A hierarchical filler was synthesized by growing multi-walled carbon nanotubes (MWCNTs) on aluminosilicate fly ash cenospheres (FACs). The process involved depositing a uniform ferromagnetic Fe catalyst layer (55 nm) via magnetron sputtering, followed by the chemical vapor deposition of a dense MWCNT array (50-60 nm diameter). Composite samples containing 20 wt.% of this filler in a polyurethane matrix were prepared. Their microwave properties were characterized by measuring the scattering parameters (S-parameters) over the 1-13 GHz frequency range. Subsequently, the complex permittivity and permeability were extracted from the Sparameter data using the Nicolson-Ross-Weir algorithm. The results reveal that MWCNTs introduce significant resistive losses (increased epsilon''), while the annealed Fe layer tunes the magnetic response. This dual-component modification enables independent tuning of the composite's dielectric and magnetic properties. Our study demonstrates a scalable method for transforming low-cost industrial by-products into lightweight, functional materials with tailorable electromagnetic characteristics.

The article is devoted to the study of the effect of the power, pressure, and deposition time in the magnetron sputtering process on the initial properties of graphene, produced via chemical vapor deposition. Sn-graphene composites were obtained by depositing a 5 nm thick tin coating onto CVD-graphene. The working gas pressure was varied from 1 to 8 Pa, and the target power ranged from 4 to 16 W. The resulting materials were characterized using scanning electron microscopy (SEM), energy dispersive X-ray analysis (EDAX), and Raman spectroscopy. The resistance of graphene before and after deposition was also determined. Based on the analysis of the structural and electrical properties, the possibility of obtaining a composite without significant alteration of the graphene structural properties was established. It was also shown that defect formation in graphene is influenced both by the characteristics of the sputtered flux, defined by power and pressure, and by the deposition time. An increase in the defect density correlates with longer deposition times and with a decrease in the coating growth rate.

When methane hydrate was formed from a water droplet on a graphene substrate, a hydrate film initially appeared on the free water surface and then slowly grew across the graphene surface to completely or partially cover the entire visible graphene surface. Water for film growth came from the film-covered droplet and caused collapse of the initially formed hydrate film. These observations explained the mechanism by which graphene and graphite promoted gas hydrate nucleation.

This article explores the application of high-power impulse magnetron sputtering (HPIMS) with an additional discharge generated by a small anode to synthesize titanium dioxide coatings. The effect of resputtering on film porosity is examined. The films were annealed at 500°C in air and nitrogen to obtain the crystalline anatase phase. The effect of the additional discharge on the charged particle current to the substrate is examined. Differences in coating porosity are identified. The dimensions of the coherent scattering region (CSR) were measured and found to be comparable to the film thickness. Microstress and Urbach energy values were also calculated, and an analysis of the correlation between these parameters for porous coatings was performed.

A resonator on a locked mode in a transcendental (evanescent) waveguide is presented. The resonator contains a segment of a cylinder mounted in a circular waveguide coaxially with its inner surface. The electromagnetic field was localized near the cylinder and a resonance was excited at a frequency of 4 GHz on the TEM oscillation mode. The cutoff frequency for the lowest ТЕ11 mode in the selected waveguide was 7 GHz; therefore, at lower frequencies, the electromagnetic wave could not propagate along the waveguide and the locked TEM mode was implemented. The main losses are concentrated in the cylinder, thus making it possible to use this resonator to study the effect of modification of the cylinder surface on its Q factor. The paper describes the method of using such a resonator for this purpose and presents the results of a study of the effect of annealing and graphene coating of the copper surface on its properties. Graphene was synthesized on copper by the method of chemical deposition from the gas phase (CVD).

The task of developing new nanomaterials for effective water purification is currently extremely urgent. Here we demonstrate a method of synthesis of highly efficient, magnetic catalysts based on manganese, iron, cobalt and zinc oxides using the plasma-arc method. Due to the large number of contact zones between different types of semiconductor materials, such photocatalysts are extremely efficient. By changing the pressure in the synthesis chamber in the range from 5 Torr to 50 Torr, as well as the annealing temperature of nanoparticles in a muffle furnace in the range from 150 degrees & Scy; to 800 degrees & Scy;, the properties of the catalysts can be changed over a wide range of values. It has been shown that the catalyst Mn3O4@Fe2O3@CoO@ZnO@graphite is the most effective for the decomposition of methylene blue in the presence of hydrogen peroxide and UV exposure. This catalyst was synthesized at pressure 5 Torr and annealing temperature 600 degrees & Scy;. This catalyst has magnetic properties, so it can easily be separated from the system using a magnetic field. Due to the presence of a porous carbon layer on the outer surface of catalytic nanoparticles, their properties do not change during storage. In a solution of hydrogen peroxide, nanoparticles form microscopic clusters that are capable of moving under the influence of selfdiffusiophoresis, as well as magnetic force in a non-uniform magnetic field. Due to the mobility of the catalyst, mass transfer processes during wastewater treatment can be significantly intensified.

