Pub Date : 2024-03-04DOI: 10.15826/chimtech.2024.11.1.09
E. A. Zauer
The modern instrumentation for flame atomic emission spectrometry (FAES) is overviewed: the main technical (composition of the fuel gas used, dispersing element, number of analytical channels, reference channel, detecting element, sampling method) and analytical (determined elements, range of determined concentrations, limits and the accuracy of their determination, the duration of a single measurement, the equired amount of the analyzed sample) characteristics of flame photometers for industrial and clinical use as well as spectrophotometers currently made by various manufacturers such as Sherwood Scientific Ltd., BWB Technologies UK Ltd., Labtron Equipment Ltd., Labnics Equipment Ltd. and JENWAY Ltd (UK); A.KRÜSS Optronic (Germany); Cole Parmer Instrument Company and Labfon Equipment Inc. (USA); Inesa Analytical Instrument Co., Ltd (China); OJSC Zagorsk Optical and Mechanical Plant, Unico-SIS LLC and VMK-Optoelectronics LLC (Russia); Manti Lab Solutions, Labtronics, Systonic, Globe Instruments, Electronics India, Lasany (India). The main areas of application of FAES are presented – bioenergy, agriculture (analysis of plants, soil extracts and fertilizers), mineral raw materials (geology), clinical medicine and pharmaceuticals, food industry, environmental control (analysis of drinking, technical and waste water), nuclear energy, metallurgy and chemical industry, as well as some features and problems associated with the preparation of samples for analysis by the FAES method. The review includes references to works on the practical application of FAES, published mainly from 1998 to 2023.
{"title":"Modern instrumentation and practical application of flame atomic emission spectrometry","authors":"E. A. Zauer","doi":"10.15826/chimtech.2024.11.1.09","DOIUrl":"https://doi.org/10.15826/chimtech.2024.11.1.09","url":null,"abstract":"The modern instrumentation for flame atomic emission spectrometry (FAES) is overviewed: the main technical (composition of the fuel gas used, dispersing element, number of analytical channels, reference channel, detecting element, sampling method) and analytical (determined elements, range of determined concentrations, limits and the accuracy of their determination, the duration of a single measurement, the equired amount of the analyzed sample) characteristics of flame photometers for industrial and clinical use as well as spectrophotometers currently made by various manufacturers such as Sherwood Scientific Ltd., BWB Technologies UK Ltd., Labtron Equipment Ltd., Labnics Equipment Ltd. and JENWAY Ltd (UK); A.KRÜSS Optronic (Germany); Cole Parmer Instrument Company and Labfon Equipment Inc. (USA); Inesa Analytical Instrument Co., Ltd (China); OJSC Zagorsk Optical and Mechanical Plant, Unico-SIS LLC and VMK-Optoelectronics LLC (Russia); Manti Lab Solutions, Labtronics, Systonic, Globe Instruments, Electronics India, Lasany (India). The main areas of application of FAES are presented – bioenergy, agriculture (analysis of plants, soil extracts and fertilizers), mineral raw materials (geology), clinical medicine and pharmaceuticals, food industry, environmental control (analysis of drinking, technical and waste water), nuclear energy, metallurgy and chemical industry, as well as some features and problems associated with the preparation of samples for analysis by the FAES method. The review includes references to works on the practical application of FAES, published mainly from 1998 to 2023. ","PeriodicalId":9964,"journal":{"name":"Chimica Techno Acta","volume":"106 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-03-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140398241","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}
Pub Date : 2024-02-29DOI: 10.15826/chimtech.2024.11.1.08
M. Karunakaran, Ravi Subban, A. Thangamani, C. Thangavel
