Fabrication and Characterization of Haemocompatible TiO2 Films by Thermal and Anodic Oxidation Techniques.

M. L. VERA; A. E. ARES; M. R. ROSENBERGER ; C. E. SCHVEZOV

Rosario

Taller; 1º Taller de Órganos Artificiales, Biomateriales e Ingeniería de Tejidos” (BIOOMAT); 2009

Centro Binacional de Criobiología Clínica y Aplicada UNESCO Chair in Criobiology Facultad de Ciencias Bioquímicas y Farmacéuticas Universidad Nacional de Rosario - Argentina and Sociedad Latinoamericana de Biomateriales, Ingeniería de Tejidos y Órganos Ar

A protective titanium dioxide (TiO2) film covers the surface of the titanium (Ti) and its alloys in ambient conditions. This natural oxideis 2 to 7 nm thick, and it is one of the main responsible for the success of titanium alloys as an implantable material. Thicker TiO2 filmscan be produced on a titanium alloy, as the Ti-6Al-4V, by thermal or anodic oxidation. In this study, TiO2 films on Ti-6Al-4V as substratewere produced by thermal and anodic oxidation techniques and compared. On one hand, TiO2 films produced by thermal oxidation weregrowth in air atmosphere at 500 and 600ºC during different times of process: 0.5, 1, 2 and 24 hour. On the other hand, TiO2 films producedby anodic oxidation technique were growth in a 1M H2SO4 solution at voltages from 10V to 100V, during 1 min. The surface characterizationwas performed by optical and scanning electron microscopy, and by X-ray diffraction (XRD) operated with glancing angle geometry withan angle of incidence of 1°. Films of different colours were obtained, with thickness ranged from 20 to 200 nm. Smooth and compactfilms were obtained at time processes below 1 hour by the thermal technique and at voltages below 50V by the anodic technique. Porous films were obtained at long times and voltages larger than 50V. Crystalline phases of TiO2 (anatase and rutile) were obtained by thermal treatment and by the anodic treatment at high voltages. The films produced at low voltages are amorphous; these amorphous films could be transformed to crystalline by a thermal treatment with a slightly increase of the thickness and no change in the roughness. These smooth and crystalline films are suitable to biomedical applications and devices in contact with blood, were haemocompatibility are necessary