This paper presents a straightforward and easily scalable method for producing buckypapers. These thin films consist of single-walled carbon nanotubes (SWCNTs) dispersed on a PET substrate using an airbrushing technique, followed by solvent evaporation. Notably, this process requires minimal equipment complexity. The study investigates the electrical properties of buckypapers made from both purified and unpurified SWCNTs, as well as chemical vapor deposition graphene. Specifically, we focus on their electromagnetic interference (EMI) shielding effectiveness in theS-band of microwaves (2-4 GHz). To evaluate this, we installed buckypaper and graphene plates within a waveguide cross section. The results show that these buckypapers exhibit high overall shielding effectiveness. It is found that buckypapers based on purified carbon nanotubes have higher shielding parameters (due higher electrical conductivity measured by TRL method) than those based on unpurified CNTs. In summary, our approach offers a practical route for manufacturing effective EMI shielding materials, with potential applications in various technological domains.

This article discusses the synthesis of hollow Al2O3 nanoparticles via electric arc spraying and subsequent material calcination in air. The effect of buffer gas pressure on the size and thickness of the synthesised hollow nanoparticle enclosure is investigated. Based on experimental data and numerical modelling data for the respective processes, a mechanism for the formation of various-sized nanoparticles based on changes in the residence time of carbon is proposed.

This work is devoted to the study of barrier properties of graphene coating against hydrogen permeation into E110 zirconium alloy. For the first time, the kinetics of hydrogen absorption by the graphene-coated zirconium alloy with a single-layer graphene coating obtained by chemical vapour deposition (CVD) is studied in this work. It was shown that the graphene coating exhibits barrier properties and reduces hydrogen absorption rate by E110 zirconium alloy in the temperature range (350-550)degrees C. The activation energy for hydrogen absorption was reduced from 72 to 61 kJ/mol. Phase transformations in zirconium alloy during hydrogenation can result in degradation of protective properties of graphene coating.

The wettability, evaporation droplets, and corrosion were experimentally studied for textured copper samples with graphene and smooth copper samples with fluorographene. With increase in the fluorination time, the wettability on fluorographene surfaces grew. Textured graphene surfaces have shown the maximum starting contact angle of 93°. Unlike smooth surfaces with graphene, the textures had a more stable contact line. With the fluorination time increase from 20 to 240 hours, inhomogeneous structures were formed on the surface of fluorographene, which led to roughness increase 2.6–2.7 times. With longer fluorination of graphene, the corrosion current became higher, which is associated with the defectiveness and high hydrophilicity of the surface. With longer fluorination time, the corrosion current became 1.6 times higher. As (EDS) analysis showed, corrosion led to about 10 to 15-fold decrease in the amount of fluorine on fluorographene. The highest anti-corrosion properties were demonstrated by a copper sample subjected to laser texturing, on which several layers of graphene were synthesized.

Fly ash cenospheres serve as an inexpensive filler for various composites. Coating their surface with metal significantly alters the properties of the resulting composites. In this study, aluminosilicate cenospheres receive a copper coating using a plasma method with magnetron sputtering. Based on these copper-coated cenospheres, composites are created, and their dielectric properties are investigated in a parallel plate capacitor cell under isotropic pressures ranging from 1 to 75 atm. Composites based on pure fly ash cenospheres exhibit pressure-invariant properties, including the dielectric constant and loss factor. However, for composites based on copper-coated fly ash cenospheres, an abrupt increase in electrical conductivity is observed as the pressure increases. Interestingly, significant changes in electrodynamics characteristics are not detected under the influence of anisotropic stress. The methodology tested in this work can be utilized for creating smart materials based on cenospheres.

To date, the use of graphene in photodetecting devices has attracted great attention, since due to the absence of a band gap and the linear law of dispersion of free charge carriers, graphene has a wide range of photon registration and fast response time. However, due to the low amount of incident light absorption by graphene, the efficiency of graphene devices is limited, so improving the efficiency of light absorption remains one of the key tasks. In this paper, we present a method for enhancing the photoresponsivity and external quantum efficiency of graphene based on modification of the graphene surface by highly lightabsorbing titanium nanoparticles by magnetron sputtering.

When manganese-based catalytic micromotors move, gas bubbles are not responsible for their movement.

The possibility of using the magnetron sputtering method for graphene surface functionalization is studied. In this work, the HiPIMS method was used to obtain tin oxide nanoparticles on the CVD-graphene surface. Samples with varying sputtering time of 5-30 seconds were obtained. The results of XRD and SEM showed that particles with average sizes of 6.6, 7.4, and 58 nm were obtained. The phase associated with tin oxide, being observed for the composite, was deposited for 30 s. Raman spectra of light scattering are analyzed and the variation in vibrational properties of graphene is discussed. The sensory properties of the composite on NO2 are also discussed in the paper.

