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Formación de una nueva sílice mesoestructurada cúbica Ia-3d a través de síntesis asistida por tribloqueo de
Katarina Flodström1, Viveka Alfredsson, Niklas Källrot
1Physical Chemistry 1, Lund University, P.O. Box 124, SE- 221 00 LUND, Sweden. katarina.flodstrom@fkem1.lu.se
Journal of the American Chemical Society
|April 10, 2003
Resumen
Los investigadores sintetizaron una nueva sílice mesoporosa con grandes células unitarias y una gran superficie. Este nuevo material exhibe una simetría de cabeza cúbica, potencialmente basada en la superficie mínima de la tiroides.
Área de la Ciencia:
- Ciencia de los materiales Ciencia de los materiales.
- Nanotecnología La nanotecnología es la nanotecnología.
- Química Química es la química.
Sus antecedentes:
- Los materiales de sílice mesoporosa son cruciales en la catálisis y separación.
- El desarrollo de nuevas estructuras con arquitecturas de poros controlados es un área de investigación en curso.
- Los métodos de síntesis existentes a menudo producen estructuras con células unitarias más pequeñas.
Objetivo del estudio:
- Para sintetizar y caracterizar una nueva estructura de sílice mesoporosa.
- Para investigar las propiedades estructurales, incluida la simetría y las dimensiones de la célula unitaria.
- Explorar el potencial del uso de sales de yoduro en la síntesis de sílice mesoporosa.
Principales métodos:
- Síntesis utilizando copolímeros triblock (Pluronics P103 o P123) con la adición de yoduro de sodio (NaI).
- Caracterización utilizando dispersión de rayos X de ángulo pequeño (SAXS) para determinar la simetría.
- Análisis de micrografías electrónicas para dilucidar la estructura de los poros.
- Determinación del área de superficie mediante técnicas de adsorción de gases.
Principales resultados:
- Síntesis exitosa de una sílice mesoporosa con simetría de cabeza cúbica.
- Se observaron muy grandes dimensiones de la unidad celular (hasta 250 Å como sintetizado, 222 Å calcinado).
- Se logró una gran superficie de aproximadamente 700 m2/g.
- Se sugirió una similitud estructural con el MCM-48, lo que indica una superficie mínima de tiroides.
Conclusiones:
- La adición de NaI a la mezcla de síntesis permite la formación de una nueva sílice mesoporosa con simetría de Iad.
- El material sintetizado posee células unitarias excepcionalmente grandes y una gran superficie.
- Se propone que la estructura se base en la superficie mínima de la tiroides, ofreciendo nuevas posibilidades para el diseño de materiales.
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