Mykola Kartel; Liudmyla Karachevtseva; Wang Bo; Daryna Haliarnyk; Olga Bakalinska; Tetyana Kulyk; Borys Palyanytsya; Yevgen Demianenko; Anatoliy Grebenyuk; Volodymyr Kuts
Abstract
The possible mechanisms of decomposition of benzoyl peroxide were investigated by the method of density functional theory with the exchange-correlation functionality of B3LYP, a basis set of 6-31G (d, p). It was carried out a comparative analysis of the quantum chemical calculations of the electronic ...
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The possible mechanisms of decomposition of benzoyl peroxide were investigated by the method of density functional theory with the exchange-correlation functionality of B3LYP, a basis set of 6-31G (d, p). It was carried out a comparative analysis of the quantum chemical calculations of the electronic structure of carbon nanoclusters simulating the active surface of sp < sub>2 carbon materials, including their modifications by the heteroatoms N and O. The energy parameters of the benzoyl peroxide molecule and all possible products of its decomposition, as well as the interaction of the free radical Ph-COO• with model graphite-like nanoclusters were considered. The calculations are compared with the experimental results of the catalytic activity of the varieties of activated charcoal and the catalase enzyme in the reaction of the benzoyl peroxide decomposition in a non-aqueous medium. It has been established that in the benzoyl peroxide molecule, regardless of the polarity of the medium, the weakest is the bond (O-O). The greatest ability to decompose benzoyl peroxide, which is much larger than that of catalase, was detected on the N-containing carbonaceous materials. It is shown that the free radical Ph-COO• is lighter and kinetically, and thermodynamically interacted with the graphite-like plane of the model N-containing carbon nanoclusters.
Liudmyla Karachevtseva; Mykola Kartel; Wang Bo; Yurii Sementsov; Viacheslav Trachevskyi; Oleg Lytvynenko; Volodymyr Onyshchenko
Abstract
Carbon nanotubes are among the most anisotropic materials known and have extremely high values of Young's modulus. The possibilities to enhance the properties of nanostructured surfaces were demonstrated on “polymer-multiwall carbon nanotube” composites. Influence of sp < sup > 3 hybridization ...
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Carbon nanotubes are among the most anisotropic materials known and have extremely high values of Young's modulus. The possibilities to enhance the properties of nanostructured surfaces were demonstrated on “polymer-multiwall carbon nanotube” composites. Influence of sp < sup > 3 hybridization bonds on polymer crystallization and strengthening was investigated in composite films of polyethyleneimine, polypropylene and polyamide with multiwall carbon nanotubes. It was established that the effective way to enhance the strength properties of “polymer-multiwall carbon nanotube” composites is the composite crystallization and sp < sup > 3 C-C tetrahedrons organization between nanotubes supported by resonance γω(C?)? and γω(CH2) vibrations in the intrinsic electric field 6×10 3 V/cm between nanotube and polymer matrix. Tensile strength for polyamide-6 composites at 0.25% CNT increases 1.7 times and tensile deformation – 2.3 times.
Mykola Kartel; Yuriy Sementsov; Galyna Dovbeshko; Liudmyla Karachevtseva; Stanislav Makhno; Tatiana Aleksyeyeva; Yulia Grebel
Abstract
An effective cheap method for graphene nanoparticles (GNP) production with controlled size distribution was developed based on anodic oxidation of condensed exfoliated graphite. As it is shown, under certain condition the GNP could be self-organized into a 3-dimensional structure that could be important ...
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An effective cheap method for graphene nanoparticles (GNP) production with controlled size distribution was developed based on anodic oxidation of condensed exfoliated graphite. As it is shown, under certain condition the GNP could be self-organized into a 3-dimensional structure that could be important for understanding of the GNP interaction with different type of surfaces. Based on this feature, a synthesis method for preparation of composites containing GNP and polychlorotrifluoroethylene (PCTFE) was developed. Raman spectroscopy of GNP and GNP/PCTFE revealed a good crystalline structure of synthesized nanoparticles. Laser correlation spectroscopy and electron microscopy studies show that average size of particles ranges from tens to thousands nanometers and thickness consists ten or more graphene layers. We found that conductivity of GNP is of electronic nature. The real and imaginary parts of complex permittivity in the microwave range and electric conductivity at low frequencies were found to be a nonlinear function of a volume content of GNP in GNP/PCTFE composite. It could be explained by a presence of the percolation threshold equals to 0.5 wt.%. Low percolation threshold of GNP/PCTFE composite as self-organized 3D structure, could be a certificate of high surface energy for the particles strongly interacting with the surrounding media.
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