Electrical and Thermal Conductivity of Ternary Composites Graphite Nanoplatelets/TiO2/Epoxy

Вовченко, Л. Л.; Len, T. A.; Matzui, L. Yu.; Turkov, O. V.; Perets, Yu. S.

doi:10.21272/jnep.11(3).03007

Cited by 5 publications

(4 citation statements)

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“…In addition, in the temperature range from 77 to 300 K, this composite is characterized by a minimum of electrical resistance at 140 K, and then a monotonic increase in electrical resistance is observed. A similar change in temperature coefficient of resistance (TCR) from negative to positive with an increase in the GNP content was observed for previously studied composites with a combined filler, GNP/BaTiO3 and GNP/TiO2 [46].…”

Section: Concentration and Temperature Dependences Of The Electricalsupporting

confidence: 78%

Concentration and Temperature Dependences of Thermal and Electrical Conductivity of Polymer Hybrid Composites Graphite Nanoplatelets/Fe/Epoxy

Perets¹,

Yakovenko²,

Вовченко³

et al. 2022

Metallofiz. Noveishie Tekhnol.

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The concentration and temperature dependences of the electrical and thermal conductivity of epoxy-based (L285) composite materials (СM) with a combined graphite nanoplatelets/carbonyl iron (GNP/Fe) filler are studied. The content of GNP is varied from 0.7 to 4.0% vol., and the content of Fe was 5.6% vol. As found, the addition of Fe particles in the GNP/L285 composite leads to a decrease in thermal conductivity and a more complex dependence of thermal conductivity on the concentration of GNP. Such changes in thermal conductivity for three-phase CM can be related to an increase in thermal contact resistance at the interfacial boundaries of the matrix-filler, the number of which increases significantly with the addition of Fe particles. Experimental concentration dependences of thermal conductivity of two-and three-phase CM with GNP filler are described in the framework of the combined model of mixtures. The features of the temperature dependences of the thermal conductivity of two-phase CM GNP/L285, Fe/L285 and three-phase composites GNP/Fe/L285 are determined by increasing the concentration of phonons and increasing phonon-phonon scattering when heated. As found, the addition of 5.6% vol. of dispersed Fe particles in a two-phase GNP/L285 composite has almost no effect on the percolation threshold, the value of which is φc = 1.8% vol. This means that electrically conductive chains are formed mainly from GNP particles in the hybrid composite, and electrically conductive particles

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Section: Concentration and Temperature Dependences Of The Electricalsupporting

confidence: 78%

Concentration and Temperature Dependences of Thermal and Electrical Conductivity of Polymer Hybrid Composites Graphite Nanoplatelets/Fe/Epoxy

Perets¹,

Yakovenko²,

Вовченко³

et al. 2022

Metallofiz. Noveishie Tekhnol.

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“…In the PVDF/TiO 2 /CNT ternary composites, on the one hand, the volume exclusion effect of TiO 2 can increase the contact opportunity of CNTs with each other; on the other hand, the well-dispersed CNTs can form more conductive pathways/networks in the matrix. In addition, TiO 2 as a semiconductor material may exhibit a bridging effect to form hybrid conductive pathways/networks consisting of CNT–TiO 2 –CNT structures, according to the previous literature . The above three factors are conducive to decrease the tunneling distance and form more conductive pathways .…”

Section: Discussionmentioning

confidence: 94%

“…In this case, the combinational use of BaTiO 3 and CNTs provided a high dielectric constant and a low dielectric loss for PVDF/BaTiO 3 /CNT ternary nanocomposites without compromising their piezoelectric properties below the percolation threshold. Vovchenko et al found that graphite nanoplate (GNP)/titanium oxide (TiO 2 )/epoxy ternary composites are characterized by the lower percolation threshold and enhanced electrical conductivity compared to GNP/epoxy binary composites . The combination of two-dimensional conductive GNP and zero-dimensional semiconductive TiO 2 particles led to the electrical transport in composites through various conductive pathways, namely, GNP–GNP chains, TiO 2 chains, and combined GNP–TiO 2 –GNP chains.…”

Section: Introductionmentioning

confidence: 99%

“…The spherical TiO 2 nanoparticles have characteristics such as nontoxicity, high-hardness, low cost, high dielectric constant, and low dielectric loss. As the second filler, they are used to enhance the dispersion of CNTs and electrical properties of PVDF composites. , Although many studies on PVDF composites with CNTs or TiO 2 have been conducted, ,,− which mainly focus on increasing dispersion by modifying nanofillers or the synergistic effect of two conductive fillers to enhance the electrical properties of PVDF, investigation about two fillers with different properties is still relatively less; their dispersing mechanism is still unclear.…”

Section: Introductionmentioning

confidence: 99%

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Synergistic Effect Based on Enhanced Local Shear Forces in PVDF/TiO₂/CNT Ternary Composites

Zhang

Zhao

Huang

et al. 2020

Ind. Eng. Chem. Res.

