水热制备锌、硅、镁、铁等元素掺杂羟基磷灰石及其表征

微量元素掺杂是赋予羟基磷灰石材料更多生物学功能的一条有效途径, 但不同元素的掺杂行为尚待进一步揭示。本研究使用并行水热合成方式, 制备分别含有锌、硅、镁、铁、锰、铜、锶、硒、钴的9种羟基磷灰石粒子, 并对其物理化学特性进行研究。结果表明, 元素掺杂显著改变了羟基磷灰石粒子的形貌和晶体生长方向, 但不改变其物相组成和官能团。晶体的(211)和(112)晶面衍射峰的强度均降低, 结晶度下降。元素实际掺杂效率分析结果显示锰>锌>镁>铁(三价)>锶>钴>铜>硒>硅, 与元素的离子半径大小相关。锰、锌、镁三种元素掺杂量较高, 因其离子半径与其替代的钙离子接近。铜元素掺杂效率较低是由于其在合成溶液中与氨产生络合作用, 硅元素和硒元素则因几何结构和电荷(SiO₃^2-、SeO₃^2-/PO₄^3-)差异导致掺杂率低。本研究揭示了掺杂行为与离子特性之间的联系, 为功能化羟基磷灰石的设计和开发提供有益的参考基础。

Hydrothermal Preparation and Characterization of Zn,Si, Mg,Fe Doped Hydroxyapatite

Doping of trace elements is an effective way to endow hydroxyapatite with more biological functions. But the behaviors of different element doping remained to be further revealed. Here, nine kinds of hydroxyapatite particles containing zinc, silicon, magnesium, iron, manganese, copper, strontium, selenium, and cobalt, respectively, were prepared by parallel hydrothermal synthesis, and their physicochemical properties were studied. The results show that the morphology and crystal growth direction of hydroxyapatite particles are significantly changed, while the phase composition is maintained. The peak intensity of (211) and (112) plane diffraction peaks decreased, accompanied by decreased crystallinity. Analysis results show that the actual doping efficiency obeys the tendency of manganese > zinc > magnesium > iron (trivalent) > strontium > cobalt > copper > selenium > silicon. Among these elements, doping amounts of Mn, Zn and Mg are higher, because their ion radii are closed to that of Ca ²⁺. The low doping efficiency of copper is caused by its complexation with ammonia in synthetic solution, while silicon and selenium are caused by different geometry and charge of SiO₃^2-, SeO₃^2- from that of PO₄^3-. This study reveals the reasonable relationship between doping behavior and ion characteristics, providing a useful reference for design and development of functionalized hydroxyapatite.