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rdf:type
lifeskim:mentions
pubmed:issue
19
pubmed:dateCreated
2004-5-12
pubmed:abstractText
Wet chemical methods involving ultrasound and amide solvents were used to purify and separate large bundles of single-walled carbon nanotubes (SWNTs) into individual nanotubes that could then be transported 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 purification schemes were investigated (HCl- and HNO(3)-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 were used to study the evolution of the products. Raman scattering was used to probe possible wall damage during the chemical processing. We found that both HCl and HNO(3) could be used to successfully remove the Ni-Y below approximately 1 wt %. However, the HNO(3)-reflux produced significant wall damage (that could be reversed by vacuum annealing at 1000 degrees 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 step was observed. HNO(3)-refluxed tubes were found to disperse the best into the amide solvents, perhaps because of significant wall functionalization. AFM was used to study the filament diameter and length distributions in the final product, and interesting differences in these distributions were observed, depending on the chemical processing route.
pubmed:language
eng
pubmed:journal
pubmed:status
PubMed-not-MEDLINE
pubmed:month
May
pubmed:issn
0002-7863
pubmed:author
pubmed:issnType
Print
pubmed:day
19
pubmed:volume
126
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
6095-105
pubmed:year
2004
pubmed:articleTitle
Debundling and dissolution of single-walled carbon nanotubes in amide solvents.
pubmed:affiliation
Centro de Desenvolvimento da Tecnologia Nuclear - CDTN/CNEN, Belo Horizonte, MG, Brazil.
pubmed:publicationType
Journal Article