Biomimetic synthesis of spherical nano-hydroxyapatite with polyvinylpyrrolidone as template

Abstract

Spherical nano-hydroxyapatite (HA) was synthesised successfully. Ca(NO 3 ) 2 ˙4H 2 O and (NH 4 ) 3 PO 4 ˙3H 2 O were used as reagents and polyvinylpyrrolidone (PVP) as template. The crystal phase, chemical composition, microstructure of the obtained HA were characterised by X-ray powder diffraction analysis, Fourier transform infrared spectroscopy, X-ray fluorescence spectrometry, thermogravimetric analysers microcomputer differential thermal analysers and transmission electron microscopy. The results show that the concentration of PVP significantly affects the morphologies of the nanometre HA. Spherical nano-hydroxyapatite particle with diameter of 30–50 nm can be synthesised using PVP of a certain concentration (0˙5–5%) as template. The crystallinity of HA decreases continuously as the PVP content increases. Spherical apatite crystal forms because of a high affinity between HA and PVP.