Multicomponent systems LiCl–LiBr–Li<Subscript>2</Subscript>SO<Subscript>4</Subscript> and LiCl–LiBr–Li<Subscript>2</Subscript>SO<Subscript>4</Subscript>–Li<Subscript>2</Subscript>MoO<Subscript>4</Subscript>

Phase equilibria in the LiCl–LiBr–Li₂SO₄ ternary system and the LiCl–LiBr–Li₂SO₄–Li₂MoO₄ quaternary system were studied by differential thermal analysis. The compositions and temperatures of minima in the ternary and quaternary systems were determined to be (31.2 mol % LiCl, 46.8 mol % LiBr, 22.0 mol % Li₂SO₄, 460°C) and (25.2 mol % LiCl, 30.2 mol % LiBr, 14.6 mol % Li₂SO₄, 30.0 mol % Li₂MoO₄, 411°C), respectively.     

Ternary Systems LiBr–LiVO<Subscript>3</Subscript>–Li<Subscript>2</Subscript>CrO<Subscript>4</Subscript> and KBr–KVO<Subscript>3</Subscript>–K<Subscript>2</Subscript>CrO<Subscript>4</Subscript>

The binary system KVO₃–K₂CrO₄ and two ternary systems, LiBr–LiVO₃–Li₂CrO₄ and KBr–KVO₃–K₂CrO₄, were studied. In the ternary systems, the compositions and melting points of eutectic alloys were determined by differential thermal analysis: (49.0 mol % LiBr, 5.0 mol % LiVO₃, 46.0 mol % Li₂CrO₄, 400°C) and (17.0 mol % KBr, 78.0 mol % KVO₃, 5.0 mol % K₂CrO₄, 458°C), respectively.     

Ionic mobility and electrophysical properties of solid solutions in PbF<Subscript>2</Subscript>–SbF<Subscript>3</Subscript> and PbF<Subscript>2</Subscript>–SnF<Subscript>2</Subscript>–SbF<Subscript>3</Subscript> systems

Ionic mobility and electrical conductivity of solid solutions with fluorite structure, obtained with solid-state approach in PbF₂–SbF₃ and PbF₂–SnF₂–SbF₃ systems, are studied by 19F NMR and electrochemical impedance spectroscopy methods. The 19F NMR spectra parameters, types of ion motions in the fluoride sublattice, and the ionic conductivity magnitude are shown to be determined by the temperature and fluoride concentration in the solid solutions. The solid solution specific conductivity in the PbF₂–SbF₃ and PbF₂–SnF₂–SbF₃ systems at 420–450 K is as high as ~10^–2 S/cm, which allows accounting the solid solutions as a base for preparation of functional materials.     

Thermoelectric power and electrochemical studies on CdI<Subscript>2</Subscript>–Ag<Subscript>2</Subscript>O–V<Subscript>2</Subscript>O<Subscript>5</Subscript>–B<Subscript>2</Subscript>O<Subscript>3</Subscript> system

A quaternary super-ion-conducting system, 20CdI₂ − 80[xAg₂O − y(0.7V₂O₅ − 0.3B₂O₃)] where 1 ≤ x/y ≤ 3, has been prepared by melt quenching technique. The electrical conductivity measured was the order of 10⁻⁴  S/cm at room temperature. The values of silver-ion transport number obtained by electromotive force technique are nearly unity. The thermoelectric power and electrochemical studies were done on the CdI₂–Ag₂O–V₂O₅–B₂O₃ system. The discharge and polarization characteristics were examined for different cathodes to evaluate the utility of these cells as power sources for low energy applications.     

