| Abstrakt: |
Hydroxyapatite crystals were formed on a titanium electrode using the hydrothermal–electrochemical method in an autoclave with two electrodes. The electrolyte dissolving NaCl, K2HPO4, CaCl2· 2H2O, trishydroxyaminomethane, and hydrochloric acid was maintained at 80°–200°C. After loading of a constant current at 12.5 mA/cm2for 1 h, the deposited amounts were measured through the weight gain of the electrode. The deposits were characterized by X-ray diffractometry, Fourier transform infrared spectroscopy, field emission-type scanning electron microscopy, field emission-type transmission electron microscopy, and energy dispersive X-ray spectroscopy. The deposited amount increased with electrolyte temperatures up to 150°C and slightly decreased above that temperature. The deposits were identified as hydroxyapatite crystal rods grown along the caxis and perpendicular to the substrate. The crystallinity of the deposited hydroxyapatite increased continuously with the electrolyte temperature and closed to stoichiometric hydroxyapatite. At 150°–160°C, the hydroxyapatite rod grew very homogeneously perpendicular to the substrate, and the edge of the needle had a flat hexagonal plane. © 1998 John Wiley & Sons, Inc. J Biomed Mater Res, 42, 387–395, 1998. |
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