Enhancing Hydrogen Separation Performance through ZIF-8 Incorporated PMMA-PC Blend-based Mixed Matrix Membranes

Abstract

This work is mainly dedicated to addressing the critical challenge of simultaneously enhancing both permeability and selectivity in polymeric membrane-based gas separations, which are currently constrained by inherent trade-off limitations. Cubical Zeolitic Imidazolate Framework-8 (ZIF-8) nanoparticles were prepared through a wet-chemical route, utilising hexadecyltrimethylammonium bromide (CTAB) as a surfactant to control the desired size and morphology. The nanocubes of average size around 150 nm were used as filler in Poly(methyl methacrylate) (PMMA) for the fabrication of mixed matrix membranes for enhanced gas separation performance. Further improvement in the performance was achieved by the polymer blending method using polycarbonate (PC) polymer. The structural, morphological, and mechanical properties of these mixed matrix membranes are characterised systematically. The 7.5% ZIF-8/PMMA-PC blended MMMs have shown a 269% rise in H2 permeability, with a 51% rise in H2/CO2, and a 105% rise in H2/N2 selectivity values. These results highlight the impact of ZIF-8 loading and blending of PMMA with PC, significantly influencing the membrane performance, thereby underscoring the potential of ZIF-8/PMMA-PC blended mixed matrix membranes in effective hydrogen separation and refinement applications.