Preparation and Characterization of Hydroxyapatite/Calcium Phosphate Powders

• Published in: Key Engineering Materials 2004-01, Vol.264-268, p.2075-2078
• Main Authors: Simsek, D, Ciftcioglu, R, Harsa, S, Ciftcioglu, M
• Format: Article
• Language: English
• ISSN: 1013-9826; 1662-9795; 1662-9795
• DOI: 10.4028/www.scientific.net/KEM.264-268.2075

The preparation of calcium phosphate based powders through chemical precipitation in order to determine the optimum conditions for the preparation of stoichiometric, thermally stable hydroxyapatite (HA) powders was investigated. The effects of parameters like pH, ageing time, and heat treatment temperature on the phase structure and morphology of the powders were investigated by SEM and XRD. HA was prepared at a Ca/P ratio of 1.67. The precipitation pH had a profound influence on the morphology and crystallite size of the powders in the 4-11 pH range. Relatively large 5 micron prismatic particles were obtained at low pH whereas the powders were formed from agglomerates of nanosized particles at high pH. Powders had a HA dominant phase structure above a pH of 8. Phase pure HA powders were obtained with close to theoretical yields at pH = 10 and 11. The crystallite sizes of the powders varied from about 30 nm at 90 C to 50-90 nm at 1250 C with the smallest crystallite sizes obtained for pH 10 and 11 powders at 1250 C. The crystallite size increased significantly with ageing temperature. 5 refs.