Evaluation and visualization of the percolating networks in multi-wall carbon nanotube/epoxy composites

Chang, Li; Friedrich, K.; Ye, Lin; Toro, P.

doi:10.1007/s10853-009-3551-3

Cited by 120 publications

(60 citation statements)

References 37 publications

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“…The physical interpretation of the critical exponent t is more complex, and still a matter of controversy, as stated in a recent review by Bauhofer and Kovacs [10]. This exponent is frequently associated to the system dimensionality, with values of t ≈ 1.3 (or slightly higher) representing a two-dimensional network and t ≈ 2 (or slightly higher) a threedimensional one [10,16,20,25]. However, the use of a scaling law for statistical percolation is limited to a concentration range very close to the percolation threshold and the use of this law to extract geometrical information about the CNT network from experimentally determined values of t is controversial, as stated by several authors [10,18,20].…”

Section: Resultsmentioning

confidence: 99%

“…This exponent is frequently associated to the system dimensionality, with values of t ≈ 1.3 (or slightly higher) representing a two-dimensional network and t ≈ 2 (or slightly higher) a threedimensional one [10,16,20,25]. However, the use of a scaling law for statistical percolation is limited to a concentration range very close to the percolation threshold and the use of this law to extract geometrical information about the CNT network from experimentally determined values of t is controversial, as stated by several authors [10,18,20]. In our case, the relatively high values of t obtained are due to the 'moderate' (2-4 orders of magnitude) changes in electrical conductivity in the vicinity of percolation, which might be related to geometrical constrains imposed by the limited thickness of the film and/or to the specific polymer employed.…”

Section: Resultsmentioning

confidence: 99%

“…where σ 0 is a scaling factor that may be comparable to the effective conductivity of the filler [19,20], φ is the CNT weight fraction, and φ c is the percolation critical concentration. The parameter t is a critical exponent that governs the scaling law in the vicinity of percolation and has been associated to the dimensionality of the system, although its physical meaning is still controversial [10,19].…”

Section: Electrical Propertiesmentioning

confidence: 99%

See 2 more Smart Citations

Influence of carbon nanotube clustering on the electrical conductivity of polymer composite films

Aguilar

Bautista-Quijano

Avilés³

2010

Express Polym. Lett.

182

109

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Abstract. Electrical conductivity of 150-200 μm thick polysulfone films loaded with 0.05-0.75% w/w multiwall carbon nanotubes was systematically investigated for two types of dispersion states, uniformly dispersed and agglomerated at the micro-scale. The percolation threshold was found at 0.11% and 0.068% w/w for the uniformly dispersed and agglomerated films, respectively. Overall, the conductivity of the films with agglomerated nanotubes was higher than that of the uniformly dispersed ones, with marked differences of 2 to 4 orders of magnitude for carbon nanotubes loadings in the upper vicinity of the percolation threshold (0.1-0.3% w/w). The increased conductivity of the agglomerated state is explained by the increased nanotube-to-nanotube contact after the percolating network has formed, which facilitates electron transfer.

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Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

Section: Electrical Propertiesmentioning

confidence: 99%

See 1 more Smart Citation

Influence of carbon nanotube clustering on the electrical conductivity of polymer composite films

Aguilar

Bautista-Quijano

Avilés³

2010

Express Polym. Lett.

182

109

View full text Add to dashboard Cite

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“…To built up structure property relations, the resultant CNT dispersion and network formation, can be analyzed on nanoscale using charge contrast imaging in scanning electron microscopy, as an alternative to transmission electron microscopy [17][18][19].…”

Section: Introductionmentioning

confidence: 99%

Morphological characterization and modelling of electrical conductivity of multi-walled carbon nanotube/poly(p-phenylene sulfide) nanocomposites obtained by twin screw extrusion

Noll

Burkhart

2011

Composites Science and Technology

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A B S T R A C TIn this study, poly(p-phenylene sulfide) based nanocomposites containing multi-walled carbon nanotubes (MWNTs) were produced by dilution of a 15 wt.% MWNT/PPS masterbatch via twin screw extrusion process. The electrical conductivities of the nanocomposites were measured and percolation threshold was observed below 0.77 vol.% MWNTs. The state of dispersion and distribution quality of MWNTs was analyzed on macroand nanoscale through transmission light and scanning electron microscopy (SEM). A good deagglomeration of primary macroagglomerates and a homogenous MWNT distribution on nanoscale was found. The dependence of conductivity on MWNT concentration was estimated using statistical percolation theory which matches the experimental data quite well.A new empirical equation was set up to fit the electrical conductivity using quantitative values of visible percolating MWNTs which were detected by charge contrast imaging in SEM.

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“…However, the electric resistance of CNT networks at compression has only been measured in [5,6] and the electric properties of CNT particulate reinforcement of polymers, for instance, in [7,8], The obtained data were analyzed to get an estimate of the resistance of CNT tangles and the contact resistance between nanotubes [5]. The aim to reveal the effect of surfacedoping of MWCNT networks on their pressure sensitivity is pursued in [6].…”

Section: Introductionmentioning

confidence: 99%

Compressive stress-electrical conductivity characteristics of multiwall carbon nanotube networks

et al. 2010

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A network of entangled multiwall carbon nanotubes is presented as a conductor whose conductivity is sensitive to compressive stress both in the course of monotonic stress growth and when loading/unloading cycles are imposed. The testing has shown as much as 100% network conductivity increase at the maximum applied stress. It indicates favorable properties of multiwall carbon nanotube networks for their use as stress-electric signal transducers. To model the conductivity-stress dependence, it is hypothesized that compression increases local contact forces between nanotubes, which results in more conductive contacts. The lack of detailed knowledge of the mechanism as well as an unclear shift from individual contacts to the whole network conductance behavior is

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Evaluation and visualization of the percolating networks in multi-wall carbon nanotube/epoxy composites

Cited by 120 publications

References 37 publications

Influence of carbon nanotube clustering on the electrical conductivity of polymer composite films

Influence of carbon nanotube clustering on the electrical conductivity of polymer composite films

Morphological characterization and modelling of electrical conductivity of multi-walled carbon nanotube/poly(p-phenylene sulfide) nanocomposites obtained by twin screw extrusion

Compressive stress-electrical conductivity characteristics of multiwall carbon nanotube networks

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