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El desarrollo de la morfología y la estructura en la vaterita hexagonal
Emilie M Pouget1, Paul H H Bomans, Archan Dey
1Laboratory of Materials and Interface Chemistry and Soft Matter CryoTEM Research Unit, Eindhoven University of Technology, P.O. Box 513, 5600MB Eindhoven, The Netherlands.
Journal of the American Chemical Society
|July 31, 2010
Resumen
Los investigadores revelan cómo el carbonato de calcio amorfo se transforma en cristales de vaterita hexagonales. Los iones de amonio guían esta transformación en estado sólido, desarrollando simultáneamente el orden cristalino y la morfología de los materiales biomiméticos.
Área de la Ciencia:
- La biomineralización es la biomineralización.
- Ciencia de los materiales Ciencia de los materiales.
- La cristalografía es una técnica de cristalografía.
Sus antecedentes:
- La síntesis biomimética tiene como objetivo replicar estructuras complejas de CaCO3 .
- Los aditivos controlan la morfología cristalina mediante la inhibición selectiva de las caras cristalinas.
- La transición amorfa a cristalina en la formación de CaCO3 no se entiende completamente.
Objetivo del estudio:
- Para dilucidar la transición amorfa a cristalina durante la formación de vaterita.
- Para investigar el papel de los iones de amonio en el crecimiento de cristales de vaterita.
- Para detallar el desarrollo simultáneo del orden y la morfología.
Principales métodos:
- Microscopía electrónica de transmisión criogénica (cryoTEM).
- Las técnicas incluyeron imágenes de campo brillante, criotomografía, difracción de electrones de baja dosis e imágenes de campo cryo-oscuro.
- Se estudió la formación de cristales de vaterita en presencia de iones NH.
Principales resultados:
- La vaterita hexagonal se forma a través de una fase precursora amorfa.
- La fase amorfa se somete a una transformación en estado sólido en vaterita cristalina.
- Las transiciones de vaterita policristalina en un solo cristal, modelado por un plano de cristal inducido por NH(4)(+).
Conclusiones:
- Los iones de amonio dirigen la transformación en estado sólido del carbonato de calcio amorfo a la vaterita monocristalina.
- El desarrollo simultáneo del orden y la morfología es clave en este proceso biomimético.
- Comprender esta transición ofrece información sobre la biomineralización y el crecimiento de cristales sintéticos.
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