Abstract Nanofiltration membranes bearing high separation and anti-fouling performances represent an efficient separation technology for desalination applications. Although porous organic frameworks (POFs) are considered as a promising candidate for constructing membranes with improved water flux due to their unique advantages such as well-defined pores and tunable functionality, there is still challenge for anti-fouling property of the membranes. Zwitterions possessing balanced charge groups are very attractive for preparing anti-fouling membranes owe to their high hydration capacity. In this study, nanocomposite membranes were prepared by embedding the zwitterionic functionalized “cage-like” POFs (Z-PAF-C) into polyamide (PA) layer. The POFs blended within polymeric membranes could provide more and shorter channels for water molecules through the hybrid membranes, attributing to the novel porous structure of POFs. The zwitterionic groups derived from Z-PAF-C could enhance the hydrophilicity of membrane surface, rendering the membranes promising anti-fouling properties. The water flux of the membrane was increased distinctly from 24 L m−2 h−1 to 42.6 L m−2 h−1 under 0.2 MPa with the loading of Z-PAF-C ranged from 0 g/m2 to 0.85 g/m2 while the retention for Na2SO4 (1 g/L) was maintained at 90.6%. This study demonstrated that the introduction of the zwitterionic functionalized POFs can improve the hydrophilicity and charge negativity of membrane surface, resulting in an enhanced water flux and anti-fouling property.

中文翻译：

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用于纳滤膜的两性离子功能化“笼状”多孔有机骨架，具有高效的水传输通道和防污性能

摘要 具有高分离和防污性能的纳滤膜是一种用于海水淡化应用的高效分离技术。尽管多孔有机框架（POFs）由于其独特的优势，如明确的孔隙和可调的功能，被认为是构建具有改善水通量的膜的有希望的候选者，但膜的防污性能仍然存在挑战。具有平衡电荷基团的两性离子由于其高水合能力而对制备防污膜非常有吸引力。在这项研究中，通过将两性离子功能化的“笼状”POF（Z-PAF-C）嵌入到聚酰胺（PA）层中来制备纳米复合膜。POF 混合在聚合物膜中可以为水分子通过混合膜提供更多和更短的通道，这归因于 POF 的新型多孔结构。Z-PAF-C衍生的两性离子基团可以增强膜表面的亲水性，使膜具有良好的防污性能。在0.2 MPa下，随着Z-PAF-C的负载范围从0 g/m2到0.85 g/m2，膜的水通量从24 L m-2 h-1明显增加到42.6 L m-2 h-1而 Na2SO4 (1 g/L) 的保留率则保持在 90.6%。该研究表明，两性离子功能化POFs的引入可以提高膜表面的亲水性和负电荷性，从而提高水通量和防污性能。归因于 POF 的新型多孔结构。Z-PAF-C衍生的两性离子基团可以增强膜表面的亲水性，使膜具有良好的防污性能。在0.2 MPa下，随着Z-PAF-C的负载范围从0 g/m2到0.85 g/m2，膜的水通量从24 L m-2 h-1明显增加到42.6 L m-2 h-1而 Na2SO4 (1 g/L) 的保留率则保持在 90.6%。该研究表明，两性离子功能化POFs的引入可以提高膜表面的亲水性和负电荷性，从而提高水通量和防污性能。归因于 POF 的新型多孔结构。Z-PAF-C衍生的两性离子基团可以增强膜表面的亲水性，使膜具有良好的防污性能。在0.2 MPa下，膜的水通量从24 L m-2 h-1明显增加到42.6 L m-2 h-1，Z-PAF-C的负载范围为0 g/m2至0.85 g/m2而 Na2SO4 (1 g/L) 的保留率则保持在 90.6%。该研究表明，两性离子功能化POFs的引入可以提高膜表面的亲水性和负电荷性，从而提高水通量和防污性能。在0.2 MPa下，随着Z-PAF-C的负载范围从0 g/m2到0.85 g/m2，膜的水通量从24 L m-2 h-1明显增加到42.6 L m-2 h-1而 Na2SO4 (1 g/L) 的保留率则保持在 90.6%。该研究表明，两性离子功能化POFs的引入可以提高膜表面的亲水性和负电荷性，从而提高水通量和防污性能。在0.2 MPa下，随着Z-PAF-C的负载范围从0 g/m2到0.85 g/m2，膜的水通量从24 L m-2 h-1明显增加到42.6 L m-2 h-1而 Na2SO4 (1 g/L) 的保留率则保持在 90.6%。该研究表明，两性离子功能化POFs的引入可以提高膜表面的亲水性和负电荷性，从而提高水通量和防污性能。