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An improved understanding of the dispersion of multi-walled carbon nanotubes in non-aqueous solvents
journal contribution
posted on 2014-01-01, 00:00 authored by Sulley LiSulley Li, J S Church, Abdullah Al Kafi, Minoo NaebeMinoo Naebe, Bronwyn FoxThe homogeneous and stable dispersion of carbon nanotubes (CNTs) in solvents is often a prerequisite for their use in advanced materials. Dispersion procedures, reagent concentration as well as the interactions among reagent, defective CNTs and near-perfect CNTs will affect the resulting CNT dispersion properties. This study, for the first time, presents a detailed comparison between two different approaches for dispersing CNTs. The results enhance our understanding of the interactions between surfactant, defective CNTs and near-perfect CNTs and thus provide insight into the mechanism of CNT dispersion. Dispersions of "as-produced" short multi-walled carbon nanotubes (MWCNTs) in N,N-dimethylformamide were prepared by two different surfactant (Triton X-100) assisted methods: ultrasonication and ultrasonication followed by centrifugation, decanting the supernatant and redispersing the precipitate. Visual observation and UV-visible spectroscopy results showed that the latter method produce a more stable dispersion with higher MWCNT content compared to dispersions produced by ultrasonication alone. Transmission electron microscopy and Raman spectroscopic investigations revealed that the centrifugation/ decanting step removed highly defective nanotubes, amorphous carbon and excess surfactant from the readily re-dispersible near-perfect CNT precipitate. This is contrary to other published findings where the dispersed MWCNTs were found in the supernatant. Thermogravimetric analysis showed that 95 % of Triton X-100 was removed by centrifugation/decanting step, and the remainder of the Triton X-100 molecules is likely randomly adsorbed onto the MWCNT surface. Infrared spectral analysis suggests that the methylene groups of the polyoxyethylene (aliphatic ether) chains of the residual Triton X-100 molecules are interacting with the MWCNTs. © 2014 Springer Science+Business Media.
History
Journal
Journal of nanoparticle researchVolume
16Issue
7Article number
2513Pagination
1 - 12Publisher
SpringerLocation
Berlin, GermanyPublisher DOI
ISSN
1388-0764eISSN
1572-896XLanguage
engPublication classification
C Journal article; C1 Refereed article in a scholarly journalCopyright notice
2014, SpringerUsage metrics
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No categories selectedKeywords
CentrifugationMulti-walled CNTsNon-aqueous dispersionSurfactant assistedUltrasonicationScience & TechnologyPhysical SciencesTechnologyChemistry, MultidisciplinaryNanoscience & NanotechnologyMaterials Science, MultidisciplinaryChemistryScience & Technology - Other TopicsMaterials ScienceAQUEOUS DISPERSIONSSURFACTANTSYARNSFUNCTIONALIZATIONSPECTROSCOPYSEPARATIONSCATTERINGSPECTRASPUN
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