摘要
本文以铝胶和硅胶为原料,采用溶胶-凝胶方法进行了硅铝凝胶形成及晶化行为研究。结果表明,要形成稳定铝硅溶胶pH值必须控制在3以下,采用氨水和乙酰丙酮可调节胶凝时间。采用XRD和TEM研究了凝胶和不同温度热处理之后粉体组成和结构,从干凝胶至莫来石的整个形成过程首先是生成硅铝尖晶石,然后才是莫来石,所得到的粉体存在较为严重的二次团聚。在硅铝凝胶中引入氟化铝有助于莫来石晶须生成。
A study is on synthesis and crystallization of silica and alumina gel , using alumina sol and silica sol as raw materials by sol - gel method. The results of experiment show that stable silica-alumina gel was formed by controlling the value of pH 〈 3. Gelatinization time could be adjusted by adding ammonia or acetylacetone. Structure and composition of alumina-silica gel and powder after heat-treatment at different temperature were investigated by means of XRD and TEM. During the process of phase transition process Si-Al spinel was formed at first, and then mullite. Mullite powder was aggregated after heat-treatment at high temperature. The addition of AlF3 was helpful to the formation of mullite crystal whisker.
出处
《材料科学与工程学报》
CAS
CSCD
北大核心
2006年第3期389-392,共4页
Journal of Materials Science and Engineering
基金
国家自然科学基金项目(60301005)
浙江省科技计划资助项目(2004C21021)
关键词
硅铝凝胶
莫来石
晶化
silica-alumina gel
mullite
crystallization