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

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 (W-U) in the range of 12-57%, the ion exchange capacity (IEC) from 0.84 to 2.07 mmol g(-1), acid dialysis coefficient (U-H) from 0.37 to 20.3 (10(-3) mh(-1)) at 25 degrees 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.