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Atracción de van der Waals específica por dirección entre los nanocristales de rutilo TiO2
Xin Zhang1, Yang He2, Maria L Sushko1
1Physical and Computational Sciences Directorate, Pacific Northwest National Laboratory, Richland, WA, USA.
Science (New York, N.Y.)
|April 29, 2017
Resumen
Las fuerzas de dispersión entre los nanocristales de rutilo dependen de la orientación y la hidratación a corta distancia. Estas fuerzas pueden generar par, impactando las interacciones de partículas en soluciones y materiales.
Área de la Ciencia:
- Ciencias de los materiales
- Química de las superficies
- Nanotecnología
Sus antecedentes:
- Las orientaciones mutuas de la red influyen en las fuerzas entre las partículas cristalinas.
- La polarizabilidad de la red anisotrópica sugiere que la atracción de dispersión de van der Waals puede depender de la dirección.
Objetivo del estudio:
- Medir la atracción de dispersión de van der Waals entre los nanocristales de rutilo.
- Investigar la influencia de la orientación mutua y la hidratación superficial en esta atracción.
Principales métodos:
- Medición experimental de las fuerzas entre los nanocristales de rutilo.
- Separación de nanocristales variable, orientación mutua y hidratación de la superficie.
Principales resultados:
- En las grandes separaciones (decenas de nanómetros), la atracción es débil e independiente de la orientación.
- En las separaciones cercanas (una capa de hidratación), la atracción depende fuertemente de la alineación azimutal.
- La densidad de agua que interviene disminuye sistemáticamente la atracción de cerca.
Conclusiones:
- Las fuerzas de dispersión exhiben orientación y dependencia de hidratación a nanoescala.
- La teoría de Lifshitz predice con precisión las fuerzas medidas.
- Las fuerzas de dispersión pueden inducir un par entre las partículas que interactúan en la solución y dentro de los materiales.
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