Electrodialytic properties of aromatic and aliphatic type hydrocarbon-based anion-exchange membranes with various anion-exchange groups

Anion-exchange membranes (AEMs) with various membrane structures were prepared by introducing various amines: trimethylamine (TMA), triethylamine (TEA), tri-n-propylamine (TPA) and tri-n-butylamine (TBA) into precursor membranes prepared from chloromethylstyrene (CMS)–divinylbenzene (DVB) and glycidyl methacrylate (GMA) – DVB. Their properties for ionic transport and anti-organic fouling were examined. Almost all of the prepared AEMs have excellent ionic transport properties: transport number of anions >0.94 and membrane resistance <4 Ωcm2. The voltage change through the AEMs during electrodialysis operation using solutions containing sodium dodecylbenzene-sulfonate as a foulant indicated that there are three cases of fouling mechanism being related to membrane structure: (a) aliphatic AEMs show lower fouling than aromatic ones; (b) the lower the water content of an AEM, the more remarkable the fouling; (c) the longer the chain length of the alkyl groups of the anion-exchange groups of an AEM, the more remarkable the fouling.