用仿生涂层控制金属镁的降解速率

在纯镁试样表面形成硅钙凝胶涂层,然后采用仿生法在纯镁试样及具有凝胶涂层试样表面形成羟基磷灰石涂层.利用X射线、能谱分析及扫描电子显微镜对形成的涂层进行表征.通过将试样浸入人体模拟液(SBF)中的腐蚀实验研究涂层对镁耐蚀性的影响.实验结果表明:采用仿生涂层技术,24h后在纯镁和具有凝胶涂层试样表面均可形成HA涂层,涂层降低了金属镁在人体模拟液中的腐蚀速率,通过控制涂层的成分及形貌,试样降解速率可控.

Controlling the Biodegradation Rate of Magnesium by Biomimetic Coatings

Silica and silica calcium sol-gels were coated on the surface of magnesium, and then the hydroxyapatite (HA) coating was formed on the surfaces of pure magnesium samples by biomimetic process, regardless of the sol-gel coating. The coating layers were characterized by XRD, EDX and SEM, and the morphology of sample surfaces was observed by an emission scanning electron microscope (FESEM). The samples were subsequently immersed in the simulated body fluid (SBF) for the degradation test. The results showed that HA coating is formed on the surface of pure magnesium 24 h after biomimetic process no matter whether the sol-gels have already been coated before. It was found that the HA coating can decrease the corrosion rate of the substrate in SBF, i.e., the degradation rate of samples is controllable if controlling the chemical composition and morphology of coating layers.