Kinetics and mechanism of pH responsive cationic desorption from poly(vinyl alcohol)-borate hydrogel

Desorption of potassium chloride and calcium chloride from poly(vinyl alcohol)-borate hydrogel was studied at different pH from 3 to 10 using phthalate, phosphate and borate buffers. The rate of desorption from hydrogel was evaluated using conductance method for analysis. It was observed that rate of desorption process decreases on increasing pH of solution from acidic medium to basic medium. The mechanism responsible for the desorption of interacted K⁺ and Ca²⁺ ions in hydrogel moiety in acidic, neutral and basic medium were analyzed. The pseudo first order rate constants for desorption process at different pH were summarized and the rate of desorption of monovalent and divalent cations at various pH compared on the basis of standard deviation and linear regression constant values.