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卷 59, 编号 6 (2025)
GENERAL QUESTIONS
STRUCTURE AND REACTIVITY OF CELLULOSE UNDER MICROWAVE EXPOSURE
摘要
Optimization of the structure of cellobiose and cellodextrose using quantum chemistry methods has been carried out. Energy profiles of the initial stages of bond breaking in the cellobiose molecule have been calculated using the relaxed scanning method. The Morse potential was used to estimate the dissociation energies and equilibrium bond lengths. The average dissociation energy of bonds in the cellobiose molecule increases in the following order: O–H, C–OC, C(cycle)–C(cycle), C(cycle)–C, C(cycle)–OH, C–H, C(cycle)–H, C–OH. The largest deviation from the mean value is observed for the hydroxyl group (relative deviation is 6%). Experimental study of the effect of microwave radiation on microcrystalline cellulose revealed a decrease in the number of hydroxyl groups in the solid product.
High Energy Chemistry. 2025;59(6):375-381
375-381
ФОТОКАТАЛИЗ
EFFECT OF ULTRAVIOLET IRRADIATION ON THE PROPERTIES OF TITANIUM DIOXIDE AND PLATINUM-BASED CO CATALYST DEPOSITED ON POROUS NICKEL
摘要
A CO catalyst based on TiO2 with 12 wt% Pt platinum clusters has been synthesized. The catalyst was investigated by SRD and XRD methods. The catalyst was deposited on porous nickel. The effect of UV radiation on the catalytic properties was investigated and long-term tests were carried out for 180 days. It was found that UV radiation increases the reaction rate of CO oxidation by 3 times, decreases the activation energy of the reaction rate constant and increases the long-term stability of the catalytic properties. The activation energy of the reaction rate constant in the temperature range from 283 to 313 K was determined to be 23 ± 1 kJ/mol under UV illumination of the catalyst. The catalyst can be used in photocatalytic air purifiers.
High Energy Chemistry. 2025;59(6):382-388
382-388
RADIATION CHEMISTRY
EFFECT OF GAMMA IRRADIATION DOSE ON THE STRUCTURE OF POLYVINYL CHLORIDE POWDER
摘要
FT-IR spectra of polyvinylchloride subjected to γ-irradiation have been investigated. During γ-irradiation of the polymer in air, radiation-chemical processes occur leading to the formation of carbonyl groups, unsaturated bonds, and hydroxyl groups, which introduces significant changes in its FT-IR spectrum. Their content in the irradiated polymer depends on the γ-irradiation dose, and with increasing irradiation dose, a gradual increase in the intensity of the absorption bands of the above groups is observed, with the greatest increase with irradiation dose in the intensity of the absorption band of carbonyl groups. In the IR spectra of vacuum irradiated polyvinyl chloride a low-intensity broad absorption band of radiolysis products with unsaturated bonds appears. Their content in the irradiated polymer macromolecule increases with the irradiation dose, at the same time, the content of chlorine-containing bonds decreases with the irradiation dose. The general appearance of the IR spectra of polyvinyl chloride is strongly influenced by the presence of gaseous water molecules in the polymer sample under study, and also the relative intensities of individual IR absorption bands differ in samples of different grades of industrial polymer.
High Energy Chemistry. 2025;59(6):389-397
389-397
PARAMAGNETIC CENTERS STABILIZING IN RADIOLATED POLYSTYRENE
摘要
Low-temperature radiolysis of polystyrene has been investigated by EPR method. The accumulation of stabilized electrons, radical pairs, and at doses >100 kGy – radical structures formed by two reactions – detachment and attachment of atomic hydrogen – has been traced. In the course of radiolysis at 77 K, the reaction of H addition to the double bonds of phenyl groups prevails with the formation of two isomers of cyclohexadienyl radicals (radiation yield 0.25 per 100 eV). The formation of diphenyl cyclohexadienyl radical structures with a 5-component EPR spectrum (STR constant, α = 4.5 mTl) was detected for the first time at doses above 2000 kGy. The spectra of two unknown radicals were detected and identified: breakaway radicals at the α-carbon atom of the polymer chain ~CβH2−Cα·(Ph)−CβH2− and addition radicals at the α-carbon atom ~CαH(Ph)−Cβ·(OH)−CαH(Ph)~. Quantum chemical calculations of the radical structures of cyclohexadienyl radicals showed satisfactory agreement between the calculated and experimental data.
