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2025

Archives Journal Chemical Bulletin Vol. 8

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

https://doi.org/10.58224/2619-0575-2025-8-4-1
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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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Comparison of modifying effect of wollastonite in polyvinylchloride and epoxy composite materials

https://doi.org/10.58224/2619-0575-2025-8-4-2
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Abstract
To investigate the grain-size and phase compositions and properties of natural and synthetic wollastonite fillers and to establish the nature of their modifying effect in polymer composite materials using the example of polyvinyl chloride thermoplastic and epoxy resin thermoset.
Methods. X-ray quantitative phase analysis was used to study the filler samples, and porosity was determined using mercury porosimetry and gas absorption. The particle size of wollastonite was determined by laser diffraction. The thermal stability of the filled composites was evaluated on a derivative thermogravimetric analyser, and the thermal stability of polyvinyl chloride materials was evaluated using the Congo red method. Dynamic mechanical analysis was performed on a DMA 242 Netzsch device.
Results. The particle size distribution and phase composition of natural and synthetic calcium silicate samples, their porosity and pH of aqueous extract were studied. The influence of wollastonite properties on the viscosity of the obtained polymer-filler mixtures, the thermal stability and wear resistance of the filled composites, as well as on the tensile strength and relative elongation of polyvinyl chloride compositions was established.
Conclusions. Studied calcium silicates have proven effective for both epoxy and polyvinyl chloride materials. Despite the similarity in phase composition and acid-base characteristics of the surface, natural and synthetic wollastonite differ in particle size distribution and porosity. Natural filler is more promising for creating heat-resistant polyvinyl chloride compositions and wear-resistant epoxy compositions, while synthetic wollastonite based on rice husks provides an increase in the dynamic modulus and glass transition temperature of both types of polymers. Studies have shown that the modifying effect of the studied fillers is more prominent in epoxy polymers due to their influence on the formation of the polymer matrix cross-linked structure.
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Study of the cerebroprotective effect of a new derivative of hydroxybenzoic acid – the dikali salt N–(3-hydroxybenzoyl)taurine in various disorders of cerebral circulation

https://doi.org/10.58224/2619-0575-2025-8-4-3
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Abstract
The 21st century is not only a time of progress in innovative technologies and artificial intelligence, but also a time of global downgrade and early development of serious health disorders, especially oncological and cardiovascular diseases. Currently, various cerebrovascular disorders have become widespread, which are the main limitation factors in rational therapy. This is due to the complications of primary diagnosis of the disease and its confirmation, as well as the problems in the application of early neuroprotection and rehabilitation. The aim of the study. The research of new compound’s neuroprotective properties: the dipotassium salt of N-(3-hydroxybenzoyl)taurine, which is a derivate of hydroxybenzoic acid, by the different types of vascular (blood circulation) disorders in the brain. Materials and methods. The examination of the dipotassium salt of N-(3-hydroxybenzoyl)taurine, as a derivate of hydroxybenzoic acid. Establishing the neurological status using the Combs & D`Alecy scale and the Gracia scale. Results. The research results let to suggest the cerebroprotective properties of a new hydroxybenzoic acid derivate, which demonstrates potential comparable to Citicoline, Nicergoline, and Acetylsalicylic acid in decrease the damage of the neuropsychiatric consequences of ischemic injury. The examine compound, like these other drugs, exhibits properties aimed at stabilizing cerebral circulation and reducing the manifestations of endothelial dysfunction. Conclusions. According to study findings the dipotassium salt of N-(3-hydroxybenzoyl)taurine exhibits cerebroprotective effects in various cerebrovascular disorders.
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Quantum chemical modeling оf aqueous mustard gas solutions

