S.M. Adekenov, G. M. Baysarov, A.N. Zhabaeva, A. Sabitova, A. S. Adekenova, V. Polyakov
The article presents the results of the development of technology for isolating essential oil from the buds of Populus balsamifera L. and a medicinal substance based on it. For the first time, a technology has been developed for the quantitative isolation of essential oil from the buds of Populus balsamifera L. by the barothermal method at a temperature of 140 ºC, under a vacuum of 1333‒2000 Pa. The main components of the essential oil of Populus balsamifera L. buds, isolated by the barothermal method, were determined to be α-bisabolol, β-eudesmol, and 2-phenylethyl-2-methylbutanoate. A technological scheme for the production of essential oil substance from Populus balsamifera L. buds has been developed, including 2 stages of the main technological process and 2 stages of auxiliary work, and its pilot industrial regulations. The control points during the isolation and preparative production of the essential oil substance from the Populus balsamifera L. buds are the major components α-bisabolol and β-eudesmol. The main critical points in the production of a substance based on the essential oil of Populus balsamifera L. buds are pressure, temperature, and duration of isolation. The stages of production of the substance are controlled using a standard sample of α-bisabolol (1). A quantitative determination of 108 components of essential oil from Populus balsamifera L. buds was carried out, as well as standardization for organoleptic properties and major components. A comparative analysis of essential oil from Populus balsamifera L. buds collected in the vicinity of Karaganda and the North Kazakhstan region was carried out. A substance based on essential oil from Populus balsamifera L. buds has antimicrobial, wound-healing, and antitumor activities with relatively low toxicity.
{"title":"Technology for Isolation Essential Oil from the Buds of Populus balsamifera L.","authors":"S.M. Adekenov, G. M. Baysarov, A.N. Zhabaeva, A. Sabitova, A. S. Adekenova, V. Polyakov","doi":"10.18321/ectj1545","DOIUrl":"https://doi.org/10.18321/ectj1545","url":null,"abstract":"The article presents the results of the development of technology for isolating essential oil from the buds of Populus balsamifera L. and a medicinal substance based on it. For the first time, a technology has been developed for the quantitative isolation of essential oil from the buds of Populus balsamifera L. by the barothermal method at a temperature of 140 ºC, under a vacuum of 1333‒2000 Pa. The main components of the essential oil of Populus balsamifera L. buds, isolated by the barothermal method, were determined to be α-bisabolol, β-eudesmol, and 2-phenylethyl-2-methylbutanoate. A technological scheme for the production of essential oil substance from Populus balsamifera L. buds has been developed, including 2 stages of the main technological process and 2 stages of auxiliary work, and its pilot industrial regulations. The control points during the isolation and preparative production of the essential oil substance from the Populus balsamifera L. buds are the major components α-bisabolol and β-eudesmol. The main critical points in the production of a substance based on the essential oil of Populus balsamifera L. buds are pressure, temperature, and duration of isolation. The stages of production of the substance are controlled using a standard sample of α-bisabolol (1). A quantitative determination of 108 components of essential oil from Populus balsamifera L. buds was carried out, as well as standardization for organoleptic properties and major components. A comparative analysis of essential oil from Populus balsamifera L. buds collected in the vicinity of Karaganda and the North Kazakhstan region was carried out. A substance based on essential oil from Populus balsamifera L. buds has antimicrobial, wound-healing, and antitumor activities with relatively low toxicity.","PeriodicalId":11795,"journal":{"name":"Eurasian Chemico-Technological Journal","volume":"46 2","pages":""},"PeriodicalIF":0.5,"publicationDate":"2024-02-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140455178","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}
This work investigates the electrochemical behavior of hybrid supercapacitors with carbon-based electrodes of different porosity using 5M NaNO3 + 0.5M KBr electrolyte to optimize energy storage processes. Three types of carbon materials were synthesized: activated carbon from rice husk (RH) with a specific surface area of ~2300 m2/g and pore size < 1 nm, and templated carbons from magnesium citrate (MP-8) and glucose with SiO2 as a template (G7), having surface areas of 1976 and 1320 m2/g and pore sizes of 3.4 and 7 nm, respectively. The microporous structure of activated carbon (AC) obtained from RH shows limitations in the diffusion of electrolyte ions, which affects the charge-discharge kinetics. In contrast, the larger mesoporous structures of templated carbons promoted better adsorption and ion transport, significantly affecting the dynamics of redox reactions. The RH/MP-8 hybrid capacitor, combining high surface area and large pore size, demonstrated a 54% increase in specific capacitance, 128% increase in specific energy and 51% increase in energy efficiency at high current densities of 5 A/g, comparing to the symmetric RH/RH hybrid capacitor. This study highlights the critical importance of the relationship between electrode pore structure and electrolyte composition for optimizing supercapacitor performance, which provides valuable information for the development of efficient energy storage technologies.
