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Efectos de memoria de forma y autocuración en cristales moleculares mecanicosalientes
Durga Prasad Karothu1, James Weston1, Israel Tilahun Desta1
1New York University Abu Dhabi , P.O. Box 129188, Abu Dhabi, United Arab Emirates.
Journal of the American Chemical Society
|September 13, 2016
Resumen
Los cristales de ácido tereftálico termosaliente muestran una notable conformidad mecánica, cambiando de forma y saltando cuando se estimulan mecánicamente. Este efecto mecanosaliente, impulsado por la liberación de tensión, muestra la remodelación del dominio cristalino y las propiedades de autocuración.
Área de la Ciencia:
- Ciencias de los materiales
- La cristalografía
- Mecánica
Sus antecedentes:
- Los materiales termoalientes exhiben cambios de forma reversibles en respuesta a los estímulos térmicos.
- Los cristales de ácido tereftálico muestran propiedades termosalientes únicas, incluidas las transiciones de fase espontáneas y desencadenadas.
- Comprender el comportamiento mecánico de tales cristales es crucial para desarrollar materiales avanzados.
Objetivo del estudio:
- Para investigar el efecto mecanizante en cristales de ácido tereftálico.
- Para aclarar los mecanismos detrás del cambio de forma desencadenado y la motilidad.
- Para explorar las propiedades de auto-curación y memoria de estos cristales.
Principales métodos:
- Análisis óptico de alta velocidad para capturar cambios rápidos de forma.
- Microscopía electrónica de barrido en serie para observar la dinámica del dominio cristalino.
- Estimulación mecánica para desencadenar transiciones de fase y analizar respuestas.
Principales resultados:
- Los cristales exhiben una extraordinaria conformidad mecánica y un cambio de forma reversible.
- La mecanosaliencia, o motilidad estimulada mecánicamente, es desencadenada por el estrés local, lo que hace que los cristales salten.
- Se observó una rápida remodelación de los dominios cristalinos en una escala de tiempo de milisegundos.
- Los cristales demostraron efectos de memoria y capacidades de autocuración, parecidos a los polímeros de memoria de forma.
Conclusiones:
- El efecto mecanosaliente es una manifestación macroscópica de las transiciones de tipo martensítico en sólidos moleculares.
- Las interacciones π-π intermoleculares juegan un papel en la autocuración de los cristales dañados.
- Estos hallazgos ofrecen información sobre el diseño de materiales moleculares sensibles.
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