用于纯钛的纳米羟基磷灰石掺杂微/纳结构复合微弧氧化涂层的制备与性能

Preparation and Properties of Nano-hydroxyapatite-Doped Micro/nano-structured Micro-arc Oxidized Composite Coating for Pure Titanium

摘要:

通过微弧氧化（MAO）-水热（HT）技术在TA2纯钛表面制备了一种由二氧化钛（TiO₂）和羟基磷灰石（HA）组成的微/纳米结构复合涂层，以提高钛的耐腐蚀性能和生物相容性。通过扫描电子显微镜探究了涂层的表面微观形貌；通过原子力显微镜、水接触角探究了涂层的粗糙度和亲水性；在模拟人体体液中通过电化学阻抗谱和动电位极化测试评估了涂层的耐腐蚀性能；通过体外细胞培养实验研究了生物相容性。结果表明，通过在MAO电解液中掺杂纳米HA，可以获得负载纳米HA颗粒的微米级涂层，再进行HT处理，可以获得具有纳米片状结构的含HA微/纳米结构复合涂层。该微/纳结构复合涂层具备良好的亲水性和耐腐蚀性能。当在MAO电解液中掺杂3 g/L HA并HT处理6 h时制得的涂层性能最佳，水接触角为24.2°，极化电阻最大为2.467×10⁴ Ω·cm²。此外，涂层表面的纳米HA和微/纳结构的协同作用极大地促进了细胞增殖，展现出无细胞毒性，说明涂层具备良好的生物相容性。

Abstract:

Micro/nano-structured composite coating composed of titanium dioxide (TiO₂) and hydroxyapatite (HA) was fabricated on TA2 pure titanium through synergistic micro-arc oxidation (MAO) and hydrothermal (HT) processing to enhance the corrosion resistance and biocompatibility of titanium substrates. The surface micromorphology of the coatings was investigated by scanning electron microscope; the roughness and hydrophilicity of the coatings were investigated by atomic force microscope and water contact angle, respectively; the corrosion resistance was evaluated by electrochemical impedance spectroscopy and potentiodynamic polarization tests in simulated human body fluids; the biocompatibility was investigated by in-vitro cell culture experiments. Results demonstrate that by doping HA into MAO electrolyte, a micrometer-sized coating loaded with nano-HA particles can be obtained, and then HT treatment can be conducted to obtain the micro/nano-structured composite coating with a HA-containing nanoflake structure. This micro/nano-structured composite coating possesses good hydrophilicity and fine corrosion resistance. The coating performance achieves optimal state when the coating is prepared with 3 g/L HA and HT-treated for 6 h. In this case, the water contact angle is as low as 24.2°, and the polarization resistance is as high as 2.467×10⁴ Ω·cm². In addition, the synergistic effect of nano-HA and micro/nano-structure on the coating surface greatly promotes the cell proliferation, presenting non-cytotoxic characteristic, and indicating that the coating possesses good biocompatibility.