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电泳沉积多孔羟基磷灰石涂层及其性能的研究
The Study on Preparation and Properties of Porous Hydroxyapatite Coating by Electrophoretic Deposition
【作者】 李鹏;
【导师】 黄紫洋;
【作者基本信息】 福建师范大学 , 物理化学, 2010, 硕士
【摘要】 羟基磷灰石[Ca10(PO4)6(OH)2, Hydroxyapatite, HA]作为生物陶瓷材料呈现出良好的生物活性,但是由于HA本身的脆性,限制了HA作为承重部位骨替换材料方面的应用;然而传统医用材料的钛及钛合金具有优异的力学性能,因此制备综合两者优点的钛基HA成为当今生物陶瓷材料研究的热点之一。本文提出了分别以葡萄糖、淀粉、壳聚糖、炭粉为造孔剂运用电泳沉积(Electrophorectic deposition, EPD)方法在钛基材表面制得HA/有机物、HA/聚合物、HA/无机物三种类型的复合涂层,经烧结处理得到多孔HA涂层。采用FT-IR、SEM、XRD和TG表征涂层的组成、表面形貌、物相组成及热稳定性,黏结—拉伸实验测定涂层与基体的结合强度,人体模拟体液(Simulated Body Fluid, SBF)浸泡测定涂层的生物活性,并采用CHI660C电化学工作站对多孔HA涂层的耐腐蚀性进行测试。实验结果表明:经700°C烧结处理,复合涂层中的造孔剂微粒热分解致孔可制得多孔HA涂层,其孔径为2-30μm,涂层与基体的结合强度可达19.6MPa;在1.5SBF中浸泡5d后,多孔HA涂层表面碳磷灰石化,呈现良好的生物活性;在SBF中测得的Tafel曲线以及交流阻抗Nyquist图都表明多孔HA涂层耐腐蚀性优于纯钛。
【Abstract】 Hydroxyapatite [Ca10(PO4)6(OH)2, HA] exhibits excellent bio-activity property as bioceramic material. However, the brittleness of HA restricts it as a load-bearing bone replacement materials. Owing to titanium and titanium alloy as the traditional implant materials with excellent mechanical properties, preparation of HA coating based on titanium has become a hotspot of research in the field of bioceramic material.Three types of HA composite coating (organic, polymeric and inorganic compound) were deposited on titanium substrate used pore producer such as glucose, starch, chitosan by electrophoretic deposition and then the porous HA coating was obtained by sintering treatment process. The chemical composition, surface morphology, phase composition, and thermal stability of the porous HA coating were characterized by FT-IR, SEM, XRD and TG respectively. The bonding strength between the coating and substrate was tested by a shear strength testing experiment, the bio-activity of the coating was determined by immersion in simulated body fluid (SBF). The corrosive resistances were measured by CHI 660C electrochemical analysis in SBF too.The results show that the porous HA coating was obtained by sintering at 700℃, with pore diameter about 2-30μm and bonding strength up to 19.6 MPa. The coating surface was covered by carbonate-apatite after immersion in 1.5 times ion concentration of SBF (1.5SBF) for 5 days, indicating that the coating possesses a good bio-activity on its surface. Tafel curve and electrochemical impedance indicate that the corrosive resistance of porous HA coating is superior to pure titanium substrate.
【Key words】 hydroxyapatite; titanium substrate; electrophoretic deposition; porosity; bio-activity;