It is well known that many polymers are insulators with poor mechanical properties, which limit their use in fuel cell applications. Physicochemical properties of the polymers can be improved by adding conductive fillers. Carbon-based materials like graphite, which provides excellent mechanical strength and thermal conductivity to the polymer matrices, is of special interest because of its abundance, low cost and light weight when compared to other carbon allotropes. In the present work we describe the physicochemical properties of rooflite unsaturated polyester resin/graphite composites. Rooflite resin and three of its composites containing 1%, 3% and 5% of graphite by weight (C-2, C-3, and C-4, respectively) were synthesized and characterized by FTIR spectral data. XRD showed two peaks at 2q = 27.37°and 55.40° with d spacing value of 3.2559 nm and 1.6571 nm, respectively, indicating the change in degree of crystallinity of the composite. The calculated crystallinity for the resin is 7.3%, and for C-2, C-3 and C-4 its values are 12.1%, 14.3%, 17.1%, respectively, evidencing the interactions between the graphite and polymer matrix. The composites showed fractured surfaces and porous rough structure with randomly distributed vascularized cavities. Agglomeration occurs, when the concentration of graphite increases. The glass transition temperature for the pure resin is 65.9 °C and increases when the resin is filled with graphite. Thermogravimetric analysis (TGA) of the composites showed no marked difference between Tmax and Tfinal, and LOI values of C-3 and C-4 are above 21%, making them self-extinguishable materials that could be used for making bipolar plates. The chemical resistance investigation against water, NaCl, NaOH, acetic acid, and toluene showed more resistance to acid than alkali solutions. These rooflite resin/graphite composites could be further studied to explore the possibility of making bipolar plates, which are an essential component of fuel cells.
{"title":"Effect of graphite filler on the physiochemical properties of graphite reinforced thermoset rooflite – unsaturated polyester resin composites","authors":"M. Karunakaran, Ravi Subban, A. Thangamani, C. Thangavel","doi":"10.15826/chimtech.2024.11.1.08","DOIUrl":"https://doi.org/10.15826/chimtech.2024.11.1.08","url":null,"abstract":"It is well known that many polymers are insulators with poor mechanical properties, which limit their use in fuel cell applications. Physicochemical properties of the polymers can be improved by adding conductive fillers. Carbon-based materials like graphite, which provides excellent mechanical strength and thermal conductivity to the polymer matrices, is of special interest because of its abundance, low cost and light weight when compared to other carbon allotropes. In the present work we describe the physicochemical properties of rooflite unsaturated polyester resin/graphite composites. Rooflite resin and three of its composites containing 1%, 3% and 5% of graphite by weight (C-2, C-3, and C-4, respectively) were synthesized and characterized by FTIR spectral data. XRD showed two peaks at 2q = 27.37°and 55.40° with d spacing value of 3.2559 nm and 1.6571 nm, respectively, indicating the change in degree of crystallinity of the composite. The calculated crystallinity for the resin is 7.3%, and for C-2, C-3 and C-4 its values are 12.1%, 14.3%, 17.1%, respectively, evidencing the interactions between the graphite and polymer matrix. The composites showed fractured surfaces and porous rough structure with randomly distributed vascularized cavities. Agglomeration occurs, when the concentration of graphite increases. The glass transition temperature for the pure resin is 65.9 °C and increases when the resin is filled with graphite. Thermogravimetric analysis (TGA) of the composites showed no marked difference between Tmax and Tfinal, and LOI values of C-3 and C-4 are above 21%, making them self-extinguishable materials that could be used for making bipolar plates. The chemical resistance investigation against water, NaCl, NaOH, acetic acid, and toluene showed more resistance to acid than alkali solutions. These rooflite resin/graphite composites could be further studied to explore the possibility of making bipolar plates, which are an essential component of fuel cells.","PeriodicalId":9964,"journal":{"name":"Chimica Techno Acta","volume":"31 3","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-02-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140413176","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}
Pub Date : 2024-02-05DOI: 10.15826/chimtech.2024.11.1.07
Mary Stephanie Carranza, Neil Andrew D. Bascos, Maria Carmen Tan, Francisco Franco Jr.
