ABSTRACT
BACKGROUND: The preparation and antibacterial activity of metal ionic zirconium phosphates has been systemically investigated now, but the applications are limited owing to the discoloration or the low antibacterial activity. Here we prepared new antibacterial agents of quaternized zirconium phosphates by introducing quaternary ammonium salt bactericidal agent with high-effective, broad-spectrum and low-toxic into sodium zirconium phosphate through an ion-exchange method.OBJECTIVE: To explore the component structure and antibacterial activity of quaternized zirconium phosphates.DESIGN, TIME AND SETTING: An in vitro observational experiment was performed at Research Laboratory of Department of Chemistry, Jinan University from June to August 2009.MATERIALS: Quaternized zirconium phosphates were prepared by introducing dodecyl dimethyl benzyl ammonium chloride into sodium zirconium phosphate through an ion-exchange method.METHODS: The mol ratios of quaternary ammonium cations to cation exchange capacity of sodium zirconium phosphate in reaction solutions were 0.25: 1,0.5: 1, 1.0: 1, and 1.5 : 1, respectively, and four kinds of quaternized zirconium phosphates containing different contents of quaternary ammonium cations (QZrP-1, QZrP-2, QZrP-3, QZrP-4) were prepared through an ion-exchange method.MAIN OUTCOME MEASURES: The component structure and heat resistance of samples were measured by using an IR spectrometer, an elemental analyzer and a thermal analyzer, respectively. The minimum inhibitory concentrations (MICs) and minimal bactericidal concentrations (MICs) of the samples against Escherichia coli (E. co/i) and Staphylococci aureus (S. aureus) were estimated by a tube broth method.RESULTS: Quaternized zirconium phosphates were prepared, and the quaternary ammonium cation content increased with increasing the concentration of quaternary ammonium cations in reaction solution. The mass fraction of quaternary ammonium cations of QZrP-1, QZrP-2, QZrP-3, and QZrP-4 was 3.70%, 5.00%, 6.96%, and 10.01%, respectively. The onset temperatures of the decomposition for quaternary ammonium cations in quaternized zirconium phosphates were all higher than 345 °C, and they were preferable thermal stability. The antibacterial activity was higher when the quaternary ammonium cation content of quaternized zirconium phosphates increased. For quaternized zirconium phosphates QZrP-3 containing 6.96% mass fraction of quaternary ammonium cations, showed excellent antibacterial activity against E. coli and S. aureus.CONCLUSION: Quaternized zirconium phosphates QZrP-3 containing 6.96% mass fraction of quaternary ammonium cations,exhibited excellent thermal stability and antibacterial activity.