Loktionova E.V.

Belgorod State Technological University named after V.G. Shukhov

Development and research of formulations for the production of functional ceramic materials

https://doi.org/10.58224/2619-0575-2025-8-4-1
Abstract
The authors investigated a mixture for producing Ceram Bond ceramic adhesive (Bredent, Germany). The microstructure of the initial powder and the resulting coating after sintering at 980°C were analyzed. The resulting compositions are easily manipulated under industrial conditions and possess optimal processing properties.
Objectives: Research and development of new, effective functional ceramic coating compositions for dental prosthetics that meet high quality and durability requirements.
Methods. Analytical and experimental chemistry methods were used, as well as modern instruments and equipment. The chemical and phase composition was studied using an X-ray fluorescence spectrometer. The elemental composition of the experimental samples was determined using an energy dispersive attachment to a scanning electron microscope. The granulometric composition of the masses was determined using laser diffractometry. The microstructure of the powder and ceramic adhesive was examined using a scanning electron microscope. The structure of the coatings was recorded using an optical microscope. The preparation of the ceramic adhesive was carried out by wet grinding. The determination of water absorption, open porosity and apparent density was carried out using a vacuum chamber connected to a vacuum pump. The calculation of these parameters was carried out according to classical formulas.
Results. The analysis of the main physico-mechanical characteristics of a sample of a mixture in a paste-like state of the Ceram Bond brand, the Bredent trademark (Germany) is carried out. The compositions of experimental samples have been developed, their physico-mechanical properties have been determined, and the advantages and disadvantages of introducing flat glass and fused quartz into the combat have been identified. It has been established that coatings based on Ceram Bond adhesive are characterized by the presence of a large number of microcracks, and experimental formulations differ in a small number or completely absence of microcracks, which indicates its higher quality.
Conclusions. As a result of the work carried out, a mixture for the production of ceramic adhesive of the Ceram Bond brand of the Bredent trademark (Germany) was investigated. Experimental formulations have been developed for the production of ceramic adhesives based on fused quartz and tempered flat glass. The microstructure of the initial powder and the coating based on it after sintering at a temperature of 980℃ has been studied. It has been established that coatings based on Ceram Bond adhesive are characterized by the presence of a large number of microcracks, and the developed formulations differ in a small number or complete absence of microcracks, which indicates their higher quality.
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Kinetics and mechanism of adsorption of methylene blue dye by crushed sunflower biomass

https://doi.org/10.58224/2619-0575-2024-7-3-78-92
Abstract
Objectives: to study the kinetics and mechanism of dye adsorption by cellulose raw materials. Methods. As a sorbent, waste from crop production was used – ground sunflower stalks, initial and modified with 10% NaOH alkali, with a particle size from 1 to 2 mm. Methylene blue dye was selected as an adsorbate by preliminary tests. Adsorption isotherms were constructed to determine the maximum sorption capacity. Kinetic models of sorption of the pseudo-first and pseudo-second order are constructed. In order to determine the mechanism of the process, thermodynamic constants were determined: sorption energy (E), Gibbs energy (ΔG) and Bio coefficient (Bi).
Results. The maximum sorption capacity of the crushed biomass of sunflower stalks in relation to the dye is 0.52 mmol/g for the alkali-modified material, which is 48% higher than the initial content (0.35 mmol/g). Thus, the SP(NaOH) material showed improved sorption properties, and it was selected for further kinetic studies. The sorp-tion energy is 5.82 kJ/mol, which may indicate physical adsorption. The Gibbs energy is -6.3742 kJ/mol, less than zero, which indicates the spontaneity of this process. The adsorption equilibrium for the MG dye occurs after 120 minutes, the kinetic curve has a smooth character. The Bio coefficient is 1.812, therefore, the adsorption process is limited by mixed diffusion.
Conclusions. The analysis of the data obtained made it possible to determine the Bio coefficient reflecting the course of MG adsorption by a mixed–diffusion mechanism over the entire time range of adsorption. This indicates the complex character of the MG adsorption process and confirms the importance of taking into account various factors influencing this process when developing methods for cleaning aquatic environments from organic pollu-tants.
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PURIFICATION OF OIL-CONTAINING WASTE WATER FROM HERMETIA ILLUCENS FLY LARVAE LIPID CONCENTRATE PRODUCTION

Abstract
The work is devoted to the study of the possibility of waste water from the lipid concentrate (oil) obtained on the basis of the larvae of the Black Soldier fly (Hermetia Illucens) production treatment. Treatment of oily wastewater is not an easy task due to the specific properties and condition of the oils contained in such wastewater. Typically, wastewater containing fats and oils has a high chemical oxygen demand (COD), biological oxygen demand (BOD), large amounts of suspended solids, oils, fats, phosphates and sulfates. Various physicochemical methods are used to treat such wastewater. However, the search for inexpensive effective materials for the oils extraction from aqueous media is an actual task.
For cleaning, we used the crushed fruits of the Sycamore tree – a deciduous tree widespread in the southern strip of the Russian Federation. Model emulsions containing "Black Soldier" larvae oil were subjected to cleaning. The influence on the purification efficiency of such factors as the dose of the sycamore fruit (SF) added biomass, the SF interaction duration with the emulsion, and the pH of the medium was investigated. It was found that high purification efficiency is achieved at the SF dose of 1 g per 10 cm3; pH = 4; the duration of the contact is at least 10 minutes.
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THE USAGE OF VEGETABLE SORBENT FOR REMOVING CONGO RED DYE FROM TEST SOLUTIONS

Abstract
The research findings of sorption purification of test water environment, containing Congo red dye, by using this crop farming waste as a sorption material have indicated that the maximum sorption capacity of its biomass amounts to 0.37 mmol/g. The electronic microscopy data and the research findings of physical-chemical and sorp-tion properties of a new vegetable sorption material, obtained from sunflower (Heliánthus ánnuus) stalks, are presented. The processing of the data demonstrated that the obtained adsorption isotherm of Congo red belongs to Type V isotherms according to classification by Brunauer-Deming-Deming-Teller (BDDT) or to the S-type, according to Giles’ classification. With that, adsorption process is the most accurately described by the Freundlich model, and the process proceeds on the heterogeneous surface of the sorption material.
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