Mechanochemical-hydrothermal synthesis of carbonated apatite powders at room temperature

Crystalline carbonate- and sodium-and-carbonate-substituted hydroxyapatite (CO(3)HAp and NaCO(3)HAp) powders were prepared at room temperature via a heterogeneous reaction between Ca(OH)2/CaCO3/NaCO3 and (NH4)(2)HPO4 aqueous solution using the mechanochemical-hydrothermal route. X-ray diffraction, infrared spectroscopy. thermogravimetry. and chemical analysis were performed. Room temperature products were phase-pure CO(3)HAp and NaCO(3)HAp containing 0.8-12 wt% of carbonate ions in the lattice. Dynamic light scattering revealed that the median agglomerate size of the room temperature CO(3)HAp and NaCO(3)HAp powders was in the range of 0.35-1.6 mum with a specific surface area between 82 and 121 m(2)/g. Scanning and transmission electron microscopy confirmed that the carbonated HAp powders consisted of mostly submicron aggregates of nanosized. approximate to 20 nm crystals. The synthesized carbonated apatite powders exhibit chemical compositions and crystallinities similar to those of mineral constituents of hard tissues and therefore are promising for fabrication of bone-resembling implants. (C) 2001 Elsevier Science Ltd. All rights reserved.