Ravi Dharavath, Ashwin Murali, Abdul Wasi Tarapathi, Balasubramanian Trichy Srinivasan, R. Kammili
The conductivity of an electrolyte plays a significant role in deciding the performance of any battery over a wide temperature range from −40°C to 60°C. In this work, the conductivity of lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) at a varied salt concentration range from 0.2 M to 2.0 M in a multisolvent organic electrolyte system over a wide temperature range from −40°C to 60°C is reported. The mixed solvents used were 1,3-dioxolane (DOL), 1,2-dimethoxyethane (DME), and tetraethylene glycol dimethyl ether (TEGDME) with an equal ratio of DOL : DME : TEGDME (1 : 1 : 1 by volume). The experimental analysis performed over a wide temperature range revealed the maximum conductivity at salt concentrations ranging from 1.0 M to 1.4 M for equal molar solvents. The optimum salt concentration and maximum conductivity in a different solvent composition ratio (i.e., 3 : 2 : 1) for all the temperatures is reported herein. The temperature-dependence conductivity of the salt concentration did not fit the Arrhenius plot, but it resembled the Vogel–Tamman–Fulcher plot behavior. The present conductivity study was carried out to evaluate the overall operable temperature limit of the electrolyte used in the lithium-sulfur battery.
{"title":"Low-Temperature Conductivity Study of Multiorganic Solvent Electrolyte for Lithium-Sulfur Rechargeable Battery Application","authors":"Ravi Dharavath, Ashwin Murali, Abdul Wasi Tarapathi, Balasubramanian Trichy Srinivasan, R. Kammili","doi":"10.1155/2019/8192931","DOIUrl":"https://doi.org/10.1155/2019/8192931","url":null,"abstract":"The conductivity of an electrolyte plays a significant role in deciding the performance of any battery over a wide temperature range from −40°C to 60°C. In this work, the conductivity of lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) at a varied salt concentration range from 0.2 M to 2.0 M in a multisolvent organic electrolyte system over a wide temperature range from −40°C to 60°C is reported. The mixed solvents used were 1,3-dioxolane (DOL), 1,2-dimethoxyethane (DME), and tetraethylene glycol dimethyl ether (TEGDME) with an equal ratio of DOL : DME : TEGDME (1 : 1 : 1 by volume). The experimental analysis performed over a wide temperature range revealed the maximum conductivity at salt concentrations ranging from 1.0 M to 1.4 M for equal molar solvents. The optimum salt concentration and maximum conductivity in a different solvent composition ratio (i.e., 3 : 2 : 1) for all the temperatures is reported herein. The temperature-dependence conductivity of the salt concentration did not fit the Arrhenius plot, but it resembled the Vogel–Tamman–Fulcher plot behavior. The present conductivity study was carried out to evaluate the overall operable temperature limit of the electrolyte used in the lithium-sulfur battery.","PeriodicalId":13933,"journal":{"name":"International journal of electrochemistry","volume":"2019 1","pages":"1-5"},"PeriodicalIF":1.8,"publicationDate":"2019-11-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1155/2019/8192931","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44933254","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 challenges to be overtaken with alkaline water electrolysis are the reduction of energy consumption, the maintenance, and the cost as well as the increase of durability, reliability, and safety. Having these challenges in mind, this work focused on the reduction of the electrical resistance of the electrolyte which directly affects energy consumption. According to the definition of electrical resistance of an object, the reduction of the space between electrodes could lower the electrical resistance but, in this process, the formation of bubbles could modify this affirmation. In this work, the performance analyses of nine different spaces between stainless steel 316L electrodes were carried out, although the spaces proposed are not the same as those from the positive electrode (anode) to the separator and from the separator to the negative electrode (cathode). The reason why this is studied is that stoichiometry of the reaction states that two moles of hydrogen and one mole of oxygen can be obtained per every two moles of water. The proposed spaces were 10.65, 9.20, 8.25, 7.25, 6.30, 6.05, 4.35, 4.15, and 3.40 millimetres. From the nine different analysed distances between electrodes, it can be said that the best performance was reached by one of the smallest distances proposed, 4.15 mm. When the same distance between electrodes was compared (the same and different distance between electrodes and separator), the one that had almost twice the distance (negative compartment) presented an increase in current density of approximately 33% with respect to that where both distances (from electrodes to separator) are the same. That indicates that the stichometry of the electrolysis reaction influenced the performance.
