Glass and Ceramics最新文献

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.

In this work, a titanium oxide-modified silicon oxycarbide composite was synthesized. A combined mechanical treatment by deposition of TiO₂ on the surface of white soot and activated carbon was used. The fixation of titanium oxide was confirmed by elemental analysis data. Scanning electron microscopy (SEM) showed that the size of the deposited particles did not exceed 100 nm. The structure of the obtained materials was studied by x-ray diffraction and IR spectroscopy. It was shown that the silicon oxycarbide composite has a high degree of amorphism; the diffraction pattern contains peaks characteristic of reflections from anatase planes. The IR spectra contain bands corresponding to vibrations of the Ti–O–Ti and Ti–O–C bonds. The porosity of the synthesized samples was investigated by low temperature nitrogen adsorption/desorption. It was found that the composite has a sufficiently developed porous structure with a predominance of meso- and macro pores. The material is proposed to be used as a photocatalyst for the degradation of organic compounds in cleaning processes.

A cubic pyrochlore with the composition Bi₂Ni_1/2Co_1/2Ta₂O_9±δ (sp. gr. Fd–3m, a = 10.5261(8) Å) was synthesized from the corresponding oxides by the solid phase reaction method for the first time. The complex oxide is characterized by a porous microstructure formed by partially fused crystallites of elongated shape with an average longitudinal size of 1 – 2 μm. The chemical state of the transition element cations in pyrochlore was characterized by x-ray photoelectron spectroscopy (XPS) and x-ray absorption near edge structure (NEXAFS). A characteristic shift of the Ta4f spectrum by 0.8 eV into the low energy region is observed for the pyrochlore. The charge state of the tantalum cations corresponds to a value of +(5 – δ). The absorption spectrum of pyrochlore near the Co2p absorption edge is a superposition of the CoO and Co₃O₄ spectra. According to the nature of the XPS, and NEXAFS Ni2p spectra the nickel ions are in the Ni(II, III) state.

This paper analyzes composite materials based on K 25 hollow glass microspheres modified with silver nanoparticles (Ag NPs). The nanoparticles were produced by an eco-friendly green method using an aqueous plant extract from Taraxacum root as a reducing agent. The synthesis of the nanoparticles and their deposition on the surface and within the pores of the microspheres were achieved simultaneously through ultrasonic treatment, followed by thermal processing at 300 – 350°C. The developed composites, consisting of K 25 hollow glass microspheres with supported silver nanoparticles, were characterized using scanning electron microscopy (SEM), infrared (IR) spectroscopy, and x-ray diffraction (XRD). The elemental composition was determined by energy-dispersive x-ray spectroscopy (EDS). The results demonstrate the effectiveness of the proposed method for depositing silver nanoparticles onto the surface of glass microspheres.

This study investigates the morphology of nickel and cobalt oxides deposited on various substrates, specifically γ-alumina and silica gel. The primary objective of this study was to examine the influence of synthesis methods, such as impregnation and mechanochemical synthesis, on the textural properties and surface morphology of the resulting composites. We employed scanning electron microscopy (SEM), energy-dispersive x-ray spectroscopy (EDS), and low-temperature nitrogen adsorption/desorption (the Brunauer–Emmett–Teller (BET) method) to analyze the characteristics of the composites. The findings of the study demonstrated that the synthesis method significantly affects the particle size and shape of the oxides, as well as the distribution of nickel and cobalt oxides on the substrate surfaces. Although the impregnation method ensures a uniform distribution of metal oxide particles, they exhibit a higher tendency for agglomeration, particularly in the case of cobalt oxide. The mechanochemical method enhances the mobility of components and improves adhesion, resulting in a higher dispersion of the metal oxides. This is achieved through controlled encapsulation of the oxides within the substrate. The findings may facilitate the development of novel composite materials with improved catalytic and structural properties.

Ceramics in the Ca₂P₂O₇–Ca₃(PO₄)₂ system were obtained from powder mixtures containing calcium hydroxyapatite Ca₁₀(PO₄)₆(OH)₂ and monocalcium phosphate monohydrate Ca(H₂PO₄)₂· H₂O. Fish scale powder was used as a natural source of natural calcium hydroxyapatite Ca₁₀(PO₄)₆(OH)₂. The molar ratios of Ca₁₀(PO₄)₆(OH)₂ /Ca(H₂PO₄)₂· H₂O in the initial powder mixture equal to 1/4, 3/5 and 2/1, respectively, ensured the formation after firing of ceramics having a desirable phase composition, including calcium pyrophosphate Ca₂P₂O₇ and/or tricalcium phosphate Ca₃(PO₄)₂ . The homogenization of the components was carried out by repeated passing of the powder mixture through a sieve with a mesh size of 200 μm. Plastic molding of the samples was carried out using ethyl alcohol as a binder. According to XRD data, the phase composition of all samples after the addition of alcohol, molding, and drying included monocalcium phosphate monohydrate Ca(H₂PO₄)₂· H₂O and calcium hydroxyapatite Ca₁₀(PO₄)₆(OH)₂. Monetite CaHPO₄ and brushite CaHPO₄· 2H₂O were also present in the phase composition of the samples. The phase composition of prepared highly porous ceramic samples with relative density 27 – 55% after firing in a temperature range of 900 – 1100°C included β-tricalcium phosphate β–Ca₃(PO₄)₂ and/or β-calcium pyrophosphate β–Ca₂P₂O₇.