Abstract Glasses based on lithium tetraborate obtained by solid-phase synthesis and doped with earth elements Sm3 +, Gd3 + have been investigated. The absorption and photoluminescence spectra were measured. The phenomenon of transfer of excitation energy from gadolinium ions to samarium ions is considered. A diagram of the energy levels of Sm3+ and Gd3+ in the studied glasses is proposed.

Abstract The dependence of the zeta-potential of the surface of the synthesized under hydrothermal conditions silicates of the subgroup of kaolinite (Al2Si2O5(OH)4 ⋅ nH2O) with spherical, spongy, and platy particle morphologies on the pH of the medium is studied for the first time. It is shown that all the synthesized samples change the sign of the surface from negative (in alkaline and neutral media)

Abstract— The structural (volume porosity, specific surface area, and average pore radius) and electrokinetic characteristics are studied for silicate and AgI-doped microporous glasses and quartz-like nanocomposites based on them. The change in the structure and surface parameters is analyzed for vitreous materials by doping with silver iodide in the porous space and high-temperature treatment of the

Abstract The effect of the polymer matrix on the degree of reinforcement of nanocomposites for polymer/organoclay nanocomposites is investigated. It is shown that the elastic modulus and the structure of the nanofiller in the polymer matrix are only a function of the elastic modulus of the matrix polymer and can be either higher or lower than the nominal value of this parameter. In the case of an elastomeric

Abstract A one-stage method for the synthesis of a mixed phosphor Sr2SiO4:Eu2+, Сa10Si6O21Cl2:Eu2+, Сa6Sr4(Si2O7)3Cl2:Eu2+ is developed in a microwave. The phase composition and spectral-brightness properties of phosphors are studied depending on the synthesis conditions. The optimal conditions for the synthesis of phosphors in a microwave oven are determined: 750°C, 10 min. Phosphor, synthesized under

Abstract The system xBa(PO3)2·(99 – x)(AlF3–BaF2–CaF2–MgF2–SrF2)–1NdF3, where x = 2, 5, 10, 15, 20, 30, and 40 mol %, is considered. The dependences of the thermal coefficient of linear expansion, Tg, Tx. Tx–Tg, HV, and K1C on the concentration of Ba(PO3)2 are determined. It is found that an increase in the concentration of Ba(PO3)2 with the uniform replacement of the fluoride component leads to a

Abstract The ability of layered perovskite-like titanates HLnTiO4 and H2Ln2Ti3O10 (Ln = La, Nd) to exfoliate into nanosheets in aqueous media under various conditions has been studied. Along with protonated titanates, their inorganic-organic hybrids with methylamine and n-butylamine were used as precursors for lamination. Exfoliation was carried out according to chemical and physical-chemical strategies

Abstract In this paper, the reaction mechanism of glassy waste in both single-glass and glass–Ca(OH)2 systems was investigated. However, while adding Ca2+ or Al3+ ions into reaction solutions, the ions interacted with the Si-rich hydrated layer on the surface of glass particles and produced zeolite or anorthite crystals between glass particles. As for glass-Ca(OH)2 system, besides facilitating the

Abstract Nanopowders of BaHfO3 and BaZrO3, are synthesized by the cocrystallization of nitric acid salts. Ceramic materials based on them with a crystalline cubic structure of the perovskite type, grain size 70–75 nm, and open porosity 8–10% are obtained. The mechanisms of proton electrical conductivity and the pathways of hydrogen migration in ceramic materials of the BaHfO3 and BaZrO3 composition

Abstract Composite materials based on matrices of high-silica nanoporous glasses activated with bismuth and cerium ions are synthesized. It is found that the samples, depending on the conditions of their synthesis, exhibit blue-green luminescence (λlum = 416–539 nm at λexc = 357–410 nm) due to the presence of Bi3+ and Ce3+ ions. Characteristic vibrations of CeO2 and α-Bi2O3 are identified in the composite

Abstract The promising development of the smart electric power industry is based on the use of functional materials created based on the latest achievements in science and technology. The properties of intelligent materials change when exposed to any external factors. The ability of such materials to convert one type of energy into another and the ability to control this conversion make it possible

