Abstract Nanocarbon composites present a new type of nanomaterials consisted of electric conducting carbon nanoparticles and a non-conducting matrix. A typical example of such composites is a polymer matrix doped with carbon nanotubes (CNT). Due to a high aspect ratio of nanotubes insertion of very small quantity of CNT (on the level of 0.01%) promotes the percolation transition resulting in an enhancement of the conductivity of the material by 10–12 orders of magnitude. Another type of nanocarbon composite is a film consisted of partially reduced graphene oxide (GO) produced as a result of thermal reduction of graphite oxide material. Distinctive peculiarity of both types of nanocomposites relates to the dependence of the specific resistivity of the materials on the applied voltage. Such a behavior is caused by non-ideal contacts between neighboring carbon particles involving into the composite. The resistance of this contact depends drastically on the intra-contact field, which promotes the dependence of the material resistivity on the applied voltage. The model description of such a non-linear dependence has been presented. The calculation results are compared with both literature data and the measured data obtained for reduced GO thermally treated at various temperatures.

A new modification of the gas discharge method for fullerene production is developed. Powdered amorphous carbon particles admitted into the flowing plasma of a plasmatron are used as a source of carbon atoms, in distinct from the conventional approach, where this aim is reached through the thermal vaporization of a graphite anode. The fullerene yield vs carbon black feeding rate has a smooth maximum, reaching about 2%. A physical model for vaporization of a small carbon particle in a weakly ionized plasma is built, which allows one to establish the interconnection between the time taken for vaporization of a particle, its size and the plasma temperature. Estimations based on this interconnection show that the effective vaporization of particles of micron size is reached using He or Ar gas carrier flowing with velocity of about 100 cm/s through the plasmatron channel of about 10 cm in length. The results of preliminary experiments are in agreement with those estimations. The main advantages of the proposed approach relate to continuous input of carbon feedstock materials into plasma zone, relatively low energy cost of carbon vaporization and usage of low cost carbon black produced from waste hydrocarbons.

Resonant charge-exchange cross sections and the relevant transport (diffusion) cross sections for excited states of nitrogen and oxygen atoms have been calculated. The calculation is performed using the asymptotic approach, based on the single-electron asymptotic representation of the electron wave function. The ground-state cross sections are in a good agreement with those calculated via comprehensive quantum chemical approach. The results of calculations demonstrate a reasonable accuracy and a high convenience of this approach in determination of cross sections for the manifold of excited states of atoms.

We have undertaken to investigate optical absorption spectra of matrix-isolated halogenofullerene molecules C60Cl60, C60Cl24, and C60Br24 in the visible and near-IR regions of the spectrum. The results for C60Cl24 presented here, show that this molecule possesses a rich well-structured spectrum. The analysis of the spectrum allows to suggest a tentative scheme of the electron energy levels of C60Cl24 molecule in the region of its HOMO=LUMO gap. The optimized geometry of C60Cl24 and its charge distribution calculated at the AM1 level are also presented. The Shpol'skii effect in the absorption spectrum of C60Cl24 molecules embedded in crystalline toluene was clearly detected, in agreement with our theoretical investigation of the geometrical structure of C60Cl24 centers in toluene crystals.

X-ray excited Anger electron spectroscopy (XAES) and XPS were used to studying chemical states of carbon atoms in various carbon compounds. There have been shown clear distinction in the XAES of different compounds, which permits to identify carbon containing contaminations (CCC) on a surface of nanotubes and fullerene.

We analyze the conditions for the existence of LTE (Local Thermodynamic Equilibrium) in LIES plasmas. In particular we focus our attention to problems associated with non equilibrium plasmas (colisional radiative models, Boltzmann equation for electrons, fluidynamic aspects) making also use of a recent experimental study.

A plasma created by the action of a high-intensity resonant laser radiation on a vapor or a gas (Photoresonant Plasma, PRP) is considered as a version of the Laser Induced Breakdown Spectroscopy (LIBS). The physical mechanisms determining the transformation of the resonant laser radiation energy into that of a plasma are analyzed. It is shown that the transformation of resonant radiation proceeds much more quickly in comparison with the conventional off-resonant irradiation. This is one of the main advantages of use of PRP in LIES technique. There have been stated the interrelation between the quasi-stationary plasma temperature established after termination of the laser pulse and the concentration of the admixture vapor to be determined. This interrelation can be used as the basis for LIPS determination of the elemental content of the irradiated surface. The set of equations determining the time evolution of PRP is formulated. The quasi-stationary parameters of alkali metal PRP after terminating the laser irradiation and also during the irradiation have been evaluated on the basis of the analysis of these equations.

The effect of negative oxygen ion destruction upon breakdown conditions in atmospheric air is analyzed. It is shown that ozone accumulation due to plasmochemical reactions occurring in ionized air produces a reduction in the breakdown voltage, related to negative O− ion destruction upon collision with ozone molecules under realistic conditions. A relationship is derived for electric field breakdown intensity and ozone molecule lifetime for the real atmosphere.