{"title":"Straight-Parallel Electrodes and Variable Gap for Hydrogen and Oxygen Evolution Reactions","authors":"M. J. Lavorante, Carla Yanina Reynoso, J. Franco","doi":"10.1155/2019/5392452","DOIUrl":"https://doi.org/10.1155/2019/5392452","url":null,"abstract":"The challenges to be overtaken with alkaline water electrolysis are the reduction of energy consumption, the maintenance, and the cost as well as the increase of durability, reliability, and safety. Having these challenges in mind, this work focused on the reduction of the electrical resistance of the electrolyte which directly affects energy consumption. According to the definition of electrical resistance of an object, the reduction of the space between electrodes could lower the electrical resistance but, in this process, the formation of bubbles could modify this affirmation. In this work, the performance analyses of nine different spaces between stainless steel 316L electrodes were carried out, although the spaces proposed are not the same as those from the positive electrode (anode) to the separator and from the separator to the negative electrode (cathode). The reason why this is studied is that stoichiometry of the reaction states that two moles of hydrogen and one mole of oxygen can be obtained per every two moles of water. The proposed spaces were 10.65, 9.20, 8.25, 7.25, 6.30, 6.05, 4.35, 4.15, and 3.40 millimetres. From the nine different analysed distances between electrodes, it can be said that the best performance was reached by one of the smallest distances proposed, 4.15 mm. When the same distance between electrodes was compared (the same and different distance between electrodes and separator), the one that had almost twice the distance (negative compartment) presented an increase in current density of approximately 33% with respect to that where both distances (from electrodes to separator) are the same. That indicates that the stichometry of the electrolysis reaction influenced the performance.","PeriodicalId":13933,"journal":{"name":"International journal of electrochemistry","volume":" ","pages":""},"PeriodicalIF":1.8,"publicationDate":"2019-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1155/2019/5392452","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46374838","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}
Maheeka Yapa Abeywardana, N. Laszczynski, M. Kuenzel, D. Bresser, S. Passerini, B. Lucht
LiNi0.5Mn1.5O4 (LNMO), which has an operating voltage of 4.8 vs Li/Li+ and a theoretical capacity of 147 mAh g−1, is an interesting cathode material for advanced lithium ion batteries. However, electrolyte decomposition at the electrode can gradually decrease the capacity of the battery. In this study, the surface of the LNMO cathode has been modified with phosphoric acid (PA) to improve the capacity of the LNMO/graphite full cell. Modification of LNMO cathodes by PA is confirmed by surface analysis. Additionally, the presence of lithium bis-(oxalato) borate (LiBOB) as an electrolyte additive further enhances the performance of PA modified LNMO/graphite cells. The improved performance of PA modified cathodes and electrolytes containing LiBOB can be attributed to the suppressed Mn and Ni deposition on the anode. Elemental analysis suggests that the Mn and Ni dissolution is significantly reduced compared to unmodified LNMO/graphite cells with standard electrolyte.
