低温水热合成高纯硅酸锆粉体_英文_.docx

2009 年 2 月February，2009JOURNAL OF THE CHINESE CERAMIC SOCIETY低温水热合成高纯硅酸锆粉体方培育，吴建青(华南理工大学材料科学与工程学院，特种功能材料教育部重点实验室，广州 510640)摘要：以氧氯化锆和硅酸乙酯为原料，以 NaF 为矿化剂降低合成温度，采用水热法在 160～240 ℃合成了高纯的 ZrSiO4 粉体。用 X 射线衍射、扫描电镜和能谱仪表征了 ZrSiO4 粉体的物相组成和显微结构。用氮气等温吸附 Brunauer–Emmett–Teller 法测试了 ZrSiO4 粉体的表面积和孔结构。结果表明：当 F 与 Zr 的摩尔比为 2 时，ZrSiO4 的结晶温度可降低到 160 ℃。ZrSiO4 粉体为纳米纤维组成的椭球，大小约为 1 μm。探讨了 ZrSiO4 粉体的形 成机制和 F 离子的降低结晶温度的作用，F 离子可以代替 O 离子形成 Zr—F 和 Si—F 键，降低形成 ZrSiO4 的能量势垒，促进了 ZrSiO4 的结晶。关键词：水热合成；硅酸锆；粉体；矿化剂；结晶中图分类号：TQ174文献标志码：A文章编号：0454–5648(2009)02–0304–07LOW TEMPERATURE SYNTHESIS OF HIGH-PURITY ZIRCON POWDER BY AHYDROTHERMAL METHODFANG Peiyu，WU Jianqing(College of Materials Science and Engineering, Key Laboratory of Specially Functional Materials, Ministry of Education, South China University of Technology, Guangzhou 510640, China)Abstract: High-purity zircon powders were prepared using zirconium oxychloride and tetraethoxysilane as starting materials by the hydrothermal method at 160–240 ℃ for 4 h. NaF was added to the gel as mineralizer to promote crystallization of zircon. The phasecomposition and microstructure of zircon powders were identified by X-ray diffraction, scanning electronic microscopy and energy dispersive X-ray spectroscopy. The surface area and pore structure were measured by N2 adsorption using the Brunauer–Emmett– Teller method. The results show that the starting crystallization temperature of zircon powder can be decreased to 160 ℃ with an F to Zr mole ratio of 2. The zircon powders were ellipsoids composed of nanofibers with the size of about 1 μm. The formation mechanism and effect of F ions on lowering the crystallization temperature of zircon were investigated. When F ions replaced O ions, Zr—F and Si—F bonds can be formed, and it can lower the forming energy potential of zircon and promote the crystallization of zircon.Key words: hydrothermal method; zircon; powder; mineralizer; crystallizationZircon (ZrSiO4) can be extensively applied as a re-fractory because of its hi