E. I. Efremova, M. Lazov, M. R. Kobrin, V. V. Fomichev
{"title":"Solid solutions in disulfide systems Re(IV)S2–Ti(IV)S2, Re(IV)S2–Mo(IV)S2, and Re(IV)S2–W(IV)S2","authors":"E. I. Efremova, M. Lazov, M. R. Kobrin, V. V. Fomichev","doi":"10.32362/2410-6593-2024-19-3-258-266","DOIUrl":"https://doi.org/10.32362/2410-6593-2024-19-3-258-266","url":null,"abstract":"Objectives. Chalcogenides of transition elements with low oxidation states, as well as their substituted derivatives, remain a poorly studied class of chemical compounds. Rhenium disulfide has many distinctive features and great application potential as a new twodimensional semiconductor. This is due to its unusual structure and unique anisotropic properties. The presence of weak interlayer bonding and a unique distorted octahedral (1T) structure suggests the possibility of creating new phases on its basis. The aim of this work is to obtain and study phases in systems Re(IV)S2–Ti(IV)S2, Re(IV)S2–Mo(IV)S2, and Re(IV)S2–W(IV)S2.Methods. The samples were obtained by high-temperature solid-phase ampoule synthesis in a vacuum. The study was carried out using X-ray phase analysis and X-ray photoelectron spectroscopy.Results. The regions of existence of solid solutions, intercalates and two-phase regions in the resulting systems were established.Diffraction patterns were obtained for the new phases and the crystal lattice parameters were calculated. Based on data relating to the binding energies of core electrons with the nucleus, the study showed the valence states of the elements after synthesis. The study also confirmed that all phases obtained as a result of synthesis contain transition elements in the oxidation state (IV).Conclusions. Intercalated solid solutions are formed in areas rich in rhenium, while in areas close to titanium and molybdenum disulfides, intercalated phases are attained. In the ReS2–WS2 system there is a region of solid solutions, including 30, 50, and 70 mol % rhenium disulfide. Their structure is a polymorphic modification of the structure of the original components. The presence of rhenium, molybdenum, and tungsten in these phases in the oxidation state (+IV) was confirmed. The data obtained on phase formation in dichalcogenide systems can be practically used in the creation of materials with unique electronic, magnetic, and optical properties with a wide range of applications.","PeriodicalId":12215,"journal":{"name":"Fine Chemical Technologies","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-07-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141672050","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
V. Loginov, M. Gubenko, A. Burdennyy, I. Pronina, P. Postnikov, Yu. A. Efimova, F. V. Radus, E. S. Mochalova, T. Kazubskaya
{"title":"Methylation of a group of microRNA genes as a marker for the diagnosis and prognosis of non-small cell lung cancer","authors":"V. Loginov, M. Gubenko, A. Burdennyy, I. Pronina, P. Postnikov, Yu. A. Efimova, F. V. Radus, E. S. Mochalova, T. Kazubskaya","doi":"10.32362/2410-6593-2024-19-3-232-239","DOIUrl":"https://doi.org/10.32362/2410-6593-2024-19-3-232-239","url":null,"abstract":"Objectives. Lung cancer, representing a difficult-to-diagnose heterogeneous malignant neoplasm, is characterized by an asymptomatic course up to late stages, a high incidence of adverse outcomes, and a high probability of metastasis. Its most common form is non-small cell lung cancer (NSCLC). Recent studies have demonstrated a significant role of non-coding RNAs—in particular, microRNAs—in the development of NSCLC. MicroRNAs, which function as post-transcriptional regulators of the expression of protein-coding genes, including those associated with oncogenesis, are involved in the processes of cell proliferation, differentiation, and apoptosis. One of the approaches for regulating the expression of microRNAs themselves is to change the methylation of the CpG island adjacent to the microRNA gene or overlapping it. It has been shown that microRNA genes are several times more likely to undergo methylation than protein-coding genes. The aim of the present work is to study changes in the level of methylation of a number of microRNA genes and compile a potential panel of markers for the diagnosis and prognosis of NSCLC.Methods. Samples of