乳液溶胶-凝胶法制备莫来石纳米晶微球

Preparation of Nanocrystalline Mullite Contained Microspheres by sol-gel process in oil-in-water emulsion

摘要:

以仲丁醇铝为铝源，正硅酸乙酯为硅源，利用乳液溶胶-凝胶法制备了氧化铝/二氧化硅复合凝胶微球，并通过热处理对复合凝胶微球进行了结晶化处理；采用扫描电镜(SEM)、差热/热重分析(DTA/TG)、X射线衍射(XRD)研究了仲丁醇铝与正硅酸乙酯的相对含量以及热处理温度对复合凝胶球微结构及结晶的影响。结果表明：过量的正硅酸乙酯会导致分散相凝胶不充分从而形成液滴融合状的微结构；所得氧化铝/二氧化硅凝胶球经过1000oC热处理后，球体内形成了莫来石纳米晶，经谢乐公式计算，微球体内的纳米晶平均尺寸为12 nm。

Abstract:

Alumina/silica microspheres were prepared by sol-gel process in oil-in-water emulsion with aluminum sec-butoxide as aluminum source and tetraethoxysilane as silicon source, crystallization was achieved by heat treatment at 1000 oC. The effect of addition of tetraethoxysilane and heat treatment on the crystalline structure and microstructure of the microspheres were studied via scanning electron microscopy, X-ray diffraction and thermogravimertic/diifrental thermal analysis analysis. The results showed that increasing addition of tetraethoxysilane inhibited the gelation of the disperse phase in emulsion, which induced the conglutination of the disperse phase. After heat-treated at 100 oC, the mulite phase in the alumina/silica microspheres was generated and the resulting grain size was12 nm.