模板诱导/均相沉淀法对HAP形貌的控制及其机理研究

Morphology Control and Mechanism of Hydroxyapatite Synthesized by a Template-Mediated Homogenous Precipitation Route

通过添加不同的有机模板剂、改变同种模板剂浓度,用模板诱导/均相沉淀法合成了具有不同形貌的羟基磷灰石(HAP),并用XRD、SEM对样品进行了表征。测试了不同反应溶液的表面张力,结合晶体生长理论初步解释了有机模板剂控制HAP形貌的机理。结果表明:模板剂种类的变化及其在反应溶液中浓度的变化,可以改变反应体系的表面能γlg,影响不同成核晶面的界面能γsl,从而改变HAP最终的生成形貌。当γlg小于28 mN/m时,产物均为板片晶组成的球花;当γlg^(28 mN/m, 48 mN/m)时,为晶须和片晶球花组成的混合形态;当γlg大于48 mN/m时,产物均为HAP晶须。

Different morphologies hydroxyapatites (HAPs) were synthesized in a controllable way by a template- mediated homogeneous precipitation route. The morphologies and compositions of synthesized HAPs were charact- erized by SEM and XRD, and the surface tensions of different reaction solutions were tested. The template-mediated mechanism for the morphology control according to the crystal growth theory was explained. The results suggested that with the changes of template agent types and the concentrations of reaction solution, the surface energy γlg of precursor liquid can be changed. Then the interface energy γsl of the nucleation at the different crystal plane could be affected. The morphologies of synthesized HAPs were controlled by the precursor liquid surface tension γlg and the crystal interface energy γsl. When γlg was controlled under 28 mN/m, the morphology of HAP was controlled to become nanoflower. When γlg was controlled between 28 mN/m and 48 mN/m, the HAPs had the mixed morphologies with whisker and nanoflower. While γlg was controlled above 48 mN/m, the HAPs was controlled to became whisker.