Influence of synthesis and composition on mullite crystallization

摘要

Gels with nominal compositions AL_2O_3 . SiO_2 and 2Al_2 O_3 . SiO_2 have been prepared using two sol-gel routes, the first one by long gelation time of a solution of TEOS and aluminum nitrate nonahydrate, the second one starting from TEOS and Al alkoxides with different processing conditions. Xerogels with different levels of homogeneity as depicted by their crystallization schemes have been obtained.