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The effectiveness of using borate (borax) and fluoride (sodium fluoride) fluxes in the sintering of crystalline (sand) and amorphous (diatomite) silicate raw materials was considered. The change in the density and appearance of samples with varying amounts of fluxes during their heat treatment at different temperatures was described. It was shown that the introduction of 4 wt.% of borax reduces the temperature necessary to reach a density of 1500 kg/m3 by 100°C, and 6 wt.% of borax by 200°C. It was shown that the introduction of fluxes increases the amount of x-ray amorphous glass phase due to depolymerization of the silicon-oxygen network and the formation of a low-temperature melt. [ABSTRACT FROM AUTHOR]

The main trends in the production of foam glass materials were considered. The basic principles of physicochemical interaction of glass components with the pore-forming agent were described. The general tendencies in gas release during the heat treatment of foam glass batch mixtures using the compounds most commonly used as pore-forming agents (carbonates, carbon, silicon carbide) were revealed. Critical analysis of known studies was given. It revealed differences and inaccuracies in the descriptions of gas release reactions and showed the lack of justification for the choice of a particular pore-forming agent. [ABSTRACT FROM AUTHOR]

Liquid-phase porophores are shown to hold promise in the synthesis of foam glass. The dynamics of the change in the size of glass particles in the process of obtaining the charge was studied. It is shown that additional comminution of the particles of the glass powder occurs on mixing. The influence of the charge mixing time on the structure of the foam glass was studied. It was established that the density of the resulting foam glass is directly proportional to the charge mixing time. The changes occurring in the material structure in association with the processes involved in the distribution of the liquid pore-forming mixture on the particles of glass powder during mixing and subsequent changes in the dynamics of the thermal destruction of glycerin are described. [ABSTRACT FROM AUTHOR]

The possibility of foaming of phosphate glass matrices for the synthesis of complex micronutrient fertilizers with prolonged action is considered. The region of glass formation in the K2O–CaO–P2O5 system has been studied. The optimal composition of the initial glass is selected. Foaming of the initial mixtures is carried out using one-stage and two-stage technology; their internal structure, phase composition, and resistance to water are studied. It has been established that foaming using the two-stage technology makes it possible to obtain a material with stable structure and properties, which is important when it is used as a fertilizer with prolonged action. [ABSTRACT FROM AUTHOR]

A simple method for the preparation of a foam glass/CoFe2O4 composite material has been proposed for the first time. We have demonstrated the conceptual feasibility of utilizing glass scrap and plant ash and slag for the preparation of cellular glassy materials suitable for use as supports of catalytically active substances. The synthesized composite materials have been characterized by X-ray diffraction and electrode microscopy. A possible mechanism of cobalt(II) ferrite structure formation on the surface of foam glass has been discussed. We have studied the photocatalytic properties of the synthesized materials for the oxidative destruction of an organic dye in the presence of hydrogen peroxide. The synthesized support has been shown to be inert in the catalytic process studied. The foam glass/CoFe2O4 composite material exhibits high catalytic activity under the conditions studied here: complete removal of the organic dye from a solution takes 210 min after the reaction onset. [ABSTRACT FROM AUTHOR]

An experimental investigation has been made of the dielectric properties of planar Cu-Cr/Ba[sub 0.5]Sr[sub 0.5]TiO[sub 3] and YBa[sub 2]Cu[sub 3]O[sub 7-δ]/Ba[sub 0]Sr[sub 0.5]TiO[sub 3] structures in the temperature range 78-300 K. It is shown that the use of YBa[sub 2]Cu[sub 3]O[sub 7-δ] electrodes in Ba[sub 0.5]Sr[sub 0.5]TiO[sub 3] film structures ensures that there is no dielectric hysteresis in the paraelectric phase. At the same time, the dielectric nonlinearity is preserved and the dielectric losses are reduced. [ABSTRACT FROM AUTHOR]