LiNi0.5Mn1.5O4（LNMO）的工作电压为4.8 vs Li/Li+，理论容量为147 mAh g−1，是先进锂离子电池的一种有趣的正极材料。然而，电解质在电极处的分解会逐渐降低电池的容量。在本研究中，用磷酸（PA）对LNMO阴极的表面进行了改性，以提高LNMO/石墨全电池的容量。通过表面分析证实了PA对LNMO阴极的改性。此外，双（草酸）硼酸锂（LiBOB）作为电解质添加剂的存在进一步增强了PA改性的LNMO/石墨电池的性能。PA改性的阴极和含有LiBOB的电解质的性能提高可归因于抑制了Mn和Ni在阳极上的沉积。元素分析表明，与具有标准电解质的未改性LNMO/石墨电池相比，Mn和Ni的溶解显著减少。
{"title":"Increased Cycling Performance of Li-Ion Batteries by Phosphoric Acid Modified LiNi0.5Mn1.5O4 Cathodes in the Presence of LiBOB","authors":"Maheeka Yapa Abeywardana, N. Laszczynski, M. Kuenzel, D. Bresser, S. Passerini, B. Lucht","doi":"10.1155/2019/8636540","DOIUrl":"https://doi.org/10.1155/2019/8636540","url":null,"abstract":"LiNi0.5Mn1.5O4 (LNMO), which has an operating voltage of 4.8 vs Li/Li+ and a theoretical capacity of 147 mAh g−1, is an interesting cathode material for advanced lithium ion batteries. However, electrolyte decomposition at the electrode can gradually decrease the capacity of the battery. In this study, the surface of the LNMO cathode has been modified with phosphoric acid (PA) to improve the capacity of the LNMO/graphite full cell. Modification of LNMO cathodes by PA is confirmed by surface analysis. Additionally, the presence of lithium bis-(oxalato) borate (LiBOB) as an electrolyte additive further enhances the performance of PA modified LNMO/graphite cells. The improved performance of PA modified cathodes and electrolytes containing LiBOB can be attributed to the suppressed Mn and Ni deposition on the anode. Elemental analysis suggests that the Mn and Ni dissolution is significantly reduced compared to unmodified LNMO/graphite cells with standard electrolyte.","PeriodicalId":13933,"journal":{"name":"International journal of electrochemistry","volume":"1 1","pages":""},"PeriodicalIF":1.8,"publicationDate":"2019-07-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1155/2019/8636540","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41636315","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}
Ragi Kooliyat, Joby Thomas Kakkassery, V. P. Raphael, Sini Varghese Cheruvathur, Binsi M. Paulson
Schiff base 2,2’-(5,5-dimethylcyclohexane-1,3-diylidene)bis(azan-1-yl-1-ylidene) diphenol (DmChDp) was synthesized and characterized using spectroscopic methods (IR, UV, NMR, and Mass) and cyclic voltammetric (CV) studies. The corrosion inhibition potency of (DmChDp) on mild steel (MS) in 1M HCl and 0.5M H2SO4 was investigated. The corrosion monitoring techniques employed for this purpose are gravimetric and electrochemical methods (EIS and potentiodynamic polarization studies). The study reveals that the Schiff base, DmChDp, acts as excellent corrosion inhibitor on mild steel in 1M HCl. DmChDp obeys Langmuir adsorption isotherm both in 1M HCl and 0.5M H2SO4 on MS. Polarization studies show that DmChDp behaves as a mixed type inhibitor in both media. Scanning electron microscopic analysis established the protective nature of DmChDp on mild steel surface. The impact of temperature on the corrosion of MS was also evaluated using gravimetric method.