NSCLC tumors were collected and clinically characterized at the Blokhin National Medical Research Center of Oncology, Ministry of Health of the Russian Federation, Moscow, Russia. High-molecular-weight DNA was isolated from tissues using a standard method. The level of methylation was analyzed using bisulfite conversion of DNA and quantitative methyl-specific polymerase chain reaction with real-time detection. The significance of differences between the studied groups was assessed by the nonparametric Mann–Whitney U test for independent samples. Differences were considered significant at p < 0.05.Results. The analysis of methylation levels of microRNA genes revealed a significant (p < 0.05) increase in the methylation level of eight microRNA genes: MIR124-1/2/3, MIR125В-1, MIR129-2, MIR137, MIR375, MIR1258, and MIR339 (p < 0.01, false discovery rate ≤ 0.25). On the basis of receiver operating characteristic analysis, a panel of markers is proposed for the diagnosis of NSCLC according to the nature of methylation of the studied microRNA genes in the tumor and in the normal tissue.Conclusions. Our results, which contribute to the understanding of molecular mechanisms involved in NSCLC development, can be used in the development of new diagnostic and prognostic approaches in clinical oncology.","PeriodicalId":12215,"journal":{"name":"Fine Chemical Technologies","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-07-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141672007","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
D. S. Polyansky, E. I. Ryabova, A. A. Derkaev, N. S. Starkov, I. S. Kashapova, D. Shcheblyakov, A. P. Karpov, I. Esmagambetov
{"title":"Development of technology for culturing a cell line producing a single-domain antibody fused with the Fc fragment of human IgG1","authors":"D. S. Polyansky, E. I. Ryabova, A. A. Derkaev, N. S. Starkov, I. S. Kashapova, D. Shcheblyakov, A. P. Karpov, I. Esmagambetov","doi":"10.32362/2410-6593-2024-19-3-240-257","DOIUrl":"https://doi.org/10.32362/2410-6593-2024-19-3-240-257","url":null,"abstract":"Objectives. To develop an effective technology for the cultivation of Chinese hamster ovary (CHO) cells stably producing GamP2C5 antibody which is a component I of the GamCoviMab candidate drug for emergency prevention and therapy of infection caused by SARS-CoV-2 virus; to select optimal cultivation parameters and to scale this technology in production.Methods. The study was performed on CHO GamP2C5 (clone 78) cell culture, producing a single-domain antibody fused to the Fc fragment of human IgG1 GamP2C5. Different culture media and supplements were used. Cells were cultured in Erlenmeyer flasks, Biostat® RM 20 wave-mixed bioreactor, Ambr® 250 mini bioreactors, STR 200 stirred-tank bioreactor.Results. Using molecular-genetic and biotechnological methods, a stable clone producer of CHO GamP2C5 antibody, clone 78, was obtained. Then a technique was worked out for the cultivation of the obtained clone producer on different culture media. The most suitable cultivation regimes, culture media, and optimal supplements were selected. This technology was tested in laboratory conditions in a 10-L reactor, and then successfully scaled up for production at the MedGamal Branch of the Gamaleya National Research Center for Epidemiology and Microbiology.Conclusions. This study demonstrates the fundamental feasibility of developing and scaling up a culture technology, in order to produce a drug based on a modified single-domain antibody with virus neutralizing activity against different strains of SARS-CoV-2 virus.","PeriodicalId":12215,"journal":{"name":"Fine Chemical Technologies","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-07-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141672893","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"PROTAC® technology and potential for its application in infection control","authors":"M. A. Zakharova, M. Chudinov","doi":"10.32362/2410-6593-2024-19-3-214-231","DOIUrl":"https://doi.org/10.32362/2410-6593-2024-19-3-214-231","url":null,"abstract":"Objectives. To describe the pharmaceutical technology of controlled degradation of protein molecules (PROTAC®, Proteolysis Targeting Chimera), approaches to the design of the PROTAC® molecule, methods