SOL-GEL DERIVED POROUS HYDROXYAPATITE COATINGS

The preparation of hydroxyapatite coatings on alumina substrates by a sol-gel method was investigated. A mixed ethanol solution of Ca(NO3)(2 ) . 4H(2)O and P2O5 was used as a dipping source. The samples were cha racterized by solid-state P-31 nuclear 5 magnetic resonance spectrosco py, differential thermal analysis, thermogravimetry, X-ray diffraction , scanning electron microscopy and infrared reflection spectroscopy. T he coating obtained at 500 degrees C had good hydroxyapatite crystalli nity, adhesive strength of about 10 MPa and dense morphology. The coat ing obtained at 750 degrees C also had good crystallinity and adhesive strength but porous morphology. (C) 1998 Chapman & Hall.