Chemistry-crystallization relations in molecular mullite gels

摘要: Abstract Sol-gel chemistry profoundly affects the crystallization of molecular aluminosilicate gels. Segregation transition alumina-yielding species during gel synthesis results in epitaxial nucleation spinel at 980°C. When conditions leading to alumina segregation are avoided, t-mullite crystallizes However, it is shown, for first time, that these gels phase-separated prior by a hydrothermal reaction known as dealumination. synthesized and heated avoid this mechanism phase separation, crystallize directly o-mullite 700°C. This temperature ∼ 500°C lower than those previously reported.