Synthesis of HA nanoparticles in the presence of anionic and cationic polyelectrolyte

Hydroxyapatite (HA) nanopowders have been synthesized by an inverse microemulsion system using cyclohexane, ananionic surfactant and aqueous solutions of calcium nitrate tetrahydrate and biammonium hydrogen phosphate in the presence of anionic and cationic polyelectrolyte with the inducement of ultrasound irradiation. The Prepared HA in the presence of anionic polyelectrolyte has a different morphology from samples which are synthesized in the presence of cationic polyelectrolyte. Cationic polyelectrolyte (poly diallyl dimethyl ammonium chloride PDADMAC) leads to the formation of needle-like HA (10nm in diameter and 100nm in length). Formation of HA at room temperature was confirmed by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR) and morphology of the samples which were characterized using transmission electron microscopy (TEM).