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Reorganizaciones estructurales que rigen el flujo en vidrios coloidales
Peter Schall1, David A Weitz, Frans Spaepen
1Van der Waals-Zeeman Institute, University of Amsterdam, Valckenierstraat 65, 1018 XE Amsterdam, Netherlands. pschall@science.uva.nl
Science (New York, N.Y.)
|December 22, 2007
Resumen
Los investigadores visualizaron reorganizaciones estructurales en vidrios coloidales bajo corte. Identificaron zonas de transformación de corte localizadas, revelando cómo las tensiones y las fluctuaciones térmicas influyen en las propiedades del vidrio.
Área de la Ciencia:
- Ciencia de los materiales Ciencia de los materiales.
- Física de la materia condensada Física de la materia condensada
- Reología Reología.
Sus antecedentes:
- Los reordenamientos estructurales son clave para las propiedades del vidrio como la resistencia al flujo, la capacidad térmica y la constante dieléctrica.
- La visualización directa de estos reordenamientos en gafas atómicas sigue siendo un desafío.
Objetivo del estudio:
- Para obtener imágenes directas de reorganizaciones estructurales inducidas térmicamente en vidrios bajo corte aplicado.
- Caracterizar la energía de formación y la topología de las zonas de transformación de corte.
Principales métodos:
- Utilizó un sistema de vidrio coloidal para obtener imágenes tridimensionales directas.
- Tensión de cizallamiento aplicada para inducir reordenamientos estructurales.
- Empleó modelos de continuidad para analizar la física subyacente.
Principales resultados:
- Zonas de transformación de cizallamiento localizadas e irreversibles identificadas.
- Determinó la energía de formación y la topología de estas zonas.
- Observó que las transformaciones pueden promover subsecuentes transformaciones cercanas.
Conclusiones:
- La visualización directa de los reordenamientos estructurales en vidrios coloidales es posible.
- La interacción de la tensión aplicada y las fluctuaciones térmicas gobierna la formación de la zona de corte en las gafas.
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