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El origen físico subyacente a la pérdida de entropía durante la hidratación hidrofóbica
1National Institute of Chemistry, Hajdrihova 19, 1000 Ljubljana, Slovenia. aljaz.godec@ki.si
Journal of the American Chemical Society
|September 26, 2012
Resumen
El efecto hidrofóbico no es causado por el agua ordenando alrededor de las partículas. En cambio, surge de las correlaciones de muchos cuerpos en el agua.
Área de la Ciencia:
- Química Física es la química física.
- La biofísica es la biofísica.
- Química computacional es la química computacional.
Sus antecedentes:
- El efecto hidrofóbico (HE) impulsa el ensamblaje biomolecular en el agua.
- Tradicionalmente, HE se atribuye a la ordenación del agua y a los orígenes entrópicos.
- Los modelos existentes se centran en la estructura media del agua y las correlaciones en pares.
Objetivo del estudio:
- Desafiar la visión tradicional del efecto hidrofóbico.
- Presentar una nueva comprensión a nivel molecular de la educación superior.
- Investigar el papel de las fluctuaciones colectivas y las correlaciones de muchos cuerpos en HE.
Principales métodos:
- Simulaciones por computadora de las interacciones agua-soluciones.
- Análisis de las fluctuaciones colectivas en los grupos de agua.
- Examen de las correlaciones de muchos cuerpos más allá de las interacciones en pares.
Principales resultados:
- La imagen tradicional de HE basada en la estructura media del agua es incorrecta.
- HE es impulsado por correlaciones de muchos cuerpos que afectan a la conmutación de enlaces de hidrógeno.
- Estas correlaciones implican una compensación no local de las fluctuaciones del campo electrostático.
Conclusiones:
- Se propone un nuevo modelo para HE basado en la maximización del ruido electrostático.
- Este ruido surge de fluctuaciones no locales en la red de enlaces de hidrógeno.
- Las fuertes correlaciones entre al menos cuatro moléculas de agua son clave para la HE.
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