In this paper, the performance of a composite particle for the deposition of ZnO/Cr2O3 on a zinc electrolyte was examined. Its susceptibility to corrosion in 3.5% NaCl, using linear polarization, was investigated. The developed crystal was characterized by using scanning electron microscope (SEM) equipped with an energy dispersive spectrometer (EDS). The strengthening properties of the coated samples, i.e. the mechanical response, were studied using a high sensitive diamond microhardness indenter and a MTR-300 rigid wear tester. From the results, the effect of the composite coatings interestingly influenced the performance regarding microhardness, durability, corrosion mitigation and wear damage. In general, the micro-hardness value for the Zn-ZnO material was 125.0 HVN, while it was 130.5 HVN for Zn-8ZnO-16Cr2O3 composite coating. For Zn-8ZnO-20Cr2O3, a better hardness performance was noted with 138.0 HVN. From the wear study, Zn-8ZnO shows 0.018 g/min dissociation against the counter body with the best wear performance obtained at 0.005 g/min. The corrosion properties of the developed composite coating also tend towards a more positive region, with a corrosion rate of 0.850 mm/yr. This shows that the role of composite particulates maximally contributes to improve the strengthening characteristics of the developed coating.
{"title":"Potential of Composite Incorporation on the Mechanical Behavior of Multilayer Coatings","authors":"O. Joseph, O. Fayomi, A. O. Inegbenebo, A. Ayoola","doi":"10.4152/pea.2021390301","DOIUrl":"https://doi.org/10.4152/pea.2021390301","url":null,"abstract":"In this paper, the performance of a composite particle for the deposition of ZnO/Cr2O3 on a zinc electrolyte was examined. Its susceptibility to corrosion in 3.5% NaCl, using linear polarization, was investigated. The developed crystal was characterized by using scanning electron microscope (SEM) equipped with an energy dispersive spectrometer (EDS). The strengthening properties of the coated samples, i.e. the mechanical response, were studied using a high sensitive diamond microhardness indenter and a MTR-300 rigid wear tester. From the results, the effect of the composite coatings interestingly influenced the performance regarding microhardness, durability, corrosion mitigation and wear damage. In general, the micro-hardness value for the Zn-ZnO material was 125.0 HVN, while it was 130.5 HVN for Zn-8ZnO-16Cr2O3 composite coating. For Zn-8ZnO-20Cr2O3, a better hardness performance was noted with 138.0 HVN. From the wear study, Zn-8ZnO shows 0.018 g/min dissociation against the counter body with the best wear performance obtained at 0.005 g/min. The corrosion properties of the developed composite coating also tend towards a more positive region, with a corrosion rate of 0.850 mm/yr. This shows that the role of composite particulates maximally contributes to improve the strengthening characteristics of the developed coating.","PeriodicalId":20334,"journal":{"name":"Portugaliae Electrochimica Acta","volume":"1 1","pages":""},"PeriodicalIF":1.2,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70918544","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}
Two carbon paste electrodes for oxymetazoline hydrochloride were constructed based on ion pair complexes of this drug, with sodium tetraphenylborate (NaTPB) or ammonium reineckate, using dibutyl phthalate and dioctyl phthalate as solvent mediators, respectively. The developed electrodes displayed a fast, stable response over the concentration range from 3.98x10 to 1x10 M oxymetazoline hydrochloride, with a near-nernstian slope of 59.0, 58.2 mV of concentration decade and a limit of detection (LOD) of 3.31x10 and 3.72x10 M, in the oxymetazoline-tetraphenylborate and oxymetazoline-reineckate cases, respectively. The developed electrodes have been successfully applied for oxymetazoline hydrochloride determination in the Afrin nasal drop pharmaceutical formulation.
