Effect of the Concentrations of the Starting Solution on the Syntheses and Powder Properties of Hollow Tricalcium-Phosphate Microspheres by Ultrasonic Spray-Pyrolysis Technique

Abstract

We synthesized tricalcium phosphate (TCP) microspheres using an ultrasonic spray-pyrolysis technique, and investigated the effect of the concentrations of the starting solution on the powder properties. The XRD pattern showed that the crystalline phases of the resulting powders were β-TCP/HAp biphase in the case of pyrolysis temperature at 850 °C and TCP single phase at 1000 °C. The Ca/P molar ratios were determined by XRF to be at 1.50±0.03. The particle shapes of the powders were observed by SEM; the diameters of the microspheres were narrowly distributed from 0.5 to 4 µm. The mean particle diameters of the resulting powder increased with the concentration of the starting solutions and could be controlled in the range of 0.85-1.4 µm. When the compressed powder was sintered at 1050 °C for 5 h , the relative density of the sintered compact attained to 97%. The TCP microspheres had good sinterability.