Partition equilibrium between charged membrane and single electrolyte aqueous solution

Ionic partition equilibrium in charged membrane immersed in solution of sin gle electrolyte with monovalence or multi-valence is systematically investi gated and several expressions are established for determination of partitio n coefficients. On this basis, the effects of the ratio of membrane charge density to bulk electrolyte solution concentration, the charge sign and val ence of electrolyte ions and the type of membrane on the partition equilibr ium were analyzed and simulated within chosen parameters. It is revealed th at ion partition is not related solely with the respective concentrations b ut also definitely with the concentration ratio of fixed group to bulk solu tion in addition to the charge sign and the valence. For a counterion, the partition coefficient increases with this ratio and the valence; while for a coion, the partition coefficient decreases with this ratio and the valenc e. The theoretical calculations were compared with the experimental data an d a good agreement was observed.