Silk fibroin (SF) has been continuously explored as a biomaterial due to its biocompatibility, tunability, and self-healing properties. In this work, we present a novel approach to the modification of bacterial cellulose (BC) with SF β-sheet dominant structures induced via ultrasonication. Secondary structure analysis through infrared spectroscopy, thioflavin T assay, and circular dichroism spectropolarimetry revealed a conversion of silk I to silk II structures within the protein mixture. Cold field emission scanning electron microscope images revealed the tightly packed fibers coated with the protein. Thermogravimetric curves demonstrated higher resistance to temperature degradation supplemented by broader and flatter DSC curves attributed to the highly bonded and dense composite. Successful conversion of amide I to amide II and amide III allowed for the more stable β-crystals to contribute to a more thermodynamically stable double-network hydrogel. The conversion of silk I to silk II structures offers a viable and highly biocompatible material that is both thermodynamically and biochemically stable for various potential biomedical applications.
蚕丝纤维素（SF）因其生物相容性、可调性和自愈性，一直被视为一种生物材料。在这项工作中，我们提出了一种通过超声波诱导细菌纤维素（BC）改性为 SF β 片状主导结构的新方法。通过红外光谱法、硫黄素 T 检测法和圆二色光谱定量法进行的二级结构分析表明，蛋白质混合物中的丝 I 结构已转化为丝 II 结构。冷场发射扫描电子显微镜图像显示了包裹蛋白质的紧密纤维。热重曲线显示出更高的抗温度降解能力，同时还辅以更宽更平整的 DSC 曲线，这归功于高度粘合和致密的复合材料。将酰胺 I 成功转化为酰胺 II 和酰胺 III 可使更稳定的 β 晶体形成热力学上更稳定的双网水凝胶。蚕丝 I 到蚕丝 II 结构的转化为各种潜在的生物医学应用提供了一种可行的高生物相容性材料，这种材料在热力学和生物化学方面都很稳定。
{"title":"Modification of bacterial cellulose using silk fibroin β-sheet crystals induced by ultrasonication","authors":"Mary Stephanie Carranza, Neil Andrew D. Bascos, Maria Carmen Tan, Francisco Franco Jr.","doi":"10.15826/chimtech.2024.11.1.07","DOIUrl":"https://doi.org/10.15826/chimtech.2024.11.1.07","url":null,"abstract":"Silk fibroin (SF) has been continuously explored as a biomaterial due to its biocompatibility, tunability, and self-healing properties. In this work, we present a novel approach to the modification of bacterial cellulose (BC) with SF β-sheet dominant structures induced via ultrasonication. Secondary structure analysis through infrared spectroscopy, thioflavin T assay, and circular dichroism spectropolarimetry revealed a conversion of silk I to silk II structures within the protein mixture. Cold field emission scanning electron microscope images revealed the tightly packed fibers coated with the protein. Thermogravimetric curves demonstrated higher resistance to temperature degradation supplemented by broader and flatter DSC curves attributed to the highly bonded and dense composite. Successful conversion of amide I to amide II and amide III allowed for the more stable β-crystals to contribute to a more thermodynamically stable double-network hydrogel. The conversion of silk I to silk II structures offers a viable and highly biocompatible material that is both thermodynamically and biochemically stable for various potential biomedical applications.","PeriodicalId":9964,"journal":{"name":"Chimica Techno Acta","volume":"201 4","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-02-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139862430","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}
Pub Date : 2024-02-05DOI: 10.15826/chimtech.2024.11.1.07
Mary Stephanie Carranza, Neil Andrew D. Bascos, Maria Carmen Tan, Francisco Franco Jr.
Silk fibroin (SF) has been continuously explored as a biomaterial due to its biocompatibility, tunability, and self-healing properties. In this work, we present a novel approach to the modification of bacterial cellulose (BC) with SF β-sheet dominant structures induced via ultrasonication. Secondary structure analysis through infrared spectroscopy, thioflavin T assay, and circular dichroism spectropolarimetry revealed a conversion of silk I to silk II structures within the protein mixture. Cold field emission scanning electron microscope images revealed the tightly packed fibers coated with the protein. Thermogravimetric curves demonstrated higher resistance to temperature degradation supplemented by broader and flatter DSC curves attributed to the highly bonded and dense composite. Successful conversion of amide I to amide II and amide III allowed for the more stable β-crystals to contribute to a more thermodynamically stable double-network hydrogel. The conversion of silk I to silk II structures offers a viable and highly biocompatible material that is both thermodynamically and biochemically stable for various potential biomedical applications.
