Bioactive Treatment of Metal Surface by Hydrothermal-Electrochemical Method

本论文采用水热-电化学方法在生物复合材料表面沉积生物活性涂层进行表面改性。在平成9号中，用水热-电化学法在双电极高压灭菌器中在纯钛板上形成了羟基磷灰石晶体。电流恒定为12.5 mA/cm2，溶解氯化钠、磷酸二氢钾、氯化钙、三羟氨基甲烷和盐酸的电解液保持在80ﾟC-200ﾟC，对电极为铂板，对电极为20×20×0.5 mm，工作电极为纯钛(JIS1)。在恒流加载1h后，用X射线衍射仪、傅里叶变换红外光谱、场发射型扫描电子显微镜和能量色散X射线能谱对电极上的沉积层进行了表征。所有的沉积物都是针状的羟基磷灰石晶体，并且随着电解液温度的升高，针状物的宽度和长度都增加了。在150ﾟC以下，大部分针状晶体垂直于衬底生长，而在其上方针状晶体的旋转角度变化较大。在平成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分别在100、150和200ﾟ℃下加热，电流保持在12.5 mA/cm~2，时间为10-120min。对应于沉积量的重量增益与加载时间的平方根呈线性关系，且在150ﾟC时斜率最大。六方晶体的单面长度随加载时间的平方根呈线性增长，在200min C时斜率最大，为1.48µm/ﾟ；

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>.