{"title":"Potentiometric Determination of Oxymetazoline Hydrochloride Using Modified Carbon Paste Electrodes","authors":"Y. M. Issa, M. Khalil, S. I. Zayed, N. Mustafa","doi":"10.4152/pea.2021390505","DOIUrl":"https://doi.org/10.4152/pea.2021390505","url":null,"abstract":"Two carbon paste electrodes for oxymetazoline hydrochloride were constructed based on ion pair complexes of this drug, with sodium tetraphenylborate (NaTPB) or ammonium reineckate, using dibutyl phthalate and dioctyl phthalate as solvent mediators, respectively. The developed electrodes displayed a fast, stable response over the concentration range from 3.98x10 to 1x10 M oxymetazoline hydrochloride, with a near-nernstian slope of 59.0, 58.2 mV of concentration decade and a limit of detection (LOD) of 3.31x10 and 3.72x10 M, in the oxymetazoline-tetraphenylborate and oxymetazoline-reineckate cases, respectively. The developed electrodes have been successfully applied for oxymetazoline hydrochloride determination in the Afrin nasal drop pharmaceutical formulation.","PeriodicalId":20334,"journal":{"name":"Portugaliae Electrochimica Acta","volume":"1 1","pages":""},"PeriodicalIF":1.2,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70918874","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 corrosion inhibition effect of ethanol extract of Acacia nilotica leaves (ANLE) on mild steel in 0.1 M H2SO4, containing 0.1-0.5 g/L, has been studied using weight loss, Potentiodynamic Polarization (PDP), Fourier Transforms Infra-Red (FTIR) spectroscopy, UV-visible spectroscopy, High-Performance Liquid Chromatography (HPLC) and Scanning Electron Microscopy (SEM) methods. The results from weight loss and PDP show that the inhibition efficiency depends on the concentration of the plant extract, as well as on the time of exposure of the mild steel samples in H2SO4 solutions. The optimum inhibition efficiencies of the extract obtained from weight loss and potentiodynamic measurements were found to be 87.57% and 61.85%, respectively. Thermodynamic parameters, such as Ea, ΔH, ΔG and ΔS, were evaluated at 0.5 g/L, and the results were found to be -78.54 kJ/mol, 74.66 kJ/mol., -17.92 kJ/mol and -90.59 kJ/mol, respectively. From the calculated values of activation energy and free energy of adsorption, and from the trend in the variation of inhibition efficiency with temperature, the inhibitor mechanism of adsorption was found to be physical adsorption, exothermic, spontaneous, being best described by Langmuir adsorption model, because the regression coefficients (R) values calculated from the plots were closest to unity, confirming a highest degree of linearity. Mild steel surface morphology, in ANLE presence and absence, was studied using SEM. FTIR spectroscopy and UV-visible spectroscopy analyses were used to confirm the adsorption process onto the metal surface. Spectra analysis obtained from FTIR study indicated that ANLE was adsorbed onto the mild steel surface via C-O and N=O functional groups. HPLC was also used to find the main component responsible for inhibition, at 5.990 min, which was Catechin. The obtained results revealed that ANLE acts as a good inhibitor and could serve as an effective mild steel corrosion inhibitor in a 0.1 M H2SO4 solution.
采用失重、动电位极化(PDP)、傅里叶变换红外光谱(FTIR)、紫外可见光谱(uv -可见光)、高效液相色谱(HPLC)和扫描电镜(SEM)等方法，研究了尼罗卡叶乙醇提取物(ANLE)在0.1 M (0.1 ~ 0.5 g/L) H2SO4中对低碳钢的缓蚀作用。失重和PDP的结果表明，植物提取物的缓蚀效果取决于浓度，以及低碳钢样品在H2SO4溶液中的暴露时间。失重法和动电位法的最佳抑菌率分别为87.57%和61.85%。在0.5 g/L条件下，对Ea、ΔH、ΔG、ΔS等热力学参数进行了计算，结果分别为-78.54、74.66 kJ/mol。、-17.92 kJ/mol和-90.59 kJ/mol。从吸附活化能和自由能的计算值，以及抑制效率随温度的变化趋势来看，缓蚀剂的吸附机理为物理吸附、放热、自发，Langmuir吸附模型最能描述缓蚀剂的吸附机理，因为从图中计算的回归系数(R)值最接近统一，线性程度最高。用扫描电镜研究了低碳钢在有角和无角情况下的表面形貌。利用红外光谱和紫外可见光谱分析证实了金属表面的吸附过程。红外光谱分析表明，ANLE通过C-O和N=O官能团吸附在低碳钢表面。高效液相色谱法发现，在5.990 min时起抑制作用的主要成分为儿茶素。结果表明，ANLE是一种良好的缓蚀剂，在0.1 M H2SO4溶液中可以作为有效的低碳钢缓蚀剂。