{"title":"Optimization of the Porous Structure of Carbon Electrodes for Hybrid Supercapacitors with a Redox Electrolyte Based on Potassium Bromide","authors":"V.V. Pavlenko, K.M. Temirkulova, A.Yu. Zakharov, Y.A. Aubakirov, Zh.E. Ayaganov","doi":"10.18321/ectj1542","DOIUrl":"https://doi.org/10.18321/ectj1542","url":null,"abstract":"This work investigates the electrochemical behavior of hybrid supercapacitors with carbon-based electrodes of different porosity using 5M NaNO3 + 0.5M KBr electrolyte to optimize energy storage processes. Three types of carbon materials were synthesized: activated carbon from rice husk (RH) with a specific surface area of ~2300 m2/g and pore size < 1 nm, and templated carbons from magnesium citrate (MP-8) and glucose with SiO2 as a template (G7), having surface areas of 1976 and 1320 m2/g and pore sizes of 3.4 and 7 nm, respectively. The microporous structure of activated carbon (AC) obtained from RH shows limitations in the diffusion of electrolyte ions, which affects the charge-discharge kinetics. In contrast, the larger mesoporous structures of templated carbons promoted better adsorption and ion transport, significantly affecting the dynamics of redox reactions. The RH/MP-8 hybrid capacitor, combining high surface area and large pore size, demonstrated a 54% increase in specific capacitance, 128% increase in specific energy and 51% increase in energy efficiency at high current densities of 5 A/g, comparing to the symmetric RH/RH hybrid capacitor. This study highlights the critical importance of the relationship between electrode pore structure and electrolyte composition for optimizing supercapacitor performance, which provides valuable information for the development of efficient energy storage technologies.","PeriodicalId":11795,"journal":{"name":"Eurasian Chemico-Technological Journal","volume":"142 ","pages":""},"PeriodicalIF":0.5,"publicationDate":"2024-02-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140456154","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}
E. Dmitriyeva, I.A. Lebedev, E.A. Bondar, A. Fedosimova, S. Ibraimova, B.M. Nurbaev, A. S. Serikkanov, B.A. Baytimbetova
This study investigates the effects of annealing time on the optical and electrical properties of tin dioxide coatings, specifically surface resistivity and specific conductivity. The thickness of the film, as well as its density and void density, were calculated from the interference peaks. The results suggest that as the duration of annealing increases, the density of the film decreases and the void volume increases. The lack of interference peaks in the transmission spectra of films containing additives is caused by the development of dendritic structures within the films. As the annealing duration is extended to 6 h, the surface resistivity increases, resulting in a decrease in the specific conductivity of all films. As the duration of annealing increases, the surface resistivity of the films studied increases and therefore their overall quality decreases.
{"title":"Influence of Annealing Time on the Optical and Electrical Properties of Tin Dioxide-Based Coatings","authors":"E. Dmitriyeva, I.A. Lebedev, E.A. Bondar, A. Fedosimova, S. Ibraimova, B.M. Nurbaev, A. S. Serikkanov, B.A. Baytimbetova","doi":"10.18321/ectj1543","DOIUrl":"https://doi.org/10.18321/ectj1543","url":null,"abstract":"This study investigates the effects of annealing time on the optical and electrical properties of tin dioxide coatings, specifically surface resistivity and specific conductivity. The thickness of the film, as well as its density and void density, were calculated from the interference peaks. The results suggest that as the duration of annealing increases, the density of the film decreases and the void volume increases. The lack of interference peaks in the transmission spectra of films containing additives is caused by the development of dendritic structures within the films. As the annealing duration is extended to 6 h, the surface resistivity increases, resulting in a decrease in the specific conductivity of all films. As the duration of annealing increases, the surface resistivity of the films studied increases and therefore their overall quality decreases.","PeriodicalId":11795,"journal":{"name":"Eurasian Chemico-Technological Journal","volume":"34 6","pages":""},"PeriodicalIF":0.5,"publicationDate":"2024-02-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140456233","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}
T.H. Sargsyan, L.A. Stepanyan, M. H. Israyelyan, H.I. Hakobyan, S. M. Jamgaryan, A.A. Gasparyan, A. Saghyan
Using the 9-fluorenylmethoxycarbonyl protecting group, 9-fluorenylmethoxycarbonyl-(S)-β-(N-imidazolyl)-α-alanine protected non-protein amino acid, not described in the literature, were developed. Then 9-fluorenylmethoxycarbonyl-(S)-α-methylphenylalanine, 9-fluorenylmethoxycarbonyl-(S)-α-allylglycine, 9-fluorenylmethoxycarbonyl-(S)-α-propargylglycine were synthesized by the same method. It was shown, that the 9-fluorenylmethoxycarbonyl-(S)-β-(N-imidazolyl)-α-alanine (3) inhibited the growth of Gram-negative Salmonella tуphimurium G-38 and 9-fluorenyl-methoxycarbonyl-(S)-α-methyl-phenylalanine (4) inhibited the growth Gram-positive Bacillus subtilis 17-89 bacteria.
