Журнал нано- та електронної фізики (Journal of nano- and electronic physics)
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Item Features of Microstructure and Percolation Behavior of Polypropylene Glycol, Filled by Multiwalled Carbon Nanotubes(Sumy State University, 2017) Lysenkov, E.A.; Klepko, V.V.; Lysenkova, I.P.The research of the microstructure features, percolation behavior and impedance of systems based on polypropylene glycol and multiwalled carbon nanotubes (MWCNTs) is conducted using the methods of optical microscopy and impedance spectroscopy. It is set that in the investigated systems the typical percolation transition is observed at some threshold MWCNTs concentration (0.45 %). The fractal behavior of those systems was revealed. Using the method of impedance spectroscopy the corresponding percolation threshold of 0.45 % was found. The critical index of conductivity t = 1.3 was determined in the framework of McLachlan equation. The processes of charge transfer in the systems concerned were found to be described well by the proposed equivalent circuit.Item Microwave Properties of Carbon Nanotubes Grown by Pyrolysis of Ethanol on Nickel Catalyst(Sumy State University, 2014) Rodionov, V.V.; Kuzmenko, A.P.; Emelyanov, S.G.; Chervyakov, L.M.; Dobromyslov, M.B.The efficiency of carbon nanotubes produced by CVD-method on a nickel catalyst at a protection from microwave radiation is shown. These data are confirmed by scanning electron microscopy, energy disper-sive X-ray analysis and spectral analysis of the microwave radiation in the frequency range 26-40 GHz. The observed value of the transmission coefficient S21, up to – 42.7 dB, is in agreement with considered possible absorption mechanisms of electromagnetic wave energy in carbon nanoscale systems “CNT-nickel nanoparticles”. The application of carbon powder materials in shielding of electromagnetic radiation has been theoretically justified. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/36283Item Influence of Structural Features and Physico-chemical Properties of Metal-carbon Nanocomposites with Ferromagnetic Metal Inclusions on Microwave Radiation(Sumy State University, 2014) Kozhitov, L.; Kuzmenko, A.; Muratov, D.; Rodionov, V.; Popkova, A.; Yakushko, E.; Dobromyslov, M.Metal-carbon nanocomposites on the basis of polyacrylonitrile and compounds of metals (Fe, Ni, Co) synthesized at IR-heating and studied by SEM, X-ray phase analysis, Raman scattering, IR Fourier spec-troscopy are characterized by the carbon nanostructured amorphous graphite matrix with uniformly dis-tributed nanoparticles of metals (10-30 nm), their oxides and compounds – FeNi3 and FeCo, multilayered carbon nanotubes (~ 7-22 nm), and in the composition of Fe-Co / C fullerene-like formations – C60. All nanocomposites feature high absorption of electromagnetic waves in the frequency range 20-40 GHz. Two absorption mechanisms are proposed: dielectric loss in the amorphous carbon matrix and scattering of electric and magnetic components by ferromagnetic inclusions. Absorption was – 8.68 dB for Fe-Ni / C, – 12.93 dB for Fe / C, and – 7.07 dB for Ni / C and for Fe-Co / C was found to be maximum in the whole range studied (more than – 40 dB) with a peak of – 52.83 dB at 24.27 GHz, which is explained probably by both high nanocomposite electric conductivity 2 S / m and high specific magnetization of phase FeCo. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/36259Item Obtaining New Dental Materials Reinforced with Carbon Nanotubes(Sumy State University, 2014) Zaporotskova, I.V.; Elbakyan, L.S.The article seeks to explore the change of strength properties of composite polymer material on the basis of fast-hardening dental plastic "Carbogen", when reinforcing its coal-native nanotubes. Were discussed peculiarities of composition of Carboante, ways of creation of polymeric composition deposits by doping their carbon nanotubes, the results of measuring the strength characteristic characteristics obtained new polymer materials. On the basis of the analysis of the practical and the theoretical-sky research, conclusions were drawn on the feasibility of a new filling material with the use of carbon nanotubes with unique strength characteristics and use of their in dentistry. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/36112Item Field Emission Behaviour of the Single Wall Carbon Nanotubes Grown by Plasma Enhanced Chemical Vapour Deposition (PECVD) System(Сумський державний університет, 2013) Kumar, Avshish; Parveen, Shama; Husain, Samina; Ali, Javid; Harsh; Husain, M.Single wall carbon nanotubes have been grown on Fe using Plasma Enhanced Chemical Vapour Deposition (PECVD) system. The thickness of the Fe film prepared by RF sputtering system was about 10 nm. The field emission characteristic was measured which showed good enhancement factor. The grown CNTs were characterized by various techniques such as SEM, Raman study etc. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/31006