{"title":"Corrosion Inhibition Potential of Ethanol Extract of Acacia nilotica Leaves on Mild Steel in an Acidic Medium","authors":"I. Jimoh, B. Usman","doi":"10.4152/pea.202102105","DOIUrl":"https://doi.org/10.4152/pea.202102105","url":null,"abstract":"The corrosion inhibition effect of ethanol extract of Acacia nilotica leaves (ANLE) on mild steel in 0.1 M H2SO4, containing 0.1-0.5 g/L, has been studied using weight loss, Potentiodynamic Polarization (PDP), Fourier Transforms Infra-Red (FTIR) spectroscopy, UV-visible spectroscopy, High-Performance Liquid Chromatography (HPLC) and Scanning Electron Microscopy (SEM) methods. The results from weight loss and PDP show that the inhibition efficiency depends on the concentration of the plant extract, as well as on the time of exposure of the mild steel samples in H2SO4 solutions. The optimum inhibition efficiencies of the extract obtained from weight loss and potentiodynamic measurements were found to be 87.57% and 61.85%, respectively. Thermodynamic parameters, such as Ea, ΔH, ΔG and ΔS, were evaluated at 0.5 g/L, and the results were found to be -78.54 kJ/mol, 74.66 kJ/mol., -17.92 kJ/mol and -90.59 kJ/mol, respectively. From the calculated values of activation energy and free energy of adsorption, and from the trend in the variation of inhibition efficiency with temperature, the inhibitor mechanism of adsorption was found to be physical adsorption, exothermic, spontaneous, being best described by Langmuir adsorption model, because the regression coefficients (R) values calculated from the plots were closest to unity, confirming a highest degree of linearity. Mild steel surface morphology, in ANLE presence and absence, was studied using SEM. FTIR spectroscopy and UV-visible spectroscopy analyses were used to confirm the adsorption process onto the metal surface. Spectra analysis obtained from FTIR study indicated that ANLE was adsorbed onto the mild steel surface via C-O and N=O functional groups. HPLC was also used to find the main component responsible for inhibition, at 5.990 min, which was Catechin. The obtained results revealed that ANLE acts as a good inhibitor and could serve as an effective mild steel corrosion inhibitor in a 0.1 M H2SO4 solution.","PeriodicalId":20334,"journal":{"name":"Portugaliae Electrochimica Acta","volume":"1 1","pages":""},"PeriodicalIF":1.2,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70918524","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 technical feasibility of the continuous flow electrocoagulation process for hospital wastewater treatment was evaluated. The wastewater physicochemical characterization was performed according to the chemical oxygen demand ( COD) , biochemical oxygen demand (BOD), total suspended solids (TSS), naproxen, phenol and phosphates parameters. An experimental Box-Behnken design and statistical response surface methodology (RSM) were used to evaluate the simple and combined effects of the independent parameters (pH, potential, retention time), and to optimize electrocoagulation process conditions, considering the COD response variable. The removal percentage was: COD (75.5%), BOD (59.2%) phenols (80.7%), phosphates (85.3%), TSS (75.6%) and naproxen (55.7%), under optimal electrocoagulation conditions at pH (7.92), potential (40 V) and retention time (15 min). The electrocoagulation process proved to be an efficient and technically viable alternative for hospital wastewater treatment.
