溶胶-发泡法制备超细氧化铝  

Preparation and Characteristics of Ultrafine Alpha-alumina by Sol-frothing Process

作　　者：孙家跃[1] 肖昂[1] 杜海燕[1] 李庚申[1] 

机构地区：[1]北京工商大学化学与环境工程学院,北京100037

出　　处：《精细化工》2004年第4期257-261,共5页Fine Chemicals

基　　金：北京市自然科学基金(No.2042007);北京市教委科技发展计划重点项目(No.KZ200410011007)

摘　　要：以Al(NO3)3·9H2O和氨水为原料,用溶胶-发泡法制得α Al2O3超细粉末,研究了铝盐的浓度、氨水的滴加速度、分散剂、吸附剂和发泡剂等因素对氧化铝粒径的影响,并用XRD、DTA-TG、IR和BET等方法对样品进行了表征。XRD分析表明,在1200℃下焙烧的氧化铝样品为纯的α相。DTA-TG结果表明,样品在高温固相反应期间有两个明显的失重峰,另外在327 0,386 0,404 0和587 0℃,样品有4个较为明显的吸热峰。IR表征表明,在876 39～448 72cm-1,随着样品粒径的增大,红外吸收带会明显变窄。比表面积和孔隙度分析结果表明,γ Al2O3和α Al2O3的比表面积分别为126 8290m2/g和78 8238m2/g,且它们都属于中孔材料。研究结果表明,该工艺制备的α Al2O3粉体粒度较均匀、平均粒径小于50nm。Ultrafine (nanosized) α-Al_2O_3 powders were prepared from aluminum nitrate nonahydrate and ammonia by sol-frothing process.Effects of the concentration of aluminum nitrate solution,the rate of adding ammonia,frothing reagent,dispersant and adsorbent were investigated.XRD,DTA-TG,IR and BET were used to characterize the products.The powder calcined at 1200 ℃ was alpha-alumina without any other phases by XRD analysis.DTA-TG showed that there were two obvious steps of weight loss and four exothermic peaks at 327.0,386.0,404.0 and 587.0 ℃.IR indicated that the flat and broad band in the region 811.43～448.72 cm^(-1) tended to narrow with the increase of particle size.BET technique and the isotherm indicated the specific surface area of 126.8290 m^2/g and 78.8238 m^2/g respectively for gamma and alpha alumina that belonged to the mesoporous material.The results revealed that the obtained α-Al_2O_3 powder by the sol-frothing method had narrow particle size distribution and average particle size of 42 nm without obvious agglomeration.

关 键 词：氧化铝 超细 溶胶-发泡法 

分 类 号：O612.3[理学—无机化学]