PVP对溶胶凝胶法制备负热膨胀ZrW_2O_8粉体形貌及性能的影响

以PVP为添加剂,采用溶胶凝胶法制备ZrW_2O_8粉体,研究添加剂对粉体形貌的影响及其负热膨胀特性。对其前驱体进行热重-差热分析(TG-DSC),以X射线粉末衍射(XRD),扫描电子显微镜(SEM)对产物结构及形貌进行表征。结果表明所得粉体为单一立方α-ZrW_2O_8相。加入PVP后,可以有效地改变粉体的形貌,随着加入量的增大,粉体的形貌从无规则的团聚体转变为长棒状、扇形及短棒颗粒。原位X射线粉末衍射分析表明,所得ZrW_2O_8粉体具有良好的负热膨胀特性。

Effect of PVP on Morphology and Property of Negative T hermal Expansion ZrW2 O8 Pow ders by Sol-gel M ethod

ZrW2 O8 powders were prepared by sol-gel method with PVP as the additive .The effect of PVP on the morphology was studied and negative thermal expansion property of ZrW2 O8 powders was also investigated .The precursor of ZrW2 O8 was analysized by thermogravimetric and differential scan-ning calorimetry (TG-DSC) .The structure and morphology of the resulting powder were character-ized by powder X-ray diffraction (XRD) and scanning electron microscopy (SEM ) respectively .The results show that the resulting powder is single cubicα-ZrW2 O8 phase .The addition of PVP can effec-tively change the morphology of the powder ,with the increasing amount of PVP ,morphology of the particles changes from irregular aggregates to rod-like ,fan-shaped and short rod particles .The results of in-situ X-ray diffraction measurement indicate that ZrW2 O8 powder prepared with the addition of PVP has good negative thermal expansion property .