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The influence of the dispersion method on the electrical properties of vapor-grown carbon nanofiber/epoxy composites.

Cardoso P, Silva J, Klosterman D, Covas JA, van Hattum FW, Simoes R, Lanceros-Mendez S - Nanoscale Res Lett (2011)

Bottom Line: The influence of the dispersion of vapor-grown carbon nanofibers (VGCNF) on the electrical properties of VGCNF/Epoxy composites has been studied.A homogenous dispersion of the VGCNF does not imply better electrical properties.In fact, it is demonstrated that the most simple of the tested dispersion methods results in higher conductivity, since the presence of well-distributed nanofiber clusters appears to be a key factor for increasing composite conductivity.PACS: 72.80.Tm; 73.63.Fg; 81.05.Qk.

View Article: PubMed Central - HTML - PubMed

Affiliation: IPC/I3N--Institute for Polymers and Composites, University of Minho, Campus de Azurém, 4800-058 Guimarães, Portugal. rsimoes@dep.uminho.pt.

ABSTRACT
The influence of the dispersion of vapor-grown carbon nanofibers (VGCNF) on the electrical properties of VGCNF/Epoxy composites has been studied. A homogenous dispersion of the VGCNF does not imply better electrical properties. In fact, it is demonstrated that the most simple of the tested dispersion methods results in higher conductivity, since the presence of well-distributed nanofiber clusters appears to be a key factor for increasing composite conductivity.PACS: 72.80.Tm; 73.63.Fg; 81.05.Qk.

No MeSH data available.


Left-AC conductivity (σ) at 1 kHz versus volume fraction (ϕ) displayed in a log-linear scale. Right-DC conductivity (σDC) versus volume fraction (ϕ) displayed in a log-linear scale.
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Figure 2: Left-AC conductivity (σ) at 1 kHz versus volume fraction (ϕ) displayed in a log-linear scale. Right-DC conductivity (σDC) versus volume fraction (ϕ) displayed in a log-linear scale.

Mentions: Figure 2 shows the AC conductivity at 1 kHz (left) and the DC conductivity (right) for different volume fractions. Depending on the method of composite preparation, a distinct conductivity behavior is observed. Samples prepared by Methods 1 and 2 reveal a dramatic increase in the DC conductivity of 6 and 8 orders of magnitude (Figure 2, right), respectively, between 0.0006 and 0.003 volume fraction. Methods 3 and 4 generate samples with low conductivity that is almost independent of the volume fraction. The jump of conductivity between 0.0006 and 0.003 volume fraction is also observed for the AC measurements (Figure 2, left). These results indicate that the percolation threshold can be found between 0.0006 and 0.003 volume fraction for the composites obtained with Methods 1 and 2, and at higher volume fractions for those obtained with Methods 3 and 4.


The influence of the dispersion method on the electrical properties of vapor-grown carbon nanofiber/epoxy composites.

Cardoso P, Silva J, Klosterman D, Covas JA, van Hattum FW, Simoes R, Lanceros-Mendez S - Nanoscale Res Lett (2011)

Left-AC conductivity (σ) at 1 kHz versus volume fraction (ϕ) displayed in a log-linear scale. Right-DC conductivity (σDC) versus volume fraction (ϕ) displayed in a log-linear scale.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3211461&req=5

Figure 2: Left-AC conductivity (σ) at 1 kHz versus volume fraction (ϕ) displayed in a log-linear scale. Right-DC conductivity (σDC) versus volume fraction (ϕ) displayed in a log-linear scale.
Mentions: Figure 2 shows the AC conductivity at 1 kHz (left) and the DC conductivity (right) for different volume fractions. Depending on the method of composite preparation, a distinct conductivity behavior is observed. Samples prepared by Methods 1 and 2 reveal a dramatic increase in the DC conductivity of 6 and 8 orders of magnitude (Figure 2, right), respectively, between 0.0006 and 0.003 volume fraction. Methods 3 and 4 generate samples with low conductivity that is almost independent of the volume fraction. The jump of conductivity between 0.0006 and 0.003 volume fraction is also observed for the AC measurements (Figure 2, left). These results indicate that the percolation threshold can be found between 0.0006 and 0.003 volume fraction for the composites obtained with Methods 1 and 2, and at higher volume fractions for those obtained with Methods 3 and 4.

Bottom Line: The influence of the dispersion of vapor-grown carbon nanofibers (VGCNF) on the electrical properties of VGCNF/Epoxy composites has been studied.A homogenous dispersion of the VGCNF does not imply better electrical properties.In fact, it is demonstrated that the most simple of the tested dispersion methods results in higher conductivity, since the presence of well-distributed nanofiber clusters appears to be a key factor for increasing composite conductivity.PACS: 72.80.Tm; 73.63.Fg; 81.05.Qk.

View Article: PubMed Central - HTML - PubMed

Affiliation: IPC/I3N--Institute for Polymers and Composites, University of Minho, Campus de Azurém, 4800-058 Guimarães, Portugal. rsimoes@dep.uminho.pt.

ABSTRACT
The influence of the dispersion of vapor-grown carbon nanofibers (VGCNF) on the electrical properties of VGCNF/Epoxy composites has been studied. A homogenous dispersion of the VGCNF does not imply better electrical properties. In fact, it is demonstrated that the most simple of the tested dispersion methods results in higher conductivity, since the presence of well-distributed nanofiber clusters appears to be a key factor for increasing composite conductivity.PACS: 72.80.Tm; 73.63.Fg; 81.05.Qk.

No MeSH data available.