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Cambios reversibles en la morfología de la superficie de un cristal monocristal de diarileteno fotocrómico por
M Irie1, S Kobatake, M Horichi
1Department of Chemistry and Biochemistry, Graduate School of Engineering, Kyushu University, and CREST, Japan Science and Technology Corporation, Hakozaki 6-10-1, Higashi-ku, Fukuoka 812-8581, Japan. mail: irie@cstf.kyushu-u.ac.jp
Science (New York, N.Y.)
|March 7, 2001
Resumen
La fotoirradicación altera de manera reversible las superficies de cristal único de diarileteno. Esta reestructuración de la superficie a nivel molecular, observada a través de la microscopía de fuerza atómica, permite aplicaciones potenciales en actuadores de escala nanométrica fotodrivados.
Área de la Ciencia:
- Ciencia de los materiales Ciencia de los materiales.
- Química supramolecular de las moléculas.
- Nanotecnología La nanotecnología es la nanotecnología.
Sus antecedentes:
- Los diariletenos son compuestos fotocrómicos conocidos por sus cambios de color reversibles.
- Los cristales individuales ofrecen estructuras ordenadas para el estudio del comportamiento molecular.
- La microscopía de fuerza atómica (AFM) es una técnica clave para el análisis de superficies a nanoescala.
Objetivo del estudio:
- Para investigar los cambios morfológicos de superficie reversibles de un cristal simple de diarileteno tras la fotoirradicación.
- Para correlacionar los cambios superficiales con las reacciones de fotociclización y las alteraciones estructurales moleculares.
- Para explorar el potencial de los cristales de diarileteno como accionadores fotodrivados.
Principales métodos:
- Se utilizó la microscopía de fuerza atómica (AFM) para obtener imágenes de la superficie monocristalina.
- Se empleó la fotoirradicación con longitudes de onda específicas (UV: 366 nm, visible: >500 nm).
- Se realizó un análisis de la formación / desaparición de escalones superficiales y la creación / blanqueamiento de valles.
Principales resultados:
- El cristal simple de diarileteno exhibió cambios morfológicos superficiales reversibles, incluida la formación de escalones y la creación de valles, tras la irradiación alterna de luz UV y luz visible.
- Estos cambios morfológicos, con alturas de paso alrededor de 1 nm (una capa molecular), se correlacionan directamente con la ciclización reversible fotoinducida y la apertura de anillos de las moléculas de diarileteno.
- El cristal mostró un cambio de color térmicamente irreversible pero fotoquímicamente reversible de incoloro a azul.
Conclusiones:
- El estudio demuestra que la fotoirradicación puede inducir cambios morfológicos superficiales significativos y reversibles en los cristales simples de diarileteno.
- Estos cambios son impulsados por las bien definidas transformaciones estructurales moleculares de los diariletenos dentro de la red cristalina.
- Los cristales simples de diarileteno se muestran prometedores como actuadores a nanoescala, que responden a los estímulos de luz con modificaciones precisas de la superficie.
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