快速溶胶凝胶法制备钾霞石及其反应机理  

Synthesis and characterization of kalsilite powder using a fast sol-gel method

作　　者：郑骥[1] 马鸿文[1] 

机构地区：[1]中国地质大学(北京)矿物材料国家专业实验室

出　　处：《北京科技大学学报》2007年第1期55-58,共4页Journal of University of Science and Technology Beijing

基　　金：教育部博士学科点研究基金资助项目(No.1999049114)

摘　　要：在不使用任何有机溶剂的条件下，使用氨水调节pH值，正硅酸乙酯-硝酸钾-硝酸铝-水体系在5～12min内即迅速胶凝．干凝胶在862℃下热处理生成的钾霞石物相单一、颗粒大小均匀、平均粒径为8μm．硝酸盐水解产生的氢离子以及随后加入的氨水相当于进行了先酸后碱的催化，促使正硅酸乙酯（以TEOS表示）迅速水解、聚合．^27Al NMR分析证实铝硅酸盐溶胶聚合按照五配位铝中间体机理进行．Nitrate replaced alkoxide and alcohol solvent omitted, a TEOS-KNO3-Al（NO3）3-H2O system turned into gel in 5-12 min with pH adjusted by aqua ammonia. Dried gel treated at 862℃, pure and homogeneous kalsilite powder was prepared with an average particle size of 8μm. The TEOS hydrolysis reaction was catalyzed by H^＋ released from aluminum nitrate hydrolysis firstly, and then promoted again by OH- with the addition of aqua ammonia. The gelation time was shortened greatly owing to the catalysis mode of acid first and alkali second. A penta-coordination Al was detected by ^27Al NMR analyzing the dried aluminosilicate gel.

关 键 词：钾霞石 溶胶凝胶法 胶凝 催化剂 五配位铝中间体 

分 类 号：TQ170.7[化学工程—硅酸盐工业]