Pub Date : 2024-07-10DOI: 10.15826/chimtech.2024.11.3.03
Ravina Meena, H. Sachdeva
Variously substituted methylene bis(3-hydroxy-5,5-dimethyl-2-cyclohexene-1-one) derivatives were synthesized in 83–96% yield by the reaction of substituted benzaldehyde with 5, 5-dimethyl-1, 3-cyclohexanedione in the presence of CuO nanoparticles (NPs). Tandem grinding involves Knoevenagel condensation followed by the Michael addition in sequence for the formation of 2, 2’-arylmethylenebis (3-hydroxy-5, 5-dimethyl-2-cyclohexene-1-one) derivatives. Copper oxide NPs were synthesized by sol-gel method. The characterization of CuO NPs was done on the basis of PXRD, FTIR, SEM and TEM techniques. The synthesized derivatives were characterized on the basis of spectral analyses and corresponding melting points reported in the literature.
{"title":"Investigation of the reaction of dimedone with aromatic aldehydes in the presence of copper oxide nanoparticles","authors":"Ravina Meena, H. Sachdeva","doi":"10.15826/chimtech.2024.11.3.03","DOIUrl":"https://doi.org/10.15826/chimtech.2024.11.3.03","url":null,"abstract":"Variously substituted methylene bis(3-hydroxy-5,5-dimethyl-2-cyclohexene-1-one) derivatives were synthesized in 83–96% yield by the reaction of substituted benzaldehyde with 5, 5-dimethyl-1, 3-cyclohexanedione in the presence of CuO nanoparticles (NPs). Tandem grinding involves Knoevenagel condensation followed by the Michael addition in sequence for the formation of 2, 2’-arylmethylenebis (3-hydroxy-5, 5-dimethyl-2-cyclohexene-1-one) derivatives. Copper oxide NPs were synthesized by sol-gel method. The characterization of CuO NPs was done on the basis of PXRD, FTIR, SEM and TEM techniques. The synthesized derivatives were characterized on the basis of spectral analyses and corresponding melting points reported in the literature.","PeriodicalId":9964,"journal":{"name":"Chimica Techno Acta","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-07-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141662771","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 : 2024-05-13DOI: 10.15826/chimtech.2024.11.2.10
V. Yu. Guskov, Yulia Yu. Gainullina, Alina F. Gabdulmanova, Albina N. Gareeva
In the present work, the dispersive surface free energy was calculated by Dorris-Gray method for 30 samples of adsorbents modified with chiral supramolecular structures of uracil, 6-methyluracil, 5-hydroxy-6-methyluracil, 5-fluorouracil, thymine, melamine, cyanuric and barbirutic acids, and perylene-3,4,9,10-tetracarboxylic dianhydride. It was shown that the homologous series of n-alkanes is better suited for measuring dispersive surface free energy than the homologous series of alcohols. It was established that the classical Dorris-Gray method does not allow obtaining well interpretable data for the objects studied. This is due to a noticeable effect that inductive interactions of a polar surface as an inductor with nonpolar alkane molecules have on the calculated values. We suggested to modify the Dorris-Gray method, making it possible to obtain data on the dispersive component of the free energy of adsorption. It was shown that the changes in dispersive surface free energy as a result of the modification correlate well with data on the structure and properties of supramolecular ensembles of the modifiers used. The results obtained can be used to predict the enantioselectivity of chiral adsorbents.
