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Mesocristales de calcita con alto contenido de magnesio: un enfoque químico de coordinación
Jos J M Lenders1, Archan Dey, Paul H H Bomans
1Laboratory of Materials and Interface Chemistry, Eindhoven University of Technology, P.O. Box 513, 5600 MB Eindhoven, The Netherlands.
Journal of the American Chemical Society
|December 24, 2011
Resumen
Los investigadores desarrollaron un nuevo método para sintetizar calcita con alto contenido de magnesio, imitando procesos biogénicos. Esta técnica controla la incorporación de magnesio y evita la disolución, dando lugar a una estructura única de calcita.
Área de la Ciencia:
- La geoquímica es la geoquímica.
- Ciencia de los materiales Ciencia de los materiales.
- La biomineralización es la biomineralización.
Sus antecedentes:
- Los calcitos biogénicos a menudo contienen altos niveles de magnesio, pero la producción sintética es un desafío debido a la hidratación de iones de magnesio.
- Las rutas sintéticas estándar favorecen la aragonita o la calcita baja en Mg, con Mg a menudo perdido durante la transformación a través de la disolución-reprecipitación.
Objetivo del estudio:
- Desarrollar un nuevo método sintético para producir calcita con alto contenido de magnesio que imite las vías biogénicas.
- Para lograr una alta incorporación de Mg en la calcita sin disolución y precipitación.
Principales métodos:
- Carbonato de calcio amorfo (ACC) sintetizado que contiene magnesio en un entorno no acuoso utilizando complejos de coordinación de Ca y Mg con CO.
- Incorporación controlada de Mg mediante el ajuste de la relación de los materiales de partida.
- Cristalizó el precursor de ACC en una mezcla de solvente orgánico / agua con actividad de agua reducida para evitar la disolución.
Principales resultados:
- Se han producido con éxito mesocristales de calcita con alto contenido de magnesio con hasta 53 mol% de Mg.
- El método sintético produjo estructuras mesocristalinas, a diferencia de la típica calcita de magnesio sintético policristalino.
- Se ha demostrado un control preciso sobre el contenido de Mg a través de la estequiometría precursora.
Conclusiones:
- La nueva estrategia sintética proporciona información sobre los mecanismos biogénicos de formación de calcita de alto contenido de magnesio.
- El control preciso de la actividad del agua es crucial para sintetizar calcita alta en magnesio sin disolución.
- Este método ofrece una nueva ruta para crear materiales avanzados de carbonato de calcio.
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