{"title":"Continuous Flow Electrocoagulation as a Hospital Wastewater Treatment","authors":"A. Yanes, J. Pinedo‐Hernández, J. Marrugo-Negrete","doi":"10.4152/pea.2021390602","DOIUrl":"https://doi.org/10.4152/pea.2021390602","url":null,"abstract":"The technical feasibility of the continuous flow electrocoagulation process for hospital wastewater treatment was evaluated. The wastewater physicochemical characterization was performed according to the chemical oxygen demand ( COD) , biochemical oxygen demand (BOD), total suspended solids (TSS), naproxen, phenol and phosphates parameters. An experimental Box-Behnken design and statistical response surface methodology (RSM) were used to evaluate the simple and combined effects of the independent parameters (pH, potential, retention time), and to optimize electrocoagulation process conditions, considering the COD response variable. The removal percentage was: COD (75.5%), BOD (59.2%) phenols (80.7%), phosphates (85.3%), TSS (75.6%) and naproxen (55.7%), under optimal electrocoagulation conditions at pH (7.92), potential (40 V) and retention time (15 min). The electrocoagulation process proved to be an efficient and technically viable alternative for hospital wastewater treatment.","PeriodicalId":20334,"journal":{"name":"Portugaliae Electrochimica Acta","volume":"1 1","pages":""},"PeriodicalIF":1.2,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70919059","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}
Metallic materials remain an indispensable element in industries. The present study is aimed at the assessment of Parinari polyandra leaves inhibition properties on mild steel in a 1 M HCl solution. This was investigated using gravimetric and electrochemical methods. Physicochemical and spectroscopic analyses of the leaves extract were done using standard methods. A yield of 19.82% was obtained, while the leaves extract FTIR spectra showed bands of 3404 cm -1 and 2926 cm -1 , which indicated the presence of a strong band of phenolic O-H and C-H stretch functional groups, respectively. A maximum corrosion inhibition efficiency of 97.22% was obtained. Langmuir adsorption isotherm fitted the inhibitor data well. From electrochemical methods, the corrosion rate value of 17.626 mmpy obtained for the uninhibited mild steel was higher than 0.02044 – 2.2267 mmpy range values recorded for the mild steel surface covered with P. polyandra leaves extract in an acidic medium. SEM images showed the leaves extract inhibition effect against mild steel corrosion in a 1 M HCl solution. Electrochemical analysis using the Tafel plot also showed the leaves extract corrosion inhibition capacity, suggesting a mixed type inhibitor. Thus, P. polyandra leaves extract might act as a green corrosion inhibitor for mild steel utilized in industrial applications.
金属材料仍然是工业中不可缺少的元素。在1 M盐酸溶液中，研究了蓼叶对低碳钢的缓蚀性能。用重量法和电化学方法对其进行了研究。采用标准方法对叶提取物进行理化和光谱学分析。产率为19.82%，叶提取物的FTIR光谱在3404 cm -1和2926 cm -1波段，分别存在强的酚类O-H和C-H伸展官能团。最大缓蚀率为97.22%。Langmuir吸附等温线与缓蚀剂数据吻合较好。电化学方法表明，未经抑制的低碳钢的腐蚀速率值为17.626 mmpy，高于覆盖了聚andra叶提取物的低碳钢表面在酸性介质中所记录的0.02044 ~ 2.2267 mmpy范围值。SEM图像显示了叶片提取物在1 M HCl溶液中对低碳钢的缓蚀作用。利用Tafel图的电化学分析也显示了叶提取物的缓蚀能力，表明其为混合型缓蚀剂。因此，蓼叶提取物可作为工业应用中低碳钢的绿色缓蚀剂。
{"title":"Corrosion Inhibition of Mild Steel Using Parinari polyandra Leave Extracts in Diluted Hydrochloric Acids","authors":"F. O. Nwosu, S. O. Amusat","doi":"10.4152/pea.2021390605","DOIUrl":"https://doi.org/10.4152/pea.2021390605","url":null,"abstract":"Metallic materials remain an indispensable element in industries. The present study is aimed at the assessment of Parinari polyandra leaves inhibition properties on mild steel in a 1 M HCl solution. This was investigated using gravimetric and electrochemical methods. Physicochemical and spectroscopic analyses of the leaves extract were done using standard methods. A yield of 19.82% was obtained, while the leaves extract FTIR spectra showed bands of 3404 cm -1 and 2926 cm -1 , which indicated the