{"title":"Synthesis, Cyclic Voltammetric, Electrochemical, and Gravimetric Corrosion Inhibition Investigations of Schiff Base Derived from 5,5-Dimethyl-1,3-cyclohexanedione and 2-Aminophenol on Mild Steel in 1 M HCl and 0.5 M H2SO4","authors":"Ragi Kooliyat, Joby Thomas Kakkassery, V. P. Raphael, Sini Varghese Cheruvathur, Binsi M. Paulson","doi":"10.1155/2019/1094148","DOIUrl":"https://doi.org/10.1155/2019/1094148","url":null,"abstract":"Schiff base 2,2’-(5,5-dimethylcyclohexane-1,3-diylidene)bis(azan-1-yl-1-ylidene) diphenol (DmChDp) was synthesized and characterized using spectroscopic methods (IR, UV, NMR, and Mass) and cyclic voltammetric (CV) studies. The corrosion inhibition potency of (DmChDp) on mild steel (MS) in 1M HCl and 0.5M H2SO4 was investigated. The corrosion monitoring techniques employed for this purpose are gravimetric and electrochemical methods (EIS and potentiodynamic polarization studies). The study reveals that the Schiff base, DmChDp, acts as excellent corrosion inhibitor on mild steel in 1M HCl. DmChDp obeys Langmuir adsorption isotherm both in 1M HCl and 0.5M H2SO4 on MS. Polarization studies show that DmChDp behaves as a mixed type inhibitor in both media. Scanning electron microscopic analysis established the protective nature of DmChDp on mild steel surface. The impact of temperature on the corrosion of MS was also evaluated using gravimetric method.","PeriodicalId":13933,"journal":{"name":"International journal of electrochemistry","volume":" ","pages":""},"PeriodicalIF":1.8,"publicationDate":"2019-05-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1155/2019/1094148","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49290953","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}
Current-voltage characteristics of few-layer graphene structures (FLGS) obtained by plasma-assisted electrochemical exfoliation of graphite in Na2SO4 solution were measured. FLGS are shown to possess electronic conductivity, which indicates the predominant functionalization of the edges of graphene planes and the preservation of the structure of basal planes in obtained nanostructures as in the source graphite. The effect of humidity on the conductivity of FLGS films was studied. The resistance of films was found to increase with an increase in the relative humidity of the environment due to the shielding of FLGS flakes by a film of water. The effect of different solvents on the current-voltage characteristics of FLGS was analyzed. The conductivity of films significantly decreased in vapors of polar protic solvents, while there was a minor effect of nonpolar aprotic solvents on the conductivity of FLGS films.
{"title":"Electrical Conductivity of Films Formed by Few-Layer Graphene Structures Obtained by Plasma-Assisted Electrochemical Exfoliation of Graphite","authors":"V. Vasiliev, R. Manzhos, A. Krivenko","doi":"10.1155/2019/6478708","DOIUrl":"https://doi.org/10.1155/2019/6478708","url":null,"abstract":"Current-voltage characteristics of few-layer graphene structures (FLGS) obtained by plasma-assisted electrochemical exfoliation of graphite in Na2SO4 solution were measured. FLGS are shown to possess electronic conductivity, which indicates the predominant functionalization of the edges of graphene planes and the preservation of the structure of basal planes in obtained nanostructures as in the source graphite. The effect of humidity on the conductivity of FLGS films was studied. The resistance of films was found to increase with an increase in the relative humidity of the environment due to the shielding of FLGS flakes by a film of water. The effect of different solvents on the current-voltage characteristics of FLGS was analyzed. The conductivity of films significantly decreased in vapors of polar protic solvents, while there was a minor effect of nonpolar aprotic solvents on the conductivity of FLGS films.","PeriodicalId":13933,"journal":{"name":"International journal of electrochemistry","volume":" ","pages":""},"PeriodicalIF":1.8,"publicationDate":"2019-04-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1155/2019/6478708","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43960650","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 presents a reliable, cost-effective, rapid and in-field voltammetric method for the detection of barium. The optimized method consists of an ultrathin mercury film deposited in situ on a glassy carbon electrode in dilute potassium chloride without deoxygenation, using differential pulse anodic stripping voltammetry (DP-ASV). Application of the method allowed for the quantitative determination of barium concentration in a variety of waters and brake pad dust samples. Comparative analysis of sample results from DP-ASV with inductively coupled plasma mass spectroscopy (ICP-MS) showed a mean percent difference of 1.8%.
