Hydrothermal synthesis of hydroxyapatite

Abstract

A hydrothermal method of synthesizing hydroxyapatite by heating a precipitate, formed by mixing Ca(NO3)24H2O and (NH4)2HPO4 with distilled water, in a hydrothermal reactor at 200 °C for 24-72 hrs is described. A treatment time of 24 hrs produced single phase (as shown by XRD) hydroxyapatite powder, however for longer treatment times XRD patterns were indicative of the presence of a secondary phase, monetite (CaHPO4). SEM examination of the treated powders displayed particles of rod-like morphology with dimensions 100-500 nm in length and 10-60 nm in diameter. Preliminary results on the use of the particles for the infiltration of dentine tubules are presented.