{"title":"The Synthesis and in vitro Study of 9-fluorenylmethoxycarbonyl Protected Non-Protein Amino Acids Antimicrobial Activity","authors":"T.H. Sargsyan, L.A. Stepanyan, M. H. Israyelyan, H.I. Hakobyan, S. M. Jamgaryan, A.A. Gasparyan, A. Saghyan","doi":"10.18321/ectj1546","DOIUrl":"https://doi.org/10.18321/ectj1546","url":null,"abstract":"Using the 9-fluorenylmethoxycarbonyl protecting group, 9-fluorenylmethoxycarbonyl-(S)-β-(N-imidazolyl)-α-alanine protected non-protein amino acid, not described in the literature, were developed. Then 9-fluorenylmethoxycarbonyl-(S)-α-methylphenylalanine, 9-fluorenylmethoxycarbonyl-(S)-α-allylglycine, 9-fluorenylmethoxycarbonyl-(S)-α-propargylglycine were synthesized by the same method. It was shown, that the 9-fluorenylmethoxycarbonyl-(S)-β-(N-imidazolyl)-α-alanine (3) inhibited the growth of Gram-negative Salmonella tуphimurium G-38 and 9-fluorenyl-methoxycarbonyl-(S)-α-methyl-phenylalanine (4) inhibited the growth Gram-positive Bacillus subtilis 17-89 bacteria.","PeriodicalId":11795,"journal":{"name":"Eurasian Chemico-Technological Journal","volume":"36 3","pages":""},"PeriodicalIF":0.5,"publicationDate":"2024-02-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140455987","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}
L.V. Ignatova, Z. K. Urazova, Y. Brazhnikova, N.V. Vedyashkina
A nutrient medium was selected for the efficient production of exopolysaccharide (EPS) by A. pullulans C7 strain. The production of pullulan polysaccharide was evaluated on nutrient media with traditional carbon sources and cheap substrates that were plant wastes. For maximum EPS accumulation, we proposed an optimized Czapek-Dox medium with glucose as a carbon source, sodium nitrate as a nitrogen source, and C/N=232:1 ratio (EPS yield 12.79±0.64 g/l). Medium with grape pomace 5% (EPS yield was 15.08±0.34 g/l) and medium with topinambour tuber hydrolysate 5% (EPS yield was 14.44±0.21 g/l) was proposed as a cheap substrate. Edible films with antimicrobial activity were obtained on the basis of the isolated polysaccharide. The antibacterial activity of films against Escherichia coli 603 and Staphylococcus aureus ST228 was shown when essential oils of rosemary (zones of growth inhibition from 8.41±0.71 to 9.98±0.32 mm) and oregano (zones of growth inhibition from 8.09±0.51 to 9.54±0.24 mm) were added to pullulan. The addition of xanthan gum and glycerol to the films increased their strength and elasticity. The infrared spectrum of the pullulan film showed absorption bands characteristic of polysaccharide structures.
