Investigation on the Effect of Polymer Binder Sulfonation on Electrochemical Properties of Nanocomposite Heterogeneous Cation Exchange Membranes

In this study heterogeneous cation exchange membranes based on PVC were prepared by using tetrahydrofuran as solvent and cation exchange resin powders. The membranes were fabricated by solution casting technique. At first, the effect of polymer binder sulfonation and its concentration in the casting solution on electrochemical properties of membranes was studied. Then, superior membrane was modified again by using of iron-nickel oxide nanoparticles.The obtained results showed that increase of sulfonated polymer’s concentration in membrane matrix caused to increase of membrane water content (from 29.4% to 35.1%) and ion exchange capacity (from 2.7 to 3.2). Moreover, prepared membranes exhibited suitable transport number and selectivity between 91%-93% and 85%-89% respectively. Ionic flux was increased initially by increase of sulfonated polymer concentration up to 80 %wt in membrane matrix and then decreased again by more increase in S-polymer content from 80 to 100 %wt. Membrane electrical resistance also was declined up to 27.6% by increase of S-polymer’s ratio in membrane matrix. Furthermore, using of iron-nickel oxide nanoparticles in membrane matrix caused to improvement of membrane electrochemical characteristics obviously. The modified nanocomposite membranes exhibited more appropriate separation performance compared to un-modified ones.The obtained results are useful for electro-membrane processes especially electrodialysis in water recovery and treatment.