Development of quaternarized poly(vinyl alcohol) anion-exchange membranes for applications in electrodialysis

The main objective of this work is the development of anionic exchange membranes for the treatment of solutions containing metallic ions using the electrodialysis process. Anionic membranes were synthesized from poly(vinyl alcohol), with the insertion of quaternary ammonium groups in the polymeric matrix and subsequent crosslinking with glutaraldehyde and maleic anhydride. Different membranes were synthesized in order to evaluate the combination of physical-chemical properties and ionic transport. The morphology and structure of the membranes were investigated by scanning electron microscopy and infrared spectroscopy. The thermal transitions and stability of all the membranes were characterized using calorimetric techniques: thermogravimetric analysis, and differential scanning calorimetry, and compared with those of the individual polymers. The physical properties (ion-exchange capacity, water absorption, and dimensional stability) showed that the different crosslink agents used significantly affect the membrane properties. The electrodialysis performance of the membranes in the transport of chloride and nitrate ions showed that the membranes produced can be successfully used in this separation process. Selemion (R) AMV commercial membrane was used to compare the percentage extractions of the indicated ions with the produced membranes. (C) 2017 Wiley Periodicals, Inc.