presence of a strong band of phenolic O-H and C-H stretch functional groups, respectively. A maximum corrosion inhibition efficiency of 97.22% was obtained. Langmuir adsorption isotherm fitted the inhibitor data well. From electrochemical methods, the corrosion rate value of 17.626 mmpy obtained for the uninhibited mild steel was higher than 0.02044 – 2.2267 mmpy range values recorded for the mild steel surface covered with P. polyandra leaves extract in an acidic medium. SEM images showed the leaves extract inhibition effect against mild steel corrosion in a 1 M HCl solution. Electrochemical analysis using the Tafel plot also showed the leaves extract corrosion inhibition capacity, suggesting a mixed type inhibitor. Thus, P. polyandra leaves extract might act as a green corrosion inhibitor for mild steel utilized in industrial applications.","PeriodicalId":20334,"journal":{"name":"Portugaliae Electrochimica Acta","volume":"1 1","pages":""},"PeriodicalIF":1.2,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70919299","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}
Bashir, V. Sharma, P. Dhaundiyal, N. Shafi, Ashok Kumar
The corrosion inhibition property of Gymneme Sylvestre on aluminum in an acidic medium has been investigated. The experimental techniques include potentiodynamic polarization studies, electrochemical studies, quantum chemical calculation and weight loss method. The results revealed that Gymneme Sylvestre acts as a potential corrosion inhibitor of aluminum in an acidic medium, showing 82% inhibition efficiency at 800 ppm concentration of it. Furthermore, the different thermodynamic parameters, including activation energy, Gibbs free energy and enthalpy have been calculated. The results showed that adsorption of the Gymneme Sylvestre molecule onto the aluminum coupon surface obeys Langmuir adsorption isotherm. The quantum chemical parameters were also calculated for major constituents of Gymneme Sylvestre.
{"title":"Gymneme Sylvestre as a Green Corrosion Inhibitor for Aluminum in an Acidic Medium","authors":"Bashir, V. Sharma, P. Dhaundiyal, N. Shafi, Ashok Kumar","doi":"10.4152/pea.2021390304","DOIUrl":"https://doi.org/10.4152/pea.2021390304","url":null,"abstract":"The corrosion inhibition property of Gymneme Sylvestre on aluminum in an acidic medium has been investigated. The experimental techniques include potentiodynamic polarization studies, electrochemical studies, quantum chemical calculation and weight loss method. The results revealed that Gymneme Sylvestre acts as a potential corrosion inhibitor of aluminum in an acidic medium, showing 82% inhibition efficiency at 800 ppm concentration of it. Furthermore, the different thermodynamic parameters, including activation energy, Gibbs free energy and enthalpy have been calculated. The results showed that adsorption of the Gymneme Sylvestre molecule onto the aluminum coupon surface obeys Langmuir adsorption isotherm. The quantum chemical parameters were also calculated for major constituents of Gymneme Sylvestre.","PeriodicalId":20334,"journal":{"name":"Portugaliae Electrochimica Acta","volume":"1 1","pages":""},"PeriodicalIF":1.2,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70918676","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}
Atomic absorption spectroscopy (AAS) of samples taken from the organic phase of a water/1,2-dichloroethane (1,2-DCE) interfacial electrochemical cell, rendered nonpolarizable by the tetraphenylarsonium common-ion, revealed significant transfer of heavy metal from the aqueous phase. Heavy metal concentration found within 1,2-DCE cannot be explained via ion pair formation between the metallic species and the common-ion, nor by ion pair formation between the metallic species and the hydrophobic anion of the organic phase. Results suggest that metal may have been anomalously transferred into 1,2-DCE within water-in-oil droplets formed by spontaneous emulsification of the interfacial region.
