Study on Acid/Base Formation by Using Sulfonated Polyether Ether Ketone/Aminated Polysulfone Bipolar Membranes in Water Splitting Electrodialysis

The sulfonated polyether ether ketone (SPEEK) as a cation exchange polymer and aminated polysulfone (APSf) as an anion exchange membrane (AEM) were synthesized to prepare bipolar membranes (BPMs) through hot pressing. The water splitting electrodialysis (WSED) experiments were conducted to produce acids and bases by using the resulting SPEEK/APSf BPM. For comparative performance evaluation of the commercialized ASTOM membrane and the newly synthesized membranes in our lab, the acid/base production rate and the voltage changes according to the constant current were measured. The acid and base formation rates of the commercialized membrane from ASTOM were 2.3 and 2.7 g/L/h, respectively, whereas the rates of the membranes we developed were 1.0-2.4 and 1.5-2.7 g/L/h, respectively, depending on the amine contents in the AEM. The performance of the synthesized BPM in our lab was equivalent or higher than that of the commercialized membrane from the viewpoint of the acid/base production rates.