“…This significant feature of the charged membranes has advantages for applicability of the membranes in many industrial processes, for example, desalination of brine by means of electrodialysis (1). The fixed-charge theory was proposed by Teorell (2, 3) and Meyers and Sievers (4,5), who explained ion transport phenomena by examining the establishment of Donnan equilibria at the interfaces between the membrane and the solution.…”