of ligand and linker selection and synthesis, as well as the application of this technology in dealing with a variety of diseases and the possible limitations of its use.Results. The review covers 77 sources, mostly from 2020–2023. The review outlines the principle of PROTAC® technology: the construction of a chimeric molecule consisting of three fragments. One fragment specifically binds to the biotarget, another recruits the proteolytic system of the host cell, and the third binds them together. The main areas of the current development of the technology are described herein, as well as the opportunities and limitations of chimeric molecules in the fight against different types of infectious diseases.Conclusion. The potential to use PROTAC® technology to combat cancer as well as neurodegenerative, autoimmune, and infectious diseases is shown.","PeriodicalId":12215,"journal":{"name":"Fine Chemical Technologies","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-07-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141672385","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"L-Ornithine derivatives with structural hetaryl and alkyl moiety: Synthesis and antibacterial activity","authors":"T. G. Bodrova, U. A. Budanova, Y. Sebyakin","doi":"10.32362/2410-6593-2024-19-3-202-213","DOIUrl":"https://doi.org/10.32362/2410-6593-2024-19-3-202-213","url":null,"abstract":"Objectives. Cationic amphiphiles and antimicrobial peptidomimetics are widely investigated as antibacterial agents due to their membrane-active mechanism of action. Particular attention is focused on the rational design of compounds in this class to achieve high antimicrobial activity. The aim of the present work is to synthesize bivalent cationic amphiphiles with L-ornithine as a branching element and evaluate the effectiveness of their antibacterial action. The compounds differ in terms of hydrophobicity due to the variation of N-terminal aliphatic amino acids in the polar block and alternation of dialkyl and alkyl-hetaryl radicals in the lipophilic block.Methods. For the synthesis of nonpolar fragments of amphiphiles, methods for the alkylation of amines with alkyl bromides in the presence of carbonate salts were used. The formation of amide bonds of L-ornithine derivatives with amino acids was carried out using the carbodiimide method. For the reaction products recovery from the reaction mixture, column chromatography on silica gel and aluminum oxide activated Brockmann Grade II was used. The antimicrobial activity of the synthesized compounds against gram-positive B. subtilis 534 and gram-negative E. coli M17 bacterial strains was evaluated. Minimum inhibitory concentration (MIC) values were recorded using a serial microdilution method in a nutrient medium.Results. Developed schemes for the preparation of bivalent cationic amphiphiles based on L-ornithine derivatives are presented. Differences in the structure of aliphatic amino acids (glycine, β-alanine, γ-aminobutyric acid (GABA)), in the length of alkyl radicals (C8, C12), or in the presence of an indole moiety, were used in the design of target compounds. The high antibacterial activity of the synthesized compounds was demonstrated. The most active compounds were lipoamino acids with terminal GABA residues and asymmetrical non-polar block (tryptamyl–dodecylamine). The MIC values were 0.39 μg/mL for gram-positive bacteria and 1.56 μg/mL for gram-negative bacteria. A GABA derivative with a symmetrical lipophilic moiety based on dioctylamine demonstrated activity with an MIC of 0.78 μg/mL against B. subtilis and 3.12 μg/mL against E. coli.Conclusions. Nine new lipoamino acid cationic bivalent amphiphiles based on L-ornithine were synthesized. The structure of the obtained compounds was confirmed by nuclear magnetic resonance 1H spectroscopy and mass spectrometry data. Leading compounds in antimicrobial activity against both gram-positive and gram-negative strains of bacteria were determined. The influence of the degree of lipophilicity in the asymmetric nonpolar block on the level of exhibited antimicrobial activity is demonstrated.","PeriodicalId":12215,"journal":{"name":"Fine Chemical Technologies","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-07-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141676797","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
