INUKAI Junko Aichi-Gakuin University, Parttime Assistant Prof., 歯学部・口腔衛生学講座, 非常勤講師
ARIMOTO Norihiro Aichi-Gakuin University, Assistant Prof., 歯学部・歯科保存学第1講座, 講師 (20291768)
TSURUTA Shozo Aichi-Gakuin University, Assistant Prof., 歯学部・歯科理工学講座, 講師 (40183488)
MARUNO Shigeo Nagoya Institute of Technology, Professor, 電気情報工学科, 教授 (60024204)
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>.