摘要
研究了共沉淀法制备氧化锆超细粉末过程中团聚体的形成机理及其团聚状态的控制。结果表明,氧化锆超细粉末以二次团聚体形式存在,粉末的二次团聚结构在凝胶制备过程中就已形成。其中,一次团聚体在氢氧化锆沉淀过程中形成,二次团聚体在凝胶干燥过程中形成。在凝胶制备过程中加入高分子表面活性剂可有效地控制粉末的一次团聚状态和二次团聚状态。而采用乙醇脱水工艺只能控制粉末的二次团聚状态,对一次团聚状态影响不大。文中还讨论了粉末团聚状态与粉末物理性能参数的关系。
The mechanism of agglomerate formation during preparing ultrafine zirconia powders by coprecipitation and the control of the state of agglomeration have been investigated.It hasbeen shown that the prepared ultrafine zirconia powders have two-level agglomeration struc-ture in which the first level is formed during colloidal precipitation and the second level isformed during gel drying.The agglomeration structures of both levels can be controlled bysing macromolecular surfactants during the preparation of zirconium hydroxide gels.Alco-hol ehydration can influence the state of the second-level agglomeration but has little influ-nce n that of the first-level one.The effect of the state of agglomeration on physicalproperties f he powders has also been discussed.
基金
国家自然科学基金
关键词
共沉淀
氧化锆
超细粉末
团聚
coprecipitation
zirconia
ultrafine powder
agglomeration