Abstract Nanocrystalline ceramic samples of the ZrO2–3 mol % Y2O3 composition with varying degrees of tetragonality c/a (1.4337 and 1.0425) are obtained. The process of the low-temperature degradation of ceramics is studied by the methods of X-ray phase analysis and electron microscopy. It is found that samples with a high degree of tetragonality are more resistant to the action of a humid environment

Abstract The growth of nanocrystalization in TeO2–SeO2–Na2O glasses is achieved by the conventional heat treatment method. The influence of Na2O concentration on the physical properties of glass is evaluated. The glass transition (Tg) and onset crystallization (Tc) temperature decrease when Na2O concentration increases. Raman results show that the addition of Na2O to TeO2–SeO2 glasses may result in

Abstract In the present study Eu2O3 doped Li2O–Si2O–B2O3 glasses (LSBE) were synthesized by the melt quench technique. The physical, thermal, and spectroscopic properties of prepared glasses by various techniques have been investigated in this work. The powder X-ray diffraction study confirms the amorphous nature of glass samples. The various absorption bands assigned were observed from ground level

Abstract In this study, for the first time, the reaction–diffusion processes providing the formation of a composite diamond–silicon carbide material, which has a unique ordered microstructure, are simulated.

Abstract The results of a study of the rheological properties (shrinkage on heating, viscosity) of porous glasses (PGs) obtained as a result of through acid leaching of two-phase sodium borosilicate glass doped with small additives of P2O5 and fluoride ions, as well as bismuth-containing PGs and quartzoid glasses based on them, depending on the temperature of the heat treatment of the PG and in comparison

Abstract A criterion for the selection of materials to protect against the mechanical dynamic loading is proposed and substantiated. The mechanisms of the fracture of brittle ceramic materials that are widely used in structures that prevent penetration and are very common in practice are discussed. Unlike other estimates, the proposed formula is based on the physical principle of comparing the total

Abstract In this paper we present a new diamond synthesis method via introduction of highly reactive carbon atoms generated from chemical reactions as the raw materials of diamond. Experiments have shown that by this method the diamond can be synthesized with high yield at pressures as low as 3 GPa and temperatures as low as 900°C. Compared with the conventional phase transformation method, the pressure

Abstract In this study, the electron density functional theory method is used to obtain maps of the electron density distribution for a monolayer TiS3. The adsorption of H2 on the surface of a monolayer TiS3 decorated with Mg cations is studied. The adsorption energy is –0.156 eV/molecule, which is a fairly high value, and allows us to consider this material as promising for creating hydrogen storage

Abstract Yttrium-aluminum garnet (YAG) nanoparticles are synthesized by the coprecipitation of yttrium and aluminum hydroxides in a microreactor with freely impinging jets, followed by the thermal treatment of the coprecipitation products. According to the results of X-ray phase analysis, the coprecipitated hydroxides are X-ray amorphous. Analysis of the product of the thermal treatment of hydroxides

Abstract In this paper, we study the graphitization of the diamond surface with the [111] orientation using the ab initio molecular dynamics method. According to the results of the study, the growth of graphitization figures deep into the diamond phase is not observed: there is a simultaneous transformation, bypassing intermediate stages and stages. The C–C bond length in tetrahedra gradually increases

Abstract A combinatorial topological analysis and modeling of the self-assembly of crystal structures of LiCaSn-hP9 (space group P3m1, V = 230.36 Å3), Li2CaSn- cF16 (space group Fm-3m, V = 333.56 Å3), and Li20Ca28Sn44-oS92 (space group Cmcm, V = 2517.09 Å3) are performed using computer methods (ToposPro software package). The cyclic precursor clusters K3-0@LiCaSn involved in the self-assembly of the

Abstract The electrical and optical properties of nanocomposite materials fabricated by the dispersion of iodine in porous dielectric matrices of zeolites, zeolite-like aluminum phosphates, opals, asbestos, and porous aluminum oxide are studied. It is demonstrated that the physical properties of the produced nanocomposites depend significantly on the structure of a matrix.

