Investigation of EDTA concentration on the size of carbonated flowerlike hydroxyapatite microspheres

Ethylenediamine tetraacetic acid (EDTA) is considered as an effective
crystal growth modifier for template-assisted hydrothermal synthesis of
hydroxyapatite (HA) materials. In this work, flowerlike carbonated HA
(CHA) microspheres were synthesized using EDTA via a one-step hydrothermal
route. The phase, functional groups, morphology, and particle size
distribution of the products were examined by X-ray diffraction, Fourier
transform infrared spectrometer, field-emission scanning electron
microscopy as well as laser diffraction particle size analysis. Results
show that the morphology of the products can be well controlled by
adjusting the EDTA concentration. With an increase of the EDTA
concentration, the particle size of flowerlike microspheres decreased from
tens of microns down to a few microns. The underlying mechanism for the
morphological transition of CHA microspheres with different concentrations
of EDTA under the hydrothermal conditions was proposed. This work provides
a simple way to controllably fabricate CHA microspheres with various sizes
using the same synthesis system for biomedical applications, such as cell
carriers and drug delivery.