Abstract
Hydroxyapatite (HA) ceramics are used as artificial bones and adsorbents. The properties of HA particles are dependent on their morphology and composition. To reveal the effects of these factors, tailored HA particles are required. In the present study, HA particles with a controlled morphology and composition were prepared using the hydrothermal treatment of α- or β-tricalcium phosphate (α- or β-TCP) particles in an acidic or basic solutions at 120−240 °C. Plate-like HA particles were obtained when α-TCP was treated with the acidic solution. Rod-like HA particles were obtained when α-TCP was treated with the basic solution or when β-TCP was treated with the acidic solution. Rice-like HA particles were obtained when β-TCP was treated with the basic solution. The HA particles that were obtained under these conditions had a calcium-deficient composition, and the Ca/P molar ratio approached the stoichiometric value when the treatment temperature was increased. The morphology and composition of HA particles were controlled by selecting the starting materials and hydrothermal conditions.