https://doi.org/10.58224/2619-0575-2025-8-4-4
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Abstract
Objective: to conduct quantum chemical modeling of a sulfur mustard molecule in an aqueous medium in the built–in parameter mode and in the mode of added molecules. After optimization by thermodynamic parameters, to study possible molecular and structural changes of mustard gas in the composition of the medium.
Methods. The Gaussian software package with the GaussView visualizer was used to construct and visualize the structure of the sulfur mustard molecule and its interaction with the aquatic environment. To carry out the calculation (calculation tipe FREQ), the standard Gaussian ab initio – Hartley-Fock (RHF) and post-Hartley-Fock (MP2) methods were chosen, which alternated with calculations based on the theory of the density function (DFT): B3LYP and B3LYP-FC. The semiempirical RPM6 method is used as a boundary factor.
Results. It is shown that only a comprehensive analysis of the state of the molecule makes it possible to identify the specific contribution of each type of interaction to the structure and properties of the molecule. In an aqueous environment, the mustard gas molecule has a high stability potential, but exposure to a real molecular environment leads to a change in polarizability, atomic charge, and dipole moment vector, and in the excited state of the molecule, one of the C1-Cl1 bonds is maximally activated, practically doubling its length.
Conclusions. Despite the very poor solubility of mustard gas in water, its intermolecular interaction with the medium leads to a redistribution of energy characteristics and the formation of a nonequilibrium polarizable state of the mustard molecule in the structure of the aquacomplex, possible further destruction with the formation of toxic products, including onium cations. Further development of the obtained results will make it possible to justify the choice of conditions for targeted activation of the mustard gas molecule for detoxification in aqueous media and body fluids.
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Effect of amphiphilic polymers on the photodynamic activity of methylene blue and rose bengal in vitro experiments

https://doi.org/10.58224/2619-0575-2025-8-4-5
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Abstract
Objectives: To study the effect of amphiphilic polymers on the dark and photoinduced toxicity of dyes with photosensitizing properties – methylene blue (MB) and rose bengal (RB) – in in vitro experiments.
Methods. In vitro experiments were carried out on human lung carcinoma A549 cells and on cultures of gram-negative (Pseudomonas aeruginosa) and gram-positive (Staphylococcus aureus) bacterial cells using a phototherapeutic LED with a wavelength of λ = 530 nm (for the RB) or λ = 660 nm (for the MB).
Results. Amphiphilic polymers (Pluronic F-108 and poly-N-vinylpyrrolidone) were shown to enhance the dark and photoinduced toxicity of dyes. MB was also shown to exhibit greater activity (compared to RB) in photodynamic inactivation of Gram-negative bacteria, while RB (compared to MB) was shown to exhibit greater activity in the inactivation of Gram-positive bacteria.
Conclusions. MB in combination with amphiphilic polymers is a potential drug of choice for both photodynamic therapy (PDT) of cancer and antibacterial PDT of Gram-negative bacteria. At the same time, RB-based systems hold promise for the development of antibacterial PDT of Gram-positive bacteria.
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Influence of the complex phytogenic additive “Resovet” on detoxification systems, antioxidant protection, productivity and intestinal microbiocenosis in broilers under mycotoxicosis conditions

https://doi.org/10.58224/2619-0575-2025-8-4-6
Abstract
Mycotoxin contamination of feed poses a serious threat to the poultry industry, causing significant economic losses. Traditional adsorbents are ineffective against a wide range of toxins and can reduce the nutritional value of feed. Therefore, developing strategies to activate the animal's endogenous detoxification systems is a pressing issue. This study examined the efficacy of the complex phytogenic supplement (CPS) "Rezovet," containing N-acetylcysteine (NAC), alkylresorcinols, and indole compounds, under experimental mycotoxicosis induced by zearalenone (ZEN) and ochratoxin A (OA). An in vitro experiment on the human hepatoma cell line HepG2 demonstrated that "Rezovet" and its components reliably activate nuclear factor 2 (NRF2), the main regulator of the antioxidant and detoxification response. NRF2 activation was accompanied by an increase in glutathione-S-transferase (GST) gene mRNA expression and its total activity. Furthermore, NAC and indole-3-propionic acid induced a cytoprotective autophagic response in ZEN-exposed cells. Inhibition of autophagy by chloroquine eliminated the protective effect. In an in vivo experiment on Cobb-500 broilers (n=120), the addition of Rezovet (0.5 kg/t feed) to a diet contaminated with ZEN (0.5 mg/kg) and OA (0.25 mg/kg) significantly (p<0.05) reduced liver damage and oxidative stress (a 35% decrease in malondialdehyde levels, a 50% increase in glutathione), while simultaneously increasing GST activity by 40%. Significant improvements in productivity were recorded: livestock survival increased by 4.2%, live weight at 28 days increased by 8.5%, and feed conversion improved by 5.7% compared to the group receiving mycotoxins alone. Metagenomic analysis revealed a 152% increase in the proportion of the commensal bacterium Akkermansia muciniphila in the caecal microbiome and a suppression of urease-producing bacteria (Proteus spp., Klebsiella spp.) in the litter. The synergistic mechanism of action of Rezovet, combining the activation of cellular defense systems and the modulation of microbial communities through mechanisms described in the theory of microbial autoregulation, is discussed. Rezovet is shown to be an effective non-adsorptive agent for the biological detoxification of mycotoxins and microbiome management.
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Highly dispersed modifier of cement composites based on natural wollastonite

