EFFECT OF A HEAT TREATMENT IN THE CHEMICAL COMPOSITION AND MORPHOLOGY OF TIO2 NANOTUBES OBTAINED BY ANODIZING

Abstract

Metallic prosthesis must show biocompatibility, since it allows postponing surgical implant revisions due to prosthesis degradation or by the possible cytotoxic response that may cause an adverse effect on the patient health. The short-term biocompatibility improvement is focused on the development of nanoscale surface treatments that improve the lifecycle of the implants. This research is focused on the study of the nanotube growth in Ti CP Grade 4 alloy and the effect that a heat treatment has in the chemical composition and morphology of the nanotubes. Nanotubes were obtained through electrochemical anodization, employing an electrolyte composed of phosphoric acid and sodium fluoride. Heat treatment was applied in the anodized titanium samples, reaching the 320 °C for 30 min at high vacuum. Surface roughness parameters were quantified under a confocal microscopy. Diameter and thickness of the nanotubes were studied by Field Emission Scanning Electron. Surface composition was analyzed with Energy Dispersive X-Ray Spectroscopy. The EDS results revealed that the heat treatment is a feasible process to eliminate the retained fluorine element inside nanotubes. Nanoscale surface roughness was modified by electrochemical anodization process, increasing the specific surface area. The electrochemical anodization allows to obtain a oxide layer with nanotubular morphology, which does not collapse after applying the heat treatment on it.