Raman spectroscopy and conductivity measurements on polymer-multiwalled carbon nanotubes composites

Stéphan, C.; Nguyen, T.P.; Lahr, Bernd; Blau, Werner J.; Lefrant, S.; Chauvet, O.

doi:10.1557/jmr.2002.0055

Cited by 78 publications

(54 citation statements)

References 18 publications

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“…(%) of MWCNT, which was in accordance to other studies discussed in the literature for MWCNT and PMMA 25 . The critical exponent t is dependent on the system dimension and is set between 1.65 and 2 for three-dimensional network [28][29][30] .…”

Section: Volumetric Electrical Conductivitysupporting

confidence: 92%

“…Each sample frame was collected during 5 s. Small changes in volume fraction of conductive particle cause high changes on electrical conductivity, characterizing its percolation curve. The range between 0.1-10 S/cm was previously related for semiconductor composites of CNT dispersions in PMMA matrix [25][26][27] . In order to determine the critical percolation threshold on electrical conductivity, it was applied the power law relationship, according to the classical model of percolation theory, described in Equation 1.…”

Section: Small-angle X-ray Scatteringmentioning

confidence: 67%

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Electrical percolation, morphological and dispersion properties of MWCNT/PMMA nanocomposites

et al. 2014

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Nanocomposites of poly (methyl methacrylate) (PMMA) and carbon nanotubes have a high potential for applications where conductivity and low specific weight are required. This piece of work concerns investigations of the level of dispersion and morphology on the electrical properties of in situ polymerized nanocomposites in different concentrations of multi-walled carbon nanotubes (MWCNT) in a PMMA matrix. The electrical conductivity was measured by the four point probe. The morphology and dispersion was analyzed by Transmission Electron Microscopy (TEM) and Small Angle X-ray Scattering (SAXS). The correlation between electrical conductivity and the MWCNT amount, presented a typical percolation behavior, whose electrical percolation threshold determined by power law relationship was 0.2 vol. (%) The exponent t from the percolation power law indicated the formation of a 3D network of randomly arranged MWCNT. SAXS detected that the structures are intermediate to disks or spheres indicating fractal geometry for the MWCNT aggregates instead of isolated rods. HR-TEM images allowed us to observe the MWCNT individually dispersed into the matrix, revealing their distribution without preferential space orientation and absence of significant damage to the walls. The combined results of SAXS and HR-TEM suggest that MWCNT into the polymeric matrix might present interconnected aggregates and some dispersed single structures.

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Section: Volumetric Electrical Conductivitysupporting

confidence: 92%

Section: Small-angle X-ray Scatteringmentioning

confidence: 67%

Electrical percolation, morphological and dispersion properties of MWCNT/PMMA nanocomposites

et al. 2014

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“…The Raman spectra of MWNTs typically exhibit two optically active phonon modes [35]. The first one is an optically active inplane stretching E2g mode, the socalled graphite mode, popularly termed as the "G" band with a peak around 1580 cm 1 Table 1).…”

Section: Raman Spectroscopymentioning

confidence: 99%

Incorporation of multi-walled carbon nanotubes into high temperature resin using dry mixing techniques

Ghose

Watson

Delozier

et al. 2006

Composites Part A: Applied Science and Manufacturing

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“…Since the discovery of carbon nanotubes (CNTs) by Iijima [1], extensive studies have been conducted exploring their unique electronic, thermal, optical, and mechanical properties and their potential use in greatly enhancing the physical properties of polymer nanocomposites [2,3,4,5,6], as summarized in recent review articles [7,8]. The outstanding properties are in part attributed to their extremely high aspect ratio (lengthto-outer diameter ratio) of up to 1000.…”

Section: Introductionmentioning

confidence: 99%

Relationship between dispersion metric and properties of PMMA/SWNT nanocomposites

Kashiwagi

Fagan

Douglas

et al. 2007

Polymer

169

113

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Particle spatial dispersion is a crucial characteristic of polymer composite materials and this property is recognized as especially important in nanocomposite materials due to the general tendency of nanoparticles to aggregate under processing conditions. We introduce dispersion metrics along with a specified dispersion scale over which material homogeneity is measured and consider how the dispersion metrics correlate quantitatively with the variation of basic nanocomposite properties. We then address the general problem of quantifying nanoparticle spatial dispersion in model nanocomposites of single wall carbon nanotubes (SWNT) dispersed in poly(methyl methacrylate) (PMMA) at a fixed SWNT concentration of 0.5 % using a 'coagulation' fabrication method. Two methods are utilized to measure dispersion, UV-Vis spectroscopy and optical confocal microscopy. Quantitative spatial dispersion levels were obtained through image analysis to obtain a 'relative dispersion index' (RDI) representing the uniformity of the dispersion of SWNTs in the samples and through absorbance. We find that the storage modulus, electrical conductivity, and flammability containing the same amount of SWNTs, the relationships between the quantified dispersion levels and physical properties show about four orders of magnitude variation in storage modulus, almost eight orders of magnitude variation in electric conductivity, and about 70 % reduction in peak mass loss rate at the highest dispersion level used in this study. The observation of such a profound effect of SWNT dispersion indicates the need for objective dispersion metrics for correlating and understanding how the properties of nanocomposites are determined by the concentration, shape and size of the nanotubes. conditions. We introduce dispersion metrics along with a specified dispersion scale over which material homogeneity is measured and consider how the dispersion metrics correlate quantitatively with the variation of basic nanocomposite properties. We then address the general problem of quantifying nanoparticle spatial dispersion in model nanocomposites of single wall carbon nanotubes (SWNT) dispersed in poly(methyl methacrylate) (PMMA) at a fixed SWNT concentration of 0.5 % using a 'coagulation' fabrication method. Two methods are utilized to measure dispersion, UV-Vis spectroscopy and optical confocal microscopy. Quantitative spatial dispersion levels were obtained through image analysis to obtain a 'relative dispersion index ' (RDI) representing the uniformity of the dispersion of SWNTs in the samples and through absorbance. We find that the storage modulus, electrical conductivity, and flammability † This was carried out by the National Institute of Standards and Technology (NIST), an agency of the US Government and is not subject to copyright in the US. ‡ Correspondence to: T. Kashiwagi (E-mail: takashi.kashiwagi@nist.gov) 1 property of the nanocomposites correlates well with the RDI. For the nanocomposites containing the same amount of SWNTs, the relationships betw...

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Raman spectroscopy and conductivity measurements on polymer-multiwalled carbon nanotubes composites

Cited by 78 publications

References 18 publications

Electrical percolation, morphological and dispersion properties of MWCNT/PMMA nanocomposites

Electrical percolation, morphological and dispersion properties of MWCNT/PMMA nanocomposites

Incorporation of multi-walled carbon nanotubes into high temperature resin using dry mixing techniques

Relationship between dispersion metric and properties of PMMA/SWNT nanocomposites

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