{"title":"Dispersive surface free energy of adsorbents modified by supramolecular structures of heterocyclic compounds","authors":"V. Yu. Guskov, Yulia Yu. Gainullina, Alina F. Gabdulmanova, Albina N. Gareeva","doi":"10.15826/chimtech.2024.11.2.10","DOIUrl":"https://doi.org/10.15826/chimtech.2024.11.2.10","url":null,"abstract":"In the present work, the dispersive surface free energy was calculated by Dorris-Gray method for 30 samples of adsorbents modified with chiral supramolecular structures of uracil, 6-methyluracil, 5-hydroxy-6-methyluracil, 5-fluorouracil, thymine, melamine, cyanuric and barbirutic acids, and perylene-3,4,9,10-tetracarboxylic dianhydride. It was shown that the homologous series of n-alkanes is better suited for measuring dispersive surface free energy than the homologous series of alcohols. It was established that the classical Dorris-Gray method does not allow obtaining well interpretable data for the objects studied. This is due to a noticeable effect that inductive interactions of a polar surface as an inductor with nonpolar alkane molecules have on the calculated values. We suggested to modify the Dorris-Gray method, making it possible to obtain data on the dispersive component of the free energy of adsorption. It was shown that the changes in dispersive surface free energy as a result of the modification correlate well with data on the structure and properties of supramolecular ensembles of the modifiers used. The results obtained can be used to predict the enantioselectivity of chiral adsorbents.","PeriodicalId":9964,"journal":{"name":"Chimica Techno Acta","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-05-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140985977","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 : 2024-05-09DOI: 10.15826/chimtech.2024.11.2.09
Alan Akhmedov, R. Gamirov, Yulia Panina, Alina Baklagina, Evgenia Sokolova, Pavel V Zelenikhin, Olga Babaeva, Vasily Babaev, D. Shurpik, I. Stoikov
In this research, using the thia-Michael reaction, cationic amphiphilic meroterpenoids containing fragments of mono- and sesquiterpenoids were synthesized. The bacteriostatic and fungistatic activity of synthesized meroterpenoids against the fungi Saccharomyces cerevisiae and Candida sp., Gram-positive (Staphylococcus aureus, Staphylococcus epidermidis) and Gram-negative (Salmonella typhimurium, Klebsiella pneumoniae, Pseudomonas aeruginosa) bacteria was studied. The compound containing the farnesyl fragment was most active against Saccharomyces cerevisiae (MIC 0.039 mg/mL), Candida sp. (MIC 0.078 mg/mL), Gram-positive bacteria Staphylococcus epidermidis (MIC 0.02 mg/mL) and Gram-negative Salmonella typhimurium (MIC 0.078 mg/mL). Besides, the Ames test demonstrated the absence of direct mutagenic action in all the studied compounds.
{"title":"Cationic amphiphilic meroterpenoids: synthesis, antibacterial, antifungal and mutagenic activity","authors":"Alan Akhmedov, R. Gamirov, Yulia Panina, Alina Baklagina, Evgenia Sokolova, Pavel V Zelenikhin, Olga Babaeva, Vasily Babaev, D. Shurpik, I. Stoikov","doi":"10.15826/chimtech.2024.11.2.09","DOIUrl":"https://doi.org/10.15826/chimtech.2024.11.2.09","url":null,"abstract":"In this research, using the thia-Michael reaction, cationic amphiphilic meroterpenoids containing fragments of mono- and sesquiterpenoids were synthesized. The bacteriostatic and fungistatic activity of synthesized meroterpenoids against the fungi Saccharomyces cerevisiae and Candida sp., Gram-positive (Staphylococcus aureus, Staphylococcus epidermidis) and Gram-negative (Salmonella typhimurium, Klebsiella pneumoniae, Pseudomonas aeruginosa) bacteria was studied. The compound containing the farnesyl fragment was most active against Saccharomyces cerevisiae (MIC 0.039 mg/mL), Candida sp. (MIC 0.078 mg/mL), Gram-positive bacteria Staphylococcus epidermidis (MIC 0.02 mg/mL) and Gram-negative Salmonella typhimurium (MIC 0.078 mg/mL). Besides, the Ames test demonstrated the absence of direct mutagenic action in all the studied compounds.","PeriodicalId":9964,"journal":{"name":"Chimica Techno Acta","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-05-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140995565","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 : 2024-05-07DOI: 10.15826/chimtech.2024.11.2.08
D. Markovskaya, Victoria A. Lomakina, E. Kozlova
In this work, the photoelectrochemical properties of g-C3N4 modified with Pt, Ir and Ir/Pt bimetallic co-catalysts were studied. All prepared photoelectrodes were tested in a two-electrode cell by cyclic voltammetry, impedance spectroscopy, and the Mott-Schottky method. First, the optimal electrolyte (triethanolamine, NaCl, NaOH, Na2SO4) was selected. The highest photocurrents were recorded in 0.5 M Na2SO4. This electrolyte was used for the subsequent tests. Second, the photoelectrodes loaded with the noble metals are studied. It was shown that in case of monometallic co-catalysts, the deposition of noble metal is accompanied by the decrease of the short-circuit current density and the growth of open-circuit voltage. The simultaneous presence of bimetallic co-catalysts can significantly affect the semiconductor electron structure and photogalvanic properties. Some correlations between the short-circuit current density and the oxidation state of the noble metals were found. A linear correlation between Pt0/Pt0+Pt2+ and Jsc was observed. It was also shown that the presence of iridium in Ir3+ form favors the photocurrent generation. The highest values of the photocurrent were obtained for g-C3N4 and were equal to 0.57 mA/cm2.
