Deng Weishan, Zhang Zezhen, Liu Lulu, Zhou Zekun, Wu Lili
School of Materials Science and Engineering, Wuhan University of Technology Wuhan 430070 China
RSC Adv. 2024 May 20;14(23):16510-16519. doi: 10.1039/d4ra02838d. eCollection 2024 May 15.
Membrane separation has been shown to have significant potential in addressing the global shortage of clean water. Covalent organic frameworks (COFs) have gained significant attention in the field of membrane separation due to their structural stability and controllable pore size. Here, a modification of polyethersulfone ultrafiltration membranes with TA-assisted COFs is prepared by interfacial polymerization and co-deposition. Intriguingly, in comparison to the conventional COF synthesis method, the interfacial polymerization reaction used -butanol as the oil-phase monomer to prevent substrate corrosion. More importantly, the TA-assisted co-deposition not only introduces a large number of environmentally friendly hydrophilic groups to enhance the hydrophilicity of the membrane surface, but also the phenolic hydroxyl group contained in TA generates a quinone group upon oxidation. This group can undergo a Michael addition reaction with the amine group, followed by interfacial polymerization to regulate the COFs pore size. Consequently, the optimized membrane exhibited a high permeation flux of 122.03 L m h bar without altering the pore size structure of the original membranes and demonstrated separation performance for various dyes (Mw: 300-1300 g mol), with a retention rate of over 98%. Despite multiple filtrations of methyl blue dye, the membrane prepared by simple rinsing still exhibited high retention rates (>98%) with exceptional stability and retention performance. The optimized membrane demonstrated good hydrophilicity and dye separation performance, indicated promising potential for dye separation applications.
膜分离已被证明在解决全球清洁水短缺问题方面具有巨大潜力。共价有机框架（COF）因其结构稳定性和可控孔径在膜分离领域受到了广泛关注。在此，通过界面聚合和共沉积制备了一种用TA辅助COF改性的聚醚砜超滤膜。有趣的是，与传统的COF合成方法相比，所采用的界面聚合反应使用正丁醇作为油相单体以防止基底腐蚀。更重要的是，TA辅助共沉积不仅引入了大量环境友好的亲水基团以增强膜表面的亲水性，而且TA中含有的酚羟基在氧化时会生成醌基。该基团可与胺基发生迈克尔加成反应，随后进行界面聚合以调节COF的孔径。因此，优化后的膜在不改变原始膜孔径结构的情况下表现出122.03 L m h bar的高通量，并对各种染料（分子量：300 - 1300 g/mol）具有分离性能，截留率超过98%。尽管对亚甲基蓝染料进行了多次过滤，但通过简单冲洗制备的膜仍表现出高截留率（>98%），具有出色的稳定性和截留性能。优化后的膜表现出良好的亲水性和染料分离性能，显示出在染料分离应用中的广阔前景。