{"title":"Development of an In-Field Method for the Detection of Barium in Various Water Samples Using Differential Pulse Anodic Stripping Voltammetry","authors":"S. Ridgway, M. Wajrak","doi":"10.1155/2019/5813492","DOIUrl":"https://doi.org/10.1155/2019/5813492","url":null,"abstract":"This work presents a reliable, cost-effective, rapid and in-field voltammetric method for the detection of barium. The optimized method consists of an ultrathin mercury film deposited in situ on a glassy carbon electrode in dilute potassium chloride without deoxygenation, using differential pulse anodic stripping voltammetry (DP-ASV). Application of the method allowed for the quantitative determination of barium concentration in a variety of waters and brake pad dust samples. Comparative analysis of sample results from DP-ASV with inductively coupled plasma mass spectroscopy (ICP-MS) showed a mean percent difference of 1.8%.","PeriodicalId":13933,"journal":{"name":"International journal of electrochemistry","volume":" ","pages":""},"PeriodicalIF":1.8,"publicationDate":"2019-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1155/2019/5813492","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44399057","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 study, the relevance of a food dye, namely, Fast Green-FCF (FG-FCF), was surveyed as a new inhibitor for mild steel in HCl solution. This effect was specified by electrochemical impedance spectroscopy (EIS), one of the most widely used measurement techniques. As a result of the increment of the inhibitor concentration, it was seen that the values of polarization resistance increased and covered the metal surface of FG-FCF like a blanket. Tests endorse that the FG-FCF is chemically adsorbed on mild steel surface, according to the Langmuir isotherm. With surface characteristic analyses, such as field emission scanning electron microscope (FESEM) and atomic force microscope (AFM), it was further determined that the metal surface in HCl of FG-FCF was protected. By applying the hydrogen gas evolution technique, FG-FCF has been proven to provide the lowest surface area with all inhibited solutions from the blank due to its strong adsorption to the metal surface. Finally, it has been clarified that FG-FCF can be practically used as a good corrosion inhibitor for mild steel with the supported results.
{"title":"The Electrochemical Variation of a Kind of Protein Staining and Food Dye as a New Corrosion Inhibitor on Mild Steel in Acidic Medium","authors":"D. Özkır","doi":"10.1155/2019/5743952","DOIUrl":"https://doi.org/10.1155/2019/5743952","url":null,"abstract":"In this study, the relevance of a food dye, namely, Fast Green-FCF (FG-FCF), was surveyed as a new inhibitor for mild steel in HCl solution. This effect was specified by electrochemical impedance spectroscopy (EIS), one of the most widely used measurement techniques. As a result of the increment of the inhibitor concentration, it was seen that the values of polarization resistance increased and covered the metal surface of FG-FCF like a blanket. Tests endorse that the FG-FCF is chemically adsorbed on mild steel surface, according to the Langmuir isotherm. With surface characteristic analyses, such as field emission scanning electron microscope (FESEM) and atomic force microscope (AFM), it was further determined that the metal surface in HCl of FG-FCF was protected. By applying the hydrogen gas evolution technique, FG-FCF has been proven to provide the lowest surface area with all inhibited solutions from the blank due to its strong adsorption to the metal surface. Finally, it has been clarified that FG-FCF can be practically used as a good corrosion inhibitor for mild steel with the supported results.","PeriodicalId":13933,"journal":{"name":"International journal of electrochemistry","volume":" ","pages":""},"PeriodicalIF":1.8,"publicationDate":"2019-03-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1155/2019/5743952","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43856399","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}
Melaku Metto, Samrawit Eramias, Bekele Gelagay, Alemayehu P Washe
Screen printed carbon electrodes (SPCEs) provide attractive opportunity for sensitive and selective determination target analytes in clinical samples. The aim of the current work was to develop SPCEs based sensor for the determination of uric acid in clinical serum samples. The electrodes were pretreated by soaking in N,N-dimethylformamide for 5 minutes followed by drying in an oven at 100°C for 20 mins. The effect of surface pretreatment was characterized using cyclic voltammetry. The current response of uric acid detection was improved by a factor of 3.5 in differential pulse voltammetric measurement compared to unmodified electrode. Under the optimized conditions, the sensor displayed two dynamic linear ranges 5-100 μM and 100-500 μM with correlation coefficient, R2, values of 0.98782 and 0.97876, respectively. The limit of detection and limit of quantification calculated using the dynamic linear range 5-100 μM were 1.9 x 10−7 M and 6.33 x 10−7 M, respectively. The developed sensor displayed well separated and discerned peaks for UA in presence of the potential interferent (ascorbic acid and citric acid). The electrode was successfully applied for the detection of very low level of UA in clinical serum samples in a phosphate buffer solution (pH = 7). The proposed sensor showed a very high reproducibility and repeatability with the relative standard deviation of 0.9%. In conclusion, a simple and low cost sensor based on SPCEs is developed for sensitive and selective detection of uric acid in clinical samples.
