Covalently cross-linked pyridinium based AEMs with aromatic pendant groups for acid recovery via diffusion dialysis

this study, the pyridinium anion exchange precursor was prepared by alkylation of 4-bromomethyl benzoic acid to pyridine and then the corresponding covalently cross-linked pyridinium based AEMs were obtained by esterification reaction through the prepared pyridinium salt and polyvinyl alcohol (PVA) as a base material in presence of tetraethoxysilane (TEOS) as a crosslinker. The prepared anion exchange membranes are characterized by FTIR, SEM, TGA and DMA. T-d values are in the range of 322-335 degrees C. The tensile strength (TS) ranges from 43.74 to 47.23 MPa and elongation at break (E-b) in the range of 262.59-474.44%. The acid dialysis coefficients (U-H) are in the range of 1.28-1.88 x 10(-2) m/h, greater than the well known commercial membrane DF-120 (9 x 10(-3) m/h). The membrane containing 40 wt% of PVA has the highest separation factor (S) of 71.35. Note that the DD tests have been evaluated according to the membrane structure and its composition. (C) 2016 Elsevier B.V. All rights reserved.