High Energy Chemistry. 2025;59(6):398-403
398-403
PLASMA CHEMISTRY
INFLUENCE OF PLASMA REACTOR MODES ON THE PROCESS OF ASPHALT-RESIN-PARAFFIN DEPOSITS PROCESSING
摘要
The paper presents the results of a comprehensive study of transformation of asphalt-resin-paraffin deposits (ARPD) into carbon materials (CM) using an electric arc plasma reactor. The experiments were conducted at different treatment modes – current intensity (75–125 A) and arc discharge initiation time (5–30 s) at atmospheric pressure. Methods of X-ray diffractometry, IR spectroscopy, differential thermal analysis, X-ray fluorescence analysis, laser diffraction, and scanning electron microscopy were used in the study of the initial sample of ARPD and its products. It is established that optimal conditions of plasma processing (100–125 A, 25–30 s) provide almost complete destruction of organic matrix of ARPD with formation of graphite-like carbon structure characterized by a high degree of order and heat resistance. The presented results confirm the technological possibility of electric arc plasma processing of ARPD at atmospheric pressure as a method of simultaneous utilization of oil wastes and obtaining promising carbon materials.
High Energy Chemistry. 2025;59(6):404-417
404-417
COMPARISON OF OXIDIZING CAPACITY OF NON-THERMAL PLASMA AND IONIZING RADIATION USING EPR SPECTROMETRY
摘要
Oxidative processes during exposure of crystalline sucrose samples to non-thermal argon plasma were investigated for the first time. The aim of the work was to compare the oxidizing abilities of non-thermal plasma and gamma radiation when exposed to sucrose using EPR spectrometry. The EPR signal intensity was found to increase with increasing plasma treatment time, indicating the presence of oxidative processes and free radical formation. A decrease in the signal intensity was observed with the passage of time. On average, the signal intensity decreased by 9% at week 1, 13% at week 3, 15% at week 11 and 22% at week 22 relative to the untreated sample. Based on the data obtained, a comparative analysis was performed on the amount of free radicals formed in sucrose (carbon-centered) during treatment with non-thermal plasma and gamma radiation.
High Energy Chemistry. 2025;59(6):418-424
418-424
PLASMA CHEMICAL SYNTHESIS OF METHANOL IN A BUBBLE REACTOR WITH METAL MELT
摘要
The results of modeling of nonequilibrium radical-chain synthesis of methanol in a bubble reactor with a metallic melt are presented. Modeling was performed for a mixture of methane and oxygen (O2 concentration 10–30 vol %) at pressure 10–40 atm, initial temperature 800–900 K and radical concentration CH3 0.1–0.5 vol %. It was obtained that heat removal during exothermic reactions in the bubbles of the bubble reactor prevents the temperature rise, providing an increase in methanol yield up to 22%. Modeling of radical generation in gas discharge is performed.
High Energy Chemistry. 2025;59(6):425-433
425-433
TRANSSONIC PLASMA SYSTEM FOR WATER DISINFECTION
摘要
The efficiency of transonic plasma system application for water purification to biologically clean water is experimentally demonstrated. The method is based on the formation of a high-speed two-phase flow with a double transition through the sound barrier with plasma generation in the supersonic flow zone. The first transition is caused by the formation of supersonic flow due to the formation of a two-phase gas-liquid mixture. The second transition is caused by a sharp deceleration of the two-phase flow and formation of subsonic single-phase flow regime, which is accompanied by a jump-like increase in static pressure and local generation of ultrasonic field; electromagnetic field; electrostatic field, etc. The experiments were conducted immediately after water intake from the Moskva River and with a week's cultivation of microorganisms in a cube tank at a temperature of 15-22°. After treatment, all tested samples met the quality indicators "drinking water" according to SanPiN 2.1.4.1074-01.
