Efeito do polimento de substratos de titânio no crescimento de filmes de TIO2 por anodização

• Autor(a) principal: Marba, Victória da Costa [UNESP]
• Data de Publicação: 2016
• Tipo de documento: Trabalho de conclusão de curso
• Idioma: por
• Título da fonte: Repositório Institucional da UNESP
• Texto Completo: http://hdl.handle.net/11449/155347; http://www.athena.biblioteca.unesp.br/exlibris/bd/capelo/2017-04-18/000882085.pdf
• topic: Titânio; Metais - Oxidação anodica; Polimento eletrolítico; Filmes finos - Efeito de tamanho; Titanium

In this work it was evaluated the structure and morphology of titanium oxide films formed in different experimental conditions on polished and electrotropolished titanium surfaces using pulsed current anodization. In a first step, the effect of the anodization time (15, 30 and 60 min) was analyzed and, in a second step, the effect of the frequency of current pulses (10, 1 and 0.33 Hz ) by using a previously set time (60 min). To characterize the films, the techniques of Optical Microscopy, Scanning Electron Microscopy (SEM), Raman Spectroscopy and X-Ray Diffraction (XRD) were used. Electrochemical Impedance Spectroscopy (EIS) was used to evaluate the electrochemical behavior in a simulated physiological environment (0.9% NaCl). According to the obtained results, it was observed that an amorphous film was formed on the electrotropolished surfaces, while on the polished surfaces it was identified the presence of anatase, one of the crystalline forms of TiO2. It has also been observed that the size of crystalline grains increased as the frequency decreased. A modeling of the electrochemical interface by using EIS has shown that the crystalline film can be interpreted as being composed of a single layer, due to the absence of differences in the degree of compactness along its thickness