{"title":"Photoelectrochemical properties of Pt- and Ir-modified graphitic carbon nitride","authors":"D. Markovskaya, Victoria A. Lomakina, E. Kozlova","doi":"10.15826/chimtech.2024.11.2.08","DOIUrl":"https://doi.org/10.15826/chimtech.2024.11.2.08","url":null,"abstract":"In this work, the photoelectrochemical properties of g-C3N4 modified with Pt, Ir and Ir/Pt bimetallic co-catalysts were studied. All prepared photoelectrodes were tested in a two-electrode cell by cyclic voltammetry, impedance spectroscopy, and the Mott-Schottky method. First, the optimal electrolyte (triethanolamine, NaCl, NaOH, Na2SO4) was selected. The highest photocurrents were recorded in 0.5 M Na2SO4. This electrolyte was used for the subsequent tests. Second, the photoelectrodes loaded with the noble metals are studied. It was shown that in case of monometallic co-catalysts, the deposition of noble metal is accompanied by the decrease of the short-circuit current density and the growth of open-circuit voltage. The simultaneous presence of bimetallic co-catalysts can significantly affect the semiconductor electron structure and photogalvanic properties. Some correlations between the short-circuit current density and the oxidation state of the noble metals were found. A linear correlation between Pt0/Pt0+Pt2+ and Jsc was observed. It was also shown that the presence of iridium in Ir3+ form favors the photocurrent generation. The highest values of the photocurrent were obtained for g-C3N4 and were equal to 0.57 mA/cm2.","PeriodicalId":9964,"journal":{"name":"Chimica Techno Acta","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-05-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141002653","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 : 2024-05-06DOI: 10.15826/chimtech.2024.11.2.07
M.I. Vlasov, E.A. Surzhikov, A. Germov, E. Il'ina, I. A. Weinstein
Li7La3Zr2O12 is one the most promising materials for Li-conducting solid electrolytes. The incorporation of Ta5+ and Nb5+ into the Zr4+ sites stabilizes its cubic structure and significantly enhances Li-conductivity, due to the formation of Li vacancies. In this research, we have studied the band gap features of Ta and Nd-doped Li7La3Zr2O12. Our findings indicate that Nb ions are present not only in the +5 valence state, but also in the +4 state, leading to the formation of oxygen vacancies. In the case of the Ta-doping, such an effect was not observed. This could be the reason for the approximately one order of magnitude higher lithium conductivity observed in the case of the Ta doping, in comparison to the Nb doping.
Li7La3Zr2O12 是最有前途的锂导电固体电解质材料之一。在 Zr4+ 位点中掺入 Ta5+ 和 Nb5+ 可稳定其立方结构，并由于锂空位的形成而显著提高锂导电性。在这项研究中，我们研究了掺杂 Ta 和 Nd 的 Li7La3Zr2O12 的带隙特征。我们的研究结果表明，铌离子不仅存在于 +5 价态，还存在于 +4 态，从而导致氧空位的形成。在掺杂 Ta 的情况下，没有观察到这种效应。这可能就是掺杂 Ta 的锂导电性比掺杂 Nb 的锂导电性高出约一个数量级的原因。
{"title":"Features of electronic states in the vicinity of band gap and atomic structure of Ta- and Nb-doped Li7La3Zr2O12","authors":"M.I. Vlasov, E.A. Surzhikov, A. Germov, E. Il'ina, I. A. Weinstein","doi":"10.15826/chimtech.2024.11.2.07","DOIUrl":"https://doi.org/10.15826/chimtech.2024.11.2.07","url":null,"abstract":"Li7La3Zr2O12 is one the most promising materials for Li-conducting solid electrolytes. The incorporation of Ta5+ and Nb5+ into the Zr4+ sites stabilizes its cubic structure and significantly enhances Li-conductivity, due to the formation of Li vacancies. In this research, we have studied the band gap features of Ta and Nd-doped Li7La3Zr2O12. Our findings indicate that Nb ions are present not only in the +5 valence state, but also in the +4 state, leading to the formation of oxygen vacancies. In the case of the Ta-doping, such an effect was not observed. This could be the reason for the approximately one order of magnitude higher lithium conductivity observed in the case of the Ta doping, in comparison to the Nb doping.","PeriodicalId":9964,"journal":{"name":"Chimica Techno Acta","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-05-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141010489","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 : 2024-04-10DOI: 10.15826/chimtech.2024.11.2.05
T. Yumalin, Timur Salikhov, Biltu Mahato, Alexey Shiverskii, Sergey Abaimov, R. Salikhov
