The modification of the silicone compound with carbon nanotubes (CNTs) resulted in composites with improved physical properties and thermal stability. The carbon nanotubes were functionalized with  3-aminopropyltriethoxysilane for a more uniform distribution in the matrix. Initial and pre-oxidized CNTs containing different amounts of carboxyl groups were subjected to silanization. From 0.5 to 3 wt. % of the initial or functionalized CNTs were injected into Silagerm 2111 silicone compound. The obtained samples were characterized by FTIR and Raman spectroscopy and TG/DSC analysis. The silicon content in the silanized CNTs was determined by X-ray fluorescence spectroscopy. It was shown that the pre-oxidation of CNTs slightly affects the silicon content in the silanized nanotubes, which is up to (7.69 ± 0.92) wt. %. According to Raman mapping of the surface of silicone composites, the silanized CNTs are more uniformly distributed in the surface layer of the material than the original nanotubes. This effect has a positive effect on the physical-mechanical properties of the composites. CNTs functionalized by 3-aminopropyltriethoxysilane are 1.5 times more effective in increasing the electrical conductivity than the original CNTs. The resulting composites retain their mechanical characteristics after thermal exposure and can be operated over a wider temperature range than the original silicone compound.

The digital light processing method (DIGITAL LIGHT PROCESSING or DLP) is one of the most affordable 3D printing methods, which allows you to obtain high-precision products, which, however, are inferior in their characteristics to products obtained by other 3D printing methods. Due to their high characteristics, graphene nanostructures can solve this problem by acting as effective modifying additives. However, despite all the promise of this approach, the introduction of graphene nanostructures into actual practice has not yet occurred due to their high cost due to the imperfection of the methods of their synthesis. The paper considers the effectiveness of using few-layer graphene synthesized according to the author's method under conditions of self-propagating high-temperature synthesis from cellulose as a modifying additive to improve the complex strength and thermophysical properties of products from photopolymer resins obtained by DLP 3D printing. It was found that adding few-layer graphene makes it possible to increase Brinell hardness up to 1.8 times, bending strength up to 1.5 times, and thermal conductivity up to 2.2 times compared to the original polymer when using no more than two wt. % few-layer graphene.The data obtained indicate the high efficiency of the synthesized few-layer graphene as a modifying additive in creating products from photopolymer resins using the DLP 3D printing method. 

In this paper, the properties of electrochemical sensor made of screen-printing technology application with graphite-base paste were investigated. The main electrically conductive component in the original paste developed in this study is exfoliated graphite. The electrodes were studied using optical and scanning electron microscopy methods to confirm the quality and integrity of the screen-printing process results. Electrochemical measurements (chronoamperometry and cyclic voltammetry) of printed electrodes show that the performance of this exfoliated graphite-based paste is similar to that of a commercially available graphite paste despite the radically lower content of carbon.  The biosensor prototype manufactured in this work is characterized by anisotropic surface morphology formed by mixed carbon black with milled carbon particles (exfoliated graphite and microcrystalline graphite). This prototype has a very good linearity of response to glucose in a wide range from 1 to 40 mM, while manifesting the values of currents and sensitivity comparable to a commercially available analogue. 

Solid solutions of Ca₁₀(PO₄)₆(OH)_2–xFx, x = 0.0; 0.2; 0.5; 1.0; 1.5; 2.0 were obtained by reacting Ca₁₀(PO₄)₆(OH)₂, Ca₃(PO₄)₂ and СаF₂ in the course of a solid-state synthesis reaction at 1200 °C for 3 h in air. Synthesis products were identified using X-ray phase and X-ray fluorescence analysis, infrared and impedance spectroscopy. According to the results of X-ray phase analysis, the synthesized solid solutions had the structure of hexagonal apatite, the extreme members of the series of solid solutions corresponded to the JCPDS standards (Ca₁₀(PO₄)₆(OH)₂ – No. 9-0432; Ca₁₀(PO₄)₆F₂ – No. 00-003-0736). Vibrational spectra of solid solutions corresponded to the apatite structure with characteristic absorption bands of tetrahedra of РО₄^3–, ОН^– groups. An increase in the fluorine content in solid solutions was accompanied by a typical shift of the 631 cm^–1 band to the region of large values of wave numbers, and its intensity successively decreased. With an increase in the fluorine content in solid solutions at a frequency of 1 kHz, the dielectric loss tangent did not undergo significant changes, and the permittivity slightly decreased. Based on the results of physicochemical analysis, the fundamental relationships “composition – structure – properties” for the studied synthesis products were determined. The influence of the composition and synthesis conditions on the crystallographic (elementary cell parameters) and electrical (dielectric permittivity, dielectric loss tangent, conductivity) characteristics of the synthesized solid solutions was assessed. Solid solutions of fluorine-substituted calcium hydroxyapatite are promising for use in medical practice. 