{"title":"Obtaining Edible Pullulan-based Films with Antimicrobial Properties","authors":"L.V. Ignatova, Z. K. Urazova, Y. Brazhnikova, N.V. Vedyashkina","doi":"10.18321/ectj1547","DOIUrl":"https://doi.org/10.18321/ectj1547","url":null,"abstract":"A nutrient medium was selected for the efficient production of exopolysaccharide (EPS) by A. pullulans C7 strain. The production of pullulan polysaccharide was evaluated on nutrient media with traditional carbon sources and cheap substrates that were plant wastes. For maximum EPS accumulation, we proposed an optimized Czapek-Dox medium with glucose as a carbon source, sodium nitrate as a nitrogen source, and C/N=232:1 ratio (EPS yield 12.79±0.64 g/l). Medium with grape pomace 5% (EPS yield was 15.08±0.34 g/l) and medium with topinambour tuber hydrolysate 5% (EPS yield was 14.44±0.21 g/l) was proposed as a cheap substrate. Edible films with antimicrobial activity were obtained on the basis of the isolated polysaccharide. The antibacterial activity of films against Escherichia coli 603 and Staphylococcus aureus ST228 was shown when essential oils of rosemary (zones of growth inhibition from 8.41±0.71 to 9.98±0.32 mm) and oregano (zones of growth inhibition from 8.09±0.51 to 9.54±0.24 mm) were added to pullulan. The addition of xanthan gum and glycerol to the films increased their strength and elasticity. The infrared spectrum of the pullulan film showed absorption bands characteristic of polysaccharide structures.","PeriodicalId":11795,"journal":{"name":"Eurasian Chemico-Technological Journal","volume":"77 1","pages":""},"PeriodicalIF":0.5,"publicationDate":"2024-02-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140455766","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}
B. T. Omarov, K. Zhantasov, M. Zhantasov, Z. Altybayev
The work presents research results of the change comparison of brown coals and the study of the physicochemical properties of humic substances obtained from brown coals of the Karazhyra, Ekibastuz, and Kyzyl-Kiya deposits after hydrodynamic treatment in a rotary-pulsation apparatus. It is shown that the hydromechanical effect on humic acids leads to a change in their composition, accompanied by a decrease in the degree of aromaticity and an increase in the content of oxygen-containing fragments. Mechanical treatment of brown coals under oxidizing conditions maximizes the efficiency of extraction of water-soluble components and humic acids. The structural parameters and functional composition of humic acid molecules during the treatment of brown coals under oxidation-reduction conditions change depending on the conditions. The elemental and functional composition (using IR spectroscopy and potentiometry) of humic substances in brown coals and their molecular weight distribution using size-exclusion chromatography were studied. The influence of the content of metal-binding centers, dispersity, and ash content of humic substances was studied before and after treatment. At a temperature of 70 ºC a rotation time of 10 s, 98.7% of humic acids passes into the solution, which is the best indicator.
{"title":"Changes in the Physicochemical Characteristics of Humic Acids in a Hydrodynamic Rotor-Pulsation Apparatus","authors":"B. T. Omarov, K. Zhantasov, M. Zhantasov, Z. Altybayev","doi":"10.18321/ectj1544","DOIUrl":"https://doi.org/10.18321/ectj1544","url":null,"abstract":"The work presents research results of the change comparison of brown coals and the study of the physicochemical properties of humic substances obtained from brown coals of the Karazhyra, Ekibastuz, and Kyzyl-Kiya deposits after hydrodynamic treatment in a rotary-pulsation apparatus. It is shown that the hydromechanical effect on humic acids leads to a change in their composition, accompanied by a decrease in the degree of aromaticity and an increase in the content of oxygen-containing fragments. Mechanical treatment of brown coals under oxidizing conditions maximizes the efficiency of extraction of water-soluble components and humic acids. The structural parameters and functional composition of humic acid molecules during the treatment of brown coals under oxidation-reduction conditions change depending on the conditions. The elemental and functional composition (using IR spectroscopy and potentiometry) of humic substances in brown coals and their molecular weight distribution using size-exclusion chromatography were studied. The influence of the content of metal-binding centers, dispersity, and ash content of humic substances was studied before and after treatment. At a temperature of 70 ºC a rotation time of 10 s, 98.7% of humic acids passes into the solution, which is the best indicator.","PeriodicalId":11795,"journal":{"name":"Eurasian Chemico-Technological Journal","volume":"110 ","pages":""},"PeriodicalIF":0.5,"publicationDate":"2024-02-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140456334","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}
The dissolution of hydrolyzed polyacrylamide, commonly used in gel treatments for enhanced oil recovery, takes between 2‒3 to over 24 h at 20‒25 °C. The duration is influenced by factors such as polymer molecular weight and brine salinity. In injection/production wells, gel treatments often involve injecting 50‒150 m3 of polymer solution within 1‒2 days, resulting in the injection of partially dissolved polymer. This raises concerns about the stability and strength of gels containing partially dissolved polymer particles. This study demonstrates that when undissolved polymer particles are kept suspended during the gelation process, there is no significant visual distinction between gels obtained from 30 min or 12 h of polymer mixing. Additionally, viscometer measurements reveal that gels formed with shorter polymer mixing times exhibit higher resistance to shearing. This observation supports the concept that undissolved polymer particles act as a composite material, improving the gel strength. This paper does not advocate for the use of partially dissolved polymer gelants. Undissolved polymer particles cannot effectively penetrate porous media. Gelants containing such particles are primarily suited for addressing fracture conformance issues. Therefore, future research will focus on examining the impact of polymer mixing time on gel syneresis and resistance to washout from fractures.
