MICROSTRUCTURE OF HYDROXYAPATITE THICK FILM Wei-Lun Shieh

摘要

Hydroxyapatite (HA, Ca_(10)(PO_4)_6(OH)_2) thick films were prepared from the precursors Ca(NO_3)_2, PO(C_2H_5O)_3, and various solvents including methanol, ethanol, and H_2O. Polycrystalline ZrO_2 and Al_2O_3 ceramics were used as the substrates. A gel with a different Ca/P value was prepared, and then it was preheat treated at T velence 40 deg-80 deg C before dipping or spinning coating. The gel-coated specimens were heat-treated at T velence 25 deg-600 deg C to study their morphologies and phase transformations at high temperature. Most of the gel-coated specimens started to form the hydroxyapatite crystallines at T velence approx 600 deg C upon heating. This phenomenon was also identified from the corresponding X-ray diffraction patterns. A porous HA film on the ZrO_2 substrate was formed at T > = 600 deg C. Furthermore, the HA thick films obtained from sol-gel and coprecipitation methods were also compared.