Synthesis of Hydroxyapatite by an Oxidative Decomposition Method of Calcium Chelate

Abstract

Preparation of hydroxyapatite (Hap) was investigated by a homogeneous precipitation technique. The precipitates were obtained by mixing solutions of Ca (NO₃)₂, (NH₄)₂HPO₄, EDTA-Na and H₂O₂ at 90°C. The products were identified as carbonate-containing hydroxyapatite by the X-ray diffraction and IR spectrometry. When pH value of the reacting solution was higher than 10, Ca/P molar ratio of the precipitate was 1.67. Synthesized Hap powders by this method had specific surface area of 5-35m²/g, and the Hap particles showed clear hexagonal pyramidal ideomorphic shapes.