{"title":"The Effect of Polymer Mixing Time on the Strength of HPAM-Cr(III) Gels","authors":"I. Gussenov","doi":"10.18321/ectj1518","DOIUrl":"https://doi.org/10.18321/ectj1518","url":null,"abstract":"The dissolution of hydrolyzed polyacrylamide, commonly used in gel treatments for enhanced oil recovery, takes between 2‒3 to over 24 h at 20‒25 °C. The duration is influenced by factors such as polymer molecular weight and brine salinity. In injection/production wells, gel treatments often involve injecting 50‒150 m3 of polymer solution within 1‒2 days, resulting in the injection of partially dissolved polymer. This raises concerns about the stability and strength of gels containing partially dissolved polymer particles. This study demonstrates that when undissolved polymer particles are kept suspended during the gelation process, there is no significant visual distinction between gels obtained from 30 min or 12 h of polymer mixing. Additionally, viscometer measurements reveal that gels formed with shorter polymer mixing times exhibit higher resistance to shearing. This observation supports the concept that undissolved polymer particles act as a composite material, improving the gel strength. This paper does not advocate for the use of partially dissolved polymer gelants. Undissolved polymer particles cannot effectively penetrate porous media. Gelants containing such particles are primarily suited for addressing fracture conformance issues. Therefore, future research will focus on examining the impact of polymer mixing time on gel syneresis and resistance to washout from fractures.","PeriodicalId":11795,"journal":{"name":"Eurasian Chemico-Technological Journal","volume":"22 7","pages":""},"PeriodicalIF":0.5,"publicationDate":"2023-11-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139255950","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}
In this work, an extract of the Tamarix hispida (TH-10) was prepared in 10 vol.% water-ethanol solution. Based on the properties of antioxidant, and anti-inflammatory activity, various gelatin films containing (10–15 wt.%) gelatin were obtained. The fabricated gelatin films containing TH-10 extract were used as wound dressings for burns. Their deformation properties, physical and mechanical properties, and SEM micrographs were defined. An additional film structure was determined by using a Fourier transform infrared spectrometer (FT-IR). The strength of polymer films containing TH-10 depends on gelatin content. This indicates that the gelatin film binds the TH-10 with the help of hydrophobic interactions. It was found that the higher amount of gelatin leads to lower tear resistance of films. This is due to the formation of micro-cracks on the surface of films leading to their easy rupture. During the study of tensile strength, it was proven that the optimal amount of glycerin in the film is 5 vol.%. The polymer film containing 12 wt.% gelatin and 1 wt.% TH-10 was recognized as the most effective composition in terms of strength and elasticity properties for application as wound dressing materials.