蚕丝纤维素（SF）因其生物相容性、可调性和自愈性，一直被视为一种生物材料。在这项工作中，我们提出了一种通过超声波诱导细菌纤维素（BC）改性为 SF β 片状主导结构的新方法。通过红外光谱法、硫黄素 T 检测法和圆二色光谱定量法进行的二级结构分析表明，蛋白质混合物中的丝 I 结构已转化为丝 II 结构。冷场发射扫描电子显微镜图像显示了包裹蛋白质的紧密纤维。热重曲线显示出更高的抗温度降解能力，同时还辅以更宽更平整的 DSC 曲线，这归功于高度粘合和致密的复合材料。将酰胺 I 成功转化为酰胺 II 和酰胺 III 可使更稳定的 β 晶体形成热力学上更稳定的双网水凝胶。蚕丝 I 到蚕丝 II 结构的转化为各种潜在的生物医学应用提供了一种可行的高生物相容性材料，这种材料在热力学和生物化学方面都很稳定。
{"title":"Modification of bacterial cellulose using silk fibroin β-sheet crystals induced by ultrasonication","authors":"Mary Stephanie Carranza, Neil Andrew D. Bascos, Maria Carmen Tan, Francisco Franco Jr.","doi":"10.15826/chimtech.2024.11.1.07","DOIUrl":"https://doi.org/10.15826/chimtech.2024.11.1.07","url":null,"abstract":"Silk fibroin (SF) has been continuously explored as a biomaterial due to its biocompatibility, tunability, and self-healing properties. In this work, we present a novel approach to the modification of bacterial cellulose (BC) with SF β-sheet dominant structures induced via ultrasonication. Secondary structure analysis through infrared spectroscopy, thioflavin T assay, and circular dichroism spectropolarimetry revealed a conversion of silk I to silk II structures within the protein mixture. Cold field emission scanning electron microscope images revealed the tightly packed fibers coated with the protein. Thermogravimetric curves demonstrated higher resistance to temperature degradation supplemented by broader and flatter DSC curves attributed to the highly bonded and dense composite. Successful conversion of amide I to amide II and amide III allowed for the more stable β-crystals to contribute to a more thermodynamically stable double-network hydrogel. The conversion of silk I to silk II structures offers a viable and highly biocompatible material that is both thermodynamically and biochemically stable for various potential biomedical applications.","PeriodicalId":9964,"journal":{"name":"Chimica Techno Acta","volume":"19 19","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-02-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139802786","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}
Pub Date : 2024-02-02DOI: 10.15826/chimtech.2024.11.1.06
Nataliia Tarasova, Maxim Mashkovtsev, Maxim Domashenkov, Denis Khionin, Roman Bastrikov, A. Bedarkova
Perovskite or perovskite-related structural materials are widely studied for their many functional properties. They can be used as components of electrochemical devices such as solid oxide fuel cells and electrolyzers. Layered perovskites can also be considered as promising materials for use in these devices. In this paper, the possibility of heterovalent (acceptor and donor) and isovalent doping of La and In sublattices of layered perovskites BaYLaInO4 and BaGdLaInO4 was made for the first time. The structure and electrical properties of these oxides were studied. Electrical conductivity values increase in the series BaYInO4–BaLaInO4–BaGdInO4. However, the doping is an unsuitable strategy for improving the electrical properties of BaYInO4 and BaGdInO4 oxides. Further search for highly conductive materials with the layered perovskite structure can be aimed at materials with a different composition of the cation sublattice.
