MG SOLUTE EFFECTS ON THE DISSOLUTION KINETICS OF SILICATE GLASS

The dissolution of soda lime silicate glass was studied in sodium bera te buffer solutions (pH 8.1) containing varying concentrations of Mg. The experimental data were expressed in terms of the equation Q=kt(alp ha). In the absence of Mg, at pH 8.1, alpha was found to be I and chan ging the concentration of Na in the solution did not influence a Howev er, Na concentration did alter the rate constant (k). The higher the N a concentration in the buffer the faster the dissolution. Under condit ions of constant concentration of sodium in the buffet; increasing Mg concentrations in the leachant reduced the glass leach rate and change d the kinetics of glass leaching. At the lower Mg concentration range, alpha approximate to 1, the leach rates are high; at the higher Mg co ncentration range, alpha approximate to 0.5, the leach rates are low.