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High-performance polymer composites fabricated by the addition of hybrid fillers have been attracting great attention from the industry and researchers due to their synergistic effect and relatively low cost. In this work, a systematical synergistic mechanism on enhancing the dispersibilities and electrical properties is proposed based on the poly(vinylidene fluoride)/titanium oxide/carbon nanotube (PVDF/TiO2/CNT) ternary composites prepared by simply melt blending. The local shear forces enhanced by rigid TiO2 submicron particles drive the initially dispersed small CNT agglomerates broken into smaller CNT agglomerates or single CNTs in the ternary composites. In addition, the well-dispersed hybrid fillers restrict reaggregation with each other. The more available phase interfaces provided by better-dispersed hybrid fillers lead to the improvement of the dielectric properties. The more conductive pathways/networks, caused by the good dispersion combined with the volume exclusion effect and the bridging effect of TiO2 particles, induce a liquid–solid transition and result in the change in the AC conductive mechanism from electron hopping conductivity to conductive pathways/network conductivity in PVDF composites near the percolation threshold. This provides significant information about the construction of the tunable electrical properties by tailoring the hybrid network structure in ternary composites.

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Microwave absorption in epoxy composites filled with MoS2 and carbon nanotubes

Вовченко

Matzui

Yakovenko

et al. 2022

Journal of Applied Physics

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In this study, the microwave absorbing properties of epoxy composites filled with micro-sized MoS2 and carbon nanotubes (CNT)/MoS2 were investigated in the frequency range of 1–67 GHz. Sample characterization was performed using electron microscopy and Raman spectroscopy methods. Direct current (DC) conductivity, complex permittivity, and shielding properties of composite materials with 50 wt. % of MoS2 and 1.5–2 wt. %CNT/50 wt.%MoS2 were measured. The permittivity of 50 wt. % MoS2/epoxy composite was found to be equal to 7.3, decreasing monotonically down to 4.5 at 67 GHz, while the imaginary part is equal to 1 and does not change. The addition of 2 wt. % of CNTs increases the real part of permittivity εr′ up to 30 at 1 GHz (13 at 67 GHz) and also leads to a large increase of the imaginary part of permittivity, with the most pronounced relaxation peak εr′′=10 at 10 GHz. Such an increase of dielectric loss correlates with the increase of DC conductivity up to 3.2 × 10−5 S/m as compared to the two-phase composite 50 wt. %MoS2/epoxy (σdc = 1.7 × 10−9 S/m). It was shown that 50 wt. %MoS2/epoxy composite exhibited an effective microwave absorption bandwidth of 9.9 GHz at the sample thickness of 2.0 mm with reflection loss minimum of -20.0 dB at 51.5 GHz. 2 wt. %CNT/50 wt. %MoS2/epoxy composite with a thickness of 0.9 mm showed a reflection loss minimum of −38 dB at 20.2 GHz with the absorption bandwidth of 3.68 GHz. The influence of sample thickness on position, width, and depth of EMR absorption maximums for the composites filled with MoS2 and mixed filler CNT/MoS2 was also determined.

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Electrical and Thermal Conductivity of Ternary Composites Graphite Nanoplatelets/TiO2/Epoxy

Cited by 5 publications

References 0 publications

Concentration and Temperature Dependences of Thermal and Electrical Conductivity of Polymer Hybrid Composites Graphite Nanoplatelets/Fe/Epoxy

Concentration and Temperature Dependences of Thermal and Electrical Conductivity of Polymer Hybrid Composites Graphite Nanoplatelets/Fe/Epoxy

Synergistic Effect Based on Enhanced Local Shear Forces in PVDF/TiO₂/CNT Ternary Composites

Microwave absorption in epoxy composites filled with MoS2 and carbon nanotubes

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Electrical and Thermal Conductivity of Ternary Composites Graphite Nanoplatelets/TiO2/Epoxy

Cited by 5 publications

References 0 publications

Concentration and Temperature Dependences of Thermal and Electrical Conductivity of Polymer Hybrid Composites Graphite Nanoplatelets/Fe/Epoxy

Concentration and Temperature Dependences of Thermal and Electrical Conductivity of Polymer Hybrid Composites Graphite Nanoplatelets/Fe/Epoxy

Synergistic Effect Based on Enhanced Local Shear Forces in PVDF/TiO2/CNT Ternary Composites

Microwave absorption in epoxy composites filled with MoS2 and carbon nanotubes

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Synergistic Effect Based on Enhanced Local Shear Forces in PVDF/TiO₂/CNT Ternary Composites