Preparation of ZIF-8@PEBAX/PVDF nanocomposite membrane by the combination of self-assembly and in-situ growth for removing thiophene from the model gasoline

Metal-organic frameworks (MOFs) have gained attention in the development of MOFs/polymer hybrid membranes for pervaporation. However, the agglomeration of MOFs particles and interfacial defects limit its further application. In this study, we present a novel approach to fabricate a ZIF-8@PEBAX/PVDF nanocomposite membrane for removing thiophene from the model gasoline by combination of self-assembly and in-situ growth. Firstly, a PVDF supporting membrane was modified to have a negative charge. Next, positively charged zinc ions were attracted onto the negatively charged PVDF supporting membrane through electrostatic interaction. Afterwards, the Zinc ions deposited PVDF membrane was immersed into dimethylimidazole solution to form a uniform ZIF-8 layer. Finally, the ZIF-8 layer was coated with poly (ether-block-amide) (PEBAX) using the pouring method. Experimental results showed that the separating efficiency of the ZIF-8@PEBAX/PVDF nanocomposite membrane was improved significantly compared to that of pristine PEBAX membrane. The optimal permeation flux and enrichment factor of membrane were 27.80 kg·(m2·h)-1 and 6.9, respectively.