulting equation allows the estimation of the effective permeability of composite membranes as a function of the reduced permeation polarizability and the volume fraction of the filler. This method can be applied to estimate effective permeability of gases and liquids through mixed matrix membranes prepared with different polymer matrix, as continuous phase, and organic (polymer or liquid crystal mixture) or inorganic (zeolites, activated carbons) compounds as filler even at relatively high volume fractions of this compound. A comparison among estimated values of the effective permeability and experimental data reported in the literature generally shows good agreement although there are a number of observations that are not easily explained with any of these models. (c) 2005 Elsevier B.V. All rights reserved.