可降解纯镁表面氨基三甲叉膦酸涂层的腐蚀降解性能研究

Abstract

镁及其合金因其具有在生物体内的可降解性、较好的生物相容性和优异的力学性能，因而被广泛研究应用于生物体的植入器件。然而，其过快的腐蚀降解速度以及由局部腐蚀导致过快的力学性能丧失等问题极大地限制了镁及其合金在临床中的应用。因此，本文利用液相沉积的方法在纯镁表面构建一层氨基三甲叉膦酸涂层。通过扫描电子显微镜(SEM)、傅立叶红外分析(FTIR)、X射线能谱仪(XPS)、电化学测试(PDP)以及长期浸泡实验对涂层进行表征。实验结果表明：氨基三甲叉膦酸涂层通过共价固定和螯合沉积的方式有效地构建在纯镁表面，暂态以及长期浸泡过程中明显提高了材料的耐腐蚀性能，且抑制了镁基体的局部腐蚀，增强了材料在长期服役过程中的稳定性。 Magnesium and its alloys have been wildly used in biodegradable implant because of their bio-degradability, good biocompatibility and excellent mechanical property. At present, the rapid corrosion rate and premature mechanical failure of the implants caused by localized corrosion are the main factors that limited the application of biodegradable magnesium-base implant. In order to improve the corrosion resistance of magnesium, a uniform and dense organic phosphonate coating, amino trimethylenephosphonic acid (ATMP) was deposited on alkaline pretreated magnesium through dip-coating effectively. The coatings were characterized by scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), X-ray spectroscopy (XPS), electrochemical test (PDP) and long term immersion test. The results showed a homogeneous and compact ATMP coating was formed on Mg surface by covalently surface-immobilizing and chelating reaction. And the corrosion resistance of magnesium has been improved significantly. Meanwhile, the localized corrosion was inhibited effectively during long term immersion test.