Glass and Ceramics最新文献

This paper examines mesoporous TiO₂-montmorillonite composites synthesized by hydrothermally activated impregnation (115°C, 0.5 – 5.0 h) of mechanochemically and thermally activated montmorillonite with titanium polyhydroxy complexes. The materials were characterized using x-ray diffraction (XRD), infrared (IR) spectroscopy, low-temperature nitrogen adsorption/desorption, scanning electron microscopy (SEM), electrophoretic light scattering, and energy-dispersive spectroscopy (EDS). The duration of hydrothermal treatment significantly influenced the crystallite size of titanium dioxide and the anatase-to-rutile phase ratio, as well as the surface morphology and textural properties of the composites. Photometric analysis was used to evaluate the adsorption capacity and photocatalytic activity of the composites toward Rhodamine B as a model dye. Overall, hydrothermal treatment substantially enhanced the photocatalytic activity of the composites. However, prolonged treatment duration resulted in a decline in this effect. The obtained composites exhibited a pronounced synergistic effect of adsorption and photocatalysis in removing Rhodamine B from a highly concentrated (40 mg/L) aqueous solution.

The process of soft mechanochemical synthesis of CuO/ZnO/Al₂O₃ composites using copper/zinc hydroxocarbonates and alumina as starting materials was studied. The regularities occurring at the stage of mechanochemical activation and sucsequent thermal treatment were investigated by means of x-ray diffraction (XRD) and synchronous thermal analysis methods. The influence of the energy intensity of the mill on the textural properties of the composite was demonstrated. Low-temperature nitrogen adsorption-desorption showed that in the process of mechanochemical synthesis the total specific surface area of the samples changes insignificantly, while the type of processing has a significant effect on textural properties including pore size distribution, active surface area, and copper dispersion. Temperature ranges of composite activation for catalytic applications were obtained by the method of thermo-programmed reduction. The positive influence of the mechanical activation on the formation of the composite structure was observed. This allows its use as the main component of the catalyst for the production of ammonia, hydrogen, and methanol.

The physicochemical properties of the commercial bentonite S-4205-02 (Bentovin) and its structural parameters were determined. Clay agglomerates were predominantly up to 10 – 20 microns in size. X-ray spectral analysis revealed a relatively high content of Fe₂O₃, Na₂O, CaO, which corresponds to the iron-aluminum variant of montmorillonite with a predominance of Na⁺ and Ca²⁺ ions in the interlayer space. The presence of potassium indicates the presence of illite. According to XRD data, the main component of the product is montmorillonite with impurities of quartz/cristobalite, kaolinite, illite, and hematite. Thermal analysis curves and IR spectrum of bentonite were analyzed. The textural characteristics of the powder were determined. The specific surface area was 58 ± 6 m²/g. Based on bentonite and orthophosphoric acid, a geopolymer bentonite-phosphate binder was synthesized for the first time. XRD and IR spectral analysis show that the interaction of aluminosilicate powder with orthophosphoric acid leads to the complete destruction of the montmorillonite structure with the formation of aluminum and silicon phosphates.

An energy and resource saving plasma technology for glazing of autoclave-hardened building materials was developed. It is found that the introduction of colemanite into the composition of the initial charge allows to increase the performance indicators, including frost resistance, water resistance, and microhardness. The characteristics of the formation of the macrostructure and microstructure of the glaze layer at the front surface treatment by plasma jet are studied.

Natural quartz sands, widely used in glass, refractory, ceramic, foundry, and other industries, frequently do not meet the particle size distribution requirements set by the industry standards. This study proposes an effective method for processing silica sand to enhance the particle size distribution using a pneumatic cross flow separator.

A novel magnetic-rheological method has been developed for the diagnostics of the magnetic susceptibility of ferro impurity particles. These particles, which are present in the raw components of glass and ceramic products, are typically removed by magnetic separation. The new method is presented in three variants, and the results of determining the magnetic susceptibility of ferro impurities in natural sand and feldspar are presented.

The possibility of using pegmatite dumps in the production of ceramic materials is demonstrated. The results of the study, which focused on the dielectric and technological properties of microcline pegmatite, indicate its potential for use in the production of electrotechnical porcelain. Compositions of porcelain tiles based on plagioclase pegmatite, clay, kaolin, quartz with low water absorption (0.43 – 0.28%) were developed. The production of facing tiles with high flexural strength (32 MPa) was achieved through the use of microcline-plagioclase pegmatite and fine-grained waste from pegmatite beneficiation, clay, kaolin, and finely ground quartz.

This paper examines the effects of plasma-chemical treatment on the structure of vermiculite promoted with zirconium oxychloride using scanning electron microscopy, x-ray diffraction, infrared spectroscopy, and x-ray photoelectron spectroscopy. The experimental findings demonstrate that plasma-chemical treatment enhances the catalytic activity and stability of the material while preserving the chemical characteristics of the system. This improvement is attributed to the transition of metals, particularly zirconium, into their oxide forms.

Polishing suspensions and powders available on the world market for polishing of a wide range of optical parts used in the production of laser gyroscopes (LG) are presented. Their main technical parameters, determining the quality of polished surfaces of optical parts, are given. The list of polishing suspensions and powders most suitable for the production of optical parts of LGs is offered.

This work presents an analysis of the growth prospects of the ceramic membranes market based on the systems analysis methodology. Prevailing commercial trends in the industry are discussed for the most common segments, such as application, technology, regions, and materials. In addition, the industry needs and dynamics of the foreign and Russian membrane market are analyzed. Sales forecasts in the ceramic membranes industry until 2029 are estimated, and the main growth factors for the global ceramic membranes market are provided. The feasibility and relevance of developing the industry in Russia is substantiated, and examples of companies that are world leaders in the ceramic membrane market are provided.