| Antibacterial agents are important for people in pursueing quality life. However, the development of inorganic antibacterial agents in China is far behind Japan and other developed countries and can not meet the need for modern society. Therefore, it is very necessary to develop more safe, non-toxic and long effective antibacterial agents.This study mainly focused on the preparation of silver nanoparticles encaged in mesoporous silica, i.e., the Ag@mSiO2 Nano Composite, and their antibacterial performance. Using polyvinylpyrrolidone as the protecting agent, sodium hypophosphites as the reducing agent, silver sol was synthesized by a chemical reduction method. Adding hexadecyl trimethyl ammonium bromide (CTAB) as template and tetraethyl orthosilicate (TEOS) as silica source into the above silver sol, silica shells were grown in-situ on the silver nanoparticles to form the core-shell structured Ag@mSiO2 nano compounds. The CTAB template was then removed by solvent-extraction and the Ag@mSiO2 nano compounds were dried by super-critical fluid drying technology. This core-shell structured nanocomposite material can prevent Ag particles being detached from the silica matrix and reduce the color change of silver ions with time.TEM, SEM, XRD, FT-IR and N2 adsorption-desorption isotherm analyses indicated that the formed Ag@mSiO2 nanoparticles were interconnected spheres with ordered mesoporous structure and a very high BET surface area. The antibacterial performances of Ag@mSiO2 nanoparticles against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) were tested using the popular twofold serial dilution method to obtain the minimal inhibitory concentration (MIC) and minimal bactericidal concentration (MBC), respectively. When the silver content was 2.3 wt%, the MIC for Escherichia coli (E-coli) and Staphylococcus aureus (S. aureus) was 156μg/mL. The results demonstrated that the Ag@mSiO2 nanoparticles possess good antibacterial properties. |
PDF Full Text Request