Ethylenediamine tetraacetic acid (EDTA) is considered 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 hydrothermal conditions is 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.

乙二胺四乙酸（EDTA）被认为是用于模板辅助水热合成羟基磷灰石（HA）材料的有效晶体生长改性剂。在这项工作中，通过一步水热法使用EDTA合成了花状碳酸化HA（CHA）微球。通过X射线衍射，傅立叶变换红外光谱仪，场发射扫描电子显微镜以及激光衍射粒度分析检查产物的相，官能团，形态和粒度分布。结果表明，通过调节EDTA浓度可以很好地控制产物的形态。随着EDTA浓度的增加，花状微球的粒径从数十微米减小到几微米。提出了水热条件下不同浓度EDTA的CHA微球形态转变的潜在机理。这项工作提供了一种简单的方法，可以使用相同的合成系统针对生物医学应用（例如细胞载体和药物递送）可控制地制造具有各种尺寸的CHA微球。