Modificação, caracterização de superfície de titânio CP tratado por plasma de H2 - N2 - O2 e avalição da biotividade da superfície tratada

Abstract

Currently, the study of oxynitrided surfaces emerges as one of the most promising ways to obtain improvements in several properties of titanium and expand its applications. In this context, the plasma-assisted surface modification technique stands out due to its versatility, low impact on the environment and for being economically viable. Thus, samples were subjected to plasma treatment for surface modification. Six study conditions were established for this doctoral work, where thermochemical treatments were carried out in plasma atmospheres containing mixtures of H2 – N2 – O2. Grazing X-ray diffraction (GIDRX), X-ray induced photoelectron spectroscopy (XPS), Raman spectroscopy and energy dispersive spectroscopy (EDS) were used for chemical composition analyses. To assess the bioactivity, the samples were immersed in a simulated body solution for 7 days. The surface energy and contact angle were obtained by the sessile drop method. The results showed that the fluxes used in the pretreatment and treatments were adequate to oxynitrite the titanium surface in a predominantly diffusive process with about 6 µm thickness. In wettability, there is a direct relationship between an increase in nitrogen flux in the working atmosphere with an increase in the contact angle and a reduction in the polar coordinate and surface tension of the treated surfaces. In the results referring to hydroxyapatite nucleation, the highest degree of bioactivity is highlighted under the experimental conditions of maximum oxygen flow and lower oxygen flow, in intermediate conditions and absence of oxygen flow, a behavior equivalent to a control sample is observed.