Gas permeation model for mixed matrix membranes: the new renovated Maxwell model

Abstract

ABSTRACT The accurate prediction of gas separation properties of mixed matrix membranes (MMMs) is essential to eliminate the tedious experimental work. In this work, a new model is proposed to predict the gas permeability of MMMs, considering the role of interface voids between the polymer matrix and inorganic fillers. The new model is developed based on an analogy with a model derived for thermal conduction through the particulate composites using effective medium theory. The new model is validated using the gas permeability data of four sets of MMMs containing spherical micro- or nano-fillers reported in the literature. The results show an excellent agreement between new model predictions and gas permeability experimental data with deviations lower than 10% in comparison with the other models (29–43%). In addition, the value of the thickness of the interface voids layer for MMMs, which is difficult to directly determine by experimental methods, is correctly predicted using the new model. Therefore, a new theoretical model named as renovated Maxwell model considering the effect of filler/polymer interface voids is developed to accurately predict the gas permeability of MMMs.