Browsing by Author "Tytarenko, Valentina V."
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Item Adsorption of Co, Ni, Cu, Zn Metal Ions on Fullerene C60 and on Single-Wall Carbon Nanotubes C48 as a Driven Force of Composite Coatings’ Electrodeposition(Oles Honchar Dnipro National University, 2021) Tytarenko, Valentina V.; Shtapenko, Eduard Ph.; Voronkov, Eugene O.; Vangara, Aruna; Zabludovsky, Vladimir A.; Kolodziejczyk, Wojciech; Kapusta, Karina; Okovytyy, Sergiy I.EN: Composite electrodeposited films fabricated from aqueous solution of electrolytes that contain ions of metals along with carbon nanomaterial particles such as fullerene C60 were investigated. Results for the cathodic polarization curve showed an increase in charge-transfer resistance. Phase composition analysis for metal films revealed the presence of carbon nanoparticles (CNPs) inside the metal matrix and significant changes in the crystal lattice. As it shown on microphotographies, addition of CNPs changes columnar growth patterns of metallic films to microlayered structure due to passivation of the surface. Density Functional Theory was used for calculation of thermochemical, electronic and structural properties of metal ions complexes with CNPs. Calculated binding energies of the CNPs-Me2+ complexes suggests that an adsorption of Co2+, Ni2+, Cu2+, and Zn2+ ions on the surface of fullerene C60 and SWNT C48 is possible and thermodynamically favorable. Binding affinity was found to be significantly stronger when the metal ion was adsorbed onto a surface of SWNT C48, than adsorption to the fullerene C60. With Cu2+ complexes being the most thermodynamically stable, binding affinities were increasing in a row Co2+Item Diffusion at the Film-Substrate Interface During Nickel Electrocrystallization on a Copper Substrate(ФГУП "Наука", Москва, 2018) Shtapenko, Eduard F.; Zabludovsky, Vladimir A.; Tytarenko, Valentina V.EN: The results of experimental studies of the diffusion layer at the interface between a nickel electrolyte film and a copper substrate are presented. Studies have shown that in the transition layer, diffusion of the deposited metal into the substrate material occurs. The depth of the diffusion layer and, consequently, the concentration of interstitial nickel atoms strongly depend on the electrocrystallization conditions: 2 μm in the constant-current mode and 4 μm under laser-assisted deposition. The diffusion coefficient of nickel adatoms in polycrystalline copper is 8.3 × 10–16 m2/s in the constant-current deposition mode and 3.3 × 10–13 m2/s under laser-assisted deposition.Item Model of Dispersed Phase Particle Distribution in a Composite Electrolytic Coating(Springer Science + Business Media, США, 2020) Tytarenko, Valentina V.; Zabludovsky, Vladimir A.; Shtapenko, Eduard Ph.EN: A model is proposed to evaluate distribution of dispersed phase particles in a composite metal coating. This model is based on calculation of degree of surface occupation by particles and their distribution in volume. Effective parameters applied for electrolytic composites evaluation at the microscale level were formulated, and method for the parameters evaluation was set out. It was shown that density of distribution and portion of particles with certain size in a coating depend on electrodeposition modes. Generation of higher-fine crystalline close-packed structures of coatings in conditions of pulse relative duration increase from 2 to 50 and unchanged current frequency 50 Hz is caused by both increase of oversaturation at the crystallization front that results in higher non-equilibrium process of crystallization and also by passivation effect of UDD particles on the surface which is formed. Non-equilibrium conditions of crystallization give rise to more intensive penetration of disperse phase particles with smaller size (~ 0.25–1 μm) into growing coating, decrease of microlayers thickness from 4 to 2 μm and increase of UDD particles concentration from 1.43 to 2.47 mas.%.Item Pulse Current Electric Rhodium Plating(Eugen G. Leuze Verlag, 2021) Shtapenko, Eduard Ph.; Zabludovsky, Vladimir A.; Tytarenko, Valentina V.; Garnich, Ruslan Ph.EN: The paper covers the study of the structure and properties of rhodium coatings obtained by pulse current from an aqueous electrolyte solution containing no surfactants. The authors determined the optimal parameters of the pulse current that forms finer-crystalline, dense and hard coatings. The use of pulse unipolar current made it possible to obtain high-quality rhodium coatings without the use of surfactants.Item Study of the Short-Range Order of Co-W Alloys Electrodeposited Using Pulse Current(Vasyl Stefanyk Precarpathian National University, 2023) Gerasimenko, Dmitriy; Tytarenko, Valentina V.ENG: Pulsed electrodeposition modes allowed to obtain amorphous Co-W alloys. Using X-ray phase and spectral analysis methods, it was established that the deposition modes and the concentration of the amorphizing component (sodium tungstate salts) in an aqueous electrolyte solution affect the amorphization of alloys. The short-range atomic order was studied by X-ray diffraction analysis and the sizes of the regions of ordered arrangement of atoms were determined in X-ray amorphous Co-W alloys obtained by pulsed electrodeposition. The radial distribution function of atoms was analysed. The assumption is made that cobalt and tungsten atoms combine into configurations that are irregular polyhedrons.