Solid-Liquid Equilibria in the Quaternary Systems KCl–MgCl<Subscript>2</Subscript>–SrCl<Subscript>2</Subscript>–H<Subscript>2</Subscript>O and NaCl–KCl–SrCl<Subscript>2</Subscript>–H<Subscript>2</Subscript>O at 348 K

Solid-liquid equilibria in the quaternary systems KCl–MgCl₂–SrCl₂–H₂O and NaCl–KCl–SrCl₂–H₂O at 348 K were measured by the isothermal solution saturation method. The composition of the equilibrium solid phase, solubilities of salts, and densities of saturated solution in the two systems were determined. Phase diagrams, water content diagrams and solution density diagrams of quaternary systems were plotted according to experimental data. The phase diagram of the quaternary system NaCl–KCl–SrCl₂–H₂O has one invariant point, three univariant curves as the boundary of NaCl, KCl and SrCl₂ · 2H₂O. This phase diagrams were simple co-saturation type without complex salt and solid solution. For the quaternary system KCl–MgCl₂–SrCl₂–H₂O, one complex salt KCl · MgCl₂ · 6H₂O (Car) had been found in this system, consisted of five univariant curves, two invariant points and four crystallization regions of MgCl₂ · 6H₂O (Bis), KCl, SrCl₂ · 2H₂O and KCl · MgCl₂ · 6H₂O. And the densities transformation rules were simply discussed. Simultaneously, the solubilities and densities data in invariant point of the quaternary system NaCl–KCl–SrCl₂–H₂O had been compared with the experimental data of previous researchers.     

Structure and thermal properties of the fritted glazes in SiO<Subscript>2</Subscript>–Al<Subscript>2</Subscript>O<Subscript>3</Subscript>–CaO–MgO–Na<Subscript>2</Subscript>O–K<Subscript>2</Subscript>O–ZnO system

In this work, the structure and thermal properties of aluminosilicate fritted glazes in SiO₂–Al₂O₃–CaO–MgO–Na₂O–K₂O–ZnO system with (4.0 mol%) and without addition of ZnO were examined by GIXRD, FTIR, MAS-NMR and thermal methods (DTA, DIL). It has been found that the all experimental glazes are amorphous material (transparent glazes). On the base of spectroscopic investigations, it was found that zinc ions exist in the network glazes in the octahedral coordination—Zn²⁺ ions play a network modifier role in structure of glazes. An analysis of the data obtained from thermal tests showed that addition of ZnO into chemical composition results in decrease in glass transition temperature value (T _g) for all glazes (DTA, DIL). The coefficient of thermal expansion (α) is decreased as the whole measurement range for one series of fritted glazes.     

Thermal studies of ZnO–B<Subscript>2</Subscript>O<Subscript>3</Subscript>–P<Subscript>2</Subscript>O<Subscript>5</Subscript>–TeO<Subscript>2</Subscript> glasses

The effect of TeO₂ additions on the thermal behaviour of zinc borophosphate glasses were studied in the compositional series (100 − x)[0.5ZnO–0.1B₂O₃–0.4P₂O₅]–xTeO₂ by differential scanning calorimetry, thermodilatometry and heating microscopy thermal analysis. The addition of TeO₂ to the starting borophosphate glass resulted in a linear increase of glass transition temperature and dilatometric softening temperature, whereas the thermal expansion coefficient decreased. Most of glasses crystallize under heating within the temperature range of 440–640 °C. The crystallization temperature steeply decreases with increasing TeO₂ content. The lowest tendency towards crystallization was observed for the glasses containing 50 and 60 mol% TeO₂. X-ray diffraction analysis showed that major compounds formed by annealing of the glasses were Zn₂P₂O₇, BPO₄ and α-TeO₂. Annealing of the powdered 50ZnO–10B₂O₃–40P₂O₅ glass leads at first to the formation of an unknown crystalline phase, which is gradually transformed to Zn₂P₂O₇ and BPO₄ during subsequent heating.     

Distribution of niobium and lanthanum between two immiscible melts in the system LaPO<Subscript>4</Subscript>–SiO<Subscript>2</Subscript>–NaF–Nb<Subscript>2</Subscript>O<Subscript>5</Subscript>–Fe<Subscript>2</Subscript>O<Subscript>3</Subscript>

The system LaPO₄–SiO₂–NaF–Nb₂O₅–Fe₂O₃ is characterized by immiscibility fields in the liquid state region. Addition of iron expands fields of immiscibility of melts and decreases the temperature of their coexistence. A fraction of 87–90% of niobium is extracted into iron silicate melt, and 92–98% of lanthanum is extracted into phosphate salt melt.     

