Highly selective mixed-matrix membranes with layered fillers for molecular separation

Abstract

Two-dimensional (2D) layered porous materials are of a considerable interest to researchers due to differences in the sizes of in-plane and out-of-plane confinement. These layered materials have been blended with polymers for the fabrication of mixed-matrix membranes (MMMs) for applications involving separation. The polymers in MMMs serve as a matrix and the 2D layered materials serve as filler used to enhance the separation performance (diffusivity and selectivity) of the polymeric matrix. Unfortunately, the existing models for estimating the effective diffusivity of MMMs with layered fillers are unable to provide reliable predictions. This study proposed a numerical approach to the estimation of effective diffusivity and the selectivity of MMMs using layered fillers based on the mass transfer simulations. In the proposed models, we took into account two critical parameters of the layered fillers: anisotropic diffusivity and orientation distributions. The predictive ability of the proposed approach was evaluated via comparison with experimental data. Finally, we outline the design of highly selective MMMs with layered porous materials based on the proposed methodology.