Abstract
This study focuses on researching the structural characteristics of a segment of sulfonated polyether ether ketone (SPEEK) polymer at two different hydration levels using density functional theory (DFT) and molecular dynamics (MD) simulation techniques. We examine the role of hydrogen bonds and specific electrostatic interactions between the polymer's fixed-charged groups and the cations Na+ and Mg2+, given their practical importance in applications involving electrodialysis and reverse electrodialysis for transporting ions with multiple charges. Furthermore, molecular dynamics simulations are performed to explore counter-ion diffusion within a cation exchange membrane, considering variations in membrane hydration levels. This study provides valuable insights into the fundamental factors that govern ion transport and membrane performance in reverse electrodialysis applications.