丝网印刷碳电极（SPCE）为临床样品中敏感和选择性测定目标分析物提供了有吸引力的机会。目前工作的目的是开发基于SPCEs的传感器，用于测定临床血清样品中的尿酸。电极通过在N，N-二甲基甲酰胺中浸泡5分钟进行预处理，然后在100°C的烘箱中干燥20分钟。用循环伏安法表征了表面预处理的效果。在微分脉冲伏安测量中，与未修饰的电极相比，尿酸检测的电流响应提高了3.5倍。在优化条件下，传感器显示出5-100μM和100-500μM两个动态线性范围，相关系数R2分别为0.98782和0.97876。使用5-100μM的动态线性范围计算的检测限和定量限分别为1.9 x 10−7M和6.33 x 10−7M。在存在潜在干扰物质（抗坏血酸和柠檬酸）的情况下，所开发的传感器显示出良好分离和辨别的UA峰。该电极成功应用于在磷酸盐缓冲溶液（pH＝7）中检测临床血清样品中非常低水平的UA。所提出的传感器显示出非常高的再现性和重复性，相对标准偏差为0.9%。总之，开发了一种基于SPCEs的简单低成本传感器，用于灵敏和选择性地检测临床样品中的尿酸。
{"title":"Voltammetric Determination of Uric Acid in Clinical Serum Samples Using DMF Modified Screen Printed Carbon Electrodes","authors":"Melaku Metto, Samrawit Eramias, Bekele Gelagay, Alemayehu P Washe","doi":"10.1155/2019/6318515","DOIUrl":"https://doi.org/10.1155/2019/6318515","url":null,"abstract":"Screen printed carbon electrodes (SPCEs) provide attractive opportunity for sensitive and selective determination target analytes in clinical samples. The aim of the current work was to develop SPCEs based sensor for the determination of uric acid in clinical serum samples. The electrodes were pretreated by soaking in N,N-dimethylformamide for 5 minutes followed by drying in an oven at 100°C for 20 mins. The effect of surface pretreatment was characterized using cyclic voltammetry. The current response of uric acid detection was improved by a factor of 3.5 in differential pulse voltammetric measurement compared to unmodified electrode. Under the optimized conditions, the sensor displayed two dynamic linear ranges 5-100 μM and 100-500 μM with correlation coefficient, R2, values of 0.98782 and 0.97876, respectively. The limit of detection and limit of quantification calculated using the dynamic linear range 5-100 μM were 1.9 x 10−7 M and 6.33 x 10−7 M, respectively. The developed sensor displayed well separated and discerned peaks for UA in presence of the potential interferent (ascorbic acid and citric acid). The electrode was successfully applied for the detection of very low level of UA in clinical serum samples in a phosphate buffer solution (pH = 7). The proposed sensor showed a very high reproducibility and repeatability with the relative standard deviation of 0.9%. In conclusion, a simple and low cost sensor based on SPCEs is developed for sensitive and selective detection of uric acid in clinical samples.","PeriodicalId":13933,"journal":{"name":"International journal of electrochemistry","volume":" ","pages":""},"PeriodicalIF":1.8,"publicationDate":"2019-02-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1155/2019/6318515","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46383850","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
V. Nguyễn, Q. L. Thu, T. Nguyen, Quoc Cuong Ly, Ly Pham Thi, Ha Pham Thi, Thanh Dinh Thi Mai
This study presents the effect of heat treatment on porosity, phase composition, microhardness, and wear and corrosion resistances of the thermal sprayed NiCr20 coating after sealing with aluminum phosphate. The annealing temperatures were varied in a range of 400 to 1000°C. The obtained results indicated the porosity of coating decreased with increasing the annealing temperature. After treatment at temperatures in range of 800-1000°C, more than 90% of initial pores in the coating were successfully filled with the sealants. The XRD data revealed not only the formation of new phases of other compounds, but also the interaction between coating and sealant. After heat treatment, wear resistance of coating was 12 times higher than that without heat treatment. The corrosion test in H2SO4 solution indicated that the presence of sealant in coatings increased their corrosion resistance. From these findings, application of these NiCr20 coatings to protect steel against wear and corrosion appears very promising.