High Energy Chemistry. 2025;59(6):434-439
434-439
НАНОДИСПЕРСНЫЕ СИСТЕМЫ И МАТЕРИАЛЫ
CONFORMATIONAL CHANGES IN THE STRUCTURE OF ADSORBED POLYELECTROLYTE CHAINS ON THE CHARGED SURFACE OF A SPHERICAL NANOPARTICLE
摘要
The structure rearrangement of polyelectrolyte shell on the surface of a charged spherical nanoparticle is investigated by methods of statistical theory of macromolecules and molecular dynamics. A mathematical model of conformational changes of adsorbed polyelectrolyte on the surface of a spherical nanoparticle is presented, and radial dependences of the concentration of macrochain links depending on the sign and magnitude of the nanoparticle charge are obtained. Molecular dynamic modeling of polypeptides with different degrees of polyelectrolyte on the surface of a charged spherical gold nanoparticle was performed. When the absolute value of the opposite sign charge on the spherical nanoparticle increased with respect to the charge of the macrochain, the polyelectrolyte shell at the surface of the nanoparticle was dense, while a loose layer of neutral macrochain links was formed at the periphery. On the uniformly charged surface of the spherical nanoparticle, the polyelectrolyte shell gradually swelled with increase in the absolute value of the nanoparticle charge and desorbed the earlier the higher the degree of polyelectrolyticity of the macrochain was.
High Energy Chemistry. 2025;59(6):440-450
440-450
ЛАЗЕРНАЯ ХИМИЯ
STRUCTURAL FEATURES OF POLYVINYL ALCOHOL FILMS FORMED FROM AQUEOUS SOLUTION UNDER THE INFLUENCE OF LASER IRRADIATION OF VISIBLE WAVELENGTHS
摘要
By the method of differential scanning calorimetry (DSC) it is shown that films of polyvinyl alcohol (PVA) obtained from aqueous solution under the action of laser irradiation of visible wavelengths (445, 532 and 650 nm) have different structural organization, which significantly affects their electrical conductivity and thermal stability. The dependence of the activation energy of change in the specific electrical conductivity of films on the enthalpy of melting, which is determined by the wavelength (frequency) of laser exposure during the formation of films, has been found.
High Energy Chemistry. 2025;59(6):451-458
451-458
MOLECULAR PHOTONICS
QUANTUM-CHEMICAL STUDY OF THE PENTAFLUORINATED DYE BORON DIFLUORIDE DIBENZOYLMETHANATE AND ITS EXCIPLEXES WITH BENZENE AND TOLUENE ON SILICA SURFACE
摘要
TDDFT calculations of 5F-DBMBF2 exciplexes with benzene and toluene in the gas phase and on the silica gel surface were performed. The formation energies of exciplexes and adsorption energies of the dye on silica gel, as well as the transition wavelengths in the fluorescence spectra of isolated and adsorbed exciplexes were calculated. The presence of different in magnitude and oppositely directed spectral shifts upon the adsorption of DBMBF2 and 5F-DBMBF2 exciplexes on silica was shown. The values of of Mulliken charges on atoms, electron density transfer in the exciplexes, and its change upon the adsorption of the exciplexes on silica were calculated. It is shown that the introduction of fluorine atoms as a strong acceptors, into the DBMBF2 molecule leads to an increase in the interaction energy of the dye molecule with the silica surface and in the energy of formation of the exciplexes, increases electron density transfer in the exciplexes and the bathochromic shift of the exciplex fluorescence spectrum compared to the spectrum of the free dye. Calculations predict an extremely weak hypsochromic shift in the fluorescence spectra of 5F-DBMBF2 exciplexes with benzene and a weak bathochromic shift in the spectra of 5F-DBMBF2 exciplexes with toluene upon adsorption on silica.
High Energy Chemistry. 2025;59(6):459-466
459-466
КРАТКИЕ СООБЩЕНИЯ НАНОДИСПЕРСНЫЕ СИСТЕМЫ И МАТЕРИАЛЫ
THIOACETAMIDE SOLUTION IN TRIBUTYLPHOSPHATE AS A SULFUR PRECURSOR FOR THE SYNTHESIS OF MONODISPERSE LEAD SULPHIDE QUANTUM DOTS
High Energy Chemistry. 2025;59(6):467-470
467-470