{"title":"Study of the Mechanical Properties of Gelatin Films with Natural Compounds of Tamarix hispida","authors":"Shynar Zhumagaliyeva, G.G. Abdikarim, A.B. Berikova, Zh.A. Abilov, J. Koetz, M.T. Kopbayeva","doi":"10.18321/ectj1519","DOIUrl":"https://doi.org/10.18321/ectj1519","url":null,"abstract":"In this work, an extract of the Tamarix hispida (TH-10) was prepared in 10 vol.% water-ethanol solution. Based on the properties of antioxidant, and anti-inflammatory activity, various gelatin films containing (10–15 wt.%) gelatin were obtained. The fabricated gelatin films containing TH-10 extract were used as wound dressings for burns. Their deformation properties, physical and mechanical properties, and SEM micrographs were defined. An additional film structure was determined by using a Fourier transform infrared spectrometer (FT-IR). The strength of polymer films containing TH-10 depends on gelatin content. This indicates that the gelatin film binds the TH-10 with the help of hydrophobic interactions. It was found that the higher amount of gelatin leads to lower tear resistance of films. This is due to the formation of micro-cracks on the surface of films leading to their easy rupture. During the study of tensile strength, it was proven that the optimal amount of glycerin in the film is 5 vol.%. The polymer film containing 12 wt.% gelatin and 1 wt.% TH-10 was recognized as the most effective composition in terms of strength and elasticity properties for application as wound dressing materials.","PeriodicalId":11795,"journal":{"name":"Eurasian Chemico-Technological Journal","volume":"1 2","pages":""},"PeriodicalIF":0.5,"publicationDate":"2023-11-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139254754","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}
I. Rakhimbek, N. Baikalov, A. Konarov, A. Mentbayeva, Y. Zhang, Z. Mansurov, M. Wakihara, Z. Bakenov
Recent advances in the development of lithium-sulfur batteries (Li-S) demonstrated their high effectiveness owing to their tremendous theoretical specific capacity and high theoretical gravimetrical energy. Nevertheless, the potential commercialization of Li-S is significantly held by the insulating nature of sulfur and complicated RedOx reactions during the electrochemical charge-discharge processes. This paper presents nickel nanoparticles embedded carbon nanofibers interlayer (Ni@CNF) between a cathode and a separator as an additional physical barrier against lithium polysulfides shuttle for their efficient conversion during the charge-discharge cycling. Furthermore, the interlayer provides an auxiliary electron pathway with subsequent lowering of the charge transfer resistance. The electrochemical analysis of a Li-S cell with the Ni@CNF interlayer demonstrated high initial discharge capacities of 1441.2 mAh g-1 and 1194.2 mAh g-1 at 0.1 and 1.0 C rates, respectively, with remarkable capacity retention of ~83% after 100 cycles. This study revealed the advantageous impact of Ni@CNF towards solving the major issues of lithium-sulfur batteries, i.e., sluggish kinetics and the shuttle effect.
锂硫电池（Li-S）的理论比容量大，理论重力能量高，因此其开发工作取得了最新进展，显示出其高效性。然而，硫的绝缘性和电化学充放电过程中复杂的氧化还原反应严重阻碍了锂硫电池的商业化潜力。本文介绍了在阴极和分隔层之间嵌入碳纳米纤维夹层（Ni@CNF）的镍纳米粒子，该夹层是防止多硫化锂穿梭的额外物理屏障，可在充放电循环过程中实现锂的高效转化。此外，中间膜还提供了一条辅助电子通路，从而降低了电荷转移电阻。对带有 Ni@CNF 中间膜的锂-S 电池进行的电化学分析表明，在 0.1 和 1.0 C 速率下，初始放电容量分别为 1441.2 mAh g-1 和 1194.2 mAh g-1，100 个循环后容量保持率高达约 83%。这项研究揭示了 Ni@CNF 在解决锂硫电池的主要问题（即缓慢的动力学和穿梭效应）方面的优势。
{"title":"Efficient Polysulfides Conversion Kinetics Enabled by Ni@CNF Interlayer for Lithium Sulfur Batteries","authors":"I. Rakhimbek, N. Baikalov, A. Konarov, A. Mentbayeva, Y. Zhang, Z. Mansurov, M. Wakihara, Z. Bakenov","doi":"10.18321/ectj1517","DOIUrl":"https://doi.org/10.18321/ectj1517","url":null,"abstract":"Recent advances in the development of lithium-sulfur batteries (Li-S) demonstrated their high effectiveness owing to their tremendous theoretical specific capacity and high theoretical gravimetrical energy. Nevertheless, the potential commercialization of Li-S is significantly held by the insulating nature of sulfur and complicated RedOx reactions during the electrochemical charge-discharge processes. This paper presents nickel nanoparticles embedded carbon nanofibers interlayer (Ni@CNF) between a cathode and a separator as an additional physical barrier against lithium polysulfides shuttle for their efficient conversion during the charge-discharge cycling. Furthermore, the interlayer provides an auxiliary electron pathway with subsequent lowering of the charge transfer