No 4 (2025)
Synthesis, structure and properties of complex compounds
Vibrational spectroscopy study of complex gallium(III) fluorides with amino acid glycine
Abstract
The Gly–GaF3·3H2O–H2O(HF) system was studied by vibrational spectroscopy methods. A number of complex gallium(III) fluorides were obtained: (GlyH)3[GaF6], (GlyH)(Gly···GlyH)[GaF5(H2O)]·H2O, (GlyH)6[GaF5–F–GaF5]·F and (GlyH)[GaF4(H2O)2·0,5H2O.The vibrational (IR, Raman) spectra of the obtained compounds were analyzed, and band assignments were made. A distorted octahedral structure of the anions was established in the structures of all the obtained compounds, with the outer-sphere glycine cations being in the protonated state, with the outer-sphere glycine cations being in the protonated state.
Vestnik of the Far East Branch of the Russian Academy of Sciences. 2025;(4):5-18
5-18
Physical chemistry of surface and nanosized systems
Characteristics and properties of TiO2–SiO2–Bi coatings on titanium formed by plasma electrolytic oxidation
Abstract
Film composites Ti/TiO₂–SiO₂–Bi were formed by the method of one-stage pulsed plasma electrolytic oxidation (PEO). The obtained samples were studied by the methods of X-ray phase analysis, energy-dispersive analysis, electron microscopy, diffuse reflectance and impedance spectroscopy. X-ray phase analysis showed that all PEO coatings contain metallic bismuth and titanium oxide in the modifications of rutile and anatase. It is shown that a change in the pulse duration has a significant effect on the morphology, elemental composition and optical properties of the coatings. Analysis of the Mott–Schottky diagrams showed that all the obtained composites are n-type semiconductors. For all bismuth-modified samples, a shift in the potentials of flat bands to the cathode region is observed compared to the unmodified sample, which indicates the formation of a Schottky barrier at the metal-semiconductor interface. The number of charge carriers (Nd) increases with increasing PEO pulse duration, but in all cases it is lower compared to the Ti/TiO2sample.It was found that modification of titanium dioxide films with bismuth leads to an improvement in their optical properties and the emergence of stable photocurrents under the action of visible light.
Vestnik of the Far East Branch of the Russian Academy of Sciences. 2025;(4):19-27
19-27
Effect of cerium compounds in hybrid polymer-containing coatings on the corrosion activity of magnesium and its alloys
Abstract
The paper presents a method for forming a hybrid protective coating on MA8 alloy formed by plasma electrolytic oxidation (PEO) with subsequent impregnation of the resulting heterooxide layer with cerium compounds and biopolymer treatment. The coating has a developed surface and contains magnesium, oxygen, calcium and phosphorus, which imparts bioactive properties to it. The introduction of cerium nitrate into the coating increases corrosion resistance without damaging the coating structure. Electrochemical studies (PDP and EIS) confirmed a significant improvement in the protective properties of hybrid coatings: the GP-NC01 sample demonstrates a 5,9-fold decrease in the corrosion current density and a 22-fold increase in polarization resistance compared to the base PEO coating. Volumetric tests revealed a 4-fold decrease in the volume of released hydrogen after 7 days of exposure to NaCl. The highest inhibitor efficiency (83%) was achieved for samples with a hybrid coating, which confirms the promise of a combined approach for protecting magnesium alloys.
Vestnik of the Far East Branch of the Russian Academy of Sciences. 2025;(4):28-39
28-39
Electrochemical Formation of Polymer/Gold and Platinum Nanoparticle Nanocomposites
Abstract
The mechanism of electrochemical formation of a nanocomposite based on polymethylolacrylamide with inclusion of gold and platinum nanoparticles was studied using chronoamperometry and impedance spectroscopy. It was found that the process is complex and includes electrochemical (formation of radicals, synthesis of AuNPs and PtNPs nanoparticles, electrodeposition of a Zn sublayer) and chemical (initiation of polymerization and formation of a polymer layer, inclusion of nanoparticles into the polymer matrix) stages occurring simultaneously for 5–10 minutes. It was found that as a result of these processes, the electrode capacitance passes through a maximum, and the resistance increases, which is associated with both the deposition of a new crystalline phase on the cathode and the insulating effect of the polymer. The inclusion of metal nanoparticles in the film increases the electrical conductivity of the nanocomposite.
Vestnik of the Far East Branch of the Russian Academy of Sciences. 2025;(4):40-53
40-53
Formation of fumarate-containing smart coating for anti-corrosion protection of magnesium alloy MA8
Abstract
This study presents a method for fabricating composite protective coatings on the MA8 magnesium alloy, combining plasma electrolytic oxidation (PEO), impregnation of the protective layer with sodium fumarate (used as an environmentally friendly corrosion inhibitor), and polycaprolactone treatment for controlled active agent release. The sample with the composite coating exhibits a low corrosion rate of 0,12 mm/year and maintains stable anticorrosion properties for 7 days. The active corrosion protection mechanism involves three stages: inhibitor release from the PEO layer pores, migration to damaged surface areas, and the adsorption on metallic magnesium or magnesium corrosion products. The polymer layer extends the duration of the inhibitor protective effect. The proposed method enables controlled biodegradation of magnesium alloys, making them promising candidates for implant materials.
