Glass Physics and Chemistry最新文献

As construction waste, waste glass has great harm to the environment. It is essential to find an effective method to reuse waste glass. In this paper, the effect of glass powder on the performance of concrete is studied. The results show that the addition of glass powder leads to the increase of friction and the deterioration of working performance. ICP and TG show that the early volcanic ash effect of glass powder is not obvious. The addition of glass powder reduces the early compressive strength, but with the increase of age, the compressive strength of concrete increases. Through MIP, UPV and SEM-EDS, it is shown that with ageing, the addition of glass powder improves durability and no significant difference in hydration products is observed. Thus, the addition of glass powder can provide good economic and environmental benefits. Therefore, glass powder can be mixed according to actual engineering needs.

Ceramic materials based on B₄C–SiC are obtained by using the method of hot slip casting followed by reaction sintering (impregnation with liquid silicon). Composite ceramic samples are characterized by low density and porosity, and have strong mechanical characteristics. The microstructure of the obtained material is studied, and the uniformity of the distribution of boron carbide and silicon carbide particles in the structure of ceramic materials is demonstrated.

New vitreous composite materials (CMs) with two magnetic subsystems are synthesized by impregnation magnetite-containing matrices from iron-containing nanoporous glasses in aqueous MnCl₂ and H₂C₂O₄ solutions and the subsequent formation of manganese oxides Mn_xO_y (x = 1, 2, 3; y = 1, 2, 3, 4) inside the pore space of the matrices as a result of thermolysis of the reaction product of the dopants (MnC₂O₄). The chemical (elemental) and phase compositions, the valence-coordination state of iron and manganese, and the characteristics of the magnetic state of the synthesized CMs are studied and compared with the characteristics of nanoporous matrices.

The change in the resistive characteristics of lead silicate glasses (LSGs) after treatment in alkaline and acid solutions is studied. It is established that the chemical treatment of glasses and, accordingly, blanks of microchannel plates (MCPs) affects the high-temperature ionic conductivity at a constant activation energy of electrical conductivity. It is shown that the treatment of glasses in NaOH and HF solutions can significantly change the electrical resistance.

The mechanochemical activation of zeolite (clinoptilolite and clinoptilolite–stilbite) rocks with acidic salts—sodium hydrogen phosphate and ammonium hydrogen phosphate—with the weight ratio of the initial components of 1 : 1 in an IVS-4 vibratory attritor (1500 rpm, 0.6 kW, specific power 4 W/g, steel grinding set) is studied. The structure, chemical and phase composition, and thermal stability of salt-modified zeolite samples are studied by infrared spectroscopy, atomic emission spectrometry, X-ray phase analysis, and differential scanning calorimetry. The specific volume resistance of pelletized samples is measured using a three-electrode circuit. It is established that the electrical conductivity of high-silica zeolite rocks modified with sodium and ammonium hydrophosphates is 2.2 × 10^–6 up to 2.4 × 10^–5 S m^–1 at 25°C. It is shown that the mechanochemical activation of clinoptilolite and clinoptilolite–stilbite rocks with sodium hydrogen phosphate in a vibratory attritor at a mechanical energy dose of 2.4 kJ/g increases the conductivity of mechanically activated zeolites by factors of 140 and 470 at 25°C, and by factors of 30 and 490 at 100°C, respectively. This allows us to consider mechanochemical activation as a promising method for improving the electrical properties of mineral materials.

The effect of the refractive index n_D and mean dispersion (n_F – n_C) on the nonlinear refractive index of laser and optical glasses for active elements and elements of white optics of high-power pulsed radiation amplifiers is studied. It is shown that the nonlinear refractive index of the studied glasses will not exceed the maximum allowable value of 1.20 × 10^–13 cm²/B² if their refractive index in the green (yellow) region of the spectrum is below 1.550, and the average dispersion is less than 0.00820. It is found that the nonlinear refractive index of the studied glasses depends almost linearly on both the refractive index and the average dispersion. It is proposed that athermal phosphate crowns with a nonlinear refractive index below the specified limiting value can serve as the base for obtaining neodymium glasses with a low nonlinear index.

An approach is proposed to reduce the stability of the cubic phase of lead selenide by thermal oxidation with atmospheric oxygen and its transformation into an ordered monoclinic phase of lead selenite. An estimated thermodynamic analysis (TA) of the course of possible chemical reactions of lead selenide oxidation with oxygen is carried out. The kinetics of lead selenide oxidation with atmospheric oxygen are studied by X-ray emission analysis, X-ray diffractometry, optical reflection in the infrared region of the spectrum, studies of conductivity in direct and alternating currents, and nuclear magnetic resonance. For the PbSeO₃ structure, the Goldschmidt stability factor was estimated and it was shown that the structure can be classified as perovskite-like and have ferroelectric properties.

The possibility of radiation synthesis of luminescent ceramics from a mixture of Ba and Mg fluorides and WO₃ oxide is shown for the first time. Synthesis is implemented in a powerful electron beam with an energy of 1.4 MeV by direct exposure of the charge to radiation. It is shown that the characteristic band is observed in the photoluminescence spectrum of the synthesized materials due to the introduction of tungsten, which indicates the incorporation of tungsten into the lattice during radiation synthesis without the use of additional substances in the charge.

The viscosity of potassium–boron melts is measured in the temperature range 918–1699 K using a vibrational viscosimeter. The content of potassium oxide is varied from 0.74 to 28.46 mol %. The parameters of the viscous flow in melts (the configuration–activation energy(ε_h) and the shifting energy of the bridging oxygen atoms’ bonds (U_∞)) using the configuration–activation model are calculated for two temperature intervals 918–1400 K and 1400–1699 K. The glass transition temperature (T_g) is measured by differential scanning calorimetry (DSC) and the concentration dependence of the glass transition temperature on the content of potassium oxide in the melt is shown.

Using computer methods (ToposPro software package), a combinatorial topological analysis and modeling of the self-assembly of Zr₇₂P₃₆-oS108 (a = 29.509 Å, b = 19.063 Å, c = 3.607 Å, V = 2029.49 ų, Cmmm), Zr₁₈Ni₂₂-tI40 (a = b = 9.880 Å, c = 6.610 Å, V = 645.23 ų, I4/m, and Zr₄Ni₄-oS8 (a = 3.271 Å, b = 9.931 Å, c = 4.107 Å, V = 133.43 ų, Cmcm) crystal structures are carried out. For the crystal structure of Zr₇₂P₃₆-oS108, 40 variants of the cluster representation of the 3D atomic net with the number of structural units 5, 6, and 7 are established. Structural units in the form of a pyramid K5 = 0@PZr₄, tetrahedron K4 = 0@Zr₄, and supratetrahedron K9 = Zr(Zr₄P₄) of four connected tetrahedra. For the crystal structure of Zr₁₈Ni₂₂-tI40 also defined supratetrahedra K9 = Ni(Zr₄Ni₄) are defined. For the crystal structure of Zr₄Ni₄-oS8, the tetrahedral cluster precursor K4 = Zr₂Ni₂ is defined. The symmetry and topological code of the processes of self-assembly of 3D structures from cluster precursors is reconstructed in the following form: primary chain → layer → framework.