Investigation on the enhancement of solvent‐resistant nanofiltration membrane performance utilizing PDA‐UiO‐66@CNT as an interlayer

With the growing complexity of separation systems, the application of thin film composite nanofiltration (TFN) membranes in organic solvent separation faces numerous challenges. To augment its solvent stability, an in‐situ constructed dopamine hydrogel doped with UiO‐66@CNT was developed as an intermediate layer on a polyetherimide (PEI) ultrafiltration membrane. Subsequent interfacial polymerization on this interlayer led to the formation of a solvent‐resistant nanofiltration membrane with a vast covalent bond structure, large specific surface area, and enhanced hydrophilicity. Our findings revealed that when the CNT loading in the UiO‐66@CNT composite nanoparticles was 2 wt%, the TFN‐U2C2 membrane exhibited a maximum pure water flux of 126.32 L/(m2·h) and a methanol flux of 45.45 L/(m2·h). The rejection rates for Congo red aqueous and methanol solutions were 96.88% and 92.14%, respectively. The membrane also demonstrated commendable anti‐fouling properties. Remarkably, even after 48 h of immersion in various organic solvents, the membrane retained its morphology and separation efficiency. Compared to the TFN‐U2 membrane without CNT addition, the enhancement in separation performance was considerably significant. Hence, this membrane has significant potential for application in treatment of wastewater containing organic solvents and is promising in related fields. Schematic diagram of TFN‐U2Cx structure.