{"title":"Arc Thermal Spray NiCr20 Alloy Coating: Fabrication, Sealant, Heat Treatment, Wear, and Corrosion Resistances","authors":"V. Nguyễn, Q. L. Thu, T. Nguyen, Quoc Cuong Ly, Ly Pham Thi, Ha Pham Thi, Thanh Dinh Thi Mai","doi":"10.1155/2019/8796958","DOIUrl":"https://doi.org/10.1155/2019/8796958","url":null,"abstract":"This study presents the effect of heat treatment on porosity, phase composition, microhardness, and wear and corrosion resistances of the thermal sprayed NiCr20 coating after sealing with aluminum phosphate. The annealing temperatures were varied in a range of 400 to 1000°C. The obtained results indicated the porosity of coating decreased with increasing the annealing temperature. After treatment at temperatures in range of 800-1000°C, more than 90% of initial pores in the coating were successfully filled with the sealants. The XRD data revealed not only the formation of new phases of other compounds, but also the interaction between coating and sealant. After heat treatment, wear resistance of coating was 12 times higher than that without heat treatment. The corrosion test in H2SO4 solution indicated that the presence of sealant in coatings increased their corrosion resistance. From these findings, application of these NiCr20 coatings to protect steel against wear and corrosion appears very promising.","PeriodicalId":13933,"journal":{"name":"International journal of electrochemistry","volume":" ","pages":""},"PeriodicalIF":1.8,"publicationDate":"2019-01-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1155/2019/8796958","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45884781","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}
Gabriel O. Resende, S. Teixeira,, I. F. Figueiredo, Alexandre A. Godoy, Dafne Júlia F. Lougon, B. Cotrim, F. C. Souza
Heterocyclic compounds containing the 1,2,3-triazole moiety can be synthesized through click-chemistry, which is rapid reactions with good yields allowing the synthesis of great derivatives diversity by making minor changes in the reagents. The products were obtained with good yields through a synthetic route which uses ready available nonexpensive commercial reagents and without any further purification of any product or intermediate. The carbon steel anticorrosive activity was tested through weight loss and electrochemical assays in acid media. It was observed relevant inhibition efficiency (> 90%) for inhibitors 1 and 2. From Langmuir isotherm, it was hypothesized the adsorption of inhibitors on the carbon steel surface might occur by physical and chemical interaction; however, the activation energy raised suggests a physisorption process for the interaction of the inhibitor on the carbon steel surface.
{"title":"Synthesis of 1,2,3-Triazole Derivatives and Its Evaluation as Corrosion Inhibitors for Carbon Steel","authors":"Gabriel O. Resende, S. Teixeira,, I. F. Figueiredo, Alexandre A. Godoy, Dafne Júlia F. Lougon, B. Cotrim, F. C. Souza","doi":"10.1155/2019/6759478","DOIUrl":"https://doi.org/10.1155/2019/6759478","url":null,"abstract":"Heterocyclic compounds containing the 1,2,3-triazole moiety can be synthesized through click-chemistry, which is rapid reactions with good yields allowing the synthesis of great derivatives diversity by making minor changes in the reagents. The products were obtained with good yields through a synthetic route which uses ready available nonexpensive commercial reagents and without any further purification of any product or intermediate. The carbon steel anticorrosive activity was tested through weight loss and electrochemical assays in acid media. It was observed relevant inhibition efficiency (> 90%) for inhibitors 1 and 2. From Langmuir isotherm, it was hypothesized the adsorption of inhibitors on the carbon steel surface might occur by physical and chemical interaction; however, the activation energy raised suggests a physisorption process for the interaction of the inhibitor on the carbon steel surface.","PeriodicalId":13933,"journal":{"name":"International journal of electrochemistry","volume":" ","pages":""},"PeriodicalIF":1.8,"publicationDate":"2019-01-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1155/2019/6759478","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43051111","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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