Comparative analyses of the electrical properties and dispersion level of VGCNF and MWCNT: Epoxy composites |
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Authors: | Paulo Cardoso Jaime Silva Maria Conceição Paiva Ferrie van Hattum Senentxu Lanceros‐Mendez |
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Affiliation: | 1. Center/Department of Physics, University of Minho, Campus de Gualtar, 4710‐057 Braga, Portugal;2. IPC/I3N—Institute for Polymers and Composites, University of Minho, Campus de Azurém, 4800‐058 Guimar?es, Portugal |
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Abstract: | The electrical properties and dispersion of vapor‐grown carbon nanofibers (VGCNF) and multiwalled carbon nanotubes (MWCNT)—epoxy resin composites are studied and compared. A blender was used to disperse the nanofillers within the matrix, producing samples with concentrations of 0.1, 0.5, and 1.0 wt % for both nanofillers, besides the neat sample. The dispersion of the nanofillers was qualitatively analyzed using scanning electron microscopy, transmission optical microscopy, and grayscale analysis. The electrical conductivity and the dielectric constant were evaluated. The percolation threshold of MWCNT epoxy composites is lower than 0.1 wt % while for VGCNF lies between 0.1 and 0.5 wt %. The difference on the dispersion ability of the two nanofillers is due to their intrinsic characteristics. Celzard's theory is suitable to calculate the percolation threshold bounds for the VGCNF composites but not for the MWCNT composites, indicating that intrinsic characteristics of the nanofillers beyond the aspect ratio are determinant for the MWCNT composites electrical conductivity. © 2012 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys, 2012 |
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Keywords: | dispersion electrical properties epoxy resin fillers MWCNT nanocomposites percolation threshold thermosets VGCNF |
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