High performance anion exchange membrane with proton transport pathways for diffusion dialysis

Abstract

Abstract High performance anion exchange membranes (AEM) with proton transport pathways were fabricated through cationic functionalization of bromo-methylated poly (phenylene oxide) (BPPO) by a nucleophile dimethylamino pyridine (DMAP). The reaction was selectively occurred at dimethylamino functionalities of DMAP to form quaternary amine groups. The pyridine groups on DMAP having a dibasic nature promoted the formation of proton transport pathways and contributed to hydrophilicity of the membranes. The obtained membranes had the water uptake (WU) in the range of 12–57%, the ion exchange capacity (IEC) from 0.84 to 2.07 mmol g−1, acid dialysis coefficient (UH) from 0.37 to 20.3 (10−3 m h−1) at 25 °C. Interestingly, these membranes exhibited superior separation factor (S) values of 73–351 compared to a commercial DF-120 membrane and most reported membranes in literature. Moreover, the prepared membranes showed excellent thermal, chemical and mechanical stability.