N. Sevostyanova, S. Batashev, A. S. Rodionova, D. K. Kozlenko
{"title":"Effect of 2-hexanol and methanol on the one-pot process of dehydration and alkoxycarbonylation for the synthesis of esters","authors":"N. Sevostyanova, S. Batashev, A. S. Rodionova, D. K. Kozlenko","doi":"10.32362/2410-6593-2024-19-3-192-201","DOIUrl":"https://doi.org/10.32362/2410-6593-2024-19-3-192-201","url":null,"abstract":"Objectives. To study the possibility of one-pot synthesis (combination of two processes in one reactor) for the following pairs of processes: (1) dehydration of 2-hexanol and isomerizing alkoxycarbonylation of the resulting 2-hexene, in order to obtain 2-hexyl heptanoate, and (2) dehydration of 2-hexanol and isomerizing methoxycarbonylation of the resulting 2-hexene, in order to obtain methyl esters of C7 carboxylic acids. To investigate the effect of the concentrations of 2-hexanol and methanol on the rate of the one-pot synthesis.Methods. One-pot synthesis was studied in a toluene medium in a steel batch reactor designed to operate at elevated pressure and equipped with a glass insert, a magnetic stirrer, a sampler, and gas input and discharge devices. Samples of the reaction mass were taken during the combined process and were analyzed by means of gas–liquid chromatography with a flame ionization detector.Results. The possibility of one-pot combination was demonstrated for 2-hexanol dehydration catalyzed by methanesulfonic acid, as well as for the isomerizing alkoxycarbonylation of the resulting 2-hexene with 2-hexanol and CO, catalyzed by the Pd(PPh3)2Cl2–XANTPHOS–methanesulfonic acid system. The dependencies of the rates of the dehydration of 2-hexanol and the formation of esters of C7 carboxylic acids on the concentration of 2-hexanol were shown to pass through a maximum. The possibility of the one-pot process was proved for the synthesis of esters from 2-hexanol, methanol, and CO with the predominant formation of heptanoic acid esters in the presence of the above catalytic system. The rates of dehydration of 2-hexanol and the formation of 2-hexyl esters of C7 carboxylic acids were found to decrease with increasing the concentration of methanol in the reaction mass. Under mild conditions (temperature 115°C, CO pressure 3 MPa) with the addition of methanol, the total fraction of 2-hexyl and methyl heptanoic acid esters among C7 carboxylic acid esters was determined to be 85.5%.Conclusions. The reactions of intramolecular acid–catalytic dehydration of 2-hexanol and isomerizing alkoxycarbonylation of the resulting 2-hexene, catalyzed by the Pd(PPh3)2Cl2–XANTPHOS–methanesulfonic acid system, can be performed as a one-pot process. Methanesulfonic acid simultaneously functions as a catalyst for the dehydration of 2-hexanol and a cocatalyst for the palladium–phosphine system for the alkoxycarbonylation of hexenes. In the presence of the Pd(PPh3) 2Cl2–XANTPHOS–methanesulfonic acid catalytic system, processes for the synthesis of heptanoic acid esters from 2-hexanol, methanol, and CO can be combined within one reactor. An increase in the methanol concentration negatively affects the rate of the dehydration of 2-hexanol and the formation of 2-hexyl esters of C7 carboxylic acids. A small amount of methanol in the reaction mass leads to an increase in the fraction of heptanoic acid esters among C7 carboxylic acid esters.","PeriodicalId":12215,"journal":{"name":"Fine Chemical Technologies","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-07-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141676850","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
V. A. Gabrin, T. Nikiforova, V. Kozlov, P. Razgovorov
