Abstract：
Membrane fouling and the trade-off between membrane permeability and selectivity restrict the potential applications of membrane filtration for water treatment. ZIF-8 was found having great permeability and antibiofouling performance, but with issue on particle aggregation makes it difficult to achieve high ZIFs loading and fabricate a defect-free molecular sieving membrane in previous research. In this study, we formed a scalable antibiofouling surface with improved permeability and fouling resistance on a PEI-ZIF-PAA membrane using a layer-by-layer assembly technique. The synergistic effects of being sandwiched between two different polyelectrolyte layers with opposite charges endowed the ZIF nanoparticles with improved stability and scalability for membrane modification. The PEI-ZIF-PAA membrane exhibited a satisfactory water flux of 120.78 LMH, which was 46.97% higher than that of the pristine PES membrane. The normalized water flux loss was serious in the absence of ZIF-8, and the flux increased with the ZIF-8 concentration. Antifouling tests suggested that the PEI-ZIF-PAA membrane possessed good antifouling performance due to the much higher surface hydrophilicity and positive Lewis acid-base interactions with foulants. The HA rejection increased with the ZIF-8 concentration and reached a maximum of 92.1% in the presence of 1.00% (w/v) ZIF-8. The membrane regeneration was tested under physical and chemical cleaning with flux recovery rates of about 85% and 95%. XDLVO analysis showed that the total interaction energy between HA and the PEI-ZIF-8-PAA membrane was 26.45 mJ/m2, and the superior antifouling performance was mainly attributed to Lewis acid-base interactions. This study indicates that ZIF-8 nanocrystals are promising materials for fabricating novel membranes for sewage treatment.
摘要：
膜污染以及膜渗透性和选择性之间的权衡限制了膜过滤在水处理中的潜在应用。发现ZIF-8具有良好的渗透性和抗生物污染性能，但是，由于存在颗粒聚集问题，因此在先前的研究中难以实现高ZIFs负载并制造无缺陷的分子筛膜。在这项研究中,我们使用逐层组装技术在PEI-ZIF-PAA膜上形成了具有改善的渗透性和抗污染性的可扩展的抗生物污染表面。夹在具有相反电荷的两个不同聚电解质层之间的协同作用赋予ZIF纳米颗粒用于膜改性的改善的稳定性和可缩放性。PEI-ZIF-PAA膜表现出令人满意的120.78LMH的水通量，比原始PES膜高46.97%。在没有ZIF-8的情况下，归一化水通量损失严重，并且通量随ZIF-8浓度的增加而增加。防污测试表明，PEI-ZIF-PAA膜具有较高的表面亲水性和与污垢的正路易斯酸-碱相互作用，因此具有良好的防污性能。HA排斥随ZIF-8浓度而增加,并且在1.00%(w/v)ZIF-8存在下达到92.1%的最大值。在物理和化学清洗下测试膜再生，Fux回收率约为85%和95%。XDLVO分析表明，HA与PEI-ZIF-8-PAA膜之间的总相互作用能为26.45mJ/m2，优异的防污性能主要归因于Lewis酸碱相互作用。这项研究表明，ZIF-8纳米晶体是制造新型污水处理膜的有前途的材料。