Vestnik of the Far East Branch of the Russian Academy of Sciences. 2025;(4):54-66
54-66
Advanced materials
New oxyfluoroniobate glasses in CdNbOF5–BaF2–ErF3 systems
Abstract
New glasses have been synthesized in the CdNbOF5–BaF2–хErF3(х = 0−5.0 mol. %) system. The glasses are two-phase. The ratio of amorphous phases, depending on the erbium trifluoride content in the glass, affects the thermal, crystallization, structural and optical characteristics of the glasses. When the ErF3content in the glass is 3 mol. %, rearrangements in the glass structure occur, leading to an increase in the connectivity of oxyfluoroniobate networks. Glasses in the CdNbOF5–BaF2–ErF3system are characterized by green luminescence of Er3+, corresponding to the transitions:4S3/2→4I15/2(544 nm),2Н11/2→4I15/2(551 nm). The luminescence intensity increases with an increase in the ErF3content to 2 mol. %. A further increase in the content of erbium trifluoride in the glass composition leads to a gradual decrease in the luminescence intensity, caused by concentration quenching and changes in the structure and phase composition at given dopant concentrations.
Vestnik of the Far East Branch of the Russian Academy of Sciences. 2025;(4):67-77
67-77
Synthesis, properties and applications of oxide, oxofluoride and fluoride carbon polymers
Abstract
The paper presents original methods of synthesis and results of fluorination of natural and artificial polymers using the example of wood, cellulose, lignin, graphite oxide, carbon nanotubes and perfluoroalkene. The synthesized compounds have been studied using scanning electron microscopy, energy dispersion spectroscopy, chromatography-mass spectrometry, X-ray photoelectron spectroscopy. Fluorocarbon compounds have been tested as energy-intensive cathode materials for lithium and sodium chemical current sources, piezoelectric materials, as well as hydrophobic, antifriction, anti-wear coatings.
Vestnik of the Far East Branch of the Russian Academy of Sciences. 2025;(4):78-96
78-96
Synthesis of complex oxides in plasma of pulsed high-voltage discharge
Abstract
This article demonstrates two fast methods for synthesizing complex oxides in air high-voltage pulsed discharge plasma. In one of them, a powder containing CuO/Cu2O/Y2O3/Y2BaCuO/YBa2Cu3O6,32was synthesized, from which CuO/YBa2Cu3O6,91composite was obtained by calcination, including a superconducting phase below 87 K. In the other variant, Cr2NiO4/NiO/Ni composite was synthesized. The magnetic properties of the obtained substances were studied. The methods can be used for the rapid synthesis of high-temperature superconductors with a variety of oxide compositions and other complex oxides in order to search for new functional materials.
Vestnik of the Far East Branch of the Russian Academy of Sciences. 2025;(4):97-108
97-108
Chemical technology
Comprehensive processing of the datolite ore using fluorite concentrate and ammonium sulphate
Abstract
The paper presents the research results on integrative processing of datolite ore using the fluorite concentrate and ammonium sulphate. It is shown that fluorination can be carried out without expensive ammonium bifluoride, using chemical interactions fluorite concentrate and ammonium sulphate. The products are easily separated to obtain complex fluorammonium salts of boron, silicon and calcium sulphate in the gypsum form.
Vestnik of the Far East Branch of the Russian Academy of Sciences. 2025;(4):109-116
109-116
Analysis of natural and man-made objects
The possibilities of instrumental neutron activation analysis with the radionuclide source Cf-252 for the determination of strategic metals in mineral raw materials
Abstract
The review examines the prospects for involvement in the processing of gold-bearing and rare earthmetal ores that are considered to bestrategic mineralresources.Itprovides information about the mineral resource base of goldand describes themineral formations and associations of gold intheseores.The article also provides informationon the state of the mineral resource baseforrare earth metals,includingscandium,based ondatafrom published sources such asthe journals “Mining Industry” and “Gold and Technology”. Due to the complexnatureoftheseores andtheirlow content of valuable components,obtainingaccurate analytical datacan be challenging. However, thereviewdiscussesmodern analytical methods thatcan helpaccurately determine theconcentrationof strategic metals intheseore objects. The method of instrumental neutron activation analysis(INAA), which belongs to the group of non-destructive methods, provides the analysis of representative samples and is characterized by high accuracy (correctness) of definitions, is considered in detail. The article presents the nuclear physical characteristics of the elements often determined by this method. Examples of the determination of Au, Sc, andrare earth elements (REE)in ore samples andwaste materials usingthe INAAtechniquewith a Californium neutron sourceare given.
