Nitrogen-doped titanium dioxide nanofilms for medical application

Abstract

The results of study of nitrogen-containing titanium dioxide nanofilms (N-TiO2) are pre-sented in this work. These nanofilms are used in biomedicine as a biocoating of the implants that is why the problem of increasing resistance is very essential. Biocoatings were deposited by reactive magnetron sputtering at different bias voltages Ub = 0-100 V. Doping of the oxide film with nitro-gen, with technological replacement of oxygen by nitrogen atoms, changes the material properties: antithrombogenic qualities appear and hemocompatibility rates increase. The corrosion resistance rates of the film are also increased. The biocoatings are partially dissolved, when interacting with biological fluids, with a further release/formation of compounds with an N-O bond, which are es-sential for human activity. X-ray diffraction (XRD) was used to study the phase transition and crystallinity of nanofilms. The rutile phase dominates (68%) when a negative bias in these films was used. The volume of the fraction increases permanently with increasing of nitrogen content in the composition of the reactive gas, while the volume fraction of anatase decreases to 10%. The surface morphology was studied using scanning electron microscopy. It was established that the films have a more fine-grained structure than at the displacement equals zero. Chemical stability and the presence of elements were observed using X-ray fluorescence spectrometry (XFS) and atomic emission spectrometry (AES). The results of measurement of the contact angle and the sur-face energy are presented. The results of the study showed the influense of bias voltage on the phase composition, surface morphology and chemical properties of N-TiO2 nanofilms. The analysis of the results suggests that N-TiO2 films under consideration may play the role of nitric oxide depot directly in the field of pathology if they serve as implants coating.