Co-deposition of hyperbranched polyethyleneimine and dopamine on anion exchange membrane for improved antifouling performance

Hyperbranched polyethyleneimine (PEI) holds great potential for membrane-separation materials owing to the dendritic structure. However, their utilization in constructing antifouling anion exchange membranes (AEMs) remains significant challenge. Herein, a novel strategy of employing hyperbranched PEI to design antifouling AEMs was demonstrated. Hyperbranched PEI and dopamine were co-deposited on the surface of AEMs to prepare antifouling AEMs. Dopamine can easily form polydopamine (PDA) and enhance the hydrophilicity and electronegativity of membrane surface. The hydrophilic and electronegative membrane surface enabled the ability to block foulants, endowing the AEMs with improved antifouling performance. Meanwhile, the dendritic structure of hyperbranched PEI tended to assemble the low-barrier pathway for ion transport and maintained the desalination performance of AEMs. Thus, the obtained PEI-1800&PDA/AEM achieved 1.93 times variation of the electrical conductivity for diluted solution of commercial AEM after antifouling experiment, while the variation is close to that of commercial AEM after desalination experiment. This study offers new insight into fabricating hyperbranched PEI-based membranes for high-performance materials.