| Abstract: | A series of semihomogeneous cation‐exchange membranes were prepared with binary blend systems, such as sulfonated phenolphthalein poly(ether ether ketone) (SPEEK‐C)/sulfonated poly(phenylene sulfide) (SPPS), or ternary blend systems, such as phenolphthalein poly(ether ether ketone) (PEEK‐C)/SPEEK‐C/SPPS, by solution blending and phase inversion, in which PEEK‐C and SPEEK‐C acted as binders and SPPS powder acted as a polyelectrolyte. Compared with homogeneous and heterogeneous membranes, the prepared semihomogeneous membranes had good electrochemical properties and mechanical strength as well as good dimensional stability. The fundamental properties of the membranes, such as the ion‐exchange capacity, water content, electrical resistance, transport number, diffusion coefficient of the electrolytes, and streaming potential, were largely dependent on both the loading of the SPPS resin and the sulfonation degree of PEEK‐C. Through the adjustment of these two important parameters, a series of semihomogeneous membranes with the desired conductivity and selectivity and the proper water content for different industrial purposes, such as electrodialysis, diffusional dialysis, and proton exchange, were achieved. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 92: 1478–1485, 2004 |
