Dielectric behaviour of carbon nanotubes particles-filled polyester polymer composites

Samir, Z.; Merabet, Youssef El; Graça, M.P.F.; Teixeira, S. Soreto; Achour, M. E.; Costa, L.C.

doi:10.1177/0021998316665682

Cited by 20 publications

(16 citation statements)

References 22 publications

(21 reference statements)

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“…Figure shows the frequency dependencies of ε ″ for nanocomposites reinforced with a 3% loading of C‐Dots for temperatures between 200 to 390 K. It can be seen that it increases with temperature, reaching a high value at low frequencies. This is due to the high conductivity, due to the insertion of the C‐Dots, that hidden the relaxation peaks, and consequently, the modulus formalism has to be used, by means of .…”

Section: Resultsmentioning

confidence: 99%

Thermal properties and electric modulus approach to the analysis of dielectric relaxation of nanocomposites based on carbon dots

et al. 2019

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The investigation of thermal and dielectric properties of carbon dots dispersed in PMMA has been conducted in freestanding thin solid films. Thermal properties were studied using differential scanning calorimetry. Impedance spectroscopy, in the frequency range 100 Hz to 100 kHz and temperatures between 200 and 390 K, was used for the electrical characterization. Using the electric modulus formalism, it has been found that the Havriliak‐Negami model of dielectric relaxation is adequate to fit the experimental data, from which the relaxation parameters can be calculated. The inclusion of C‐Dots in PMMA provides a plasticizing effect on the polymer structure, giving rise to an increase in the mobility of PMMA chains, and consequent changes in the relaxation parameters.

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Section: Resultsmentioning

confidence: 99%

Thermal properties and electric modulus approach to the analysis of dielectric relaxation of nanocomposites based on carbon dots

et al. 2019

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“…The real and the imaginary parts of the complex permittivity were calculated from the measured admittance,

Y^{*} = G + i B = i C_{o} ω . ε^{*} (ω)

of the equivalent circuit leading to

ε' (ω) = 2 h . B / ε_{0} . {normald}^{2} π^{2} F

and

ε'' (ω) = 2 h . G / ε_{0} . {normald}^{2} π^{2} F

, where B is the susceptance, G is the conductance,

F = \frac{ω}{2 π}

is the frequency,

ε_{0}

is the vacuum dielectric constant, and h and d are the thickness and the diameter of the sample, respectively. The measurements were performed, in the frequency range 40 Hz to 1 MHz, under isothermal conditions, for temperatures ranging between 200 and 400 K. Estimating relative errors on both real and imaginary parts of the complex permittivity are Δε′/ε′=Δε″/ε″≤5% .…”

Section: Methodsmentioning

confidence: 99%

Optical and dielectric properties of PMMA (poly(methyl methacrylate))/carbon dots composites

et al. 2018

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The optical and the dielectric properties of an original nanocomposite based on the incorporation of carbon dots (C‐dots) in poly(methyl methacrylate) (PMMA) at several filler loading were studied. The optical characterization demonstrated the preservation of the excitation dependent intense emission of the C‐dots in the polymer, ascribed to the presence of organic fluorophores formed during the nanoparticle synthesis. The composite PMMA/C‐dots dielectric properties were investigated in the frequency range from 40 Hz to 1 MHz and over the temperature range from 200 to 400 K. The dielectric response was obtained using the complex permittivity or the modulus formalisms, depending on the concentration of filler in the polymer matrix. A relaxation phenomenon was induced by the incorporation of the C‐dots in the PMMA matrix. In addition, both the real and imaginary parts of the dielectric permittivity and electric modulus changed with the volume fraction of the C‐dots, suggesting that the presence of the fillers greatly affect the dielectric properties of the polymer matrix because of polarization phenomenon induced by the nanoparticles. POLYM. COMPOS., 40:E1312–E1319, 2019. © 2018 Society of Plastics Engineers

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“…To ensure better fit of observations in Figures 2(b), 4(b) and 5(b), the Debye formula (equation (13)) is to be replaced with the Havriliak–Negami equation following the approach of Samir et al. 47…”

Section: Discussionmentioning

confidence: 99%

“…Figures 1(b c at frequencies f above 12 GHz reported in literature 21,27,30 and not observed in other experimental studies. To ensure better fit of observations in Figures 2(b), 4(b) and 5(b), the Debye formula (equation (13)) is to be replaced with the Havriliak-Negami equation following the approach of Samir et al 47 Deviations from the Debye model are conventionally attributed 48 to the influence of DC electrical conductivity of filler, whose effect is accounted for by the additional term À DC =ð 0 !Þ in equation (12). To evaluate the importance of this term, we calculate the quantities 0 f , 00 f and the AC conductivity of filler…”

Section: Discussionmentioning

confidence: 99%

Modeling dielectric permittivity of polymer composites filled with transition metal dichalcogenide nanoparticles

Drozdov

Christiansen

2020

Journal of Composite Materials

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A model is developed for the dielectric permittivity of polymer nanocomposites reinforced with transition metal dichalcogenide fillers at microwave frequencies. The model takes into account aggregation of nanoparticles into clusters (that involve both filler and matrix components) and the aspect ratio of aggregates. The governing equations involve four material parameters that are found by matching observations on the real and imaginary parts of the dielectric permittivity of polymers reinforced with MoS2 and WS2 micro- and nanospheres, MoS2 nanosheets and nanoflowers, and composite heterostructures formed by MoS2 and MoS2-CoS2 nanoparticles with graphene and reduced graphene oxide. Good agreement is demonstrated between results of simulation and the experimental data at frequencies in the S, X, and Ku bands of the electromagnetic spectrum. It is shown that composite heterostructures have superior dielectric properties compared with those of neat transition metal dichalcogenide nanoparticles.

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Dielectric behaviour of carbon nanotubes particles-filled polyester polymer composites

Cited by 20 publications

References 22 publications

Thermal properties and electric modulus approach to the analysis of dielectric relaxation of nanocomposites based on carbon dots

Thermal properties and electric modulus approach to the analysis of dielectric relaxation of nanocomposites based on carbon dots

Optical and dielectric properties of PMMA (poly(methyl methacrylate))/carbon dots composites

Modeling dielectric permittivity of polymer composites filled with transition metal dichalcogenide nanoparticles

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