In the article, the purpose of the research was to determine the important parameters of the organic compounds sorption – synthetic dyes methylene blue (MB) and malachite green (MG), on mesoporous carbon (MPC) from aqueous solutions in a limited volume. For the sorbent used, the elemental composition and the BET surface area were determined by nitrogen adsorption, which amounted to 2360 m²⋅g^–1. Absorption mechanisms were analyzed using kinetic dependences and sorption isotherms, for which empirical equations of pseudo-first and -second order, the Elovich equation and the intraparticle diffusion equation, as well as Langmuir, Freindlich, Dubinin-Radushkevich equations were used. In the course of kinetic studies, it was found that equilibrium occurs after 15 min of extraction with an adsorption capacity of 2446.6 mg⋅g^–1 for MB and 2043.1 mg⋅g^–1 for MG. It should be noted that the extraction of dye molecules proceeded predominantly by a mixed-diffusion mechanism and was controlled by a second-order reaction by a pseudo-second order model. The activation energy was 0.016 kJ⋅mol^–1 for MG molecules, and 0.013 kJ⋅mol^–1 for MB ones, which confirmed the physical mechanism of dye uptake. Thus, in the course of experimental studies, the high efficiency of the developed sorbent for the purification of aqueous systems from organic compounds was confirmed. 

The present paper examines the state of pollution of soils in the city of Tyumen regarding heavy metals contained therein: nickel (Ni), cobalt (Co), manganese (Mn), copper (Cu), cadmium (Cd), lead (Pb) and chromium (Cr). Soil sampling was carried out in autumn 2021 within the city residential areas. The sampling points were chosen in the sites of increased anthropogenic load – near highways and industrial enterprises. In soil samples, the content of acid-soluble and mobile fractions of heavy metals and organic matter was determined, and the pH factor was also measured. The analysis showed that significant excesses, from 3.2 to 14.3 MPC level, were found on nickel in 11 soil samples, and all the soil samples belong to the zones of motor transport impact. In one sample, No. 29, which belongs to the impact zone of such large industrial enterprises as the Elektrostal Tyumen Metallurgical Plant (Ural Mining and Metallurgical Company-Steel, UMMC Steel) and the Motor Plant, the MPC for nickel was exceeded by 8.1 times. There were also excesses in the copper contents in 11 samples, from 1.5 to 4.9 MPC, and in both the zones of motor transport impact and the territories affected by the building materials enterprises, railway junction, and UMMC Steel. For lead, there was a two-times excess in two samples  in the zone of motor transport impact, 4.4 times  – in the impact zone of the Construction Machinery Plant, and 29.7 times  – in the zone of impact of Velizhansky Highway. For cobalt, chromium and manganese, the MPC values for the acid-soluble fractions were not exceeded. For the mobile fractions, excesses were also observed for manganese. The highest excesses of the MPC level for nickel and copper were found in the Vostochny (Eastern) and Central districts of the city, in the areas affected by motor transport and the large enterprises. 

The review is devoted to the current state of research and achievements in the field of modification of lubricants. To improve the tribological characteristics of lubricants, various additives, in particular, nanoparticles, are used. These additives avoid direct contact, reduce friction and wear. Given that graphene significantly improves the tribological characteristics of lubricants, the main methods for its production are considered. It is shown that the most promising technology for obtaining graphene to modify lubricants is liquid-phase shear exfoliation of crystalline graphite, since oil mixtures with nanoplates are evenly distributed in grease and ensure its stable operation in friction pairs. A variant of mixing graphite nanoplates with grease in a rotary disperser is considered. It is shown that, along with an increase in tribological characteristics, the lubricant modified with graphite nanoplates creates an antifriction film on friction surfaces. The compositions of the antifriction film and the results of its use are analyzed. The ways of improving the technology of modifying greases with graphite nanoplates are outlined. First of all, it is necessary to modernize the main equipment:  a drum rod mill; node for classifying graphene-containing suspensions according to the nanoplates size; rotary disperser. Considering that the maximum effect is observed when using an antifriction film + grease modified with graphite nanoplates, it is necessary to study in detail the antifriction film formation and determine its optimal content in the lubricant.