De novo synthesis of amino-functionalized ZIF-8 nanoparticles: Enhanced interfacial compatibility and pervaporation performance in mixed matrix membranes applying for ethanol dehydration

The incorporation of attainable amine functionality in zeolitic imidazolate framework-8 (ZIF-8) is utilized to enhance the pervaporation performance for ethanol/ water separation applications. Using 2-aminobenzimidazole, a ligand with NH 2 -functionalized group, displacement of the ZIF-8 original ligand during de novo synthesis while preserving the ZIF-8 initial structure, which produces a novel mixed- linker ZIF material (ZIF-8-NH 2 ) with smaller nanocrystal size, controllable pore size, and enhanced hydrophilicity. A series of different mixed matrix membranes (MMMs) were fabricated by incorporating ZIF-8-NH 2 into poly(vinyl alcohol) (PVA) matrix. Various characterization techniques, such as FTIR, 1 H NMR, XRD, SEM, TGA, and Contact angle etc. were employed to demonstrate the properties of prepared ZIF nanoparticles and the MMMs. The results indicated that ZIF-8-NH 2 and the MMMs were perfectly fabricated, which were attributed to better dispersion and compatibility between them. In particular, 7-ZIF-8-NH 2 /PVA MMM exhibited a comparable total flux of 142 g/m 2 ·h and water/ethanol separation factor of 925, which were increased by 73 and 524%, on the basis of the pristine PVA membrane. In addition, different nanofillers, APTES crosslinking, ZIF-8-NH 2 loading, operating temperature, feed concentration, and membrane stability were evaluated in detail. This study might provide a promising prospect for designing MOF-based MMMs with the introduction of various functional groups.