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Tejas multicolores complejas y fenómenos críticos en cristales líquidos tetrafílicos
Xiangbing Zeng1, Robert Kieffer, Benjamin Glettner
1Department of Materials Science and Engineering, University of Sheffield, Sheffield, UK.
Science (New York, N.Y.)
|March 12, 2011
Resumen
La adición de cadenas laterales incompatibles a las moléculas en forma de T crea panales de cristales líquidos complejos con múltiples composiciones celulares. Se observó una transición reversible entre las fases de panal separadas por fases y las fases de panal mezcladas, análoga a las transiciones magnéticas.
Área de la Ciencia:
- Ciencia de los materiales Ciencia de los materiales.
- Física de la materia blanda Física de la materia blanda
- La cristalografía es una técnica de cristalografía.
Sus antecedentes:
- Las moléculas en forma de T forman panales de cristal líquido con núcleos aromáticos y cadenas laterales flexibles.
- Estas estructuras exhiben paredes celulares aromáticas y interiores llenos de cadenas laterales.
- Estudios anteriores se centraron en arquitecturas moleculares más simples.
Objetivo del estudio:
- Investigar el impacto de agregar una segunda cadena lateral incompatible (moléculas en forma de X) a los sistemas de cristales líquidos en forma de T.
- Explorar la formación de complejos patrones de tiling y diferentes composiciones celulares.
- Caracterice las transiciones de fase termoreversibles observadas.
Principales métodos:
- Síntesis y caracterización de moléculas en forma de T y X. Síntesis y caracterización de moléculas en forma de T y X.
- Análisis del comportamiento de la fase de los cristales líquidos utilizando métodos microscópicos y térmicos.
- Análisis estructural de patrones de panales y composiciones celulares.
Principales resultados:
- La adición de moléculas en forma de X indujo complejos mosaicos de panal con hasta cinco distintas composiciones celulares ("colores") y formas poligonales.
- La frustración geométrica entre cadenas laterales incompatibles impidió la separación de fase limpia, lo que condujo a la complejidad.
- Se observó una transición termoreversible entre una fase multicolor (separada por fases) y una fase de panal de un solo color (mezclado).
Conclusiones:
- Las cadenas laterales incompatibles en los cristales líquidos pueden dar lugar a intrincadas estructuras autoensambladas con complejidad emergente.
- La transición de fase observada es análoga a la transición de Curie en los sistemas magnéticos, impulsada por reorientaciones moleculares.
- Este trabajo amplía la comprensión del autoensamblaje en materia blanda y sistemas frustrados.
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