Preparation and antibacterial activity of Ag-TiO2 composite film by liquid phase deposition (LPD) method

Abstract

A liquid phase deposition (LPD) method has been devised for the deposition of Ag-TiO2 thin films on ceramic tiles with glazed surface at a low temperature. The Ag-TiO2 thin films obtained were well-adhered, homogenous and coloured by interference of reflected light. The films were characterized by X-ray diffraction and scanning electron microscopy. From these analyses, it was found that silver ions were trapped in TiO2 matrix and their reduction could be achieved at 600°C annealing temperature. The antibacterial activity against S. aureus and E. coli has been studied applying the so called antibacterial-drop test. The Ag-TiO2 thin films exhibited a high antibacterial activity. AAS was used for the quantitave determination of silver ion concentration releasing from the Ag-TiO2 thin film. The releasing rate of silver ions from the Ag-TiO2 film was 0·118 μg/ml during 192 h. The antibacterial effect of Ag-TiO2 thin film before and after aging in a weathering chamber for 48 h was compared and the results show that the antibacterial activity is not compromised after weathering.