Preparation of hollow and spherical beta-tricalcium phosphate particles - Effect of citric acid addition to the spraying solution

摘要

The microstructural changes taking place during the heating of beta-calcium phosphate (beta-Ca_3(PO_4)_2) agglomerates were examined. The spray-pyrolyzed powder was composed of dense spherical agglomerates with diameters of 1 to 10 mu m, When the spray pyrolyzed powder was heated up to 900 deg C for 10 mm. only beta-Ca_3(PO_4)_2) was detected. The spherical agglomerates contained many pores ranging from 0.05 to 8 mu m. The beta-Ca_3(PO_4)_2 compact fired at 900 deg C for 2 h was immersed in the physiological saline at 37 deg C for 1 approx 7 d. The results revealed that the amounts of both Ca and P dissolved into the saline were larger than those in the case of sintered beta-Ca_3(PO_4)_2) compact, originating from the powder that had been prepared by the spray-pyrolysis without using citric acid.