TiO_2 与TiO_2 -SiO_2 薄膜的表面性质及生物活性研究

SURFACE CHARACTERISTICS AND BIOACTIVITY OF TiO_2 AND TiO_2-SiO_2 FILMS

采用溶胶 -凝胶法在医用NiTi形状记忆合金表面制备了TiO2 与TiO2 -SiO2 薄膜 .用X射线 (XRD) ,红外光谱 (FT -IR) ,X射线光电子能谱 (XPS)和原子力显微镜 (AFM)对薄膜的表面组成、结构与形貌进行了研究 .将表面涂有薄膜的试样浸入模拟体液 (SBF) ,用XPS分析Ca ,P在薄膜表面的沉积情况 .结果表明 :TiO2 -SiO2 膜具有比TiO2 膜更高的生物活性 ,主要原因是TiO2 -SiO2 薄膜表面存在较多的羟基基团 ,在模拟体液中诱导磷灰石沉积的能力较高 ;此外 。

TiO 2 and TiO 2-SiO 2 films were prepared on the surface of biomedical NiTi alloy by sol-gel method. The surface composition, microstructure and surface morphology of the films were studied by XRD, FT-IR, AFM and XPS, respectively. The TiO 2 films heat_treated at 500 ℃ for 1 h are nanosize particle_packed and anatase crystallites are the main phase in the film. The TiO 2-SiO 2 films heat_treated at 500 ℃ for 1 h are amorphous, and micropores exists in the films. The NiTi alloy coated with TiO 2 or TiO 2-SiO 2 films were immersed in simulated body fluid (SBF) for a period and the concentrations of Ca, P deposited on the surface of the films were measured to identify the bioactivity of films. The results show that the bioactivity of TiO 2-SiO 2 film is higher than that of TiO 2 film. The main reason is that more hydroxyl exists on the surface of TiO 2-SiO 2 film, which induces apatite to deposit. Additionally, surface morphology of the film also has an effect on the bioactivity of the film.