Preparing hydroxyapatite powders with controlled morphology.

We developed a synthesis method for hydroxyapatite particles with different morphologies. The process involved chemical precipitation and spray drying, which produced spherical, agglomerated hydroxyapatite granules with controlled particle sizes and structures. These granules contained nanoparticles with an average crystalline size of about 10 nm. We controlled the morphologies of the granules by adjusting the spray-drying conditions, such as the volume fraction of feed slurry and the atomization pressure. The spray-dried granules were doughnut shapes, solid spheres, or hollow spheres, and their sizes were controlled by varying the atomization pressure and the concentration of the feed slurry.