VOL 83, No. 4 (2010)

The processes of glass clarification are closely related to its redox potential, for the quantitative assessment of which an indicator indicator was used - the proportion of ferrous iron, proportional to the absorption index of glass in the range 900 - 1100 nm. The appearance of midges in optical glasses is explained by the increased solubility of nitrogen in molten glass with an increased reduction potential. Mixing cullet with an increased reduction potential to the container glass melt with an oxidizing potential and vice versa violates the solubility of sulfur in the molten glass, increases the risk of midges and foaming of the molten glass. Tab. 3, ill. 5, bibliography: 16 titles.

By means of dielectric IR spectroscopy and Raman spectroscopy, the presence in the structure of lanthanum borogermanate (LBG) glass of three-coordinated boron atoms, which are absent in the LaBGeO ₅ crystal, has been confirmed. The grouping ratio [BO ₃] / [BO ₄] does not depend on the conditions for obtaining glass. An assumption was made about the presence in the glass composition of amorphous nanosized regions of two types, approximately the same chemical composition, but different structure. The regions of the first type contain preferably four-coordinated boron atoms and are the basis for the formation of nuclei of stillwellite crystals, while the regions of the second type are more disordered, and in them most of the boron atoms are located in the centers of oxygen triangles. Il. 3, bibliography: 12 titles.

The influence of the composition of the charge based on various silica raw materials and the redox characteristics of its components on the foaming processes in the production of glass-foam materials is considered. It was found that foaming mixtures belonging to the transitional redox group are optimal for foaming, the value of the oxidation coefficient of which is in the range of 25 - 100. Oxidizing and reducing mixtures are characterized by a low coefficient of foaming and a high degree of heterogeneity, which requires adjusting the composition by changing the ratio of the reducing agent and oxidizing agent. Tab. 3, ill. 3, bibliography: 8 titles.

It is shown that the method of precursor synthesis by spraying hot solutions highly concentrated in zirconium into concentrated ammonia solutions, in combination with mechanical treatment in optimal modes, provides PSZD nanopowders, from which ceramics with high mechanical strength (800 MPa) can be made even with this method of powder consolidation. like semi-dry pressing. The effect of the temperature of synthesis of hydroxides on the characteristics of powders and ceramics has been studied. Tab. 2, ill. 6, bibliography: 10 titles.

A classification of methods for measuring the rheological properties of ceramic pastes for extrusion is given. Depending on the magnitude of the shear stresses at which the tests are carried out, it is proposed to divide the research methods into structural-mechanical and rheological. The characteristics of the most informative methods, as well as structural-mechanical and rheological parameters obtained during these measurements are given. Recommendations are given on the use of each of the methods both for scientific research and for controlling the parameters of molding pastes in the production of extruded ceramic products. Il. 8, biliogr .: 21 titles.

The prospects of using glass enamel coatings for antibacterial protection of steel panels have been confirmed. A methodological approach has been developed for obtaining antibacterial glass composite coatings. Based on the R ₂ O - RO - TiO ₂ - P ₂ O ₅ - SiO _{2 system}, a glass matrix with a programmed structure was obtained, bactericidal zinc phosphate nanopowders and glass composite coatings based on them were obtained. The composition of the coating with the maximum antibacterial effect against E. Coli bacteria has been determined. Tab. 1, ill. 3, bibliography: 6 titles.