Activation energy for the mullitization of a diphasic gel obtained from fumed silica and boehmite sol

被引：28

作者：

Boccaccini, AR

Khalil, TK

Bücker, M

机构：

[1] Tech Univ Ilmenau, FG Werkstofftech, D-98684 Ilmenau, Germany

[2] Atom Energy Author, Hot Labs Ctr, Cairo, Egypt

[3] Univ Jena, Tech Inst, D-07743 Jena, Germany

来源：

MATERIALS LETTERS | 1999年 / 38卷 / 02期

关键词：

mullite; sol-gel; silica; boehmite; colloidal processing; mullitization;

D O I：

10.1016/S0167-577X(98)00143-8

中图分类号：

T [工业技术];

学科分类号：

08 ;

摘要：

The activation energy for mullite formation in diphasic gels was determined by means of differential thermal analysis. The value obtained, E = 880 +/- 30 kJ/mol, is lower than most data reported in the literature for diphasic gels (similar to 1000 kJ/mol), but considerably higher than the value determined fur single phase gels (similar to 300 KJ/mol). The relatively low value for the activation energy determined, in comparison with other diphasic gels, is attributed to the particular combination of precursors used (fumed silica nanopowders and boehmite sol). It is suggested that the mullitization reaction proceeds by a nucleation and growth mechanism, in agreement with previous results. (C) 1999 Elsevier Science B.V. All rights reserved.

引用

页码：116 / 120

页数：5

共 14 条

[1] Mullite fabrication from fumed silica and boehmite sol precursors [J].