Fabrication and characterization of a hydroxyapatite nanopowder by ultrasonic spray pyrolysis with salt-assisted decomposition

Ultrasonic spray pyrolysis using the salt-assisted decomposition method, a process which adds specific salts into a precursor solution, was used to fabricate nano-sized hydroxyapatite (HAp) particles. The added salts (NaNO3) interrupt agglomerate formation of the primary nanoparticles in the synthesis process. The final nano-sized particles were obtained after a washing process that was used to remove the salts from the secondary particles which were formed by the salts and HAp particles. The nano-sized particles were rod-type and single phase HAp with high crystallinity and good stoichiometry. The effects of the amount of salts added and the synthesis temperature were investigated and discussed regard to the aspect ratio of HAp.