Design Of Anion Exchange Membrane For Electro-desalination

Desalination is a practical approach to produce freshwater from brackish water.Electro-desalination(e.g.,ED,EDI,CDI,and Shock ED)utilizes electric current as driving force and the high-performance IEMs as the separator.Among all desalination techniques,electro-desalination(E-DES)considers an advanced technology for desalting regarding clean water.There are two main schemes to maintain the E-DES technique considers;one is electrodialysis(ED),and the other is capacitive deionization(CDI).Hence,the base conformation of AEMs is usually fabricated through moieties being functionalized in quaternary ammonium cations,imidazole cations,guanidinium cations,etc.Consequently,the AEMs membrane with quaternary ammonium cations functional groups has significantly affected scientific research and ion separation application(usually E-DES).Herein this dissertation,the conformational(extended conjugated ?-electron)affects the brominated poly(2,6-dimethyl-1,4-phenylene oxide)BPPO/(para-polybenzimidazole)p-PBI polymer matrix,moreover incorporating the(Metal-Organic Frameworks)MOFs particles influenced by VU-irradiation on the nitrogen-rich p-PBI-based polymer is also a subject for E-DES.Therefore,in this thesis dissertation,our innovative works discussed in separate chapters as below:Chapter two focuses on crosslinking alkaline stable novel AEMs;an AEM with sound desalination and the alkaline stable feature has been fabricated through functional group optimization by cross-linking with brominated 2,6-dimethyl-1,4-phenylene oxide(BPPO)polymer matrix.The 1-naphthol derivatives(i.e.,2-[dimethylaminomethyl]naphthalen-l-ol,and 2,7-bis[dimethylaminomethyl]naphthalen-l-ol)have the functional groups provide conjugated?-electron,which might increase the alkaline stability of the AEMs,and thus ensure its long-term stability when operating the E-DES process over the limiting current density condition.In comparison with the commercial membranes(Neosepta AMX),the fabricate membrane presented comparable E-DES performance.The results indicate for AEMs that are functionalized by 1-naphthol derivatives could be a promising candidate for E-DES processes.Chapter three focuses on grafting alkaline novel AEMs;the core elements with AEMs could influence the ED separation process.As regarding IEMs preparation,phase inversion is an effective method,particularly for commercial membrane production.It includes two different mechanisms:thermal-induced phase separation(TIPS),diffusion-induced phase separation(DIPS),respectively.In this study,AEMs were prepared by grafting a quaternized moiety(QM,2-[dimethylaminomethyl]naphthalen-l-ol)through brominated poly(2,6-dimethyl-1,4-phenylene oxide)(BPPO)via the TIPS method.Those membranes were applied for selective bisulfite(HSO3-)anion separation.SEM characterized the membrane surface morphology,and the compositions were magnified via a high-resolution transmission electron microscope(HRTEM).Notably,the membranes showed excellent substance stability in alkali medium and grafting tests.The ED experiment indicated that the prepared membrane exhibited better HSO3-anion separation performance than the state-of-the-art commercial Neosepta AMX(ASTOM,Japan)membrane.Chapter four focuses on MOFs cluster growth of novel AEMs;due to the MOFs particle's influence on ion separation,the nitrogen-rich p-PBI polymer has been successfully grown by UV-irradiation through tuning the nucleation and cluster growth of MOFs particles.Therefore,MOFs particles' conformation has been changed through cluster growth nucleation due to the UV-light beam absorbed methodology.HRTEM,SEM,SEM-Mapping outlined the unique conformation of nitrogen-rich p-PBI-based MOFs cluster growth AEMs.The fabricated p-PBI-MOFs cluster growth novel AEMs are shown excellent desalination.A probable ion-electrosorption conductivity mechanism has been proposed for the AEM parameter to outline ion-separation's influence with conformational effect.Therefore,E-DES probable mechanisms have been exposed regarding novel p-PBI-MOFs membrane conformational influence(concerning Na,K,Ca,Mg-based de-chlorination).Finally,we have exposed the prospective summary regarding the influence of innovative research on desalination,research significance,and electro-desalination's partial effect of prepared unique AEMs in this dissertation.Furthermore,electro-desalination,electro-diffusion,and anion-electrosorption conductivity are more complicated phenomena regarding ionic separation through AEMs.So far,those phenomena will be continued research in my further aspects in the field of anion exchange membrane.