{"title":"Concentration of heavy metal ions from aqueous media under dynamic conditions using a composite sorbent based on chitosan and silica","authors":"V. A. Gabrin, T. Nikiforova, V. Kozlov, P. Razgovorov","doi":"10.32362/2410-6593-2024-19-3-183-191","DOIUrl":"https://doi.org/10.32362/2410-6593-2024-19-3-183-191","url":null,"abstract":"Objectives. The study set out to investigate the sorption, toxicological, and regeneration properties of a composite sorbent based on chitosan hydrogel and unsuspended silicon dioxide (chitosan–colloidal silica), which manifest themselves under dynamic conditions of purification of aqueous solutions, as a means of removing heavy metal ions.Methods. The total dynamic exchange capacity of a chitosan–colloidal silica composite sorbent was evaluated under dynamic sorption conditions by passing solutions containing Zn(II), Cd(II), Cu(II), and Cr(III) ions having a concentration of 240–251 mg/L through a fixed sorption bed. The method for determining acute toxicity using daphnia (Daphnia magna Straus) is based on the direct calculation of the mortality of daphnia exposed to toxic substances contained in the test aqueous extract in comparison with a reference culture in samples that do not contain toxic substances. The regeneration ability of the sorbent was assessed by counting the number of sorption–desorption cycles using 0.1 M NaOH and 0.1 M NaHCO3 eluents, as well as aqueous solutions of H2O2 (1 and 3%).Results. The effectiveness of the chitosan–colloidal silica composite sorbent in the process of dynamic purification of aqueous media to remove Cu(II), Zn(II), Cd(II), and Cr(III) ions was established. After determining the times of ion breakthrough and saturation of the developed sorbent, its dynamic exchange capacity was calculated by processing the kinetic curves of sorption of heavy metal ions under dynamic conditions. The results of regeneration of the sorbent were presented in the context of the possibility of its reuse. It is shown that the sorbent can withstand up to five sorption–desorption cycles while maintaining a level copper cation extraction above 90%.Conclusions. Analysis of the kinetic curves demonstrated that the driving force behind the removal of heavy metals from aqueous media by means of the obtained sorbent is the external diffusion mass transfer of ions from the mobile phase of the solution. Biotesting of samples showed that the developed chitosan-based sorbent does not have acute toxicity.","PeriodicalId":12215,"journal":{"name":"Fine Chemical Technologies","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-07-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141675126","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Congratulations to Academician Ivan Aleksandrovich Novakov on his 75th birthday!","authors":"A. Editorial","doi":"10.32362/2410-6593-2024-19-3-181-182","DOIUrl":"https://doi.org/10.32362/2410-6593-2024-19-3-181-182","url":null,"abstract":"<jats:p>.</jats:p>","PeriodicalId":12215,"journal":{"name":"Fine Chemical Technologies","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-07-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141675476","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Obtaining chitosan sulfate nanoparticles in an aqueous medium and their colloidal protection with polysaccharides","authors":"V. Erasov, Yu. O. Maltseva","doi":"10.32362/2410-6593-2024-19-2-111-126","DOIUrl":"https://doi.org/10.32362/2410-6593-2024-19-2-111-126","url":null,"abstract":"Objectives. To develop a method to obtain a hydrosol of the salt of chitosan with sulfuric acid—chitosanium sulfate (ChS) hydrosol—and to study the effect of various water-soluble polysaccharides on its stability over time, as well as its resistance to indifferent and non-indifferent electrolytes.Methods. κ-Carrageenan, sodium alginate (SA), and xanthan were used as polymers which perform the function of colloidal protection for ChS nanoparticles. Capillary viscometry was used to study the viscosity of polymer solutions, their molecular weight, and their adsorption on ChS. The stability of the sols over time and their resistance to indifferent and non-indifferent electrolytes were evaluated photometrically. The hydrosol particle size was determined by means of dynamic light scattering.Results. On the surface of ChS, κ-carrageenan is adsorbed most strongly over a wide range of concentrations. The graphs of the dependencies of the relative change in the turbidity of sols with the addition of various polysaccharides on their weight concentration at a sol lifetime of 2 days have the shape of curves with a maximum. Sols with the addition of 0.0125% SA and κ-carrageenan in the range of 0.04% have the greatest stability over time. According to dynamic light scattering data, the average particle size of freshly prepared sols with the addition of