Vestnik of the Far East Branch of the Russian Academy of Sciences. 2025;(4):117-137
117-137
Development of methods for sample preparation of titanium-bearing placer slurry for extraction of useful components (Sikhote-Alin, Primorye)
Abstract
Research has been carried out on the development of the technological process of sample preparation of conditioned titanium-bearing sands from placers of ultrabasites of the Sikhote-Alin orogenic belt for metallurgical processing. The material composition and theromorphic properties of the main and associated minerals have been studied. A register of useful components (titanium, gold, platinum, rare and rare earth elements, etc.) of industrial interest has been determined. The application of the developed sample preparation methodology made it possible to bring gold-ilmenite raw materials up to industrial requirements in compliance with resource-saving principles and without causing damage to the environment.
Vestnik of the Far East Branch of the Russian Academy of Sciences. 2025;(4):138-145
138-145
Pyrolysis and chromatomass spectrometry of high-molecular-weight and low-molecular-weight polytetrafluoroethylenes
Abstract
The article provides information on the methods for studying the mechanisms of depolymerization and thermal destruction of polytetrafluoroethylene (PTFE) and its low-molecular-weight fractions. It is shown that pyrolysis gas chromatograph mass spectrometry (Pi-GC/MS) is the most widely used method for analyzing the consist and properties of high-molecular-weight and low-molecular-weight polytetrafluoroethylenes, but this method does not allow good separation of the peaks of saturated and unsaturated fluorocarbons and identification is possible only by characteristic ions. It is possible to use the Pi-GC/MS option, where the mass spectrometer operates in the negative chemical ionization mode with methane and isobutane reagent gases. The separation does not become better, but good mass spectra are recorded, where molecular ions are present. Only multidimensional gas chromatography allows complete separation of the peaks of saturated and unsaturated fluorocarbons.
Vestnik of the Far East Branch of the Russian Academy of Sciences. 2025;(4):146-159
146-159
THERMAL BEHAVIOR OF HIGH-MOLECULAR-WEIGHT NAPHTHENIC ACIDS
Abstract
Thermal behavior of high-molecular-weight naphthenic acids (ARN) has been studied by thermogravimetry, pyrolytic chromatography-mass spectrometry (Py-GC-MS), liquid mass spectrometry and infrared spectroscopy. It is shown that slight degradation of ARN occurs upon heating up to 150°C. There is no decarboxylation of ARN, the acid is thermally stable, and the formation of a rigid film structure is associated with polycondensation of ARN molecules through the formation of anhydrides. Thermal degradation of ARN begins at temperatures above 150°C and is associated with the destruction of the carbon core. The main components of thermal degradation are derivatives of cyclopentane, the structure of which is present in ARN, various oxygen-containing compounds and hydrocarbons with a molecular weight greater than 280 a.u.m.
Vestnik of the Far East Branch of the Russian Academy of Sciences. 2025;(4):160-169
160-169
Lowering the detection limit of Cd2+ using functionalized associates of spiro[indoline-benzopyran] with tetraphenylborate ion
Abstract
The development of new functionalized organic compounds capable of efficiently coordinating metal ions remains a pressing challenge in the design of chemical sensors for environmental monitoring. In this work, a significant reduction in the detection limit of Cd²⁺ ions was achieved by using a 6-formyl-substituted spiro[indoline-benzopyran]. Derivative containing a benzoxazole fragment at the 8´position of the benzopyran moiety. Incorporation of spiropyran molecules into a siloxane-acrylate latex matrix and their association with a tetraphenylborate ion, acting as a spacer to prevent π-stacking and self-quenching of luminescence, led to a notable enhancement in sensor sensitivity. The use of transparent, ion-permeable latex films modified with SP·TFB complexes enabled a five orders of magnitude decrease in the detection limit of Cd²⁺, reaching 1.66 nM.
Vestnik of the Far East Branch of the Russian Academy of Sciences. 2025;(4):170-180
170-180
Personalities
He was from the galaxy of winners!
Abstract
March 1, 2025 marked the 110thanniversary of the birth of Yuri Vladimirovich Gagarinsky, a surprisingly modest, bright and talented man, Doctor of Sciences in Chemistry, Professor, Corresponding Member of USSR Academy of Sciences, Director of the Institute of Chemistry, FEB RAS.The article presents the biography of Yuri Gagarinsky and his scientific legacy: the main scientific directions and people who stood at the origins of the Institute of Chemistry and continued the work of their Teacher.
Vestnik of the Far East Branch of the Russian Academy of Sciences. 2025;(4):181-192
181-192
IN MEMORY OF RUVEN LEIZEROVICH DAVIDOVICH
Vestnik of the Far East Branch of the Russian Academy of Sciences. 2025;(4):193-194
193-194