Preparation of aliphatic-hydrocarbon-based anion-exchange membranes and their anti-organic-fouling properties

Novel aliphatic-hydrocarbon-based anion-exchange membranes (AEMs) were prepared from glycidyl methacrylate (GMA)/divinylbenzene (DVB) by changing their cross-linker content (CLC). Their ion-transport and anti-organic-fouling properties were compared with those of aromatic-hydrocarbon-based AEMs prepared from chloromethylstyrene (CMS)/DVB copolymers. Aliphatic AEMs with CLCs less than 11.5 have excellent ion-transport properties: anion transport numbers >0.95 and membrane resistances <3.5 Ω cm2. In an electrodialysis (ED) system consisting of an AEM and an NaCl solution containing sodium dodecylbenzenesulfonate (DBS) as an aromatic foulant, the change in the voltage drop through the aliphatic AEMs during ED was lower than that with aromatic AEMs. This means that adsorption of DBS on the surface of the aliphatic AEMs is lower than that on aromatic AEMs. The aliphatic AEMs have much lower permeability coefficients for DBS in the ED system than the aromatic AEMs have. These results indicate that the anti-organic-fouling properties of aliphatic AEMs are better than those of aromatic AEMs.