Characterization of hydroxyapatite powders prepared by ultrasonic spray-pyrolysis technique

摘要

The hydroxyapatite (Hap) powder was preparedby the ultrasonic spray-pyrolysis technique; the characterizationof the resulting powders was performed. Five kinds of thestarting solutions with the Ca/P ratio of 1.67 were prepared bymixing Ca(NO3)2, (NH4)2HPO4 and HNO3; the concentrations ofCa2+ and PO43+ were in the ranges of 0.10 to 0.90 mol·dm-3 and0.06 to 0.54mol·dm-3, respectively. These solutions weresprayed into the heating zone to prepare the HAp powders. Theheating zone was composed of two electric furnaces; the lowerfurnace was used for the evaporation of the solvent from thedroplets (300-500℃)and the upper furnace for the pyrolysis ofthe precipitated metal salts (750-900℃). The easily sinterableHAp powder was prepared by spray-pyrolysing the solutionwith Ca2+ (0.50mol·dm-3) and PO43+ (0.30mol·dm-3) at thetemperatures of 800℃(the upper furnaces) and 400℃(the lower furnaces).