两性离子表面改性阴离子交换膜及其抗污染性能

Preparation and Anti-fouling Property of Zwitterionic Surface Modified Anion Exchange Membranes

受贻贝结构的启发,采用聚多巴胺(PDA)涂层沉积在季胺化溴化聚苯醚(QPPO)阴离子交换膜上(Q-PDA),然后通过Michael加成反应将含叔胺官能团的活性分子N,N-二甲基乙二胺(DMDA)接枝到含有伯胺基团的PDA活性层上(Q-P2D)。DMDA功能化后的阴离子交换膜进一步与1,3-丙烷磺酸内酯反应,制备了两性离子表面改性的抗污染阴离子交换膜(QP2DZ)。抗污染实验中,QPPO膜出现了严重的污染现象。由于PDA的亲水性阻碍了有机污染物SDBS在膜表面的粘附和团聚,Q-PDA表现出改善的抗污染性能,其"转变时间"约为109 min。由于PDA表面水合性和带负电荷或电中性的改性层与SDBS之间具有静电排斥力,此二者的双重作用,使SDBS隔离于膜表面而显著增强膜的抗污染能力。

Inspired by the mussel, we have prepared a novel an ti-fouling anion exchange membranes （AEMs） modified with zwitterionic surface, through depositing a polydopamine （PDA） on a quaternized brominated polyphenylene ether （QPPO） anion exchange membrane （Q-PDA） and followed by tethering N, N-dimethylethylenediamine （DMDA） on amine-functionalized active molecule （Q-P2D） and further grafting with 1,3-propanesultone a Michael addition reaction （Q-P2DZ）. The resultant QPPO AEM shows inferior anti-fouling performance in the anti-fouling experiment. Since the hydrophilcity of PDA hinders the adhesion and aggregation of organic foulant SDBS on the membrane surface, Q-PDA exhibits improved anti-fouling properties with a ＂transition time＂ of approximately 109 min. There is an electrostatic repulsion between the zwitterionic/negatively-charged surface and dodecylbenzene sulfonate （SDBS） foulants. The dual effects of PDA/zwitterionic prevented the SDBS absorbed on the membrane surface and significantly enhance the membrane＇s potential to resist fouling.