Batch preparation of homogeneous size hydroxyapatite based composite ceramic microspheres

A new and precise control printing method was developed for preparing homogeneous microspheres. Hydroxyapatite-sodium alginate (HA-SA) mixed suspension was used as printing material and CaCl2 solution was used as solidifying liquid to prepared ceramic microspheres by pneumatic extrusion printing technology. By adjusting the positive pressure, dwell time, and hydroxyapatite concentration, the influence of each parameter on the shape of printed microspheres was studied, and the suitable preparation parameters were determined. Then, the microspheres with uniform particle size distribution were successfully prepared in large quantities by selecting appropriate printing parameters. Then, the microspheres were dried and sintered at different temperatures. During the drying and sintering process, the microspheres showed obvious shrinkage, but still keep good sphericity. The phases of sintered microspheres are hydroxyapatite and calcium oxide. The microstructure shows typical hydroxyapatite grain characteristics.