Sol-gel preparation and properties of Ag-containing bioactive glass films on titanium

Ag-containing bioactive glass films (Ag/Ca atomic ratios of 0, 5% and 10%) were sol-gel prepared for bioactive and antibacterial modification of titanium. The gel powders calcined at 610°C are mainly amorphous confirmed by x-ray diffraction, but small diffraction peaks of Ca₃SiO₅ and silver are detected. The film surface is porous with the pore size of ~200 nm. Silver-rich sub-micro particles with sizes of 100-480 nm are present at the surface of Ag-glass films. CaP phase, metallic silver and silica are detected by x-ray photoelectron spectroscopy. The mean apparent bonding strength of the films is as high as 21±1 MPa measured by the pull-off test. The potentiodynamic polarization test shows that the coated samples have better corrosion resistance than the polished sample. The Ag-glass coatings and their wafer samples exhibit antibacterial activity against S. aureus. The coated samples are covered by apatite layer after soaked in the simulated body fluid for 2 weeks, demonstrating their bioactivity.