resistance. The electrochemical analysis of a Li-S cell with the Ni@CNF interlayer demonstrated high initial discharge capacities of 1441.2 mAh g-1 and 1194.2 mAh g-1 at 0.1 and 1.0 C rates, respectively, with remarkable capacity retention of ~83% after 100 cycles. This study revealed the advantageous impact of Ni@CNF towards solving the major issues of lithium-sulfur batteries, i.e., sluggish kinetics and the shuttle effect.","PeriodicalId":11795,"journal":{"name":"Eurasian Chemico-Technological Journal","volume":"48 7","pages":""},"PeriodicalIF":0.5,"publicationDate":"2023-11-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139255903","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}
The Crude Distillation Unit (CDU) mechanism is commonly regarded as the first stage in petroleum refining. In this study, Aspen Plus® is used to simulate the basic process of a CDU, which consists of an Atmospheric Distillation Column (ATC) and a Vacuum Distillation Column (VC). These columns are fed with two types of crude oil: KUMKOL from Kazakhstan and Soviet Export Blend, in the proportions of 0.75:0.25, 0.50:0.50, and 0.25:0.75, respectively. The goal was to do a parametric analysis and analyze the resultant streams of naphtha, kerosene, Atmospheric Gas Oil (AGO), Light Vacuum Gas Oil (LVGO), and Heavy Vacuum Gas Oil (HVGO). The simulation used the CHAO-SEA thermodynamic model, which included the Chao-Seader correlation, the Scatchard-Hildebrand model, the Redlich-Kwong equation of state, the Lee-Kesler equation of state, and the API gravity technique. Temperature, pressure, mass flow, enthalpy, vapor percentage, and average molecular weights of the streams at various phases within the CDU system were estimated. For both the ATC and VC columns, curves indicating Temperature- Pressure vs the number of stages, as well as ASTM D86 (temperature) versus stream volume % distillation, were developed. The results show that when compared to feed streams containing 0.25 and 0.50 StdVol of Kumkol Kazakhstan Oil, the feed stream with 0.75 StdVol produces more Heavy, Medium, and Light Vacuum Gas Oil (H-VGO, M-VGO, and L-VGO), as well as more Vacuum Gas (VG). These findings indicate that Kumkol Kazakhstan Oil is of high quality and has fewer contaminants, such as sulfur when compared to other accessible mixes throughout the world.
{"title":"Thermodynamic Modeling and Process Simulation of Kumkol Crude Oil Refining","authors":"M.A. Jamali, A. Bissenbay, N. Nuraje","doi":"10.18321/ectj1521","DOIUrl":"https://doi.org/10.18321/ectj1521","url":null,"abstract":"The Crude Distillation Unit (CDU) mechanism is commonly regarded as the first stage in petroleum refining. In this study, Aspen Plus® is used to simulate the basic process of a CDU, which consists of an Atmospheric Distillation Column (ATC) and a Vacuum Distillation Column (VC). These columns are fed with two types of crude oil: KUMKOL from Kazakhstan and Soviet Export Blend, in the proportions of 0.75:0.25, 0.50:0.50, and 0.25:0.75, respectively. The goal was to do a parametric analysis and analyze the resultant streams of naphtha, kerosene, Atmospheric Gas Oil (AGO), Light Vacuum Gas Oil (LVGO), and Heavy Vacuum Gas Oil (HVGO). The simulation used the CHAO-SEA thermodynamic model, which included the Chao-Seader correlation, the Scatchard-Hildebrand model, the Redlich-Kwong equation of state, the Lee-Kesler equation of state, and the API gravity technique. Temperature, pressure, mass flow, enthalpy, vapor percentage, and average molecular weights of the streams at various phases within the CDU system were estimated. For both the ATC and VC columns, curves indicating Temperature- Pressure vs the number of stages, as well as ASTM D86 (temperature) versus stream volume % distillation, were developed. The results show that when compared to feed streams containing 0.25 and 0.50 StdVol of Kumkol Kazakhstan Oil, the feed stream with 0.75 StdVol produces more Heavy, Medium, and Light Vacuum Gas Oil (H-VGO, M-VGO, and L-VGO), as well as more Vacuum Gas (VG). These findings indicate that Kumkol Kazakhstan Oil is of high quality and has fewer contaminants, such as sulfur when compared to other accessible mixes throughout the world.","PeriodicalId":11795,"journal":{"name":"Eurasian Chemico-Technological Journal","volume":"56 11","pages":""},"PeriodicalIF":0.5,"publicationDate":"2023-11-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139257584","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}
京公网安备 11010802042870号
京ICP备2023020795号-1
扫码关注我们
求助内容：
应助结果提醒方式：