制备参数对ZrO_2气凝胶超细粉织构和结构性质的影响

NFLUENCE OF PREPARATION PARAMETERS ON TEXTURAL AND STRUCTURALPROPERTIES OF ZrO_2AEROGEL ULTRAFINE POWDERS Ⅱ.AGINGTIME,CONCENTRATIONOFSALTSOLUTION,SCFDOPERATINGCONDITIONS

用超临界流体干燥（ＳＣＦＤ）法制备ＺｒＯ＿２气凝胶超细粉，详细考察了各个制备参数对其织构和结构性质的影响。结果表明，制备大孔高比表面ＺｒＯ＿２气凝胶超细粉较适宜的条件为：水凝胶在母液中老化时间尽可能长，锆盐溶液浓度～０．１７ｍｌ／ｌ，醇水交换度达到醇凝胶液相水含量～２。５２Ｗ％，操作温度～２６０℃，操作压力～７．５ＭＰａ。

Supercritical fluid drying(SCFD)method was used for synthesizing ZrO_2 aero-gel ultrafine powders with high surface areas and pore volumes from zirconyl chloride,Theinfluence of the preparation parameters on the textural and structural properties of ZrO_2aerogel ultrafine powders has been investigated.The optimum preparation conditions of ZrO_2aerogel ultrafine powder with high surface area and pore volume are:the ageing time of thehydrogel in mother liquor being kept as long as practical,the concentration of zirconium saltsolution being～0.17mol/L,the water content of liquid phase in alcogel being～2.52wt%,SCFD operating temperature being～260℃ and SCFD operating pressure being～7.5MPa.