Žurnal neorganičeskoj himii

The results of a comparative study of the composition and structure of thin films formed from film-forming sol-gel compositions based on SnCl₄/EtOH/H₂O and SnCl₄/EtOH/H₂O/NH₄ОН precursors are presented. The features of the morphology and distribution of Sn, N and Cl atoms over the surface of the films were analyzed, as well as the transparency of the films depending on the amount of ammonium hydroxide introduced into the sol-gel composition. Possible chemical processes and reaction products underlying film formation and crystallization of film surfaces are considered. It was shown that the size and shape of the resulting skeletal crystals depend on the amount of ammonium hydroxide introduced into the sol-gel system. Formation of SnO₂ crystals and crystals containing NH₄Cl was studied in the films at the nano- and micro scales by using optical and electron microscopy and X-ray phase analysis. The new data obtained make it possible to control the morphology and composition of the synthesized thin films by changing the ratio of sol-gel synthesis precursors.

The paper studies the interaction processes of the product of centrifugal thermal activation of gibbsite (CTA-GB) with aqueous solutions of nickel or cobalt nitrate in a wide range of active component concentrations (15–50 wt. %). Using X-ray phase and thermal analysis methods, it was found that the synthesis products are layered double hydroxides and pseudoboehmite. The interaction of CTA-GB in an aqueous medium without nickel or cobalt leads to the formation of pseudoboehmite only. The effect of nickel in solutions is expressed in the complete absence of pseudoboehmite formation. In the case of cobalt, pseudoboehmite formation occurs up to its concentration of 30 wt. %, and above that (40, 50 wt. %) they are also not formed. According to the results of temperature-programmed reduction with hydrogen, the products of heat treatment at 350–850°C are mixed compositions of NiO/nickel aluminate and Co₃O₄/cobalt aluminate, the transformation of which into spinels of the NiAl₂O₄ and CoAl₂O₄ type occurs almost completely at 850°C, and their synthesis based on CTA-GB products is possible without using classical coprecipitation stages (sol-gel technology).

The synthesis and electrophysical properties of spinel ferrite ZnFe₂O₄ obtained by solid-phase interaction using mechanoactivation have been considered in this study. The study encompasses a comprehensive analysis of the phase composition and crystal structure, employing X-ray phase analysis, thermogravimetric analysis, and differential thermal analysis to elucidate the thermal effects and synthesis steps. Impedance spectroscopy was employed to investigate the electrophysical properties, thereby confirming the considerable impact of firing temperature on electrical conductivity. The results demonstrate that the electrical conductivity of the material increases by an order of magnitude when the firing temperature is increased up to 1000°C. This suggests the potential for the use of ZnFe₂O₄ as a cathode material for lithium-ion and metal-ion batteries. This work emphasises the importance of optimising synthesis conditions to achieve high performance of electrode materials.

Powders containing activated carbon (BAC) and iron oxide (Fe_xO_y) with different component ratios (80/20 and 20/80 wt. %) were synthesized by chemical co-precipitation of iron salts in the pores and on the surface of the carbon. To assess the morphology, texture and structure of the composites, laser diffraction, scanning electron microscopy, low-temperature adsorption-desorption of nitrogen vapor, and X-ray diffraction were used. It was revealed that the synthesized powders are mesoporous materials with a small contribution of macropores. The sorption properties of coal, iron oxide and iron-containing composites in relation to the drug compound tetracycline were studied. It was found that the sorption efficiency of antibiotic increases in the order Fe₃O₄ < BAC < BAC/Fe_xO_y-20/80 < BAC/Fe_xO_y-80/20. The kinetics of tetracycline adsorption on the powders under study was described by equations of pseudo-first and pseudo-second order reactions.