Abstract The chemical processes occurring during the interaction of carbon (diamond) with silicon are experimentally investigated. Thermal analysis of the interaction of diamond with silicon is carried out. This made it possible to determine the mechanism of the synthesis of silicon carbide and subsequent reaction sintering of diamond particles based on Turing’s reaction-diffusion process and the formation

Abstract Polyelemental solid solutions of hexaborides in the La–Ce–Sm–B system are obtained by the solid-phase borothermal reduction of a mixture of rare-earth oxides in a 10–2 Pa vacuum at a temperature of 1450 to 1650°C. The morphology of solid solution particles is studied using scanning electron microscopy. The average particle size of the solid solutions ranged from 200 to 400 nm. It is found

Abstract The features of the synthesis of opaque quartz glass, the raw material for melting of which is quartz sand produced by the Ramensky ore mining and processing plant, are considered. For the first time in the world, the dependences of the change in the linear dimensions of quartz glass samples in various heating-cooling modes are obtained on the DIL-402 high temperature dilatometer produced

Abstract— Viscosity and thermal conductivity are calculated for multicomponent glass-forming oxide mixtures SiO2–MgO–CaO–Al2O3–FeO–K2O–Na2O based on silica. Viscosity polytherms are plotted in the temperature range of 1798–1973 K. Thermal conductivity is calculated at 1823 K. It is shown that the viscosity of oxide solutions is satisfactorily described by a ratio taking into consideration the viscosity

Abstract This paper presents the method and features of determining the chemical composition of boron-containing glass by the method of quadrupole mass spectrometry with inductively coupled plasma and laser ablation (LA-Q-ICP-MS). A number of glasses of systems Na2O–B2O3–GeO2–SiO2 and Na2O–B2O3–GeO2 with the boron content ranging from 2.2 to 16.1 wt % are studied. The analysis used the international

Abstract In this paper we report the structural, thermal, microstructural and infrared transmission properties of iodine doped (Ge20Se18Te62)100 – xIx (where x = 0, 8) chalco-halide glasses. The density of the specimen has been calculated experimentally. Differential thermal calorimetry shows a single glass transition temperature but two crystalline peaks. The role of annealing (503 and 593 K for 2

Abstract We investigated the effects of the flame-ablation treatment on the inner surface of borosilicate glass vials and the adhesion of fluorinated diamond-like carbon coating to glass vials. Transmission electron microscopy with energy-dispersive X-ray spectroscopy analysis show that the flame-ablation treatment removed the less durable layers that contained sodium borate, which might cause elution

Abstract— The method of synthesis of sodium and potassium sulfates in a thermal X-ray machine is described for the first time; the synthesis is followed by cooling to study its thermal behavior. A mixture of sodium and potassium sulfates (in a 1 : 1 ratio) is obtained for the study.

Abstract The present study demonstrates a series of environmentally friendly lanthanum and titanium doped mesoporous bioactive glass with adsorption, photocatalytic and regeneration performance for methylene blue via the sol-gel method. The materials were studied by XRD, XPS, TEM and BET. The influence of the initial dye concentration, contact time, solution pH, temperature, photocatalytic performance

Abstract Using the method of absorption Mössbauer spectroscopy on 119Sn, 121Sb, and 125Te isotopes, it is demonstrated that the local structure of germanium atoms changes during the crystallization of amorphous Ge2Sb2Te5 films (their tetrahedral symmetry changes to octahedral symmetry). The surrounding of antimony and tellurium atoms does not change, although for antimony atoms, it is similar to that

Abstract A direct preparation method for a powdered geopolymer was developed using polyvinyl alcohol as a dispersant template. Metakaolin obtained by calcination of kaolinite at 600 or 750°C was used as silica-alumina source. Powdered samples with average particle sizes of 44.2 and 42.0 µm were prepared from the metakaolin calcined at 600 and 750°C, respectively. The sample prepared from metakaolin

Abstract The temperatures of devitrification of cold crystallization, melting, and glass transition of samples of the CaO–B2O3–Al2O3–CuO system are determined by the methods of differential thermal analysis. The viscosity of alumina–calcium borate melts containing up to 8.1% of CuO is measured in the temperature range of 880 to 1300°C. It is shown that the addition of copper oxide reduces the viscosity

Abstract The information on the compatibility of lead–boron–silicate glass of various compositions and ruthenium(IV) oxide compounds is systematized. The chemical processes occurring between them are established in terms of the theory of the acid-base interaction. The informative indicators that determine the direction of such interaction are the acidity, ionic potential, or orbital electronegativity