{"title":"Atomic Absorption Spectroscopy Reveals Anomalous Transfer of Heavy Metal across a Water/1,2-DCE Interface","authors":"B. R. Silver","doi":"10.4152/pea.2021390603","DOIUrl":"https://doi.org/10.4152/pea.2021390603","url":null,"abstract":"Atomic absorption spectroscopy (AAS) of samples taken from the organic phase of a water/1,2-dichloroethane (1,2-DCE) interfacial electrochemical cell, rendered nonpolarizable by the tetraphenylarsonium common-ion, revealed significant transfer of heavy metal from the aqueous phase. Heavy metal concentration found within 1,2-DCE cannot be explained via ion pair formation between the metallic species and the common-ion, nor by ion pair formation between the metallic species and the hydrophobic anion of the organic phase. Results suggest that metal may have been anomalously transferred into 1,2-DCE within water-in-oil droplets formed by spontaneous emulsification of the interfacial region.","PeriodicalId":20334,"journal":{"name":"Portugaliae Electrochimica Acta","volume":"130 1","pages":""},"PeriodicalIF":1.2,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70919598","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Structural concrete failures in developing countries: overview about the effects of mixing water on concrete properties","authors":"A. Awoyera, A. Adesina","doi":"10.4152/pea.202101021","DOIUrl":"https://doi.org/10.4152/pea.202101021","url":null,"abstract":"","PeriodicalId":20334,"journal":{"name":"Portugaliae Electrochimica Acta","volume":"134 1","pages":"21-35"},"PeriodicalIF":1.2,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70918397","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 present work highlights the results of the application of a green inhibitor for material conservation. The anticorrosive performance of the pectin bio-polymer was established for the corrosion control of mild steel in a 1 M phosphoric acid medium. Electrochemical measurements such as potentiodynamic polarization (PDP) and electrochemical impedance spectroscopy (EIS) studies were adopted for the corrosion inhibition studies. The studies were carried out by varying the concentrations of pectin in the temperature range from 303 K to 318 K. Conditions were optimized to get maximum inhibition efficiency. The surface morphology study was done by scanning electron microscope (SEM), and elemental mapping was done using energy dispersive X-ray (EDX) studies to confirm the adsorption and interaction of the inhibitor with the material. Studies showed an increase in the inhibition efficiency with an increase in the concentration of pectin and also in the temperature. Maximum inhibition efficiency of 70% was achieved by the addition of 800 ppm of inhibitor. Pectin acted as a mixed type inhibitor by bringing down both cathodic and anodic reactions. Kinetic and thermodynamic parameters revealed chemical adsorption of pectin onto the mild steel surface. A suitable mechanism was proposed for the adsorption of pectin which was reaffirmed by the surface morphology studies. Pectin emerged as a potential eco-friendly green inhibitor for the corrosion control of mild steel, with economic benefits.
{"title":"Electrochemical Investigation on the Acid Corrosion Control of Mild Steel using Biopolymer as an Inhibitor","authors":"Y. Sushmitha, P. Rao","doi":"10.4152/pea.202003149","DOIUrl":"https://doi.org/10.4152/pea.202003149","url":null,"abstract":"The present work highlights the results of the application of a green inhibitor for material conservation. The anticorrosive performance of the pectin bio-polymer was established for the corrosion control of mild steel in a 1 M phosphoric acid medium. Electrochemical measurements such as potentiodynamic polarization (PDP) and electrochemical impedance spectroscopy (EIS) studies were adopted for the corrosion inhibition studies. The studies were carried out by varying the concentrations of pectin in the temperature range from 303 K to 318 K. Conditions were optimized to get maximum inhibition efficiency. The surface morphology study was done by scanning electron microscope (SEM), and elemental mapping was done using energy dispersive X-ray (EDX) studies to confirm the adsorption and interaction of the inhibitor with the material. Studies showed an increase in the inhibition efficiency with an increase in the concentration of pectin and also in the temperature. Maximum inhibition efficiency of 70% was achieved by the addition of 800 ppm of inhibitor. Pectin acted as a mixed type inhibitor by bringing down both cathodic and anodic reactions. Kinetic and thermodynamic parameters revealed chemical adsorption of pectin onto the mild steel surface. A suitable mechanism was proposed for the adsorption of pectin which was reaffirmed by the surface morphology studies. Pectin emerged as a potential eco-friendly green inhibitor for the corrosion control of mild steel, with economic benefits.","PeriodicalId":20334,"journal":{"name":"Portugaliae Electrochimica Acta","volume":"38 1","pages":"149-163"},"PeriodicalIF":1.2,"publicationDate":"2020-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48274606","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}
Use of Amaranthus extract, as mild steel corrosion inhibitor, in a p ickling paste with H2SO4, has been investigated. The electrochemical experim ents were conducted to bring forth results regarding various parameters, viz., c orrosion current, anodic polarization and cathodic polarization. The corrosion current gr adually decreased with time, for both uninhibited and inhibited systems. Polarization cur ves values indicate that Amaranthus extract adsorption modified anodic dissolution mech anism, as well as cathodic hydrogen evolution. From the results, it is clear t hat both cathodic and anodic reactions were inhibited, and that inhibition increased as th e inhibitor concentration increased in acidic media, but the cathode was more polarized. T his result indicated that Amaranthus extract can be classified as a cathodic inhibitor, in a 4 N H2SO4 solution. Surface analysis via scanning electron microscope (SEM) sho wed a significant improvement on the mild steel plate surface morphology, in the pre sence of optimum inhibitor concentrations. Thus, by conducting these experimen ts, our aim is to use inhibited pickling acid in the paste form, so that it can be conveniently applied on large structures, as well as on small tools, to be pickle d/c aned. As a contribution to the current interest on environmentally friendly green corrosion inhibitors, the present study investigates the inhibiting effect of Amaranthus extract, a green inhibitor which is commonly known as Pigweed.
