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Transición de fase fotoquímica versus separación de fase fotoquímica
Xia Tong1, Guang Wang, Yue Zhao
1Département de Chimie, Université de Sherbrooke, Sherbrooke, Québec, Canada.
Journal of the American Chemical Society
|July 6, 2006
Resumen
La fotoisomerización en cristales líquidos dopados con compuestos de azobenzeno permite transiciones de fase y separación fotoquímicas reversibles. Esto permite la conmutación controlada de la transmitancia utilizando UV y luz visible, lo que demuestra un material fotónico versátil.
Área de la Ciencia:
- Ciencia de los materiales Ciencia de los materiales.
- La fotoquímica es la fotoquímica.
- Cristales líquidos de cristales líquidos
Sus antecedentes:
- Los cristales líquidos nemáticos exhiben propiedades ópticas únicas.
- Los compuestos de azobenzeno se someten a fotoisomerización tras la irradiación de luz.
- El control de las fases de los materiales con la luz es un área clave en la ciencia de los materiales.
Objetivo del estudio:
- Para investigar el impacto del dopaje con altos niveles de azobenzeno en el comportamiento de los cristales líquidos nemáticos.
- Explorar el potencial de las transiciones de fase inducidas por la luz y la separación.
- Para demostrar la conmutación fotocontrolada de la transmitancia.
Principales métodos:
- Cristales líquidos nemáticos de dopaje con un 15 por ciento de peso de azobenzeno cristalino líquido.
- Irradiando la mezcla con rayos UV y luz visible.
- Observando la transición de fase fotoquímica y la separación de fase.
- Medición de la transmisión de conmutación a través de polarizadores cruzados.
Principales resultados:
- La fotoisomerización del azobenzeno indujo una transición de fase fotoquímica reversible e interconvertible y una separación de fase.
- Se lograron los modos normal e inverso de conmutación de transmitancia fotocontrolada.
- La misma mezcla de cristal líquido / azobenzeno exhibió capacidades de conmutación dual.
Conclusiones:
- El alto dopaje de azobenzeno cristalino líquido en cristales líquidos nemáticos permite un comportamiento de fase controlado por la luz.
- Las transiciones de fase fotoquímicas y la separación son reversibles e interconvertibles.
- El material demuestra potencial para aplicaciones en dispositivos fotónicos que requieren conmutación de la transmitancia controlada por luz.
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