Abstract The present study reports an experimental investigation of the effects of CaO/SiO2 mass ratio (0.4 to 1.2) and Fe/SiO2 ratio (1.26 and 1.7) on viscosity of the heterogeneous system of the CaO–SiO2–FeO–Fe2O3–PbO–MgO–ZnO–S slag at 1300°C. The viscosity was measured using rotating cylindrical viscometer, and structure of quenched slags was studied by X-ray diffraction and SEM-EDS analysis. It

Abstract The comparative analysis of the kinetics of the bulk crystallization of AsSe1.5Bix glasses (х = 0, 0.01, and 0.05) in the temperature range 210–260°C is conducted by the data of density measurement using the generalized Kolmogorov–Avrami equation and the results of phase and differential thermal analysis. The kinetics of the surface crystallization of As2Se3 glass containing 0.4 at % Bi at

Abstract Membranes based on polyvinyl alcohol crosslinked with furfural, both unmodified and modified with aminosulfonic acid with and without tetraethoxysilane (TEOS), and membranes not crosslinked with furfural but modified with aminosulfonic acid are obtained and studied. The composition, surface morphology, degree of swelling in water, and specific electrical conductivity are studied. It is found

Abstract This work aims to study the effect of sodium silicate additive on the microstructure and physical properties of foam glass fabricated from the recycled soda–lime glass regarding the process temperature of 700 to 900°C. Sodium silicate was added as a cost-effective environmental foaming agent in 10 to 30 wt % to recycled soda–lime glass powder (maximum size of 63 μm), pressed and heat-treated

Abstract Structural changes in silica glass, produced by electron irradiation, with electrons energies of 50 keV and doses of 5–80 mC/cm2 were studied by Raman spectroscopy in frequency ranges of 300–550 and of 700–1500 cm–1. It is shown that for irradiation doses less than 5 mC/cm2 the decrease of siloxane rings concentration in glass takes place. The further increase of dose results in the increase

Abstract In the present study glass samples of (40 – x)Li20 · xNa2O · 10K2O · 50B2O3 and (40 ‒ x)Li2O · xK2O · 10Na2O · 50B2O3 (0 ≤ x ≤ 40 mol %) were prepared by melt quench technique. The cut-off wavelength varies non-linearly when Li2O is replaced with Na2O or K2O. The type of electronic transition in the present glass systems is indirect allowed. Using single oscillator model, the oscillator energy

Abstract Thermal deformations of noncentrosymmetric silver and bismuth pentaborate AgBi2B5O11 are studied by the X-ray diffraction analysis of single crystals. Thermal expansion is anisotropic (αa = 18, αb = 5, αc = 1 × 10−6°C−1), which is caused by the orientation of the pentaborate B5O10 groups, along the axis of which the expansion is minimal. With increasing temperature, the degree of noncentrosymmetric

Abstract The article presents the results of a study of the biological activity of porous high-silica glass obtained based on two-phase alkali borosilicate glass. The test results show that the toxicity of the investigated porous glass (PG) in relation to Paramecium caudatum varies depending on the concentration and time of contact of the finely dispersed PG powder with water. It is assumed that the

Abstract Composite materials (CMs) containing Tb3+ ions and silver bromide, based on matrices of high-silica nanoporous glasses, are synthesized. It is found that the samples, depending on the conditions of their synthesis, possess UV (λlum = 310 nm at λexc = 266 nm) and blue-green (λlum = 400–545 nm at λexc = 316–375 nm) luminescence due to the presence of silicon defect centers and the presence of

Abstract Hydrosilicates of the kaolinite group (Al2Si2O5(OH)4 · nH2O) with spherical, nanotubular, and platy particle shapes are synthesized in hydrothermal conditions. The morphology and size of the particles, as well as the porous-textural characteristics, are studied by scanning electron microscopy (SEM) and low-temperature nitrogen absorption. The sorption capacity of the samples relative to the

Abstract The geometric and topological analysis of the crystal structure of (i) the Rh140Al403-cP549 intermetallide with cubic cell parameters a = 19.9350 Å, V = 7922.25 Å3, and the Pm-3 space group and (ii) the Mn18Pd138Al387-cP549 intermetallide with cubic cell parameters a = 20.211 Å and Pm-3 space group is conducted by the ToposPro program package. Two new cluster precursors with the symmetry -43m

Abstract The vaporization of Ti3O5 and V2O3 is studied by high-temperature mass spectrometry. Evaporation is carried out from Knudsen effusion cell made of tungsten. It is found that these oxides pass into vapor congruently with dissociation. Equations are obtained for the dependence of the partial pressures of molecular forms of the vapor on temperature in the form log p = –A/T + B.