Mass attenuation coefficients of B<Subscript>2</Subscript>O<Subscript>3</Subscript>–Al<Subscript>2</Subscript>O<Subscript>3</Subscript>–SiO<Subscript>2</Subscript>–CaF<Subscript>2</Subscript> glass system at 0.662 and 1.25 MeV gamma energies

The total mass attenuation coefficients, partial interaction and the effective atomic numbers (Z_eff) of glass system (80−x)B₂O₃–10Al₂O₃–10SiO₂–xCaF₂ (where x = 5, 10, 20, 25, 30, 35 and 40 mol %) have been calculated at photon energies 0.662 and 1.25 MeV using the WinXCom software on the basis of mixture rule. Results indicated that the total mass attenuation coefficients showed a decrease with increasing the CaF₂ concentration, due to a decrease in Compton scattering probability, which gave a dominant contribution to the total mass attenuation coefficients for the studied glass samples at both energies. However, the photoelectric absorption and coherent scattering showed an increase with increasing the CaF₂, concentrations at same energies. For a comparison, the total mass attenuation coefficients of the glass system had lower values at the energy 1.25 MeV than that at 0.662 MeV. Z_eff was found to increase linearly with the increase of CaF₂ concentrations. It was concluded that low CaF₂ concentrations in glass system, under study, have Z_eff close to that of human tissue and have higher total absorption coefficients at energy of 0.662 MeV than that at 1.25 MeV. These results are very useful in designing gamma radiation detectors using thermoluminescence technique. Therefore, it is recommended to use low CaF₂ concentration of our glass system as good gamma detectors at energy of 1.25 MeV.     

Phase transformations in the systems Ti<Subscript>2</Subscript>Fe–H<Subscript>2</Subscript> and Ti<Subscript>2</Subscript>Fe–NH<Subscript>3</Subscript>

The interactions of two-phase alloy Ti₂Fe with hydrogen and ammonia at 100–500°C were studied, the compositions of the products were found, and the conditions for producing hydride and nitride phases were determined. The potential of using the two-phase alloy in a metal hydride hydrogen accumulator operating at 20–600°C was considered.     

Interaction in the systems TlBiSe<Subscript>2</Subscript>–Tl<Subscript>9</Subscript>BiSe<Subscript>6</Subscript>–PbSe and Tl<Subscript>9</Subscript>BiSe<Subscript>6</Subscript>–Tl<Subscript>4</Subscript>PbSe<Subscript>3</Subscript>–PbSe

Phase equilibria in the systems TlBiSe₂–Tl₉BiSe₆–PbSe and Tl₉BiSe₆–Tl₄PbSe₃–PbSe were studied by differential thermal, X-ray powder diffraction, and microstructural analyses. State diagrams of the quasi-binary sections Tl₉BiSe₆–Tl₄PbSe₃, TlBiSe₂–PbSe, and Tl₉BiSe₆–PbSe were constructed, and so were projections of liquidus surfaces and isothermal sections at 600 K for the secondary quasi-ternary systems TlBiSe₂–Tl₉BiSe₆–PbSe and Tl₄PbSe₃–Tl₉BiSe₆–PbSe. The coordinates of invariant points and the boundaries of solid solutions were determined.     

Structural characterisation and thermo-physical properties of glasses in the Li<Subscript>2</Subscript>O–SiO<Subscript>2</Subscript>–Al<Subscript>2</Subscript>O<Subscript>3</Subscript>–K<Subscript>2</Subscript>O system

