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Relación entre el orden estructural y las anomalías del agua líquida
J R Errington1, P G Debenedetti
1Department of Chemical Engineering, Princeton University, New Jersey 08544-5263, USA.
Nature
|February 24, 2001
Resumen
Cuantificar el orden estructural en líquidos como el agua es un reto. Este estudio revela una región única de agua líquida donde el orden disminuye con la compresión, lo que explica las propiedades anómalas.
Área de la Ciencia:
- Química Física es la química física.
- Ciencia de los materiales Ciencia de los materiales.
- Física computacional es la física computacional.
Sus antecedentes:
- Los sólidos cristalinos tienen estructuras bien definidas, a diferencia de los líquidos y los vidrios.
- Cuantificar el orden estructural en los líquidos, especialmente el agua con enlaces de hidrógeno, es difícil.
- Las propiedades cinéticas y termodinámicas anómalas del agua están vinculadas a su estructura.
Objetivo del estudio:
- Para comprender cuantitativamente las relaciones estructura-propiedad en el agua.
- Investigar el orden de traslación y orientación en modelos de agua.
- Para identificar la base estructural de las propiedades anómalas del agua.
Principales métodos:
- Simulaciones de dinámica molecular de modelos de agua.
- Análisis de los parámetros del orden de traslación y orientación.
- Identificación de regiones estructuralmente anómalas.
Principales resultados:
- Se ha identificado una región estructuralmente anómala en el agua, delimitada por un orden extremo dependiente de la densidad.
- El orden disminuye con la compresión dentro de esta región, con un orden acoplado de traslación y orientación.
- Esta región abarca condiciones de difusividad anómala y expansión térmica.
Conclusiones:
- Las anomalías estructurales en el agua se cuantifican y se relacionan con las propiedades cinéticas y termodinámicas.
- Una cascada de anomalías ocurre secuencialmente con el aumento del orden estructural.
- Este trabajo proporciona un marco cuantitativo para comprender el comportamiento único del agua.
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