Preparation and characterization of antibacterial silver loaded montmorillonite under microwave irradiation

Abstract

Silver loaded montmorillonite (Ag-MMT) was prepared by ion exchange reaction under microwave irradiation. The effects of microwave irradiation time, AgNO3 concentration, and microwave power on the silver content of Ag-MMT were investigated using the Volhard method. The time of ion exchange reaction was found to be greatly shortened under microwave irradiation. The most suitable reaction condition was in 0.2 m AgNO3 under 100% microwave power irradiation for 4 min, and the silver content was determined and was found to be 1.23 wt%. The results of the Fourier transform infrared spectrum (FT-IR) and Ag+ release tests confirmed the successful loading of silver and its good slow-release property. The X-ray diffraction (XRD) patterns and ultraviolet-visible (UV-vis) spectra proved the existence of metallic Ag nanoparticles. The Ag-MMT showing a large inhibition zone, high inhibition ratio, and low minimum inhibitory concentration (MIC) value against Staphylococcus aureus ATCC6535 presented a very good antibacterial property.

Keywords

• antibacterial activity
• microwave irradiation
• silver loaded montmorillonite