Use of X-ray microtomography to study the homogeneity of carbon nanotube aqueous suspensions and carbon nanotube/polymer composites

Haghgoo, Majid; Plougonven, Erwan; Yousefi, Ali Akbar; Pirard, Jean‐Paul; Léonard, Angélique; Job, Nathalie

doi:10.1016/j.carbon.2011.11.031

Cited by 7 publications

(11 citation statements)

References 6 publications

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“…The homogeneous MWCNT suspensions maintained their stability for several days, and this demonstrates the remarkable ability of NaDBS to disperse nanotubes in water. Stability of the sonicated MWCNT suspensions in the presence of NaDBS was confirmed by X-ray microtomography and reported in previous work [19]. Figure 2d presents an image obtained by optical microscopy of the composite sample RFCNT_075.…”

Section: Morphology Of Mwcnt/rf Xerogel Compositessupporting

confidence: 61%

“…This is considered ideal for energy storage applications such as electrode materials in supercapacitors and rechargeable batteries. To the best of our knowledge, no study to date except our previous works [19,20], has been found that has investigated MWCNT/gel composites. Compared with single-walled carbon nanotubes, MWCNTs are easier to debundle and disperse in media, are less prone to defects occurring in mechanical mixing, and are more readily available at a reasonable cost.…”

Section: Introductionmentioning

confidence: 93%

“…A Skyscan-1172 high-resolution desktop micro-CT system (Skyscan, Kontich, Belgium) was used to obtain the X-ray scans. The details of this method can be found in references [19][20][21].…”

Section: Characterization Of the Gelsmentioning

confidence: 99%

“…In our previous work, X-ray microtomography was used as a new and non-destructive method to study homogeneity of CNT suspensions and composites [19]. Local attenuation coefficient of X-ray beams is variable throughout a composite depending on the density of components and their atomic number.…”

Section: Morphology Of Mwcnt/rf Xerogel Compositesmentioning

confidence: 99%

“…Contrary to the results by Le et al [16], their study concluded that fine dispersion could overcome the handicap of a short length or low aspect ratio of the MWCNT. Gels containing CNTs have received much less attention, although there are some examples in the literature [8,10,19]. Introducing CNTs into organic and carbon gels takes advantage of both the nanoporous structure of gels and the significant electrical characteristics of the CNTs.…”

Section: Introductionmentioning

confidence: 99%

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Correlation between morphology and electrical conductivity of dried and carbonized multi-walled carbon nanotube/resorcinol–formaldehyde xerogel composites

et al. 2015

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Monolithic multi-walled carbon nanotube (MWCNT)/resorcinol-formaldehyde (RF) composite xerogel was synthesized by sol-gel polymerization of RF monomers in a surfactant-stabilized MWCNT aqueous suspension. The resulting composite wet gel was dried under ambient conditions and pyrolyzed in a N 2 atmosphere to obtain MWCNT/carbon (C) nanoporous xerogel. TEM images showed that the nanotubes had been completely exfoliated in the starting solution before addition of the reagents. Optical microscopy and SEM micrographs revealed that there were aggregates of MWCNTs with diameters of up to 50 lm in the final composites. Nitrogen adsorption analysis and mercury porosimetry of the pristine MWCNT-free and composite gels showed that the density and pore texture of the xerogel materials were not modified by the nanotubes, but were strongly influenced by the addition of surfactant (sodium dodecyl benzene sulfonate, NaDBS). Electrical conductivity was measured for the organic (MWCNT/RF) and carbonized (MWCNT/C) composites and evaluations determined that this parameter increased in different ways as a function of MWCNT concentration. A percolating scaling law of the form r µ (/-/ c ) t was obtained with a volume percolation threshold of / c = 2.5 9 10 -4 and a critical exponent (t) of 1.0 for the organic nanocomposite. After pyrolysis, the carbonized xerogels exhibited an entirely different behavior with a continuous sharp increase in electrical conductivity with nanotube loading (4.5-fold increase at 1.64 v % MWCNT). Comparison of the data for experimental conductivity with the effective medium theory enabled estimation of an average length for the conductive strings formed by connected nanotube aggregations throughout the carbon matrix.

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Section: Morphology Of Mwcnt/rf Xerogel Compositessupporting

confidence: 61%

Section: Introductionmentioning

confidence: 93%

“…A Skyscan-1172 high-resolution desktop micro-CT system (Skyscan, Kontich, Belgium) was used to obtain the X-ray scans. The details of this method can be found in references [19][20][21].…”

Section: Characterization Of the Gelsmentioning

confidence: 99%

Section: Morphology Of Mwcnt/rf Xerogel Compositesmentioning

confidence: 99%