Novel quaternized aromatic amine based hybrid PVA membranes for acid recovery

Abstract

For the first time this study reports novel quaternized aromatic amine based anion exchange membranes (AEMs) with polyvinyl alcohol (PVA) acting as a binder and tetraethoxysilane (TEOS) as a crosslinker for acid recovery via diffusion dialysis. Physiochemical properties and electrochemical performance of prepared membranes can be tuned by varying the dosage of quaternized 4,4′-(1,1′-biphenyl-4,4′-diyldioxy)dianiline (QBAPB). All the thermo-mechanical properties like dynamic mechanical analysis (DMA) and thermo-gravimetric analysis (TGA) were investigated along with water uptake (WR), ion exchange capacity (IEC), dimensional stability etc. The effect of quaternary ammonium group and crosslinking agent (TEOS) was discussed in brief related to acid recovery and ion conducting pathway. The QBAPB/PVA membranes showed the water uptake (WR) values ranging between 23.7% and 37.9%, ion exchange capacity (IEC) between 0.65 and 1.12mmol/g, initial decomposition temperatures (IDTs) of 222–241°C, tensile strength of 16.6–18.3MPa and elongation at break of 332–403%. The dialysis coefficients (UH) for different nanocomposite membranes are found to be in the order of 0.0172–0.0252m/h, while the separation factors (S) varied from 14 to 21 at 25°C. The obtained values are much higher than that of commercial membrane DF-120B (0.004m/h for UH, 24.3 for S). The membranes reported in this manuscript could be a promising candidate for acid recovery via diffusion dialysis.