Tuning the Gas Separation Selectivity of a ZIF-90-Polymer Mixed Matrix Membrane through Post-Synthetic Functionalization

Mixed matrix membranes (MMM) are an attractive strategy due to their high selectivity and resiliency in industrially relevant gas separations. However, MMMs have been plagued with low permeability, which limits their industrial feasibility as a large material surface area is needed to achieve the required throughput. Various types of fillers have been examined to enhance the permeability of MMM. Although considerable success has been achieved, there exists a trade-off between permeability and selectivity. Metal-organic frameworks (MOFs) and zeolitic imidazolate frameworks (ZIFs) have particularly received significant attention as fillers in MMMs. As an example, ZIF-90 is highlighted as one of the most attractive materials to be used as a filler owing to its structural and chemical properties (i.e. sodalite topology, large surface area of 1320 m2 g-1, and appropriately sized pores of >11 with a relatively small window size of