This article aims to shed some light on the structure and thermo-physical properties of lithium disilicate glasses in the system Li₂O–SiO₂–Al₂O₃–K₂O. A glass with nominal composition 23Li₂O–77SiO₂ (mol%) (labelled as L₂₃S₇₇) and glasses containing Al₂O₃ and K₂O with SiO₂/Li₂O molar ratios (3.13–4.88) were produced by conventional melt-quenching technique in bulk and frit forms. The glass-ceramics (GCs) were obtained from nucleation and crystallisation of monolithic bulk glasses as well as via sintering and crystallisation of glass powder compacts. The structure of glasses as investigated by magic angle spinning-nuclear magnetic resonance (MAS-NMR) depict the role of Al₂O₃ as glass network former with four-fold coordination, i.e., Al(IV) species while silicon exists predominantly as a mixture of Q ³ and Q ⁴ (Si) structural units. The qualitative as well as quantitative crystalline phase evolution in glasses was followed by differential thermal analysis (DTA), X-ray diffraction (XRD) adjoined with Rietveld-reference intensity ratio (R.I.R.) method, Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM). The possible correlation amongst structural features of glasses, phase composition and thermo-physical properties of GCs has been discussed.     

Transformations of CO<Subscript>2</Subscript> in Two-Phase Systems C<Subscript>8</Subscript>F<Subscript>18</Subscript>–H<Subscript>2</Subscript>O and C<Subscript>6</Subscript>F<Subscript>6</Subscript>–H<Subscript>2</Subscript>O

The transformation of carbon dioxide in aqueous emulsions of perfluorons in the presence of oxygen in the air results in the formation of a mixture of oxalic acid and a minor set of organic compounds C₄–C₈. The maximum CO₂ consumption occurs in the emulsion with the C₈F₁₈: H₂O vol/vol ratio of 1: 0.42 at pH 2.4; the H₂C₂O₄ yield is 11 mol %.     

Physicochemical Analysis of the System Zr(SO<Subscript>4</Subscript>)<Subscript>2</Subscript>–Na<Subscript>2</Subscript>SO<Subscript>4</Subscript>–H<Subscript>2</Subscript>SO<Subscript>4</Subscript>–H<Subscript>2</Subscript>O at 25°С

The solubility in the quaternary water–salt system Zr(SO₄)₂ · 4Н₂О–Na₂SO₄–H₂SO₄–H₂O at 25°C was studied. It was found that, in the system, there is crystallization of not only Na₂SO₄ and Zr(SO₄)₄ · 4H₂O, but also sodium sulfate zirconates Na₂Zr(SO₄)₂(OH)₂ · 0.3H₂O, Na₄Zr(SO₄)₄ · 3H₂O, and Na₂Zr(SO₄)₂ · 3H₂O and two new compounds, S₁ and S₂, which are presumably Na₂ZrO(SO₄)₂ · 2H₂O and Na₂Zr₂O₂(SO₄)₃ · 6H₂O.     

Effects of Fe<Subscript>2</Subscript>O<Subscript>3</Subscript> on the crystallization and structure of CaO–Fe<Subscript>2</Subscript>O<Subscript>3</Subscript>–SiO<Subscript>2</Subscript> glass ceramics

Radiation-induced degradation of the weakly and strongly 4-vinylpyridine basic ion exchange resins by gamma radiolysis was investigated in the presence of air and liquid water. This study is focused on evaluating the radiolytic gases (H₂, CO, CO₂ and CH₄) and liquid products (water-solute TOC and NH₄ ⁺). The weakly basic resin yielded lower amounts of H₂ and CO and higher amounts of CO₂ than those of the strongly basic resin. Moreover, the strong basic resin tended to yield greater amounts of NH₄ ⁺. Resins were characterized by the FTIR spectroscopy technique and the results showed that the resins structures are relatively stable.     

Glass Formation in the Ternary System La<Subscript>2</Subscript>O<Subscript>3</Subscript>–As<Subscript>2</Subscript>S<Subscript>3</Subscript>–Er<Subscript>2</Subscript>O<Subscript>3</Subscript>

The boundaries of the glass formation region in the ternary system La₂O₃–As₂S₃–Er₂O₃ were found. Transparent glass of composition (La₂O₃)_0.03(As₂S₃)0.90(Er₂O₃)0.07 was studied by X-ray photoelectron and Raman spectroscopy. The intensities of the bands characterizing As–S, La–O, and Er–O bonds increased, and these bands were shifted toward higher energies. This was due to an increase in the covalence of these bonds and probably due to the formation of new bonds in the glasses. Samples in the glass formation region are resistant at 300 K to air, water, and organic solvents.     

