Synthesis and characterization of nanocrystalline hydroxyapatite and biphasic calcium phosphate using Ca(OH) sub(2) and (NH sub(4))H sub(2)PO sub(4 )

In this study, nanocrystalline hydroxyapatite and biphasic calcium phosphate prepared via wet chemical precipitation technique in an isolated N sub(2) environment that utilizes calcium hydroxide and ammonium dihydrogenphosphate as main precursors, is presented. Formation of predominantly hydroxyapatite with increasing crystallinity from 39.6 to 88.3% with corresponding crystallite sizes of 20.6 and 46.6 nm were found for the as-grown and the annealed powders, respectively. Partly phase transition of hydroxyapatite to beta -TCP phase forming biphasic calcium phosphate was observed in the 900 super(o)C annealed powders. Aggregated structures with nanopores were depicted on the surface of the as-grown sample while interconnected worm-like structures with voids forming nanopores were found for the sample annealed at 900 super(o)C. ( copyright 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)