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采用包覆法制备单一相钨酸锆(ZrW2O8)空心球。研究选择以水热合成法制备的胶体碳球作为制备空心球的模板,通过溶胶—凝胶法制备了具有网状结构的钨酸锆前驱体凝胶,经过后续简单的包覆过程得到胶体碳球—钨酸锆凝胶形成的壳核结构,并对该壳核结构进行煅烧(610℃保温10h)后除去碳球模板得到ZrW2O8空心球。实验所得ZrW2O8空心球平均粒径约3μm,球壳平均厚度为1.5μm,构成壳层结构的纳米级ZrW2O8颗粒为棒状无规则多面体,尺寸约500nm×50nm×50nm。FTIR和TG-DTA分析证明,产物为立方相ZrW2O8空心球,密度为2.8g/cm3,比理论值降低了45%;产物空心球具有良好的负热膨胀特性,在室温至200℃的温度区间内,负膨胀系数略低于理论值,平均热膨胀系数为-11.4×10-6K-1。
Single phase zirconium tungstate (ZrW2O8) hollow spheres were prepared by the coating method. The colloidal carbon spheres prepared by the hydrothermal synthesis method were selected as the templates for the preparation of hollow spheres. The zirconium tungstate precursor gel with network structure was prepared by sol-gel method. After a simple subsequent coating process, colloidal carbon Ball - zirconium tungstate gel formed shell structure, and the shell structure calcined (610 ℃ 10h) and remove the carbon template to obtain hollow ball ZrW2O8. The average particle size of ZrW2O8 hollow spheres was about 3μm and the average spherical shell thickness was 1.5μm. The nanostructured ZrW2O8 particles with shell structure were rod-like random polyhedrons with a size of about 500nm × 50nm × 50nm. FTIR and TG-DTA analysis showed that the product was cubic ZrW2O8 hollow spheres with a density of 2.8g / cm3, which was 45% lower than the theoretical value. The product hollow spheres had good negative thermal expansion characteristics, and at room temperature to 200 ℃ , The negative coefficient of expansion slightly lower than the theoretical value, the average coefficient of thermal expansion of -11.4 × 10-6K-1.