包晶或与包晶相关的结构材料因其多种功能特性而被广泛研究。它们可用作固体氧化物燃料电池和电解器等电化学设备的元件。层状过氧化物也被认为是有望用于这些设备的材料。本文首次提出了在层状过氧化物 BaYLaInO4 和 BaGdLaInO4 的 La 和 In 亚晶格中进行异价（受体和供体）和异价掺杂的可能性。研究了这些氧化物的结构和电学特性。电导率值在 BaYInO4-BaLaInO4-BaGdInO4 系列中有所增加。然而，掺杂并不是改善 BaYInO4 和 BaGdInO4 氧化物电学特性的合适策略。要进一步寻找具有层状包晶结构的高导电性材料，可以从具有不同阳离子亚晶格组成的材料入手。
{"title":"Synthesis and electrical properties of doped layered perovskites based on BaMInO4 (M = Y, Gd)","authors":"Nataliia Tarasova, Maxim Mashkovtsev, Maxim Domashenkov, Denis Khionin, Roman Bastrikov, A. Bedarkova","doi":"10.15826/chimtech.2024.11.1.06","DOIUrl":"https://doi.org/10.15826/chimtech.2024.11.1.06","url":null,"abstract":"Perovskite or perovskite-related structural materials are widely studied for their many functional properties. They can be used as components of electrochemical devices such as solid oxide fuel cells and electrolyzers. Layered perovskites can also be considered as promising materials for use in these devices. In this paper, the possibility of heterovalent (acceptor and donor) and isovalent doping of La and In sublattices of layered perovskites BaYLaInO4 and BaGdLaInO4 was made for the first time. The structure and electrical properties of these oxides were studied. Electrical conductivity values increase in the series BaYInO4–BaLaInO4–BaGdInO4. However, the doping is an unsuitable strategy for improving the electrical properties of BaYInO4 and BaGdInO4 oxides. Further search for highly conductive materials with the layered perovskite structure can be aimed at materials with a different composition of the cation sublattice.","PeriodicalId":9964,"journal":{"name":"Chimica Techno Acta","volume":"45 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-02-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139870824","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}
Pub Date : 2024-02-02DOI: 10.15826/chimtech.2024.11.1.06
Nataliia Tarasova, Maxim Mashkovtsev, Maxim Domashenkov, Denis Khionin, Roman Bastrikov, A. Bedarkova
Perovskite or perovskite-related structural materials are widely studied for their many functional properties. They can be used as components of electrochemical devices such as solid oxide fuel cells and electrolyzers. Layered perovskites can also be considered as promising materials for use in these devices. In this paper, the possibility of heterovalent (acceptor and donor) and isovalent doping of La and In sublattices of layered perovskites BaYLaInO4 and BaGdLaInO4 was made for the first time. The structure and electrical properties of these oxides were studied. Electrical conductivity values increase in the series BaYInO4–BaLaInO4–BaGdInO4. However, the doping is an unsuitable strategy for improving the electrical properties of BaYInO4 and BaGdInO4 oxides. Further search for highly conductive materials with the layered perovskite structure can be aimed at materials with a different composition of the cation sublattice.
