Correlation of electrical conductivity, dielectric properties, microwave absorption, and matrix properties of composites filled with graphene nanoplatelets and carbon nanotubes

Abstract

Articles you may be interested inEnhanced dielectric performance of three phase percolative composites based on thermoplastic-ceramic composites and surface modified carbon nanotube Appl. Phys. Lett. 106, 012902 (2015); 10.1063/1.4904937Numerical investigation on the influence factors of the electrical properties of carbon nanotubes-filled composites Effect of filament aspect ratio on the dielectric response of multiwalled carbon nanotube composites Electromagnetic characteristic and microwave absorption properties of carbon nanotubes/epoxy composites in the frequency range from 2 to 6 GHzThe DC electrical conductivity, percolation threshold, and dielectric properties of Graphene Nanoplatelets (GNPs) filled epoxy composites are studied and correlated with microwave absorption. The properties of GNPs filled composites are also compared with multiwalled carbon nanotubes (MWCNTs) composites, and GNPs are observed to have superior conductivity than MWCNTs. In all batches, the nanofillers have 0.5, 1.0, 1.5, 2.0, 2.5, 3.0, and 3.5 wt. %. All composites irrespective of the type of nanofiller and viscosity of the matrix have shown electrical percolation threshold at 3.0 wt. %. The dielectric properties, i.e., complex permittivity, tan loss, and AC conductivity, are studied in 100 Hz-5.5 MHz. The DC and AC electrical conductivities (at and below the percolation) measured in 100 Hz-5.5 MHz are correlated to the GNPs and MWCNTs epoxy composites in the microwave frequency range (11)(12)(13)(14)(15)(16)(17). The maximum return loss of À12 dB and À6 dB was determined for MWCNTs and GNPs, respectively. The effects of nanofiller shape and the viscosity of the matrix on the dispersion and interparticle spacing of the conductive fillers within the polymer matrix have been discussed based on the results of conductivity, dielectric, and absorption properties. V C 2015 AIP Publishing LLC.

Heteronanostructured Co@carbon nanotubes-graphene ternary hybrids: synthesis, electromagnetic and excellent microwave absorption properties

“…Generally, the obtained results indicate that the scope of absorption can be tuned by regulating CNT content in the obtained hybrids. Moreover, as reported previously7677, graphene is more capable of forming conducive paths and the introduction of magnetic nanoparticles can lower the complex permeability of hybrids. Therefore, the addition of graphene and Co nanoparticles in hybrids is very important for the improvement and regulation of their MA properties.…”

Graphene and MWCNT Printed Films: Preparation and RF Electrical Properties Study

“…Nevertheless, it is well known that dielectric properties of polymer-carbon material composites strongly depend on the electrical (i.e., conductivity), chemical (i.e., functional groups), geometrical (i.e., aspect ratio, specific surface area, and consequently percolation threshold), and morphological (i.e., dispersion into the matrix) properties of the filler [24,30].…”

“…Needless to say, such a difference affects the extension of the interaction between the carbon materials and the binder(s) at the graphene platelets (or MWCNTs)/polymer interface. In other words, since the two nanostructures possess two distinct electronic distribution, the effect of the van der Waals (intermolecular) forces (e.g., dipole-dipole, dipole-induced dipole, London dispersion forces, hydrogen bonds) [34,35] regulating the fillerbinder interaction may lead to different dielectric behaviors for the two cases [30]. These aspects can be particularly relevant for polar binders dielectrically relaxing in the microwave region like the PVP and PVP+PVB mixtures [35].…”

“…Therefore, the dielectric permittivity lowering (with respect to the gap dielectric that is the FR-4 and MWCNTs) can produce a reduction of the antenna capacitance, reflecting into an impedance increase and in turn causing the resonant frequency to shift to higher frequency. On the other hand, the large specific surface area of MWCNTs, and therefore the high interfacial polarization, may result into a slight shift of the resonant frequency toward lower frequency [30].…”

Fabrication and simulation of semi-transparent and flexible PMMA/ATO conductive nanocomposites obtained by compression molding at different temperatures and pressures

“…The electrical conductivity of a polymer matrix composite with conductive fillers can be empirically described by the power law: 11,12 σ = σ 0 (ρ − ρ c ) t (for ρ > ρ c )…”