Based on the substituted derivative of the decahydro-closo-decaborate anion (Ph₄P)₂[B₁₀H₉O(CH₂)₅COOH] obtained by opening the tetrahydropyran substituent in the anion [B₁₀H₉O(CH₂)₅]^–, a series of compounds Na₂[B₁₀H₉O(CH₂)₆C(O)X], where X = Trp-OMe (1), His-OMe (2), Met-OMe (3), Pld-OMe (4), containing various amino acid substituents attached to the pendant carboxyl group, were synthesized. The compounds were isolated as sodium salts. The residues of L-tryptophan (Na₂1) and L-histidine (Na₂2) contained aromatic heterocyclic groups indole and imidazole, respectively, as a side group. Compounds Na₂3 and Na₂4 contained substituted alkanes as a side group: L-methionine (Na₂3) contained a methyl ethyl sulfide group, and compound Na₂4 contained the residue of an aliphatic synthetic amino acid in which the side group was represented by γ-butyrolactam (pyrrolidin-2-one). Compounds Na₂1 and Na₂2 were found to exhibit dose-dependent antiviral activity against the influenza virus strain A/IIV-Orenburg/83/2012(H1N1)pdm09 in vitro. IC₅₀ for compound Na₂1 was 5.0 μg/ml, and for compound Na₂2 it was found to be 10.0 μg/ml. Molecular docking of the M2 protein pore and compounds Na₂1 and Na₂2 was performed. It was found that the most probable arrangement of molecules in the pore of the M2 channel is associated with the location of the heterocycle inside the pore of the M2 channel in the region of the residues His37–Trp41, and for the compound Na₂1 this an arrangement is more favorable than for Na₂2, which explains some difference in the concentrations of suppression of viral reproduction for Na₂1 and Na₂2. For compounds Na₂3and Na₂4, antiviral activity was not detected.

The heterophase reaction of interaction of silver perfluorocyclohexanoate with zinc was studied by TG, DSC and mass spectrometry. It was found that as a result of interaction in the temperature range of 320–520 K, solid zinc perfluorocyclohexanoate is formed and an intramolecular reaction of zinc fluoride formation occurs. The obtained experimental data allowed us to calculate the standard enthalpies of formation of the solid zinc complex Δ_fН°_298.15 = –5693 ± 29 kJ/mol, sublimation and formation of dimeric molecules Zn₂(C₆F₁₁COO)₄ Δ_sН°_Т = = 190±15 kJ/mol, Δ_fН°_Т = –11196 ± 40 kJ/mol.

The paper studies the four-component mutual system Na⁺,Rb⁺||Cl^–,I^–,CrO₄ ^2–, low-melting compositions based on which are promising for the development of electrolytes for chemical current sources and heat-accumulating materials. The system is divided into stable simplices using graph theory and a phase tree of the system is constructed, which includes three stable tetrahedra connected to each other by two stable triangles. Using differential thermal analysis (DTA) and thermogravimetric analysis (TGA), phase equilibria in the stable triangle NaCl–Na₂CrO₄–RbI were studied. As a result, the melting point and the content of components in the three-component eutectic were determined: E 430°C, NaCl – 20%, Na₂CrO₄ – 48%, RbI – 32% (equiv.). The composition of the crystallizing phases in the eutectic was confirmed by X-ray diffraction (XRD).

Boron oxide is considered as a good dopant for improving the ionic conductivity of solid electrolytes. This effect is usually attributed to the optimization of grain boundary conductivity. In this work, the effect of addition of 1–4 wt. % boron oxide on the ionic conductivity of Li_1.2Al_0.2Zr_0.1Ti_1.7(PO₄)₃ with the NASICON structure was investigated. The obtained materials were characterized by XRD, SEM, Raman spectroscopy, IR spectroscopy, impedance spectroscopy and MAS ²⁷Al, ⁷Li, ³¹P and ¹¹B NMR. It was shown that the introduction of B₂O₃ at the stage of synthesis of Li_1.2Al_0.2Zr_0.1Ti_1.7(PO₄)₃ leads to the production of materials doped with boron ions. The highest conductivity (2.9 × 10^–4 S/cm) at 25°C is characteristic of the sample with 2 wt. % boron oxide. At the same time, when B₂O₃ is added to the already prepared phosphate, it is predominantly localized at the interfaces, leads to the release of LiTiPO₅ impurity and does not have a significant effect on the conductivity of the prepared samples.

It was shown for the first time that open microspheres 1–10 µm in size with Cu(OH)₂ walls and unique morphology are formed as reactions of rapid hydrolysis of copper (II) cations when microdroplets of aqueous CuSO₄ solution are sprayed on the surface of alkaline solution of Na₂SO₄ at room temperature and without the use of surfactants. It has been shown that the microspheres formed under these conditions have a single hole in their walls with a size ranging from fractions to units of a micrometer and they are oriented on the surface of the alkaline solution with this hole facing towards the air. These microspheres can be transferred to various substrates using a vertical elevator technique, where they are deposited in layers with their holes predominantly oriented in the opposite direction from the substrate. It has been found that the walls of these microspheres are several hundred nanometers thick and are composed of a combination of Cu(OH)₂ nanocrystals, and nanorods, with a diameter 5–10 nm and a length up to 500 nm. When the samples are heated in air at 150°C, these nanocrystals lose water and form CuO single crystals without significant changes in their morphology. It was found that applying layers of microspheres to the surfaces of various substrates gives it superhydrophilic properties.