the polymers to ensure their greatest stability over time are 10.8 nm and 14.6 nm, respectively. For freshly prepared sols without polysaccharides, this size is 24.8 nm. The hydrosol coagulation threshold with an indifferent electrolyte (NaCl) is 9.3 times higher than that with a non-indifferent electrolyte (Na2SO4). κ-Carrageenan and SA protect the hydrosol from coagulation with an indifferent electrolyte (NaCl) at all their used amounts. At the same polymer concentrations, no protection from coagulation with a non-indifferent electrolyte (Na2SO4) was observed.Conclusions. A method was developed to obtain ChS hydrosol with a positive particle charge. The stability of ChS sols over time was studied both without and with the addition of SA, κ-carrageenan, and xanthan. Sol coagulation thresholds with indifferent and non-indifferent electrolytes, as well as the protective numbers for κ-carrageenan and SA against the coagulation of hydrosols with these electrolytes, were established. The mechanism of stability of sols at certain concentrations of water-soluble polysaccharides was explained using data on the adsorption of these polysaccharides on the surface of chitosan treated with a solution of sulfuric acid. Based on the results of the work, it can be concluded that SA and κ-carrageenan can be used for the efficient stabilization of ChS hydrosols over time and for the colloidal protection of ChS from coagulation with sodium chloride.","PeriodicalId":12215,"journal":{"name":"Fine Chemical Technologies","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-05-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141013809","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
V. S. Kuzevanov, S. Zakozhurnikov, G. Zakozhurnikova
{"title":"Effect of leakage of volatile synthesis products on silicon carbide yield in an electrothermal fluidized bed reactor","authors":"V. S. Kuzevanov, S. Zakozhurnikov, G. Zakozhurnikova","doi":"10.32362/2410-6593-2024-19-2-163-173","DOIUrl":"https://doi.org/10.32362/2410-6593-2024-19-2-163-173","url":null,"abstract":"Objectives. To calculate the effect of leakage of volatile synthesis products on silicon carbide yield in an electrothermal fluidized bed reactor, as well as to develop a general model of the synthesis of finely divided silicon carbide. This will be achieved by particularizing a mathematical model of leakage of volatile products of chemical reactions from the reaction volume of the reactor with the fluidizing inert gas.Methods. As a method to produce silicon carbide, synthesis in an electrothermal fluidized bed was studied. The model of leakage of volatile products was validated by comparing the calculation results with existing experimental data on the SiC synthesis in a hightemperature fluidized bed reactor. The comparison parameters were: mass yield of silicon carbide, and the total synthesis time in a reactor with batch loading of silicon dioxide into the reaction volume.Results. The value of the parameter p in the general model of SiC synthesis in a fluidized bed was established. The parameter p is equal to the ratio of the number of carbon-containing particles involved in the formation of SiO, to the total number of silicon dioxide particles. It also characterizes the composition of stable complexes of particles of the charge at various operating temperatures of the fluidized bed. The discrepancy between the calculated and experimental values of the masses of the synthesized silicon carbide was shown not to exceed 15.5% at a high temperature of the fluidized bed (T = 1800°C) and decreases with a decrease in the operating temperature to 4.7% at T = 1450°C.Conclusions. The general computational model for silicon carbide synthesis with a built-in procedure for calculating the leakage of volatile products of chemical reactions enables the variants of SiC production in electrothermal fluidized bed reactors to be analyzed. In this case, it is important to establish an energy-efficient working cycle without preliminary expensive experimental studies.","PeriodicalId":12215,"journal":{"name":"Fine Chemical Technologies","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-05-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141013423","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}