摘要
采用醇盐水解法制备超细γ-Al2O3粉体,利用同步热分析仪分析γ-Al2O3前驱体中溶剂分解、晶型转变,采用X射线衍射仪、BET((Bmnauer-Emen-Teller)、扫描电镜等表征了超细γ-Al2O3粉体的晶型结构、组成及其宏观物性,重点探讨了焙烧工艺对超细γ-Al2O3粉体分散稳定性的影响。结果表明,在空气气氛下以3℃/min的升温速率直接升温至850℃,保温0.5h后随炉冷制备的超细γ-Al2O3粉体在水中的分散稳定性最好,沉降时间最长,1个月后沉降粉体比例不高于0.15,由此制备的涂膜均匀致密,无孔洞,几乎无间隙。
Ultrafine γ-Al2O3 powder is synthesized by aluminum isopropoxide through a hydrolysis process. A series of changes including solvolysis and crystallization transformation of γ-Al2O3 precursor are analyzed by thermo- gravimetric-differential thermal analysis（STA）. Crystallization structure, ingredient and its physical properties of ultrafine γ-Al2O3 powder are studied through different methods, such as X-ray diffraction, Brunauer-Enmet-Teller （BET） surface area, scanning electron microscope, etc. The effect of calcination technology on dispersing stability of ultrafine γ-Al2O3 powder is mainly discussed in this article. The results indicate that dispersing stability of ultrafine γ-Al2O3 powder in water is the best with the longest settling time, less 0. 15 of settling powders＇ proportion after one month, the best coating surface, uniform densification and no pore and gap, under the condition which the maximum temperature is 850℃ and its isothermal time is 30min, the heating rate is 3℃/min.
基金
上海市青年科技启明星项目(11QB1402500)
关键词
超细γ-Al2O3
焙烧
工艺
分散稳定性
ultrafine gamma alumina, calcinations, technology, dispersing stability
