Antibacterial zeolite with a high silver-loading content and excellent antibacterial performance

The thermodynamic conditions of the AgOH precipitation-dissolution equilibrium were investigated by the solubility product principle and the Van't Hoff isobaric equation, and a mathematical expression was obtained about the influence of concentration, temperature and pH on the balance of AgOH precipitation-dissolution in the ion-exchange process. It was shown that the silver-loading process of zeolite had a theoretical equilibrium pH value under a certain concentration and temperature, and the optimal preparation conditions of silver-loaded antibacterial zeolite (Ag-Z) were 323.15 K, 0.50 mol L-1, 6.20, 4.00 h for temperature, concentration, pH and time, respectively. And the silver-loading content of Ag-Z was as high as 365.73 mg g(-1). The minimum inhibition concentrations (MICs) of the as prepared Ag-Z to Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) were as little as 1.00 mu g ml(-1) and 3.50 mu g ml(-1), respectively, and the minimum bactericidal concentrations (MBCs) were as little as 3.50 mu g ml(-1) and 5.00 mu g ml(-1), respectively. The antibacterial mechanisms were analyzed based on the quantity of released Ag+ and Na+.