Abstract The combinatorial topological analysis and modeling of self-assembly of the K78In160-hP238 (space group P-3m1, a = b = 17.211, c = 28.888 Å, V = 7410 Å3) and K8In11-hR114 (space group R-3c, a = b = 10.021 Å, c = 50.891 Å, V = 4426 Å3) crystal structures are performed by computer methods (the ToposPro software package). Icosahedra In12 (with the -3m symmetry) are the templates on which three-layer

Abstract The results of studies of the electrophysical and thermophysical characteristics of borosilicate glass designed to attenuate electromagnetic radiation in the microwave range are presented. The compositions of glass with the minimal tendency to crystallization are determined. The effect of the chemical composition of glass on its thermophysical (temperature coefficient of linear expansion (TCLE)

Abstract The Raman spectra of borosilicate glass containing 35, 40, and 45 mol % of alkali-earth metal oxide (SrO and BaO) are studied. The structural changes taking place at a gradual substitution of boron oxide by silica are determined. At a high boron oxide content, transformations among borate structural units are predominant because the main part of the modifying oxide reacts with the borate network

Abstract The role of the liquid phase in the formation of the microstructure of a clay tile possessing various physical and engineering characteristics is determined. The effect of the nature of raw materials and ratio of alkali oxides to alkaline-earth oxides on the formation of various calcium-containing crystal phases at low-temperature sintering is determined.

Abstract Hybrid ion-conducting membranes (HIMs) are obtained by the liquid-phase synthesis method, and the degree of their swelling in water and ionic conductivity are studied. The design of a multifactorial experiment by the Latin square method makes it possible to select the optimum ratio of the functional components of the HIMs. It is found that the obtained hybrid membranes are anion-conducting

Abstract This article presents the results of microcalorimetric studies of the process of the interaction of the hydration products of Portland cement with additives of glass powders of various chemical compositions. It is found that when glass is added in a powder state, an increase in the rate of hydration of Portland cement is observed.

Abstract The Al2O3 nano-coating was obtained by the decomposing of aluminum resinate (Al resinate) on the glass surfaces heated at 650°C for 30 min. The Al resinate is a product of the chemical reaction between sodium soap and aluminum chloride solution (AlCl3 solution). The sodium soap was obtained from the chemical reaction of coconut oil and the solution of sodium hydroxide (NaOH solution). The

Abstract Glasses of the 6Na2O · хB2O3 · (86 – x)SiO2 · 8Fe2O3 compositions, where x varies from 16 to 31 mol %, are studied by X-ray powder diffractometry and dilatometry. The glasses were preliminarily held at a temperature of 550°C for 8–144 h. It is determined that there are crystalline phases of magnetite and hematite in the studied glasses in addition to the amorphous component. The hematite content

Abstract The published results of a study of the diffusion of alkali cations and electrical conductivity in binary silicate, germanate, and borate glasses are compared.

Abstract In this study, a new method for generating cellular materials with improved physical and mechanical characteristics is proposed. The mechanical properties of products based on ABS-polymer with topologies, the prototypes of which are isoelectronic surfaces of a number of crystalline substances, are investigated by the method of computer simulation. As an example, in this study, we choose carbon

Abstract The microhardness of the surface layers of silicate glass formed by the diffusion of potassium ions from the composite paste consisting of potassium nitrate, alumina, and water is studied. Ion exchange processing using the composite paste leads to a significant increase of the microhardness of the glass surface from 550 to 850 MPa. It is found that the microhardness of the glass changes nonmonotonically

Abstract The paper proposes the design of a 3D printer that prints with a wax slip based on corundum powders. To activate the sintering of ceramics, the corundum grains are preliminarily clad with a two-layer shell of manganese and titanium compounds Al2O3–MnAl2O4–TiO2, which allows reducing the sintering temperature to 1400°C compared to pure corundum and ensures an even distribution of the sintering