Antibacterial Ag/SiO2 thin film on glazed ceramic tiles prepared by sol-gel method

In the present study, silver-doped silica thin films on glazed surface of ceramic tiles were well prepared by sol-gel method to achieve antibacterial activity. Thermal treatment was done in the air at 1100°C for two hours. The Ag/SiO₂ thin films were investigated through Scanning Electron Microscopy (SEM), X-ray Diffraction (XRD) and Wavelength Dispersive Spectrometry (WDS). Atomic Absorption Spectroscopy (AAS) was used for the quantitative determination of the silver ion concentration being released from Ag/SiO₂ films over a 24 day period. The antibacterial effects of Ag/SiO₂ thin films against Escherichia coli and Staphylococcus aureus were also examined. From the analysis results, it was found that high temperature treated coating consists of two phases of SiO₂ and Ag based on the trapping of the Ag phase in the Silica matrix. The presence of Ag elements on the surface of the coated tiles, were also observed. Thermal treatment at high temperatures caused sharp XRD peaks and high crystallinity in this system. Ag+ ions were released constantly and the mean release rate (±SD) was 0.104 ±0.01 μg/ml during 24 days. Coating films exhibited an excellent antibacterial performance against both bacterium.