Assembly synthesis of spherical hydroxyapatite with hierarchical structure

Spherical hydroxyapatite (HAP) crystals with hierarchical structure and controllable size has been successfully synthesized by hydrothermal method. The polyvinylpyrrolidone (PVP) as a template united with Ca2+ chelating agent is used to regulate the nucleation and crystal growth. The synthesized powders were characterized by X-ray diffraction (XRD), Fourier transform infrared spectrograph (FTIR), scanning electron microscope (SEM) and transmission electron microscopy (TEM). The results indicate that the obtained particles are uniform spherical crystals with hierarchical structure. Furthermore, the process of PVP template united with Ca2+ chelating agent is discussed.