In the present work, we have investigated concentration and temperature dependences of electrical conductivity of graphite nanoplatelets/epoxy resin composites. The content of nanocarbon filler is varied from 0.01 to 0.05 volume fraction. Before incorporation into the epoxy resin, the graphite nanoplatelets were subjected to ultraviolet ozone treatment at 20-min ultraviolet exposure. The electric resistance of the samples was measured by two-or four-probe method and teraohmmeter E6-13. Several characterization techniques were employed to identify the mechanisms behind the improvements in the electrical properties, including SEM and FTIR spectrum analysis. It is established that the changes of the relative intensities of the bands in FTIR spectra indicate the destruction of the carboxyl group -COOH and group -OH. Electrical conductivity of composites has percolation character and graphite nanoplatelets (ultraviolet ozone treatment for 20 min) addition which leads to a decrease of percolation threshold 0.005 volume fraction and increase values of electrical conductivity (by 2-3 orders of magnitude) above the percolation threshold in comparison with composite materials-graphite nanoplatelets/epoxy resin. The changes of the value and behavior of temperature dependences of the electrical resistivity of epoxy composites with ultraviolet/ozone-treated graphite nanoparticles have been analyzed within the model of effective electrical conductivity. The model takes into account the own electrical conductivity of the filler and the value of contact electric resistance between the filler particles of the formation of continuous conductive pathways.

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The methods of functionalization of carbon nanotubes and thermally exfoliated graphite by inorganic and organic compounds, which allow obtaining of oxygen‐containing groups on the nanocarbon surface were proposed. The influence of chemical treatment on the internal structure and surface morphology of nanocarbon is analyzed. The electron microscopy, Raman spectroscopy, and IR spectroscopy methods were used for investigating the structure and qualitative composition of functional groups on the chemically treated nanocarbons surface. The presented data reveal some modification of the typical nanocarbon Raman bands such as disorder band (D band), the graphite band (G band). But the changes of nanocarbon structure under chemical treatment are not dramatic.

In present work a novel method for the functionalization of carbon nanotubes is proposed. The magnetoresistance of carbon nanotubes specimens in temperature range from 1.6 K up to 85 K and in magnetic field up to 5 T was investigated. It was shown that the proposed functionalization method does not cause any new defects in structure of carbon nanotubes and does not essentially influence the resistivity of nanotubes. It is revealed the appearance of the charge carriers weak localization and interactions effects for as‐prepared and functionalized carbon nanotubes. On the basis of the experimental data, the explicit type of temperature dependence of wave function phase relaxation time and Fermi‐level energy value for as‐prepared and functionalized carbon nanotube are established.

It was investigated the influence of hydrostatic pressure on the electrical conductivity of fine crystalline graphite in the temperature range of (77-293) K. It was revealed that the reduction of electrical resistivity in specimens of fine crystalline anisotropic graphite under the hydrostatic pressure action is due to increasing overlap between the valence and conduction bands that leads to an increase in the concentration of free charge carriers. The change of the overlap between the valence and conduction bands was estimated. It is shown that a decrease in the distance between the graphite layers under pressure is an irreversible process: when load is removed, the electrical resistance increases slightly, but does not acquire the initial value.