Novel preparation of hydroxyapatite nanoparticles and nanorods with the aid of complexing agents

New complexing agents based on Schiff base compounds have been employed to fabricate nanocrystalline hydroxyapatite (HAP). The use of the Schiff bases derived from 2-hydroxybenzophenone led to the formation of HAP nanoparticles and nanorods. Moreover, hollow needle-like nanorods of HAP were formed in the presence of the Schiff base derived from 2-aminophenol. In the crystal growth mechanism proposed for HAP crystals, zero-dimensional (0-D) and one-dimensional (1-D) nanostructures were generated by considering tetradentate and bidentate coordination modes of the Schiff bases, respectively. The synthesized products were characterized by several techniques including proton nuclear magnetic resonance (1H NMR) spectroscopy, transmission electron microscopy (TEM) and X-ray powder diffraction (XRD).