Ji Wenyan, Liu Ming, Li Yuping, Liu Lulu, Wang Yuhan, Duan Feng, Su Chunlei, Li Haibo, Cao Renqiang, Yin Jingya, Wei Mingjie, Jiang Zhongyi, Cao Hongbin
Department of Chemistry, Tianjin University, Tianjin, 300072, China.
National Engineering Research Center of green recycling for strategic metal resources, Institute of Process Engineering, Chinese Academy of Sciences, Beijing, 100190, China.
Small. 2024 Dec;20(52):e2405113. doi: 10.1002/smll.202405113. Epub 2024 Oct 23.
Zwitterionic membranes demonstrate excellent antifouling property in water purification. The covalent organic frameworks (COFs), due to the ordered channels and abundant organic functional groups, have distinct superiority in constructing zwitterionic surfaces.Here, the zwitterionic COF membrane is prepared with precise framework structures and uniform charge distribution. The negatively charged 4,4'-diaminobiphenyl-2,2'-sisulphonic acid sodium (SA) and positively charged ethidium bromide (EB) fragments are used to react with 1,3,5-triformylphloroglucinol (TP) at the gas-liquid interface to prepare zwitterionic COF membrane. The complementary charged fragments in the inter-layer and inner-layer facilitate the formation of continuous and tight hydration layer on the membrane surface and pore walls to resist the adsorption of pollutants. The zwitterionic COF membrane effectively resists both negatively charged bovine serum albumin and positively charged lysozyme pollutants with flux recovery ratio (FRR) of 97% and 85%, respectively. Furthermore, the regular nano-channels and balanced interactions between water and surface/pore walls of the zwitterionic membrane result in outstanding permeability of up to 146 L m h bar and excellent dye/salt separation selectivity. The water permeation and antifouling mechanism of membranes are elucidated by experimental and molecular dynamics calculation. Zwitterionic COF membranes can find promising applications in preparing high-performance antifouling membranes.
两性离子膜在水净化中表现出优异的抗污染性能。共价有机框架（COF）由于具有有序的通道和丰富的有机官能团，在构建两性离子表面方面具有明显优势。在此，制备了具有精确框架结构和均匀电荷分布的两性离子COF膜。利用带负电荷的4,4'-二氨基联苯-2,2'-二磺酸酸钠（SA）和带正电荷的溴化乙锭（EB）片段在气液界面与1,3,5-三甲酰基间苯三酚（TP）反应制备两性离子COF膜。层间和内层中互补的带电片段有助于在膜表面和孔壁上形成连续且紧密的水化层，以抵抗污染物的吸附。两性离子COF膜能有效抵抗带负电荷的牛血清白蛋白和带正电荷的溶菌酶污染物，通量恢复率（FRR）分别为97%和85%。此外，两性离子膜规则的纳米通道以及水与表面/孔壁之间的平衡相互作用导致其具有高达146 L m⁻² h⁻¹ bar的出色渗透性和优异的染料/盐分离选择性。通过实验和分子动力学计算阐明了膜的水渗透和抗污染机制。两性离子COF膜在制备高性能抗污染膜方面具有广阔的应用前景。