Sol–gel synthesis and characterization of Al<Subscript>2</Subscript>O<Subscript>3</Subscript>–TiO<Subscript>2</Subscript> nanocrystalline powder

Al₂O₃–TiO₂ nanocrystalline powders were synthesized by sol–gel process. Aluminum sec-butoxide and titanium isopropoxide chemicals were used as precursors and ethyl acetoacetate was used as chelating agent. Thermal and crystallization behaviors of the precursor powders were investigated by thermal gravimetric-differential thermal analysis, Fourier-transform infrared spectrum and X-ray diffraction. The average crystalline size of heat treated Al₂O₃–TiO₂ powders at 1,100 °C is ~100 nm.     

Phase and extraction equilibria in H<Subscript>2</Subscript>O–sulfonol–HCl (H<Subscript>2</Subscript>SO<Subscript>4</Subscript>) and H<Subscript>2</Subscript>O–sodium dodecyl sulfate–HCl (H<Subscript>2</Subscript>SO<Subscript>4</Subscript>) systems

Solubility isotherms of water–sulfonol–hydrochloric (or sulfuric) acid and water–sodium dodecyl sulfate–hydrochloric acid systems at 75°C and a water–sodium dodecyl sulfate–sulfuric acid system at 50°C are constructed. Regions of two-phase liquid equilibrium suitable for use in extraction are found. Concentration parameters for extraction are determined. The interfacial distribution of a series of metal ions with and without such additional complexing reagents as diantipyrylmethane and diantipyrylheptane is studied.     

Phase formation in the system Zn(VO<Subscript>3</Subscript>)<Subscript>2</Subscript>–HCl–VOCl<Subscript>2</Subscript>–H<Subscript>2</Subscript>O

The phase and chemical compositions of precipitates formed in the system Zn(VO₃)₂–HCl–VOCl₂–H₂O at pH 1?3, molar ratio V⁴⁺: V⁵⁺ = 0.1?9, and 80°C were studied. It was shown that, within the range 0.4 ≤ V⁴⁺: V⁵⁺ ≤ 9, zinc vanadate with vanadium in a mixed oxidation state forms with the general formula Zn_xV⁴⁺ _yV⁵⁺ _2-yO₅ ? nH₂O (0.005 ≤ x ≤ 0.1, 0.05 ≤ y ≤ 0.3, n = 0.5?1.2). Vanadate Zn_xV₂O₅ ? nH₂O with the maximum tetravalent vanadium content (y = 0.30) was produced within the ratio range V⁴⁺: V⁵⁺ = 1.5?9.0. Investigation of the kinetics of the formation of Zn_xV₂O₅ ? nH₂O at pH 3 determined that tetravalent vanadium ions VO2+ activate the formation of zinc vanadate, and its precipitation is described by a second-order reaction. It was demonstrated that, under hydrothermal conditions at pH 3 and 180°C, zinc decavanadate in the presence of VOCl₂ can be used as a precursor for producing V₃O₇ ? H₂O nanorods 50–100 nm in diameter.     

Glass Formation in the Al<Subscript>2</Subscript>(SO<Subscript>4</Subscript>)<Subscript>3</Subscript>–(CH<Subscript>3</Subscript>)<Subscript>2</Subscript>SO–H<Subscript>2</Subscript>O System

The glass formation in the Al₂(SO₄)₃–(CH₃)₂SO–H₂O system was found for the first time. The competitive ability of ligands, dimethyl sulfoxide and water (which are strong donors), for entering the first coordination sphere of aluminum is considered. The possibility of mixed coordination of (CH₃)₂SO (via sulfur and oxygen atoms) in the first coordination sphere of aluminum with retention of the glass-forming ability of the sample was suggested on the basis of IR spectral study.