Preparation and Characterization of Nano-silver Loaded Montmorillonite with Strong Antibacterial Activity and Slow Release Property

Nano-silver loaded montmorillonite (Ag-MMT) was prepared by ion-exchange and then a UV-photoreduction two-step approach was applied. The silver content in Ag-MMT determined by Volhard method was about 6.4 wt%. The morphology and structure of as-synthesized Ag-MMT were characterized by scanning electron microscopy (SEM) and X-ray diffraction (XRD). The results showed that the Ag nanoparticles were spherical and their diameters were about 15–20 nm. Moreover, the structure of MMT did not change. The minimum inhibition concentration (MIC) of Ag-MMT was 100×10-6 and the sterilizing efficiency (SE) of Ag-MMT was approximately 100% against Escherichia coli ATCC 11229 (E. coli). In addition, the slow release property of silver in Ag-MMT was also demonstrated.