| 碱式硫酸镁晶须水热过程结晶动力学研究 |
| Hydrothermal Crystallization Kinetics of Magnesium Hydroxide Sulfate Hydrate Whiskers |
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| 摘要: 采用水热法合成了碱式硫酸镁晶须，利用扫描电镜、透射电镜、X射线能谱仪和X射线衍射仪等对产物的形貌和组成进行表征。通过考察不同温度下SO42-浓度随时间的变化，对碱式硫酸镁晶须的结晶动力学进行了研究。利用MATLAB软件和Runge-Kutta数值解法对实验数据进行处理，得出不同温度下晶须的结晶动力学方程。对晶须的几种生长机理模型进行分析发现，低温和高温的动力学模型不同，反应温度为170 ℃、180 ℃、190 ℃时的动力学模型分别为MB-1、MB-2和MB-3，结晶机理为多核控制表面生长，结晶速率由表面反应控制；反应温度为200 ℃和210 ℃时，结晶机理发生了变化，为单核控制表面生长，结晶动力学模型分别为MC-2和 MC-3。 |
| 关键词: 碱式硫酸镁 结晶 动力学 水热合成 |
| 基金项目: |
| Abstract: Magnesium hydroxide sulfate hydrate whiskers were prepared by a hydrothermal method and scanning electron microscope, transmission electron microscope, X-ray powder diffraction and energy dispersive X-ray spectroscopy were employed to investigate composition and morphology of the products. Crystallization kinetics of the whisker was studied by analyzing the change of SO42- ion concentration through the hydrothermal process at different temperatures. Experimental data were handled using software MATLAB and numerical solution of Runge-Kutta and crystallization kinetics equations at different temperatures were obtained according to the above mentioned analysis. The results showed that the mechanism for crystal growth was different when the whiskers were synthesized at different temperatures. When the reaction occurred at 170 ℃, 180 ℃ and 190 ℃, the crystallization was controlled by multi-core surface growth, and the dynamic models for the crystallization were MB-1, MB-2 and MB-3, respectively. While it changed to be controlled by single-core surface growth when the reaction temperature was 200 ℃ or 210 ℃ and the dynamic models became MC-2 and MC-3 correspondingly. |
| Keywords: magnesium hydroxide sulfate hydrate crystallization kinetic hydrothermal synthesis |
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| 高传慧,王传兴,许 军,武玉民,李先国.碱式硫酸镁晶须水热过程结晶动力学研究[J].无机化学学报,2012,28(10):2198-2204. |
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