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Buckytubes y derivados: su crecimiento e implicaciones para la formación de buckyballs
Science (New York, N.Y.)
|March 12, 1993
Resumen
La microscopía electrónica de transmisión reveló nuevas formas de buckytube de grafito y un mecanismo de crecimiento helicoidal. Los buckytubes pueden ser precursores de la formación de fullereno, con el contenido de buckytube correlacionado con el rendimiento de fullereno.
Área de la Ciencia:
- Ciencia de los materiales Ciencia de los materiales.
- Nanotecnología La nanotecnología es la nanotecnología.
- Química Química es la química.
Sus antecedentes:
- Los túbulos de grafito, también conocidos como buckytubes, son nuevas nanoestructuras de carbono.
- Estudios previos han reportado varias geometrías de buckytube.
Objetivo del estudio:
- Investigar la morfología detallada y los mecanismos de crecimiento de los buckytubes y sus derivados.
- Para explorar la relación entre los buckytubes y la formación de fullerenos.
Principales métodos:
- Microscopía electrónica de transmisión (TEM) para imágenes de alta resolución y análisis de sección transversal.
- Difracción de electrones para el análisis de la helicidad de buckytube.
- Espectrometría de pérdida de energía de electrones resuelta por transferencia de momento para el análisis de la estructura electrónica.
- Experimentos de evaporación de arco para correlacionar el contenido de buckytube con el rendimiento de fullereno.
Principales resultados:
- TEM reveló formas no reportadas previamente de los derivados de buckytube.
- Las secciones transversales detalladas aclararon los patrones de crecimiento de buckytube y las estructuras cilíndricas.
- Las observaciones sugieren un mecanismo de crecimiento helicoidal para buckytubes y derivados, análogo al crecimiento de cristales a través de dislocaciones de tornillo.
- Se analizaron la helicoidalidad y la anisotropía de la estructura electrónica.
- Se propusieron buckytubes como precursores de la formación de fullereno de cáscara cerrada (buckyball).
- Se encontró una correlación entre la cantidad de buckytube en las barras de residuos y el rendimiento de fullereno en la evaporación del arco.
Conclusiones:
- Las buckytubes exhiben diversas geometrías y un mecanismo de crecimiento helicoidal.
- Es probable que los buckytubes sean precursores de la formación del fullereno.
- La cantidad de buckytubes influye en la eficiencia de la producción.
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