包晶或与包晶相关的结构材料因其多种功能特性而被广泛研究。它们可用作固体氧化物燃料电池和电解器等电化学设备的元件。层状过氧化物也被认为是有望用于这些设备的材料。本文首次提出了在层状过氧化物 BaYLaInO4 和 BaGdLaInO4 的 La 和 In 亚晶格中进行异价（受体和供体）和异价掺杂的可能性。研究了这些氧化物的结构和电学特性。电导率值在 BaYInO4-BaLaInO4-BaGdInO4 系列中有所增加。然而，掺杂并不是改善 BaYInO4 和 BaGdInO4 氧化物电学特性的合适策略。要进一步寻找具有层状包晶结构的高导电性材料，可以从具有不同阳离子亚晶格组成的材料入手。
{"title":"Synthesis and electrical properties of doped layered perovskites based on BaMInO4 (M = Y, Gd)","authors":"Nataliia Tarasova, Maxim Mashkovtsev, Maxim Domashenkov, Denis Khionin, Roman Bastrikov, A. Bedarkova","doi":"10.15826/chimtech.2024.11.1.06","DOIUrl":"https://doi.org/10.15826/chimtech.2024.11.1.06","url":null,"abstract":"Perovskite or perovskite-related structural materials are widely studied for their many functional properties. They can be used as components of electrochemical devices such as solid oxide fuel cells and electrolyzers. Layered perovskites can also be considered as promising materials for use in these devices. In this paper, the possibility of heterovalent (acceptor and donor) and isovalent doping of La and In sublattices of layered perovskites BaYLaInO4 and BaGdLaInO4 was made for the first time. The structure and electrical properties of these oxides were studied. Electrical conductivity values increase in the series BaYInO4–BaLaInO4–BaGdInO4. However, the doping is an unsuitable strategy for improving the electrical properties of BaYInO4 and BaGdInO4 oxides. Further search for highly conductive materials with the layered perovskite structure can be aimed at materials with a different composition of the cation sublattice.","PeriodicalId":9964,"journal":{"name":"Chimica Techno Acta","volume":"91 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-02-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139810716","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}
Pub Date : 2024-02-01DOI: 10.15826/chimtech.2024.11.1.05
Selvin P. Thomas
Composites of polystyrene with different loading of silica were prepared by melt mixing in a Brabender Plasticorder at a rotor speed of 60 rpm. The mechanical properties of the composites such as tensile behavior, impact strength, and flexural properties were studied as a function of filler loading. The tensile moduli of the composites increased with silica content. To improve adhesion between the filler and the matrix, an amino silane coupling agent was used. The composites with coupling agents showed enhanced mechanical properties. Thermal properties were measured using differential scanning calorimetry (DSC), thermogravimetry (TGA) and flammability tests. Composites with 15 wt.% and 0.5 wt.% coupling agent showed optimum properties. Scanning electron microscopy (SEM) studies of the tensile fractured samples revealed the extent of filler dispersion and filler/matrix interaction. Finally, experimental results were compared with theoretical predictions.
{"title":"Interaction of silica with polystyrene: mechanical properties, polymer/filler adhesion and failure behavior","authors":"Selvin P. Thomas","doi":"10.15826/chimtech.2024.11.1.05","DOIUrl":"https://doi.org/10.15826/chimtech.2024.11.1.05","url":null,"abstract":"Composites of polystyrene with different loading of silica were prepared by melt mixing in a Brabender Plasticorder at a rotor speed of 60 rpm. The mechanical properties of the composites such as tensile behavior, impact strength, and flexural properties were studied as a function of filler loading. The tensile moduli of the composites increased with silica content. To improve adhesion between the filler and the matrix, an amino silane coupling agent was used. The composites with coupling agents showed enhanced mechanical properties. Thermal properties were measured using differential scanning calorimetry (DSC), thermogravimetry (TGA) and flammability tests. Composites with 15 wt.% and 0.5 wt.% coupling agent showed optimum properties. Scanning electron microscopy (SEM) studies of the tensile fractured samples revealed the extent of filler dispersion and filler/matrix interaction. Finally, experimental results were compared with theoretical predictions.","PeriodicalId":9964,"journal":{"name":"Chimica Techno Acta","volume":"25 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139823467","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}
Pub Date : 2024-02-01DOI: 10.15826/chimtech.2024.11.1.05
Selvin P. Thomas
Composites of polystyrene with different loading of silica were prepared by melt mixing in a Brabender Plasticorder at a rotor speed of 60 rpm. The mechanical properties of the composites such as tensile behavior, impact strength, and flexural properties were studied as a function of filler loading. The tensile moduli of the composites increased with silica content. To improve adhesion between the filler and the matrix, an amino silane coupling agent was used. The composites with coupling agents showed enhanced mechanical properties. Thermal properties were measured using differential scanning calorimetry (DSC), thermogravimetry (TGA) and flammability tests. Composites with 15 wt.% and 0.5 wt.% coupling agent showed optimum properties. Scanning electron microscopy (SEM) studies of the tensile fractured samples revealed the extent of filler dispersion and filler/matrix interaction. Finally, experimental results were compared with theoretical predictions.