The simple scaling of silicon transistors no longer ensures the advantages of high energy efficiency, driving research into nanotechnologies beyond silicon. Specifically, digital circuits based on carbon nanotube (CNT) field-effect transistors promise significant advantages in energy efficiency. However, the inability to perfectly control internal nanoscale defects and the variability of carbon nanotubes hinder the realization of very large-scale integrated systems. In this study, we investigated a novel method for fabricating transistors based on carbon nanotubes (CNTs) using epoxy mixtures, obtained the electrical properties of the transistors, and compared their microstructure and composition via the scanning electron microscopy. The carrier mobility on epoxy-based transistors was 28.87 cm²/V∙s, and the transistor switching frequency was 2.2 MHz. The samples exhibited electrical and physical stability over an extended period of time. The use of carbon nanotubes in epoxy resin as a conducting layer for transistors opens significant prospects in the field of electronics. The CNT-epoxy mixture technology allows for more flexible and rapid fabrication of thin-film transistors compared to classical methods. However, it is not appropriate to speak of a complete replacement; in this study, we present an alternative method for producing thin-film transistors, which may be of interest for specific purposes.
{"title":"CNT thin films based on epoxy mixtures: fabrication, electrical characteristics","authors":"T. Yumalin, Timur Salikhov, Biltu Mahato, Alexey Shiverskii, Sergey Abaimov, R. Salikhov","doi":"10.15826/chimtech.2024.11.2.05","DOIUrl":"https://doi.org/10.15826/chimtech.2024.11.2.05","url":null,"abstract":"The simple scaling of silicon transistors no longer ensures the advantages of high energy efficiency, driving research into nanotechnologies beyond silicon. Specifically, digital circuits based on carbon nanotube (CNT) field-effect transistors promise significant advantages in energy efficiency. However, the inability to perfectly control internal nanoscale defects and the variability of carbon nanotubes hinder the realization of very large-scale integrated systems. In this study, we investigated a novel method for fabricating transistors based on carbon nanotubes (CNTs) using epoxy mixtures, obtained the electrical properties of the transistors, and compared their microstructure and composition via the scanning electron microscopy. The carrier mobility on epoxy-based transistors was 28.87 cm²/V∙s, and the transistor switching frequency was 2.2 MHz. The samples exhibited electrical and physical stability over an extended period of time. The use of carbon nanotubes in epoxy resin as a conducting layer for transistors opens significant prospects in the field of electronics. The CNT-epoxy mixture technology allows for more flexible and rapid fabrication of thin-film transistors compared to classical methods. However, it is not appropriate to speak of a complete replacement; in this study, we present an alternative method for producing thin-film transistors, which may be of interest for specific purposes.","PeriodicalId":9964,"journal":{"name":"Chimica Techno Acta","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-04-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140719050","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 : 2024-04-09DOI: 10.15826/chimtech.2024.11.2.04
Alexander B. Kifle, N. Malakhova, A. Ivoilova, Nataliya Leonova, Svetlana Saraeva, A. Kozitsina
This study compares the electrochemical performance of screen-printed carbon electrodes (SPCEs) modified with antimony (Sb/SPCEs) under different potentiostatic pre-plating conditions. Neutral Red (NR) was employed as a novel redox probe to evaluate the electrochemical performance of Sb/SPCEs. It was demonstrated that NR in the protonated form performs quasi-reversible redox transformations at bare SPCE and Sb/SPCEs in phosphate buffer solutions (pH 5.5±0.5) in the potential range of (−0.30)–(−0.75) V, where the antimony is not electroactive. Sb/SPCEs were studied electrochemically by cyclic voltammetry (CV) / electrochemical impedance spectroscopy (EIS), and morphologically by scanning electron microscopy (SEM). Cyclic voltammetry investigations revealed the dependence of the electrochemical performance of Sb/SPCEs on the degree of coverage of the substrate with the metal. The obtained CV, EIS, and SEM data are consistent. The lowest charge transfer resistance (Rct) value (6 Ω) was obtained at Sb/SPCE with the highest degree of antimony coverage. To investigate the electroanalytical performance of Sb/SPCEs, nickel (II) ions were utilized as a model analyte. A study of roughness factors and sensitivity towards nickel (II) ions for Sb/SPCEs using two-tailed Pearson's criterion revealed a high degree of correlation between their electrochemical and electroanalytical properties. The results show that using NR as a redox probe can help controlling modification processes during the development of innovative antimony-containing sensors.
