Synthesis, Modeling, and Experimental Characterization of Graphite Nanoplatelet-Based Composites for EMC Applications

Abstract

Graphite nanoplatelets (GNPs) are bidimensional carbon nanostructures consisting of stacks of graphene sheets, having thickness in the range from one up to a few tens of nanometers, and lateral linear dimension in the micrometer range. These nanostructures represent a good candidate to replace carbon nanotubes in composites for electromagnetic applications. This paper proposes a new model based on the Maxwell-Garnett approach to compute the effective complex permittivity of GNP-filled nanocomposites. The effect of the dimensional probabilistic distribution of the nanofiller is investigated. To this purpose, an extensive experimental characterization of the morphological and physical properties of the GNPs after synthesis is performed. The proposed model is validated by comparison with the measured effective permittivity of GNP-composites with different concentrations, and it is used for the design of radar-absorbing materials in the frequency range 1-18 GHz

Fully carbon metasurface: Absorbing coating in microwaves

“…We assume that this special feature of GCS-based monolayer may find some practical applications in the future, for example for designing frequency-selective filters. Also noteworthy is that the microwave absorption performances of the GCSs monolayers considered here are generally comparable with those of other absorbers presented recently [16][17][18] (the absorption mechanism is classical Ohmic losses in conductive medium). These recent reports generally deal with materials based on polymer matrix and their operating temperature range is usually limited below 200-300…”

“…Generally, the following mechanisms of EM absorption are used for practical a) dzmitrybychanok@ya.ru; www.nano.bsu.by applications: ferromagnetic resonance 10,11 , Ohmic losses 12,13 , dipole relaxation 14 and lossy scattering in metamaterials 15 . At present, many groups focus on the investigation of carbon-based polymer composites for developing effective microwave absorbers [16][17][18] . In this paper, we considered the features of normal scattering of microwave radiation on an ordered monolayer of porous carbon spheres on a Perfect Electrically Conducting (PEC) plate, schematically shown in Fig.1.…”

Design of Carbon Nanotube-Based Broadband Radar Absorber for Ka-Band Frequency Range

“…The simplest way to obtain dispersive materials is to use the conductive inclusions inside the composite [17][18][19]. Typically, composites with conductive filler above percolation threshold have pronounced ε ∼ 1/ω dispersion in microwave frequency range.…”

Exploring Carbon Nanotubes/Batio3/Fe3o4 Nanocomposites as Microwave Absorbers

“…3). The specific MWCNT content to achieve refractive index for maximal absorption can be well predicted and controlled by use of the Maxwell Garnett mixing law [12,18] In practice, when the frequency range is fixed, the maximum of absorption is estimated, and once the corresponding composite material is produced, it is very useful to investigate the frequency dependence of the absorption coefficient of samples with various thicknesses. Fig.…”

“…There is a worldwide activity in this sector, and the search for new broadband absorbing materials is ongoing constantly [1][2][3][4][5][6]. The role of ferromagnetic resonance [7][8][9], Ohmic losses [10][11][12], dipole relaxation [13] and lossy scattering on the periodic structure of metamaterials [14] are some of the currently pursued questions. Some of these physical mechanisms can be efficiently combined in (nano)composite materials.…”