Recobrimento de aço inoxidável ABNT 409 empregando filme fino bioativo obtido via sol-gel

• Ano de defesa: 2007
• Autor(a) principal: Sonia Regina Federman
• Tipo de documento: Tese
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal de Minas Gerais; UFMG
• Palavras-chave em Português: Sol-gel; Filme fino; Recobrimento; Engenharia metalúrgica; Engenharia de minas
• Link de acesso: http://hdl.handle.net/1843/MAPO-7REN7E

In the present study, composites made up of ABNT 409 stainless steel was obtained where films produced according to the sol-gel route were deposited using the immersion method. A film of the binary system SiO2-CaO, and another one of the ternary system SiO2-CaOP2O5,were employed. The structure and properties of these films were characterized through the scanning electron microscopy (SEM) technique, coupled with the energy dispersive spectroscopy, atomic force microscopy, Fourier Transformed Infrared spectroscopy (FTIR), Raman spectroscopy, and glow discharge optical emission spectroscopy and thermal analysis. The use of these techniques revealed the formation of ahomogeneous sol-gel film, which adhere to the substrate (degree of 0 in the tape test) with no indication of cracks nor pores. After the film densification stage, AFM images showed the presence of calcium nitrate protuberances on the surface of the films. These protuberances made it possible to design the surface area of the film simply by manipulating easily accessed parameters, such as the temperature and duration of the film drying stage. The variation in temperature and duration of the thermal treatment made it possible to obtain surfaces presenting innumerous protuberances as well as surfaces exempt from such protuberances. Since one of the key aims of this work is the utilization of thesecoatings in the clinical area, the biocompatibility of the films was accessed through two methods: one method using a solution simulated to corporeal fluids and another using cell culture tests. The method using the corporeal solution suggested biocompatibility through the recipitation of a hydroxyapatite precursor (monocalcium phosphate) on the surface ofthe films. The method of cell cultures also proved the biocompatibility of the films as no toxic effects were detected in any of the samples analyzed. Another important finding was the cell viability index of the sol-gel films, which ranged from 90% to 100%, in comparison with that of the control used.