Bioactive Treatment of Metal Surface by Hydrothermal-Electrochemical Method

本论文研究了生物活性层在生物复合材料表面的热液电化学沉积改性。在平成9，羟基磷灰石晶体是用水热电化学方法在纯钛板上形成的两个电极的高压釜。电流为12.5 mA/cm^2，溶解NaCl、K_2HPO_4、CaCl_2 2H_2O、三羟基氨基甲烷和盐酸的电解液保持在80 ~ 200 C。对电极为铂板，20x20x0.5 mm，工作电极为纯钛（JIS 1）。恒流加载1小时后，利用x射线衍射仪、傅里叶变换红外光谱、场发射型扫描电镜和能量色散x射线光谱对电极上的沉积物进行表征。所有沉积物均为羟基磷灰石针状晶体，针状晶体的宽度和长度随电解质温度的升高而增大。在150°C以下，大多数针状晶体垂直于衬底生长，而在150°C以上，针状晶体与衬底的倾斜角变化较大。在Heisei 10中，重点研究了电化学沉积形成针状磷灰石晶体的机理。电解液在高压灭菌器中以100、150和200℃的温度加热，电流保持在12.5 mA/cm^2，加热10 ~ 120 min。堆积量随加载时间的平方根呈线性增加，且在150℃时斜率最大。六方晶体的单侧长度随加载时间的平方根线性增加，且在200‰时斜率最大，为1.48 μ m/min^<1/2>。

The present thesis deals with the surface modification by the hydrothermal-electrochemical deposition of bioactive layer on the composite designed for biological application. In Heisei 9, hydroxyapatite crystals were formed on pure titanium plates using the hydrothermal-electrochemical method in an autoclave with two electrodes. The current was a constant at 12.5 mA/cm^2 and the electrolyte dissolving NaCl, K_2HPO_4, CaCl_2 2H_2O, trishydroxyaminomethane, and hydrochloric acid was maintained at 80ﾟC - 200ﾟC.The counter electrode was platinum plate, 20x20x0.5 mm, and the working electrodes were pure titanium (JIS 1). After loading of the constant current for 1 hr, the deposits on the electrodes were characterized by X-ray diffractometry, Fourier transform infrared spectroscopy, field emission type scanning electron microscopy, and energy dispersive X-ray spectroscopy. All the deposits were needle-like crystal of hydroxyapatite, and both width and length of the needles increased with the electrolyte temperature. Most of the needle-like crystals grew up perpendicular to the substrate below 150ﾟC, whereas orintation angle of the needles against the substrate were more varied above it.In Heisei 10, mechanism of the formation of needle-like apatite crystal by electrochemical deposition was focused in the research. The electrolyte was heated at 100, 150 and 200ﾟC in an autoclave and the current was maintained at 12.5 mA/cm^2 for 10 - 120 min. Weigth gain, corresponding to deposited amount, linearly increased with square root of loading time and the slope at 150ﾟC was highest. The lengths of one side of the hexagonal crystals linearly increased with square root of loading time and the slope at 200ﾟC was highest, 1.48 mu m/min^<1/2>.