本研究比较了不同电位静电预镀条件下用锑修饰的丝网印刷碳电极（SPCE）（Sb/SPCE）的电化学性能。采用中性红（NR）作为新型氧化还原探针来评估 Sb/SPCE 的电化学性能。研究表明，质子化形式的 NR 在磷酸盐缓冲溶液（pH 值为 5.5±0.5）中的裸 SPCE 和 Sb/SPCE 上发生了准可逆的氧化还原转变，电位范围为 (-0.30)-(-0.75) V，其中锑不具有电活性。通过循环伏安法（CV）/电化学阻抗谱法（EIS）对锑/SPCE 进行了电化学研究，并通过扫描电子显微镜（SEM）对其形态进行了研究。循环伏安法研究表明，Sb/SPCEs 的电化学性能取决于金属对基底的覆盖程度。所获得的 CV、EIS 和 SEM 数据是一致的。锑覆盖度最高的 Sb/SPCE 的电荷转移电阻 (Rct) 值（6 Ω）最低。为了研究 Sb/SPCE 的电分析性能，使用了镍（II）离子作为模型分析物。使用双尾皮尔逊标准对 Sb/SPCE 的粗糙度系数和对镍（II）离子的灵敏度进行的研究表明，它们的电化学和电分析性能之间存在高度相关性。结果表明，在开发创新型含锑传感器的过程中，使用 NR 作为氧化还原探针有助于控制改性过程。
{"title":"Evaluation of electrochemical performance of antimony modified screen-printed carbon electrodes","authors":"Alexander B. Kifle, N. Malakhova, A. Ivoilova, Nataliya Leonova, Svetlana Saraeva, A. Kozitsina","doi":"10.15826/chimtech.2024.11.2.04","DOIUrl":"https://doi.org/10.15826/chimtech.2024.11.2.04","url":null,"abstract":"This study compares the electrochemical performance of screen-printed carbon electrodes (SPCEs) modified with antimony (Sb/SPCEs) under different potentiostatic pre-plating conditions. Neutral Red (NR) was employed as a novel redox probe to evaluate the electrochemical performance of Sb/SPCEs. It was demonstrated that NR in the protonated form performs quasi-reversible redox transformations at bare SPCE and Sb/SPCEs in phosphate buffer solutions (pH 5.5±0.5) in the potential range of (−0.30)–(−0.75) V, where the antimony is not electroactive. Sb/SPCEs were studied electrochemically by cyclic voltammetry (CV) / electrochemical impedance spectroscopy (EIS), and morphologically by scanning electron microscopy (SEM). Cyclic voltammetry investigations revealed the dependence of the electrochemical performance of Sb/SPCEs on the degree of coverage of the substrate with the metal. The obtained CV, EIS, and SEM data are consistent. The lowest charge transfer resistance (Rct) value (6 Ω) was obtained at Sb/SPCE with the highest degree of antimony coverage. To investigate the electroanalytical performance of Sb/SPCEs, nickel (II) ions were utilized as a model analyte. A study of roughness factors and sensitivity towards nickel (II) ions for Sb/SPCEs using two-tailed Pearson's criterion revealed a high degree of correlation between their electrochemical and electroanalytical properties. The results show that using NR as a redox probe can help controlling modification processes during the development of innovative antimony-containing sensors.","PeriodicalId":9964,"journal":{"name":"Chimica Techno Acta","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-04-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140723541","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 incorporation of carbon materials in batteries serves to enhance its performance by improving conductivity, achieving uniform active material distribution, increasing capacity, mitigating sulfation, extending cycle life, and considering potential environmental benefits. Even though several possible mechanisms were reported, how exactly carbon works is not fully understood. In the present study a new form of carbon black was prepared from Ageratina adenophora (CBAa) and investigated for its impact on the electrical conductivity of the negative active material in 2 V lead acid cell. The performance was compared with other commercially available carbons like Graphite PG-10, Carbon N550, Carbon N330 and Carbon Vulcan. The carbon was characterised by XRD, SEM and grain size analysis. The initial capacity of the cell was consistently higher and remained stable at 4.6 W∙h; in the life cycle analysis, the cells showed 290 cycles. The post-life cycle test analysis showed that only a white layer on multiple plates indicating the onset of sulfation and there is no corrosion. The performance of the CBAa prepared in the present work was found to be better when compared with the commercially available carbons.
