Hansen solubility parameters-guided mixed matrix membranes with linker-exchanged metal-organic framework fillers showing enhanced gas separation performance

Abstract

Membrane processes are more efficient for sustainable separations than traditional energy-intensive technologies, but they suffer from the trade-off limitation about permeability and selectivity. Construction of mixed matrix membranes (MMMs) is effective for improving molecular permselectivity. However, like all hybrid materials that are vitally affected by phase compatibility, production of MMMs with uniform filler dispersion and strong filler-matrix interaction remains extremely challenging. Moreover, there is a lack of generally available guideline for MMM construction. In this study, a versatile Hansen solubility parameters (HSPs)-guided concept, inspired by “like seeks like” principle, is developed to design high-performance MMMs. Based on HSP analysis of porous polymer matrix, metal-organic framework (MOF) filler, and casting solvent, it is found that filler phenylation can shorten HSP “distance” between different components of MMMs. Through surface linker exchange of MOFs by daughter linker that contains HSP-similar phenyls to perform phenylation, the filler-polymer compatibility and the filler dispersity in solvent and matrix are substantially improved, thereby facilitating the construction of MMMs with ultrahigh filler loading. For carbon capture and hydrogen purification, the HSP-guided MMMs exhibit remarkably enhanced permeability and selectivity, which can easily surpass the latest permeability-selectivity trade-off limitations.