Mechanochemical-hydrothermal preparation of crystalline hydroxyapatite powders at room temperature

Crystalline hydroxyapatite (HAp) powders were prepared at room temperature from heterogeneous reaction between Ca(OH)(2) powders and (NH4)(2)HPO4 solu tions via the mechanochemical-hydro thermal route. X-ray diffraction, infra red spectroscopy, thermogravimetric characterization, and chemical analysis were performed, and it was determined that the room temperature products w ere phase-pure, thermally stable HAp with a nearly stoichiometric compositi on. Dynamic light scattering revealed that the dispersed particle size dist ribution of the room temperature HAp powders was in the range of 0.15-3.0 m um with a specific surface area of approximate to 90 m(2)/g. Both specific surface area measurements and scanning electron microscopy confirmed that t he HAp powders consisted of agglomerates containing hundreds of approximate to 20 nm HAp crystals.