Persons

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Doping of graphene nanoribbons with various chemical elements leads to a change in their band structure, which significantly expands the range of applications of these objects in modern electronic devices. In this work, the authors investigate graphene nanoribbons of the «armchair» and «zigzag» types with different concentrations of pyrrole-like nitrogen at the edges. The SCC-DFTB method was used to establish the most energetically favorable configurations of pyrrole-like nitrogen at each edge of graphene nanoribbons. The relationship between the energy gaps of graphene nanoribbons and the content of the considered functional nitrogen-containing groups in them was determined. Calculations have shown that, by incorporating into the atomic lattice, pyrrole-like nitrogen at the «zigzag» edge transfers a greater amount of charge to nearby carbon atoms, which makes such nanoribbons more chemically active in comparison with «armchair» type nanoribbons. Nitrogen doped «zigzag» graphene nanoribbons may be a promising chemoresistive element of nanosensors; however, these conclusions require further calculations.

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Most promising materials for creating biointerfaces are electrically conductive materials based on carbon and its modifications. Such materials can be used for targeted stimulation of cells and tissues with high spatial resolution. In this work, carbon nanotubes are considered to be used for electrically conductive materials creation because of their outstanding electrical, mechanical and optical properties. It was shown that under the influence of laser radiation, it is possible to achieve the effect of welding with the formation of branched networks on a silicon substrate and within the biopolymer matrix. As a result of experimental studies, the radiation energy density was established at which the effect of single-walled carbon nanotubes bonding to each other appears - 0.061 J/cm. The mechanism of porous materials based on biopolymers albumin, collagen and chitosan formation containing single-walled carbon nanotubes has been determined. Materials were made from single-walled carbon nanotubes and biopolymers with controlled pore size. The pore volume was more than 60 % of the nanocomposite volume.

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The properties of the biological tissue laser nanowelding have been investigated. The high thermo- and photo stability of the solder composition based on the water albumin dispersion with the single-layer and multi-layer carbon nanotubes has been demonstrated. The specimens of the bull trachea cartilage and the pig skin were investigated as the biological tissue objects in vitro. The nanosolder usage allowed a several times increase of the tensile strength of the laser welds of a relatively traditional solder based on the albumin dispersion. The results have demonstrated the potential possibilities of a laser solder for welding of the biological tissues.

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