醇-水溶液加热法制备纳米ZrO_2粉体及相关过程的研究

Investigation of the Process of Synthesizing ZrO_2 Nanoparticles by Heating of Alcohol-Aqueous Salt Solutions

分析了醇－水溶液加热法制备纳米ＺｒＯ２（３Ｙ）粉体的过程及加热温度、时间对反应过程及最后所得粉体的影响．研究结果表明：该法制备纳米ＺｒＯ２粉体过程中发生了一系列化学反应，这些反应使Ｙ２Ｏ３前趋体在ＺｒＯ２前驱体中均匀分布，Ｙ２Ｏ２在粉体煅烧期间逐渐渗透到ＺｒＯ２颗粒中使之转变为四方相．只有当加热的温度足够高使得溶液的介电常数＜２５时，沉淀才可能发生．加热时间必须足够长，使反应完全．过短的加热时间致使沉淀不够完全时，容易产生团聚．

The reaction mechanism and parameters that influenced the process of heating ofZrOCl2 and Y(NO3)3 solution with an alcohol-water mixture as a solvent to synthesize ZrO2 (3Y)nanoparticles, the influence of the reaction temperature and time on the synthesizing processand final powder characteristics were investigated. It revealed that the reaction process could bedivided into several steps according to the occurring of different kinds of precipitates. As a result,Y(OH)_3 distributed uniformly in the gel of Zr(OH)_4 and then, when the calcination temperaturerose, the monoclinic phase in the powder decreased. Only when the reaction temperature was highenough that the dielectric constant decreased to <25, the precipitation could happen. To avoidagglomeration, reaction time should be long enough to ensure the solution react complete.