Synthesis of calcium phosphate powder from calcium lactate and ammonium hydrogen phosphate for the fabrication of bioceramics

Abstract

A calcium phosphate powder has been synthesized from aqueous 0.25, 0.5, and 1.0 M calcium lactate and ammonium hydrogen phosphate solutions atat a Ca/P = 1, without pH adjusting. According to X-ray diffraction data, the as-synthesized powder consisted of brushite (CaHPO₄ · 2H₂O) and octacalcium phosphate (Ca₈(HPO₄)₂(PO₄)₄ · 5H₂O). After heat treatment in the range 500–700°C, the powders were gray in color because of the destruction of the reaction by-product. The powders heat-treated in the range 500–700°C consisted largely of γ-Ca₂P₂O₇. The ceramics prepared from the synthesized powders by firing at 1100°C consisted of β-Ca₂P₂O₇ and β-Ca₃(PO₄)₂.