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Los conjuntos coloidales de geminis ramificados estudiados por cryo-etch-HRSEM. Microscopía electrónica de barrido de
Fredric M Menger1, Victor A Seredyuk, Robert P Apkarian
1Department of Chemistry, Emory University, Atlanta, Georgia 30322, USA. menger@emory.edu
Journal of the American Chemical Society
|October 17, 2002
Resumen
Cryo-etch-HRSEM congela y graba rápidamente las muestras coloidales, revelando estructuras detalladas. Esta técnica visualizó arreglos únicos fractales, porosos y vesiculares en nuevos tensioactivos gemini.
Área de la Ciencia:
- La ciencia coloidal es la ciencia coloidal.
- Ciencia de los materiales ciencia de los materiales.
- El microscopio de la microscopía.
Sus antecedentes:
- La comprensión de los sistemas coloidales requiere técnicas avanzadas de imagen.
- Los tensioactivos de Géminis exhiben comportamientos complejos de autoensamblaje.
Objetivo del estudio:
- Introducir la microscopía electrónica de barrido de alta resolución criográfica (cryo-etch-HRSEM) para la exploración de sistemas coloidales.
- Ilustrar la utilidad de la técnica con nuevos surfactantes gemini.
Principales métodos:
- El cryo-etch-HRSEM implica una congelación rápida (-105 ° C en 6-7 ms).
- El agua superficial se elimina a través de la sublimación (grabado).
- Las estructuras coloidales se magnifican hasta un millón de veces.
Principales resultados:
- Se visualizó una red molecular similar a un fractal en un gel de tensioactivo Gemini después de un grabado de 10 minutos.
- Se observó una estructura porosa e hidratada en un segundo coacervado de surfactante gemini.
- Vesículas esféricas identificadas en la superficie de una tercera muestra de tensioactivo Gemini.
Conclusiones:
- Cryo-etch-HRSEM proporciona información pictórica distintiva acerca de las estructuras coloidales.
- La técnica revela efectivamente la morfología de sistemas complejos de tensioactivos.
- Los nuevos tensioactivos gemini muestran diversas arquitecturas autoensambladas.
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