Preparation and characterization of high-performance anion exchange membranes for acid recovery

In this research, a series of homogeneous 3-(dimethylamino)-2,2-dimethyl-1-propanol (DMADMP)functionalized anion exchange membranes (AEMs) were prepared via solution casting method. The successful preparation of AEMs was confirmed by employing Fourier transform infrared spectroscopy. The prepared membranes denoted homogeneous structure confirmed by utilizing scanning electron microscopy. The prepared AEMs were characterized in terms of water uptake (W_R), linear swelling ratio (LSR), ion exchange capacity (IEC), thermal, chemical and mechanical stability. They exhibited water uptake of 23% to 68%, LSR of 8% to 31% and IEC of 1.46 to 2.66 mmol/g. They exhibited excellent thermal, chemical and mechanical stability. The acid recovery performance of the prepared DMADMP-functionalized membranes was evaluated using simulated mixture of HCl and FeCl₂ as model feed via diffusion dialysis at room temperature. The diffusion dialysis coefficient of acid (U_H +) was 9 (10^–3 m/h) to 32 (10^–3 m/h) whereas the diffusion dialysis coefficient of metal (U_Fe 2+) was 0.02 (10^–3 m/h) to 1.9 (10^–3 m/h). For the prepared membranes, the separation factor was 17–456 at ambient temperature. The diffusion dialysis performance of the prepared membranes was higher than commercial membrane DF-120B (U_H + = 0.004 m/h, S = 24.3) at room temperature. Results represented that the prepared DMADMP-functionalized membrane could be employed as excellent candidate for acid recovery.