Surface-modified anion exchange membranes with self-cleaning ability and enhanced antifouling properties

The development of reliable anion exchange membranes (AEMs) with superior antifouling properties is critical in practical applications of electrodialysis processes. For the first time, the AEMs were modified by poly (sodium 4-styrene sulfonate) (PSS) with titanium dioxide (TiO 2 ) nanoparticles using only one electrodeposition step to stabilize the nanoparticles on the membrane surface while improving their antifouling ability. Owing to the bonding between the sulfonic groups of PSS and TiO 2 , the TiO 2 nanoparticles were well dispersed in the modified layer. The deposition of PSS endowed the AEMs with a negatively charged surface, while the addition of TiO 2 nanoparticles further increased the charge density. The membrane resistance increased only marginally after 100-min of fouling experiments using sodium dodecyl benzene sulfonate (SDBS), due to the presence of TiO 2 on the modified AEMs. Ultraviolet (UV) irradiation was proven to be an effective approach in inducing good fouling reversibility of the TiO 2 -PSS modified AEMs through photocatalytic decomposition and hydrophilicity improvement.