{"title":"Interaction of silica with polystyrene: mechanical properties, polymer/filler adhesion and failure behavior","authors":"Selvin P. Thomas","doi":"10.15826/chimtech.2024.11.1.05","DOIUrl":"https://doi.org/10.15826/chimtech.2024.11.1.05","url":null,"abstract":"Composites of polystyrene with different loading of silica were prepared by melt mixing in a Brabender Plasticorder at a rotor speed of 60 rpm. The mechanical properties of the composites such as tensile behavior, impact strength, and flexural properties were studied as a function of filler loading. The tensile moduli of the composites increased with silica content. To improve adhesion between the filler and the matrix, an amino silane coupling agent was used. The composites with coupling agents showed enhanced mechanical properties. Thermal properties were measured using differential scanning calorimetry (DSC), thermogravimetry (TGA) and flammability tests. Composites with 15 wt.% and 0.5 wt.% coupling agent showed optimum properties. Scanning electron microscopy (SEM) studies of the tensile fractured samples revealed the extent of filler dispersion and filler/matrix interaction. Finally, experimental results were compared with theoretical predictions.","PeriodicalId":9964,"journal":{"name":"Chimica Techno Acta","volume":"64 2","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139883311","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}
Pub Date : 2024-01-30DOI: 10.15826/chimtech.2024.11.1.04
K. Obydennov, T. Kalinina, T. Glukhareva, V. Bakulev
An approach to developing a docking protocol using free software such as KNIME, DataWarrior, AutoDock Vina, AutoDockTools, OpenBabel and the SWISS-MODEL service was described. In particular, the process of generating possible isomeric structures using KNIME chemoinformatics libraries is described. A library of benzo[d]azoles containing 145 compounds with homologous models of Alternaria solani β-tubulin obtained in two ways: using the commercial Prime program and the free SWISS-MODEL service, the comparison of results was shown. Despite the less preorganization of the binding cavity of the homologous model obtained using SWISS-MODEL, the correlation of the results between the two methods were observed. The correlation coefficients were as follows: Pearson was 0.65, Spearman was 0.62. According to the docking results, 99% of the studied 2-aminobenzo[d]azoles derivatives showed a docking score of no more than –7, which indicates that these compounds are promising for studying the fungicidal activity, in particular against A. solani. Without taking into account pharmacokinetic characteristics, benzo[d]imidazole derivatives containing a sulfanilamidine substituent at the 2-amino group and thioacetyl derivatives of 2-aminobenzo[d]imidazole are of particular interest in the search for new antitubulin fungicides.
