Abstract: Direct oxidation is a simple and effective method for titanium surface treatment. In this research, a titanium sample was directly oxidized at the high temperature in two different atmospheres, air and pure oxygen, to obtain better atmosphere for titanium surface treatment. The results of the Raman spectroscopy indicated that in both atmospheres, the rutile bioactive phase (TiO2) has been formed on the titanium surface. The results of X-ray diffraction (XRD) also revealed that the surface of oxygen-treated sample was composed of the rutile phase and titanium monoxide (TiO), while at the surface of the air-treated sample, the rutile phase and titanium dioxide had been formed. Further, the results of Field Emission Scanning Electron Microscopy (FE-SEM) showed that by the surface treatment of titanium in both atmospheres, some micro-features including cracks thinner than 30 nm were formed on the surface. Because of more apatite forming ability and fewer water contact angle and more L-929 cell attachment of the air-treated titanium, it seemed that air, in comparison to the pure oxygen, is more promising atmosphere for the direct oxidation of titanium and improving its biofunctionalization.

Key words: titanium implant, surface treatment, direct oxidation, anatase, rutile, biomedical-materials