Shaping the Morphology of Metal–Organic Frameworks for Gas Separation via Mixed-Matrix Membranes

The affinity between polymer matrices and porous fillers governs the mixing efficiency and separation performance of mixed-matrix membranes (MMMs). Herein, we demonstrate the shaping of the morphology of the metal–organic framework, MFM-300(Sc), into nanoplates for gas separation using MMMs. Introducing coordinatively competing modulators as inhibitors can shape the crystallites into the desired morphology, while the introduction of sterically hindered linkers as modulators results in missing-linker defects, as evidenced by solid-state NMR spectroscopy. The nanoplate crystals of MFM-300(Sc) can be dispersed evenly in a polyimide matrix, leading to MMMs with significantly improved performance for the separation of CO2/N2 as a function of the chemical derivatization of the MOF filler. Moreover, the generality of the proposed strategy is demonstrated by the successful preparation and shaping of nanoplates of MFM-300(M) (M = Ga, In).