微波水热法合成硅酸锆纳米粉体的研究

以氧氯化锆和硅酸乙酯为原料,NaF为矿化剂,采用微波水热法(Microwave-Hydrothermal,M-H)在160-200℃下成功的制备出了高纯的硅酸锆纳米粉体。并利用X射线衍射(XRD)和扫描电镜(SEM)对所合成的硅酸锆粉体进行了研究。结果表明:微波水热可使ZrSiO4的结晶温度降低到160℃,合成时间可缩短到30min,大大的降低硅酸锆粉体的合成能耗。微波水热法合成的硅酸锆粉体颗粒呈圆片状,外形规则,粒度分布均匀(约为400nm),ZrSiO4晶体尺寸小(约为20nm)。在950℃下煅烧微波水热合成的粉体,结果表明:煅烧有利于进一步提高该粉体的结晶程度,该粉体颗粒形状及粒度均未产生显著的变化。结合测试分析,对纳米硅酸锆粉体的微波水热合成反应机理进行了初步探讨。

PREPARATION OF NANO-ZrSiO4 POWDERS BY MICROWAVE-HYDROTHERMAL METHOD

High purity zircon powders were prepared by the microwave-hydrothermal synthesis at 160~200℃ for 30min,using zirconium oxychloride and tetraethoxysilane as starting materials and NaF as a mineralizer to promote crystallization of zircon.The phase composition and microstructure of zircon powders are identified by X-ray diffraction and SEM.The results showed that： microwave-hydrothermal method could greatly cut the energy consumption of zirconium silicate powder synthesis by reducing the crystallization temperature of ZrSiO4 to 160℃ and the crystallization time to 30min.Zircon powders by microwave hydrothermal synthesis are ellipsoids.Their size and shape did not change much after being calcined at 950℃.The zircon crystal size reached the maximum（20nm）.The reaction mechanism of microwave hydrothermal synthesis of zirconium silicate was also discussed.