{"title":"Effect of carbon black from Ageratina adenophora and various other carbon anode plate additives on the performance of lead acid batteries","authors":"Subban Ravi, Baskaran Vignesh, Nagarajan Meimoorthy, Bharathamani Dhanus Kumar, Lakshmanan Sathishkumar, Nagarajan Mohankumar, Nagarajan Kannapiran","doi":"10.15826/chimtech.2024.11.2.03","DOIUrl":"https://doi.org/10.15826/chimtech.2024.11.2.03","url":null,"abstract":"The incorporation of carbon materials in batteries serves to enhance its performance by improving conductivity, achieving uniform active material distribution, increasing capacity, mitigating sulfation, extending cycle life, and considering potential environmental benefits. Even though several possible mechanisms were reported, how exactly carbon works is not fully understood. In the present study a new form of carbon black was prepared from Ageratina adenophora (CBAa) and investigated for its impact on the electrical conductivity of the negative active material in 2 V lead acid cell. The performance was compared with other commercially available carbons like Graphite PG-10, Carbon N550, Carbon N330 and Carbon Vulcan. The carbon was characterised by XRD, SEM and grain size analysis. The initial capacity of the cell was consistently higher and remained stable at 4.6 W∙h; in the life cycle analysis, the cells showed 290 cycles. The post-life cycle test analysis showed that only a white layer on multiple plates indicating the onset of sulfation and there is no corrosion. The performance of the CBAa prepared in the present work was found to be better when compared with the commercially available carbons.","PeriodicalId":9964,"journal":{"name":"Chimica Techno Acta","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-04-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140729417","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 : 2024-04-04DOI: 10.15826/chimtech.2024.11.2.02
K. Okiy, Joseph Nwabanne Tagbo, Walter Peter Echeng
Environmental pollution from chemicals utilized in manufacturing, pharmaceuticals, and chemical process industries is of serious concern nowadays due to the contamination that ensues when these chemicals are discharged into water bodies. Activated carbon adsorption provides an efficient and economically viable means for mitigation of toxic chemicals (i.e., heavy metals, dyes, pharmaceutics, and antibiotics). However, the exorbitant cost of commercial activated carbons has resulted in the search for low-cost alternatives for the treatment of contaminated effluents. An exhaustive literature survey in this area is necessary to know the extent of work done in this area and seek out the gaps that future research will provide answers to. In this review, various works on activated carbon utilization, batch adsorption, fixed-bed adsorption (experimental and numerical studies) are summarized. This review elucidates the different kinetic and isotherm models of agrowastes-derived activated carbon materials in context with pollutants (dyes, heavy metals, pharmaceuticals, miscellaneous adsorbates) removal through batch and column methods. In addition, fixed-bed column adsorption/regeneration methods using various activated carbons derived from agrowastes are discussed. Among these methods, heavy metal adsorption from aqueous solutions by the activated carbons is the most efficient. The deployment of mathematical and machine learning approaches (ANN and novel GMDH algorithms) in optimization of batch and continuous adsorption processes are also highlighted. Numerical simulation of fixed-column adsorption systems for more improved industrial-scale column designs is described. Conclusions and future challenges of chemicals removal from polluted wastewater utilizing agrowaste-derived activated carbons are also presented.