{"title":"Development of A. solani β-tubulin models and comparison of docking results for benzo[d]azoles derivatives as potential antifungal agents","authors":"K. Obydennov, T. Kalinina, T. Glukhareva, V. Bakulev","doi":"10.15826/chimtech.2024.11.1.04","DOIUrl":"https://doi.org/10.15826/chimtech.2024.11.1.04","url":null,"abstract":"An approach to developing a docking protocol using free software such as KNIME, DataWarrior, AutoDock Vina, AutoDockTools, OpenBabel and the SWISS-MODEL service was described. In particular, the process of generating possible isomeric structures using KNIME chemoinformatics libraries is described. A library of benzo[d]azoles containing 145 compounds with homologous models of Alternaria solani β-tubulin obtained in two ways: using the commercial Prime program and the free SWISS-MODEL service, the comparison of results was shown. Despite the less preorganization of the binding cavity of the homologous model obtained using SWISS-MODEL, the correlation of the results between the two methods were observed. The correlation coefficients were as follows: Pearson was 0.65, Spearman was 0.62. According to the docking results, 99% of the studied 2-aminobenzo[d]azoles derivatives showed a docking score of no more than –7, which indicates that these compounds are promising for studying the fungicidal activity, in particular against A. solani. Without taking into account pharmacokinetic characteristics, benzo[d]imidazole derivatives containing a sulfanilamidine substituent at the 2-amino group and thioacetyl derivatives of 2-aminobenzo[d]imidazole are of particular interest in the search for new antitubulin fungicides.","PeriodicalId":9964,"journal":{"name":"Chimica Techno Acta","volume":"145 ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-01-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140485530","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}
Pub Date : 2024-01-25DOI: 10.15826/chimtech.2024.11.1.03
P. A. Shcheglov, Dmitry A. Samsonov, A. B. Pavlenkov, T. Kulova, Alexey Yu. Rychagov, A. Skundin, Evgeniya Yu. Postnova
The purpose of this research is to improve the performance and reduce the activation time of reserve power sources based on lead-acid systems at lower temperatures, down to –50 °C. Physico-chemical factors affecting the activation speed of reserve power sources based on Pb–HClO4–PbO2 and Zn–HClO4–PbO2 systems are investigated using chronopotentiometry, scanning electron microscopy, and standard contact porosimetry. Two approaches to the improvement of the low-temperature performance of power sources are used. The first one is based on the substitution of lead as anodic material with zinc. This allows the increase in discharge voltage and simultaneous decrease in activation time, but brings about the instability of discharge characteristics and, finally, deteriorates the reliability of power sources. The second approach is based on the use of PbO2 cathode material with enhanced nanoporosity. The chronopotentiometric method in galvanostatic mode is applied to the quality estimation of cathodes. The criterion of applicability of cathodes for reserve power sources consists in the low discharge overvoltage (0.1–0.2 V). Efficient performance of reserve power sources possessing the stable discharge voltage (1.5–1.8 V per cell) and the unprecedentedly short activation time (under 30 ms) even at lower temperatures (down to –50 °C) is achieved. The results are verified by fabrication and testing of pilot batches of miniaturized reserve power sources having microcells’ volume of 0.02 ml. The second approach to the improvement of power sources is transferred into the industrial production.
{"title":"Fast-activating reserve power sources: is lead dead indeed?","authors":"P. A. Shcheglov, Dmitry A. Samsonov, A. B. Pavlenkov, T. Kulova, Alexey Yu. Rychagov, A. Skundin, Evgeniya Yu. Postnova","doi":"10.15826/chimtech.2024.11.1.03","DOIUrl":"https://doi.org/10.15826/chimtech.2024.11.1.03","url":null,"abstract":"The purpose of this research is to improve the performance and reduce the activation time of reserve power sources based on lead-acid systems at lower temperatures, down to –50 °C. Physico-chemical factors affecting the activation speed of reserve power sources based on Pb–HClO4–PbO2 and Zn–HClO4–PbO2 systems are investigated using chronopotentiometry, scanning electron microscopy, and standard contact porosimetry. Two approaches to the improvement of the low-temperature performance of power sources are used. The first one is based on the substitution of lead as anodic material with zinc. This allows the increase in discharge voltage and simultaneous decrease in activation time, but brings about the instability of discharge characteristics and, finally, deteriorates the reliability of power sources. The second approach is based on the use of PbO2 cathode material with enhanced nanoporosity. The chronopotentiometric method in galvanostatic mode is applied to the quality estimation of cathodes. The criterion of applicability of cathodes for reserve power sources consists in the low discharge overvoltage (0.1–0.2 V). Efficient performance of reserve power sources possessing the stable discharge voltage (1.5–1.8 V per cell) and the unprecedentedly short activation time (under 30 ms) even at lower temperatures (down to –50 °C) is achieved. The results are verified by fabrication and testing of pilot batches of miniaturized reserve power sources having microcells’ volume of 0.02 ml. The second approach to the improvement of power sources is transferred into the industrial production.","PeriodicalId":9964,"journal":{"name":"Chimica Techno Acta","volume":"345 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-01-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140495281","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}
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