https://doi.org/10.58224/2619-0575-2025-8-4-7
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Abstract
Objectives: development of a highly dispersed modifier based on natural vollastonite, which ensures the production of construction products with improved physical and mechanical properties.
Methods. The evaluation of the raw materials and the effect of their highly dispersed suspension obtained by ultrasonic dispersion on the structure and properties of cement stone and fine-grained concrete was performed using methods specified in GOST R 56593-2015 and GOST 10060-2012, as well as scanning electron microscopy, laser diffraction, nitrogen porometry, and X-ray phase analysis.
Results. The pozzolanic activity of the highly dispersed vollastonite additive was determined to be 87.3 mg/g, and it was confirmed by a 18.2% decrease in the intensity of Portlandite X-ray reflexes in the modified cement stone samples. The corrected frost resistance of the modified fine-grained concrete is noted, which is due to the integral homogeneous microstructure and the reduction in the total porosity of the cement stone from 0.0043 to 0.0019 cm3/g, i.e., by 2.4 times, compared to the control samples, with an increased concentration of crystalline phases of wateerite μ-CaCO3 and wairakite Ca(AlSi2O6)2∙2H2O. It was found that cement stone with a highly dispersed modifier has a relative increase of 32.4% and 5.4% in the concentration of crystalline phases of alite 3CaO∙SiO2 and belite β-2CaO∙SiO2, respectively.
Conclusions. The possibility of using mineral powder of substandard natural wollastonite with a specific surface area of 45786 cm2/cm3 and a particle size of 2.17 μm as a modifier of the structure and properties of fine-grained concrete has been proven and scientifically substantiated. A highly dispersed suspension of wollastonite with an average particle size of 0.405 μm, obtained by ultrasonic dispersion of the initial raw material in an aqueous medium of a polycarboxylate ester-based stabilizer for 5 minutes, with a content of 10% of the cement mass in fine-grained concrete, allows for the production of products with a bending strength of 6.8 MPa, a compressive strength of 58.5 MPa, and a frost resistance rating of F500.
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Formation of diesel fuel aerosols in the presence of propylene oxide and its derivatives

https://doi.org/10.58224/2619-0575-2025-8-4-8
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Abstract
Studying the formation of diesel fuel aerosols in the presence of propylene oxide and its derivatives in a laboratory setup allows us to closely approximate the process of real-life mixture formation in diesel engines and determine the influence of these compounds on combustion efficiency and exhaust smoke.
Objective. To identify differences in the aerosol formation characteristics of diesel fuel without additives and diesel fuel containing propylene oxide and its derivatives as additives.
Methods. The method involves using a steam generator to generate aerosols and a high-speed video camera to capture all stages of aerosol formation. A high-speed CMOS video camera, "Phantom MIRO M310" (image type – 1080p), was used to record the process under study. monochrome; maximum resolution 1280×800 pixels; maxi-mum shooting speed – 6.5 105 fps; minimum exposure time – 1 μs; maximum image bit depth – 12 bits). A SIGMA 50 mm 1:2.8D MACRO EX lens (focal length – 50 mm, relative aperture – 2.8) was used for video recording. A Multiled PT-V9 GS Vitec LED illuminator (number of LEDs – 24; luminous flux – 7700 lm; power – 84 W, disper-sion angle – 30º) was used to illuminate the recording area. A matte polycarbonate screen (2 mm thick) was used to diffuse the light from the illuminator. The LED illuminator and CMOS video camera were placed opposite each other so that the optical axis of the camera coincided with the direction of the luminous flux of the illuminator.
Results and conclusions. Introduction into the diesel engine Adding 0.1% propylene oxide and its derivatives to fuel reduces the onset of intense fuel evaporation by up to two times. In a real engine, this effect will significantly reduce the size of liquid diesel fuel droplets in the cylinder, leading to more complete combustion and reduced soot formation. This results in increased power, reduced fuel consumption, and reduced exhaust smoke.
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Sorption characteristics of bacterial cellulose obtained from the symbiotic culture of Medusomyces gisevii

