Tight ultra-filtration (TUF) membranes were constructed by in situ growing zinc imidazole frameworks micro-crystalline leaves (ZIF-L) in polyethylene imine (PEI) and polydopamine (PDA) deposit layers on porous polyethylene (PE) substrates. The effects of preparation conditions on the surface physical and chemical structures as well as on the dye/salt separation performance of the formed TUF membranes were systematically investigated. By inserting selective water permeation channels and increasing contacting surface areas, in situ-grown ZIF-L arrays tightly cross-linked in the coating matrix greatly increased water permeation without trading off dye/salt retention selectivity. The morphology of the included ZIF-L particles could be varied by adjusting the ligand/Zn molar ratio (α) in the preparation processes. Optimized PDA-PEI/ZIF-L@PE TUF membranes containing ZIF-L of cross-cross block morphology showed very high pure water permeability of 180 ± 20 L·m −2 ·h −1 ·bar −1 (LMHB) and retention selectivity (S CR/Na2SO4 and S MB/Na2SO4 ) of 267 and 43, respectively, as well as excellent stability and anti-fouling properties.
Amine-functionalized Metal-Organic Frameworks (MOFs) stand out as highly promising materials in membrane separation technology. Nevertheless, the incorporation of amine-functionalized additives may lead to uncontrollable alterations in MOF morphology. Two intact blade-like MOFs (PEI (Polyethylenimine)-ZIF-L and PAMAM (Polyamidoamine)-ZIF-L) were successfully synthesized by controlling the conditions and then introduced into Pebax 2533 to fabricate Mixed Matrix Membranes (MMMs). Hydrogen bonding and other interactions with Pebax can be formed by PEI-ZIF-L and PAMAM-ZIF-L to enhance interfacial compatibility. Simultaneously, a reversible reaction with CO 2 molecules can be undergone by the amine groups, resulting in facilitated transport in MMMs. The CO 2 separation performance of the MMMs is enhanced by this process, with the facilitation being more pronounced under humid conditions. Under humid conditions, the CO 2 permeabilities of Pebax-PEI-ZIF-L (2 wt%) and Pebax-PAMAM-ZIF-L (2 wt%) MMMs were 639.4 Barrer and 702.7 Barrer, respectively, while the CO 2 /N 2 selectivities were 26.68 and 24.35, respectively. Both permeability and selectivity exhibited a significant increase of 200% and 130%, respectively, compared to pure Pebax. Furthermore, the MMMs demonstrated excellent long-term stability during 72 h of continuous operation in a humid environment, showcasing significant potential for industrial applications, particularly in humid flue gas carbon capture.
危险品化学品经营许可证（带存储）