Control of hydroxyapatite nanoparticle morphology using wet synthesis techniques: Reactant addition rate effects

Hydroxyapatite is a widely used biomaterial that, due to its biocompatibility and biodegradability, can be applied to a variety of biomedical problems. The effect of reactant addition rate during wet synthesis on hydroxyapatite particle morphology was studied. It was found that by decreasing reactant addition rate, the size and aspect ratio of hydroxyapatite nanoparticles could be increased. Reactant addition rates tested ranged from 0.80 mL/min to 140 mL/min, with resulting particles ranging from 255 nm long rod-shaped particles to 27 nm diameter spherical particles. X-ray diffraction confirmed that at all reactant addition rates pure hydroxyapatite was generated. Controlling reactant addition rate is therefore a practical and simple approach for preparing hydroxyapatite particles with varied morphologies and particle sizes suitable for different biomedical applications.