Novel low-cost cation exchange membrane containing hydrophilic cross-linked structure for enhanced electrodialysis properties

Abstract A new mechanism for effecting ion transfer in the CEM was obtained, which was used to guide the preparation of CEM in a cheaper manner. In this paper, a series of CEMs, based on different ratios of sulfonated polyether sulfone (SPES) and polyvinyl pyrrolidone (PVP), were prepared. The ionic conductivity of S-5/P-5 was 0.076 S/cm at 70 °C, while the ionic exchange capacity was only 0.46 mmol/g. Electrodialysis (ED) experiments showed that S-5/P-5 exhibited better ED properties than a comparable commercial CEM. The desalination rates of S-5/P-5 and a commercial CEM were 94.3 and 93.7%, respectively, while the energy consumption of S-5/P-5 was lower than that of the commercial CEM. However, the cost of S-5/P-5 was about one-fourth that of a commercial CEM. The measured ionic conductivity and improved desalination properties of the prepared CEMs were attributed to their increased proper hydrophilicity, which facilitated ion transport. This study provided a simple method for lowering the cost and enhancing the CEM properties by properly increasing their hydrophilicity.