Abstract
Porous materials of calcium hydroxyapatite (CaHA) and strontium hydroxyapatite (SrHA) were prepared by hydrothermal technique from amorphous calcium phosphate and amorphous strontium phosphate, respectively. The amorphous Ca- and Sr- phosphate powders were compacted and subsequently hydrothermally treated in ammonia solution at temperatures fro 105°C to 250°C for 20h under saturated vapor pressure. The prepared porous materials consisted of rod-shaped crystals of 3-10 μm in length and with the aspect ratio in the range of 15-50. They had a porosity of about 60% with an interconnecting pore structure and compressive strength of 20-25 MPa. Both CaHA and SrHA materials were homogeneous and nonstoichiometric with Ca(Sr)/P molar ratios in the range of 1.50-1.60. The microstructure and chemical composition of the porous CaHA and SrHA materials could easily be controlled by changing the preparation conditions.
