The influence of the coordination groups of boron, aluminum and silicon on the acid-base properties of the molten glass and the change in the redox state of copper in boron-containing melts has been studied. Indicators are proposed to assess the redox potential of the molten glass. They were used to compare the acid-base properties of industrial alkali-aluminoborosilicate glasses. Tab. 4, ill. 3, bibliography: 12 titles.
Equations are proposed for calculating the concentration of structural groups of constant composition (SCG) in borate glasses containing modifier oxides of the first and second groups of the periodic system. The partial molar volumes of the CGP were established and the molar volume of glasses of the indicated systems was calculated using the additive approximation formula. The calculated values ?? V m satisfactorily approximate the experimental data of various authors - the maximum root-mean-square error of the calculation does not exceed 2.5%. Tab. 3, ill. 4, bibliography: 5 titles.
An analysis of the use of mid-IR lasers (3 - 7 ?m) for controlled laser thermal cleavage of oxide glasses is carried out. A significant improvement in the quality of this technology was shown when using CO lasers (5.1 - 6.2 ?m). Il. 4, bibliography: 8 titles.
The redox conditions of glass melting in an operating glass-making furnace using molding sand have been investigated. The data of instrumental measurements of the ORP of molten glass and the reasons for the destabilization of the technological process are presented. Il. 3, bibliography: 7 titles.
A method of obtaining a highly porous cellular material based on glass of an alkaline aluminoborosilicate system by the method of burnout additives is considered, one of the varieties of which is the burning out of a polymer matrix (polyurethane foam). The influence of the structural parameters and properties of glass on the process of obtaining a highly porous workpiece, as well as the dependence of the strength characteristics on the porosity of the samples and the specific surface area of ??the glass powder have been studied. Il. 4, bibliography: 5 titles.
Studies have shown that the "heat-soak" method used for rejection of tempered glasses does not fully guarantee that during the operation of these glasses, their self-destruction from the presence of NiS inclusions of smaller sizes is completely excluded. We believe that the cause of glass self-destruction is not so much NiS polymorphism as high stresses around NiS inclusions, and, as a consequence, limitation of the glass "life" time in accordance with the kinetic theory of long-term strength. Tab. 1, ill. eight.
The data on ionic coloration of glasses are analyzed from the standpoint of ligand field theory. The available information on glass staining with transition metal compounds has been supplemented. Data on the structure of glass-forming melts and the conditions for the formation of coloring complexes are presented. A possible mechanism of the appearance of amber staining of glasses is considered. Tab. 1, ill. 4, bibliography: 16 titles.
The modern methods and systems for monitoring the redox balance of glass as a key parameter for stabilizing the glass-making process, achieving and reproducibility of the specified performance properties of glass and glass products are considered. It is shown that it is necessary to control the protective function of glass from light radiation by the value of trichromatic characteristics - the dominant wavelength, purity and brightness of color. Il. 5, bibliography: 12 titles.
The results of IR spectroscopy of boric and silicic acids, the main components of the charge for the manufacture of microspheres, are presented. It is proved that in the structures of silicic and boric acids, water is in molecular (crystalline hydrate) and in the form of OH-groups, respectively. A formula is given for calculating the absolute degree of difference between the bands in terms of the wavenumber and intensity. It has been shown that half of the spectral bands of both acids can be used only conditionally for the identification of acids, and among them, almost one third of the bands are basic. The bands at 1195 cm -1 in the spectrum of boric acid and at 1180 and 1200 cm -1 in the spectrum of silicon are indistinguishable in position and intensity and cannot be used for analysis. The wavenumber is a necessary and sufficient feature for identifying acids in the charge, but in the case of conventionally applicable bands, without taking into account their intensity, the analysis of a mixture of acids is impossible. Tab. 2, ill. 3, bibliography: 13 titles.
The influence of OH-groups on the technological and physicochemical properties of glass is shown. The importance and expediency of carrying out research in this direction in connection with the use of new artificial and natural raw materials, as well as with a change in the composition of the atmosphere of the glass furnace due to the use of additional oxygen for fuel combustion, has been substantiated. Bibliography: 37 titles.
