TY - JOUR
T1 - Chemistry-crystallization relations in molecular mullite gels
AU - Huling, Jeffrey C.
AU - Messing, Gary L.
N1 - Funding Information:
The authors gratefully acknowledge funding from the Industrial Co-op Program of the Center for Advanced Materials and the Division of Materials Research of the National Science Foundation.
PY - 1992
Y1 - 1992
N2 - Sol-gel chemistry profoundly affects the crystallization of molecular aluminosilicate gels. Segregation of transition alumina-yielding species during gel synthesis results in the epitaxial nucleation of spinel at 980°C. When synthesis conditions leading to alumina segregation are avoided, t-mullite crystallizes at 980°C. However, it is shown, for the first time, that these gels are phase-separated prior to crystallization by a hydrothermal reaction known as dealumination. When the molecular gels are synthesized and heated to avoid this mechanism of phase separation, the gels crystallize directly to o-mullite at 700°C. This crystallization temperature for o-mullite in aluminosilicate gels is ∼ 500°C lower than those previously reported.
AB - Sol-gel chemistry profoundly affects the crystallization of molecular aluminosilicate gels. Segregation of transition alumina-yielding species during gel synthesis results in the epitaxial nucleation of spinel at 980°C. When synthesis conditions leading to alumina segregation are avoided, t-mullite crystallizes at 980°C. However, it is shown, for the first time, that these gels are phase-separated prior to crystallization by a hydrothermal reaction known as dealumination. When the molecular gels are synthesized and heated to avoid this mechanism of phase separation, the gels crystallize directly to o-mullite at 700°C. This crystallization temperature for o-mullite in aluminosilicate gels is ∼ 500°C lower than those previously reported.
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U2 - 10.1016/S0022-3093(05)80620-9
DO - 10.1016/S0022-3093(05)80620-9
M3 - Article
AN - SCOPUS:0026931262
VL - 147-148
SP - 213
EP - 221
JO - Journal of Non-Crystalline Solids
JF - Journal of Non-Crystalline Solids
SN - 0022-3093
IS - C
ER -