Debundling and Dissolution of Single-Walled Carbon Nanotubes in Amide Solvents
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- 作者：C. A. Furtado ; U. J. Kim ; H. R. Gutierrez ; Ling Pan ; E. C. Dickey ; and Peter C. Eklund
- 刊名：Journal of the American Chemical Society
- 出版年：2004
- 出版时间：May 19, 2004
- 年：2004
- 卷：126
- 期：19
- 页码：6095 - 6105
- 全文大小：956K
- 年卷期：v.126,no.19(May 19, 2004)
- ISSN：1520-5126
文摘
Wet chemical methods involving ultrasound and amide solvents were used to purify and separatelarge bundles of single-walled carbon nanotubes (SWNTs) into individual nanotubes that could then betransported to silicon or mica substrates. The SWNTs studied were produced by the arc-discharge process.Dry oxidation was used in an initial step to remove amorphous carbon. Subsequently, two acid purificationschemes were investigated (HCl- and HNO3-reflux) to remove the metal growth catalyst (Ni-Y). Finally,ultrasonic dispersion of isolated tubes into either N,N-dimethylformamide (DMF) or N-methyl-2-pyrrolidone(NMP) was carried out. Raman scattering, atomic force microscopy (AFM), and electron microscopy wereused to study the evolution of the products. Raman scattering was used to probe possible wall damageduring the chemical processing. We found that both HCl and HNO3 could be used to successfully removethe Ni-Y below ~1 wt %. However, the HNO3-reflux produced significant wall damage (that could bereversed by vacuum annealing at 1000 
C). In the dispersion step, both amide solvents (DMF and NMP)produced a high degree of isolated tubes in the final product, and no damage during this dispersion stepwas observed. HNO3-refluxed tubes were found to disperse the best into the amide solvents, perhapsbecause of significant wall functionalization. AFM was used to study the filament diameter and lengthdistributions in the final product, and interesting differences in these distributions were observed, dependingon the chemical processing route.
C). In the dispersion step, both amide solvents (DMF and NMP)produced a high degree of isolated tubes in the final product, and no damage during this dispersion stepwas observed. HNO3-refluxed tubes were found to disperse the best into the amide solvents, perhapsbecause of significant wall functionalization. AFM was used to study the filament diameter and lengthdistributions in the final product, and interesting differences in these distributions were observed, dependingon the chemical processing route.