Cheng Xiaoxiang, Lai Cunxian, Li Jinyu, Zhou Weiwei, Zhu Xuewu, Wang Zihui, Ding Junwen, Zhang Xinyu, Wu Daoji, Liang Heng, Zhao Congcong
School of Municipal and Environmental Engineering, Shandong Jianzhu University, Jinan 250101, China.
Shandong Urban Construction Vocational College, Jinan 250103, China.
ACS Appl Mater Interfaces. 2021 Dec 8;13(48):57998-58010. doi: 10.1021/acsami.1c17783. Epub 2021 Nov 24.
Polyamide (PA) chemistry-based nanofiltration (NF) membranes have an important role in the field of seawater desalination and wastewater reclamation. Achieving an ultrathin and defect-free active layer via precisely controlled interfacial polymerization (IP) is an effective routine to improve the separation efficiencies of NF membranes. Herein, the morphologies and chemical structures of the thin-film composite (TFC) NF membranes were accurately regulated by tailoring the interfacial reaction temperature during the IP process. This strategy was achieved by controlling the temperature (-15, 5, 20, 35, and 50°) of the oil-phase solutions. The structural compositions, morphological variations, and separation features of the fabricated NF membranes were studied in detail. In addition, the formation mechanisms of the NF membranes featuring different PAs were also proposed and discussed. The temperature-assisted IP (TAIP) method greatly changed the compositions of the resultant PA membranes. A very smooth and thin PA film was obtained for the NF membranes fabricated at a low interfacial temperature; thus, a high 19.2 L m h bar of water permeance and 97.7% of NaSO rejection were observed. With regard to the NF membranes obtained at a high interfacial temperature, a lower water permeance and higher salt rejection with fewer membrane defects were achieved. Impressively, the high interfacial temperature-assisted NF membranes exhibited uniform coffee-ring-like surface morphologies. The special surface-featured NF membrane showed superior separation for selected heavy metals. Rejections of 93.9%, 97.9%, and 87.7% for Cu, Mn, and Cd were observed with the optimized membrane. Three cycles of fouling tests indicated that NF membranes fabricated at low temperatures exhibited excellent antifouling behavior, whereas a high interface temperature contributed to the formation of NF membranes with high fouling tendency. This study provides an economical, facile, and universal TAIP strategy for tailoring the performances of TFC PA membranes for environmental water treatment.
基于聚酰胺（PA）化学的纳滤（NF）膜在海水淡化和废水回收领域具有重要作用。通过精确控制界面聚合（IP）实现超薄且无缺陷的活性层是提高NF膜分离效率的有效常规方法。在此，通过在IP过程中调整界面反应温度，精确调控了复合薄膜（TFC）NF膜的形态和化学结构。该策略通过控制油相溶液的温度（-15、5、20、35和50°C）来实现。详细研究了制备的NF膜的结构组成、形态变化和分离特性。此外，还提出并讨论了具有不同PA的NF膜的形成机制。温度辅助界面聚合（TAIP）方法极大地改变了所得PA膜的组成。对于在低界面温度下制备的NF膜，获得了非常光滑且薄的PA膜；因此，观察到水通量高达19.2 L m⁻² h⁻¹ bar，对Na₂SO₄的截留率为97.7%。对于在高界面温度下获得的NF膜，实现了较低的水通量和较高的盐截留率，且膜缺陷较少。令人印象深刻的是，高界面温度辅助的NF膜呈现出均匀的咖啡环状表面形态。这种具有特殊表面特征的NF膜对选定的重金属表现出优异的分离性能。优化后的膜对Cu、Mn和Cd的截留率分别为93.9%、97.9%和87.7%。三个周期的污染测试表明，低温制备的NF膜表现出优异的抗污染性能，而高界面温度则导致形成具有高污染倾向的NF膜。本研究为定制用于环境水处理的TFC PA膜性能提供了一种经济、简便且通用的TAIP策略。