研究了苋菜提取物在含H2SO4的酸洗膏中作为低碳钢缓蚀剂的应用。进行了电化学实验，得到了c腐蚀电流、阳极极化和阴极极化等参数的结果。在未抑制体系和抑制体系中，腐蚀电流随时间逐渐减小。极化曲线值表明苋菜提取物的吸附修饰阳极溶解机理，以及阴极析氢机理。从结果可以看出，在酸性介质中，阴极和阳极反应都受到抑制，并且随着抑制剂浓度的增加，抑制作用增强，但阴极更极化。结果表明，苋菜提取物在4 N H2SO4溶液中可被归类为阴极抑制剂。扫描电镜(SEM)表面分析表明，在最佳抑制剂浓度下，低碳钢表面形貌有显著改善。因此，通过进行这些实验，我们的目标是将抑制酸洗酸以糊状的形式使用，这样它就可以方便地应用于大型结构，以及小型工具上，进行酸洗。为了对绿色环保缓蚀剂的研究做出贡献，本研究对苋菜提取物的抑制作用进行了研究，苋菜提取物是一种绿色缓蚀剂，通常被称为Pigweed。
{"title":"Mild Steel Corrosion Inhibition, in 4 N Sulphuric Acid, by a Green Inhibitor","authors":"M. Srivastava","doi":"10.4152/pea.202002099","DOIUrl":"https://doi.org/10.4152/pea.202002099","url":null,"abstract":"Use of Amaranthus extract, as mild steel corrosion inhibitor, in a p ickling paste with H2SO4, has been investigated. The electrochemical experim ents were conducted to bring forth results regarding various parameters, viz., c orrosion current, anodic polarization and cathodic polarization. The corrosion current gr adually decreased with time, for both uninhibited and inhibited systems. Polarization cur ves values indicate that Amaranthus extract adsorption modified anodic dissolution mech anism, as well as cathodic hydrogen evolution. From the results, it is clear t hat both cathodic and anodic reactions were inhibited, and that inhibition increased as th e inhibitor concentration increased in acidic media, but the cathode was more polarized. T his result indicated that Amaranthus extract can be classified as a cathodic inhibitor, in a 4 N H2SO4 solution. Surface analysis via scanning electron microscope (SEM) sho wed a significant improvement on the mild steel plate surface morphology, in the pre sence of optimum inhibitor concentrations. Thus, by conducting these experimen ts, our aim is to use inhibited pickling acid in the paste form, so that it can be conveniently applied on large structures, as well as on small tools, to be pickle d/c aned. As a contribution to the current interest on environmentally friendly green corrosion inhibitors, the present study investigates the inhibiting effect of Amaranthus extract, a green inhibitor which is commonly known as Pigweed.","PeriodicalId":20334,"journal":{"name":"Portugaliae Electrochimica Acta","volume":"38 1","pages":"99-106"},"PeriodicalIF":1.2,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70917608","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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