{"title":"A review on agrowaste based activated carbons for pollutant removal in wastewater systems","authors":"K. Okiy, Joseph Nwabanne Tagbo, Walter Peter Echeng","doi":"10.15826/chimtech.2024.11.2.02","DOIUrl":"https://doi.org/10.15826/chimtech.2024.11.2.02","url":null,"abstract":"Environmental pollution from chemicals utilized in manufacturing, pharmaceuticals, and chemical process industries is of serious concern nowadays due to the contamination that ensues when these chemicals are discharged into water bodies. Activated carbon adsorption provides an efficient and economically viable means for mitigation of toxic chemicals (i.e., heavy metals, dyes, pharmaceutics, and antibiotics). However, the exorbitant cost of commercial activated carbons has resulted in the search for low-cost alternatives for the treatment of contaminated effluents. An exhaustive literature survey in this area is necessary to know the extent of work done in this area and seek out the gaps that future research will provide answers to. In this review, various works on activated carbon utilization, batch adsorption, fixed-bed adsorption (experimental and numerical studies) are summarized. This review elucidates the different kinetic and isotherm models of agrowastes-derived activated carbon materials in context with pollutants (dyes, heavy metals, pharmaceuticals, miscellaneous adsorbates) removal through batch and column methods. In addition, fixed-bed column adsorption/regeneration methods using various activated carbons derived from agrowastes are discussed. Among these methods, heavy metal adsorption from aqueous solutions by the activated carbons is the most efficient. The deployment of mathematical and machine learning approaches (ANN and novel GMDH algorithms) in optimization of batch and continuous adsorption processes are also highlighted. Numerical simulation of fixed-column adsorption systems for more improved industrial-scale column designs is described. Conclusions and future challenges of chemicals removal from polluted wastewater utilizing agrowaste-derived activated carbons are also presented.","PeriodicalId":9964,"journal":{"name":"Chimica Techno Acta","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-04-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140743472","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 : 2024-04-01DOI: 10.15826/chimtech.2024.11.2.01
Muhammad Reza, R. Rahmayani, C. Radiman
Phase inversion is used to prepare poly(vinylidene fluoride) (PVDF) microfiltration membranes by combining it with the hydrophilic polymer additive cellulose acetate (CA). For the filtration of methylene blue (MB) and acid yellow 17 (AY17), the effects of coagulant bath temperature (CBT) on the separation performance and antifouling properties are thoroughly investigated. SEM analysis shows that the membrane at higher CBT has a larger pore diameter than at lower CBT, resulting in differences in membrane surface hydrophilicity. It is found that the increase in surface hydrophilicity causes the permeability of PVDF/CA membranes to be higher at higher CBT than at lower CBT. Rejection values above 90% indicate that the membranes are more effective for MB separation at both lower and higher CBT. Otherwise, lower CBT provides better AC rejection than higher CBT. The Flux Recovery Ratio, which is higher at higher CBT, remains in the 75–95% range at lower CBT. As a result, lower CBT is better for membrane fouling resistance than higher CBT. In addition, the fouling observed at lower CBT is similar to the fouling observed at higher CBT, but lower CBT has a higher percentage of reversible fouling than higher CBT. The membranes with more reversible fouling are therefore easier to clean using the backwashing process. As a result, PVDF/CA membranes manufactured at lower CBT have better separation performance and antifouling characteristics than those manufactured at higher CBT.
{"title":"Effects of coagulant bath temperature toward separation performance and antifouling properties of PVDF/CA membranes for filtration of dyes","authors":"Muhammad Reza, R. Rahmayani, C. Radiman","doi":"10.15826/chimtech.2024.11.2.01","DOIUrl":"https://doi.org/10.15826/chimtech.2024.11.2.01","url":null,"abstract":"Phase inversion is used to prepare poly(vinylidene fluoride) (PVDF) microfiltration membranes by combining it with the hydrophilic polymer additive cellulose acetate (CA). For the filtration of methylene blue (MB) and acid yellow 17 (AY17), the effects of coagulant bath temperature (CBT) on the separation performance and antifouling properties are thoroughly investigated. SEM analysis shows that the membrane at higher CBT has a larger pore diameter than at lower CBT, resulting in differences in membrane surface hydrophilicity. It is found that the increase in surface hydrophilicity causes the permeability of PVDF/CA membranes to be higher at higher CBT than at lower CBT. Rejection values above 90% indicate that the membranes are more effective for MB separation at both lower and higher CBT. Otherwise, lower CBT provides better AC rejection than higher CBT. The Flux Recovery Ratio, which is higher at higher CBT, remains in the 75–95% range at lower CBT. As a result, lower CBT is better for membrane fouling resistance than higher CBT. In addition, the fouling observed at lower CBT is similar to the fouling observed at higher CBT, but lower CBT has a higher percentage of reversible fouling than higher CBT. The membranes with more reversible fouling are therefore easier to clean using the backwashing process. As a result, PVDF/CA membranes manufactured at lower CBT have better separation performance and antifouling characteristics than those manufactured at higher CBT.","PeriodicalId":9964,"journal":{"name":"Chimica Techno Acta","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140773191","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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