https://doi.org/10.58224/2619-0575-2025-8-4-9
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Abstract
The structural and sorption characteristics of bacterial cellulose (BC) synthesized by the symbiotic culture of Kombucha Medusomyces gisevii in nutrient media with different carbon sources (3% sucrose, 6% sucrose, 6% molasses) were studied. It was found that the maximum specific yield of BC biomass was observed when using 6% molasses (11.807 g/g), while the highest content of pure cellulose was recorded in a medium with 6% sucrose (3.81%). Scanning electron microscopy and gas adsorption analysis showed that lyophilized BC samples have a developed macroporous structure. The sorption capacity of the materials with respect to the cationic dye methylene blue was studied. It was found that lyophilized BC possesses a significantly higher sorption capacity (22.809 mg/g) compared to the native film dried by convection (11.689 mg/g). The potential of using bacterial cellulose as a basis for sorption materials and functional carriers is demonstrated.
Objectives: study of the influence of cultivation conditions and drying methods on the structural, morphological and adsorption characteristics of bacterial cellulose.
Methods. Nutrient media with varying carbon sources were used for cultivation. Sample structure was examined using a Nova NanoSem 450 scanning electron microscope (FEI Company, USA) and a TriStar II 3020 gas adsorption analyzer (Micromeritics, USA). Sorption capacity was determined using a Nabi spectrophotometer (MicroDigital Co., Republic of Korea) based on the absorption of methylene blue from an aqueous solution.
Results. Optimal cultivation conditions for maximum biomass yield and cellulose content were determined. It was found that freeze-drying produces a material with a high specific surface area and a developed porous structure, resulting in increased sorption activity.
Conclusions. Bacterial cellulose, especially its lyophilized form, demonstrates high potential as an effective and biocompatible sorbent, as well as a promising carrier of active substances and medicinal preparations.
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Adsorption of methylene blue by activated pyrolysis products of sunflower seed husks

https://doi.org/10.58224/2619-0575-2025-8-3-1
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Abstract
In the context of the global environmental crisis caused by the rapid growth of industrial and household waste, the search for effective methods of their recycling is becoming a key task of sustainable development. Traditional disposal methods, such as burial or incineration, not only require significant resources, but also lead to atmospheric pollution with negatively biologically active gases. In this context, pyrolysis of carbon-containing waste represents a promising alternative combining environmental safety and economic feasibility. Unlike combustion, pyrolysis takes place in an environment with a limited oxygen content, which minimizes CO and CO2 emissions, and also allows for the production of valuable secondary products — pyrolysis gases, liquid and solid carbon materials. The latter are suitable for use as adsorbents. Activation of pyrolysis products by chemical reagents (alkalis, acids, or steam) is used to increase the adsorption capacity, which significantly increases their porosity and adsorption capacity. In this work, the adsorption properties of sunflower husk pyrolysis products activated with an aqueous 2 M solution of potassium hydroxide (KL-21(A)), sunflower husk pyrolysis products combined with bentonite clay (KL-21(A)) and pyrolysis products of crushed worn car tires (KR-21(A)) were determined. Their effectiveness in terms of adsorption of methylene blue (MG), a model cationic dye widely used in assessing the absorption capacity of adsorbents, has been studied by spectrophotometric method. Kinetic dependences of adsorption have been established, and the maximum adsorption capacities of experimental materials have been determined depending on MG concentration. The results of experimental studies allow us to conclude that the activation of pyrolysis products of crop and communal waste with potassium hydroxide improves the adsorption characteristics of the developed material.
Objectives: to identify the adsorption properties of pyrolysis products of sunflower seed husk KL-21(A) activated with an aqueous 2 M solution of potassium hydroxide, pyrolysis products of sunflower seed husk combined with bentonite clay KL-21(A) and pyrolysis products of worn-out automobile tires KR-21(A).
Methods. A Nabi MicroDigital spectrophotometer (South Korea), laboratory instruments and reagents were used to study the adsorption properties by the spectrophotometric method.
Results. Graphical dependences of the absorption capacity on the duration and rate of adsorption are revealed, and adsorption isotherms are constructed and analyzed.
Conclusions. An adsorption-active material based on pyrolysis products of sunflower seed husks and pyrolysis products of worn-out automobile tires was obtained. The adsorption capacity of CL-21(A) samples was 474 mg/g, CLG-21(A) – 131 mg/g, and KR-21(A) – 351 mg/g. The obtained isotherms are determined by the Langmuir model.
It was found that the adsorption equilibrium occurs after 6 hours in KL-21(A) and a day later in KL-21(A) and KR-21(A).
It was found that the highest rate of adsorption is characteristic of the KL-21(A) sample and amounted to 0.00094 mmol/min or 0.300 mg/min in the first 15 minutes of exposure.
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