_tcm18-9556.gif )
High impact applications, properties and synthesis of exciting new materials
Also of interest
Physics, chemistry and biology of Soft Matter
Paper
J. Mater. Chem., 2007, 17, 95 - 104, DOI: 10.1039/b611740f
Titania and silver–titania composite films on glass—potent antimicrobial coatings
Kristopher Page, Robert G. Palgrave, Ivan P. Parkin, Michael Wilson, Shelley L. P. Savin and Alan V. Chadwick
Titania (anatase) and Ag-doped titania (anatase) coatings were prepared on glass microscope slides by a sol–gel dip-coating method. The resultant coatings were characterised by X-ray diffraction, X-ray absorption near edge structure (XANES), Raman, scanning electron microscopy (SEM), wavelength dispersive X-ray (WDX) analysis, X-ray photoelectron spectroscopy (XPS) and UV-vis techniques and shown to consist of anatase with ca. 0.2–1 atom% Ag2O. Photocatalytic activity of the coatings was determined by photomineralisation of stearic acid, monitored by FT-IR spectroscopy. Photocatalytically-active coatings were screened for their antibacterial efficacy against Staphylococcus aureus (NCTC 6571), Escherichia coli (NCTC 10418) and Bacillus cereus (CH70-2). Ag-doped titania coatings were found to be significantly more photocatalytically and antimicrobially active than a titania coating. No antimicrobial activity was observed in the dark—indicating that silver ion diffusion was not the mechanism for antimicrobial action. The mode of action was explained in terms of a charge separation model. The coatings also demonstrated significantly higher activity against the Gram-positive organisms than against the Gram-negative. The Ag2O–TiO2 coating is a potentially useful coating for hard surfaces in a hospital environment due to its robustness, stability to cleaning and reuse, and its excellent antimicrobial response.
RSS feed