Wastewater pollution with organic compounds poses a serious threat to human health. One of the possible methods for solving these problems can be the use of micro/nanomotors. Among them, manganese-based micro/nanomotors have a number of important advantages related to high catalytic activity, powerful motion, and low cost. Due to their mobility, micro/nanomotors promote an increase in the intensity of mass transfer in the reacting system. When introducing ferromagnetic elements into manganese-based micro/nanomotors, it is possible not only to increase their motion speed, but also to make their motion more controllable. Herein, for the first time it demonstrates a synthesis method for MnFe2O4@Fe3O4/graphite and Mn2O3@Fe2O3@Fe3O4/graphite magnetic catalytic micromotors, which have remarkable photocatalytic properties. Micromotors are clusters of nanoparticles whose motion in a hydrogen peroxide solution in a non-uniform magnetic field is caused by the action of magnetic force and self-diffusiophoresis. Nanoparticles are synthesized by the plasma-arc method with subsequent annealing in the air. When changing the annealing temperature, the catalytic and magnetic properties of nanoparticles can vary within a wide range of values. Micromotors MnFe2O4@Fe3O4/graphite have the most optimal catalytic and magnetic properties. The results of the research show that these micromotors are effective catalysts in the decomposition of methylene blue.

Уважаемые коллеги!Благодарим Вас за проявленный интерес к Четвертой российской конференции «Графен: молекула и 2D кристалл» и желание принять участие в её работе.Конференция проходит в научно-образовательном центре города Новосибирска -Академгородке.Мероприятие посвящено актуальным направлениям исследований и разработок в области углеродных и низкоразмерных материалов.Проведение конференции поможет координации усилий ученых в решении современных проблем материаловедения и привлечению молодых исследователей для решения актуальных научных задач.Оргкомитет выражает особую благодарность НГУ, Центру компетенций НТИ «Моделирование и разработка новых функциональных материалов с заданными свойствами», компаниям «Диаэм», «НТ-МДТ Спектрум Инструментс» и корпорации "Графеновая Долина" за финансовую поддержку и журналам Аналитика, Наноиндустрия и РЭНСИТ за информационную поддержку.Искренне надеемся, что пребывание в Новосибирском Академгородке и в стенах Новосибирского государственного университета оставит множество положительных эмоций и

This work is devoted to experimental and theoretical studies of the sputtering of electrodes in an arc discharge. The temperature distribution in the working chamber during arc discharge is analyzed depending on the discharge current. On the basis of experimental data on the anode sublimation and interelectrode distance, a fan jet is simulated, which is generated during the anode sputtering in an arc discharge. The calculation is carried out using the model describing the processes occurring in the arc plasma, jet propagation, transport of particles by the jet and their ionization. The numerical simulation results for the radial temperature distribution are consistent with the experimental data. The experiments show that an increase in the discharge current leads to an increase in the concentration of fullerenes and graphite structures in the soot. Based on the simulation data, it is shown that this effect is a result of the longer residence time of growing carbon particles in a high-temperature zone (1000-2800 K) at high arc discharge currents.

The paper is the study of electric resistance of a graphene layer washed by a liquid with different flow rate parameters. Experiments demonstrate that if the fabricated composite (graphene upon a PET/EVA polymeric substrate) is submerged into distilled water, the sample resistance increases by 120 %. Meanwhile, the flow of liquid near the graphene layer decreases this gain in the electric conductivity. The effect offers a general design of a flow rate sensor based on the graphene layer taken as a flow-sensitive matrix. The study demonstrates that this design of graphene flow sensor (tested for distilled water) exhibits a linear dependency of the sensor resistance on the flow rate.

Уважаемые коллеги!Благодарим Вас за проявленный интерес к Четвертой российской конференции «Графен: молекула и 2D кристалл» и желание принять участие в её работе.Конференция проходит в научно-образовательном центре города Новосибирска -Академгородке.Мероприятие посвящено актуальным направлениям исследований и разработок в области углеродных и низкоразмерных материалов.Проведение конференции поможет координации усилий ученых в решении современных проблем материаловедения и привлечению молодых исследователей для решения актуальных научных задач.Оргкомитет выражает особую благодарность НГУ, Центру компетенций НТИ «Моделирование и разработка новых функциональных материалов с заданными свойствами», компаниям «Диаэм», «НТ-МДТ Спектрум Инструментс» и корпорации "Графеновая Долина" за финансовую поддержку и журналам Аналитика, Наноиндустрия и РЭНСИТ за информационную поддержку.Искренне надеемся, что пребывание в Новосибирском Академгородке и в стенах Новосибирского государственного университета оставит множество положительных эмоций и

Wettability of textured surfaces of copper and carbon substrates is under study. It is revealed that the geometric parameters of the textures being created (e.g., depth and regularity) significantly affect the surface lyophilicity and the manner in which a water droplet spreads and moves. The contact angles obtained experimentally are consistent with the angles obtained via molecular dynamics simulations.