Aleksei Vozniakovskii

Dr. Aleksei Vozniakovskii

orcid

Research Focus & Metrics

Academic Career Length

8Years (2019-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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16 February 2022 in Nanomaterials
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AVAlexander Voznyakovskii
Alexander Voznyakovskii
AVAleksei Vozniakovskii
Aleksei Vozniakovskii
Sergey KidalovSergey Kidalov
Sergey Kidalov
For the first time, few-layer graphene (FLG) nanosheets were synthesized by the method of self-propagating high-temperature synthesis (SHS) from biopolymers (glucose, starch, and cellulose). We suggest that biopolymers and polysaccharides, particularly starch, could be an acceptable source of native cycles for the SHS process. The carbonization of biopolymers under the conditions of the SHS process was chosen as the basic method of synthesis. Under the conditions of the SHS process, chemical reactions proceed according to a specific mechanism of nonisothermal branched-chain processes, which are characterized by the joint action of two fundamentally different process-accelerating factors—avalanche reproduction of active intermediate particles and self-heating. The method of obtaining FLG nanosheets included the thermal destruction of hydrocarbons in a mixture with an oxidizing agent. We used biopolymers as hydrocarbons and ammonium nitrate as an oxidizing agent. Thermal destruction was carried out in SHS mode, heating the mixture in a vessel up to 150–200 °C at a heating speed of 20–30 °C/min and keeping at this temperature for 15–20 min with the discharge of excess gases into the atmosphere. A combination of spectrometric research methods, supplemented by electron microscopy data, has shown that the particles of the carbonated product powder in their morphometric and physical parameters correspond to FLG nanosheets. An X-ray diffraction analysis of the indicated FLG nanosheets was carried out, which showed the absence of formations with a graphite crystal structure in the final material. The surface morphology was also studied, and the IR absorption features of FLG nanosheets were analyzed. It is shown that the developed SHS method makes it possible to obtain FLG nanosheets with linear dimensions of tens of microns and a thickness of not more than 1–5 graphene layers (several graphene layers).

26 March 2020 in Journal of Composite Materials
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AVAleksei Vozniakovskii
Aleksei Vozniakovskii
Sergey KidalovSergey Kidalov
Sergey Kidalov
JOJ Otvalko
J Otvalko
ANAnna Neverovskaya
Anna Neverovskaya
This paper presents the results of a study of the strength and thermophysical properties of the composite material graphene nanoplatelets (GNP)–nitrile butadiene rubber (NBR) (GNP@NBR). High-quality GNP were massively produced by self-propagating high-temperature synthesis (SHS) method. It was found that the introduction of GNP in concentrations up to 6 wt.% leads to an increase in tensile strength up to 62%, resistance to tearing up to 64% thermal conductivity up to 2. The use of GNP allowed increasing the maximum operating temperature of the NBR to 125℃. Also, GNP@NBR composite showed an exceptional improvement in antifriction properties – it drops more than twice the coefficient of friction on steel under loads to 500 Newtons.

7 March 2022 in Nanomaterials
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AVAlexander Voznyakovskii
Alexander Voznyakovskii
ANAnna Neverovskaya
Anna Neverovskaya
AVAleksei Vozniakovskii
Aleksei Vozniakovskii
Sergey KidalovSergey Kidalov
Sergey Kidalov
A quantitative method is proposed to determine Stone–Wales defects for 1D and 2D carbon nanostructures. The technique is based on the diene synthesis reaction (Diels–Alder reaction). The proposed method was used to determine Stone–Wales defects in the few-layer graphene (FLG) nanostructures synthesized by the self-propagating high-temperature synthesis (SHS) process in reduced graphene oxide (rGO) synthesized based on the method of Hammers and in the single-walled carbon nanotubes (SWCNT) TUBAL trademark, Russia. Our research has shown that the structure of FLG is free of Stone–Wales defects, while the surface concentration of Stone–Wales defects in TUBAL carbon nanotubes is 1.1 × 10−5 mol/m2 and 3.6 × 10−5 mol/m2 for rGO.

1 May 2020 in Journal of Structural Chemistry
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AVAleksei Vozniakovskii
Aleksei Vozniakovskii
AVA. P. Voznyakovskii
A. P. Voznyakovskii
SKS. V. Kidalov
S. V. Kidalov
VOV. Yu. Osipov
V. Yu. Osipov
We propose a novel approach to prepare graphene nanoplatelets from cyclic biopolymers using self-propagating high-temperature synthesis. The synthesized graphene nanoplatelets have micrometer-scale linear sizes and extended specific surface areas (up to 620 m2/g). The number of nanoplatelets in a stack does not exceed five. The number of structural defects can be estimated by estimating the concentration of paramagnetic spins in graphene nanoplatelets using the EPR method. The properties of synthesized graphene nanoplatelets make them possibly applicable to be used as sorbents.

29 January 2023 in Materials
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Sergey KidalovSergey Kidalov
Sergey Kidalov
AVAlexander Voznyakovskii
Alexander Voznyakovskii
AVAleksei Vozniakovskii
Aleksei Vozniakovskii
STSofia Titova
Sofia Titova
YAYauheni Auchynnikau
Yauheni Auchynnikau
The results of studying the effect of particles of few-layer graphene (FLG) synthesized by self-propagating high-temperature synthesis (SHS) on the complex of strength and thermo physical properties of polymer composite products obtained by digital light processing (DLP) 3D printing are presented. It was discovered to achieve an increase in thermophysical and strength parameters of polymers modified by FLG compared with samples made on the unmodified base resin. This result was achieved due to low defectiveness, namely the absence of Stone–Wales defects in the structure of FLG due to the homogeneous distribution of FLG over the volume of the polymer in the form of highly dispersed aggregates. It was possible to increase hardness by 120%, bending strength by 102%, Charpy impact strength by 205%, and thermal conductivity at 25 °C by 572% at concentrations of few-layer graphene of no more than 2 wt. %.

3 March 2020 in Fullerenes, Nanotubes and Carbon Nanostructures
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AVAleksei Vozniakovskii
Aleksei Vozniakovskii
SKSergey Kidalov
Sergey Kidalov
AKAnatoly Karmanov
Anatoly Karmanov
LKLudmila Kocheva
Ludmila Kocheva
NRNatalia Rachkova
Natalia Rachkova
The technogenic human activities associated with the operation of nuclear power facilities lead to the contamination of natural water bodies and soils with radioactive substances, including heavy radionuclides, such as uranium and thorium. Purification of natural water bodies is a pressing environmental issue. A study of the adsorption capacity for heavy U238 and Th232 radionuclides by the samples of new carbon nanomaterials was conducted. Nanocarbon materials was synthesized based on vegetal polymers, such as technical lignin, starch and from lignocellulosic material—the bark. It was established that the investigated samples have different sorption indices in relation to radionuclides, which is determined by their chemical composition, as well as by the surface-capillary properties of carbonized materials. It is shown that the content of mobile and fixed forms of radionuclides on the investigated sorbents are significantly different. High sorption capacity of the carbonated lignin sample with respect to uranium are shown. A sample of nanocarbon materials synthesized based on the lignocellulosic complex of the bark exhibits high sorption properties in relation to thorium. The possibility of using the carbonic nanomaterial as the sorbents of radionuclides is shown.