M. Rahimnejad, Rosan Zokhtareh, A. Moghadamnia, M. Asghary
A sensitive, accurate electrochemical sensor based on reduced graphene oxide modified carbon paste electrode (RGO/CPE) was developed to m easure curcumin levels in human blood serum. The as-prepared electrode (RGO/C PE) was verified to outperform bare carbon paste electrode (CPE), with increased o xidation and reduction peaks at +0.505 V and +0.408 V, respectively. Curcumin measu rement was performed using cyclic voltammetry (CV) and differential pulse volt ammetry (DPV) techniques. RGO/CPE showed a desirable linear response towards curcumin, within the concentration range of 10-6000 μM; the detection li mit (S/N = 3) was 3.183 μM. Moreover, electrochemical impedance spectroscopy (E IS) and field emission scanning electron microscope (FESEM) were applied to gain fu rther insight into the electrochemical behavior of the proposed electrode. Th results revealed that the usage of RGO caused increased sensitivity of the sensor r esponse to curcumin; therefore, RGO/CPE can be considered a promising electrochemic al sensor for curcumin determination in human blood serum.
{"title":"An Electrochemical Sensor Based on Reduced Graphene Oxide Modified Carbon Paste Electrode for Curcumin Determination in Human Blood Serum","authors":"M. Rahimnejad, Rosan Zokhtareh, A. Moghadamnia, M. Asghary","doi":"10.4152/pea.202001029","DOIUrl":"https://doi.org/10.4152/pea.202001029","url":null,"abstract":"A sensitive, accurate electrochemical sensor based on reduced graphene oxide modified carbon paste electrode (RGO/CPE) was developed to m easure curcumin levels in human blood serum. The as-prepared electrode (RGO/C PE) was verified to outperform bare carbon paste electrode (CPE), with increased o xidation and reduction peaks at +0.505 V and +0.408 V, respectively. Curcumin measu rement was performed using cyclic voltammetry (CV) and differential pulse volt ammetry (DPV) techniques. RGO/CPE showed a desirable linear response towards curcumin, within the concentration range of 10-6000 μM; the detection li mit (S/N = 3) was 3.183 μM. Moreover, electrochemical impedance spectroscopy (E IS) and field emission scanning electron microscope (FESEM) were applied to gain fu rther insight into the electrochemical behavior of the proposed electrode. Th results revealed that the usage of RGO caused increased sensitivity of the sensor r esponse to curcumin; therefore, RGO/CPE can be considered a promising electrochemic al sensor for curcumin determination in human blood serum.","PeriodicalId":20334,"journal":{"name":"Portugaliae Electrochimica Acta","volume":"38 1","pages":"29-42"},"PeriodicalIF":1.2,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70917286","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}
J. A. Selvi, M. Arthanareeswari, P. Kamaraj, T. Malini, V. Elumalai, S. Revathi, N. Subasree
The inhibitory activity of ethanol extract of Nerium oleander leaf (NOLE) on carbon steel corrosion in 0.5 M and 1.0 M of hydrochloric acid solutions was studied by weight loss method and electrochemical techniques. The inh ibition efficiency (ηw) increased with an increase in the concentration of NOLE and i n temperature. Polarisation curves indicated that NOLE acts as a mixed type of inhibit or. The changes in charge transfer resistance (Rt) with increasing inhibitor (i.e. NOLE) concentrati on assured the adsorption of the inhibitor onto the metal surface. The results of ηw, ηp (inhibition efficiency obtained from polarisation study) and ηR (inhibition efficiency obtained from impedance analysis) are in par with each other. Sur face morphology study uncovered the coating of the inhibitor molecule on the metal surface. The phenomenon of physical adsorption has been established based on the inhibi t on efficiency of the inhibitor with change in temperature.
{"title":"Corrosion Mitigation by an Eco-Friendly Inhibitor: Nerium Oleander Leaf Extract on Carbon Steel in an Acidic Medium","authors":"J. A. Selvi, M. Arthanareeswari, P. Kamaraj, T. Malini, V. Elumalai, S. Revathi, N. Subasree","doi":"10.4152/pea.202006387","DOIUrl":"https://doi.org/10.4152/pea.202006387","url":null,"abstract":"The inhibitory activity of ethanol extract of Nerium oleander leaf (NOLE) on carbon steel corrosion in 0.5 M and 1.0 M of hydrochloric acid solutions was studied by weight loss method and electrochemical techniques. The inh ibition efficiency (ηw) increased with an increase in the concentration of NOLE and i n temperature. Polarisation curves indicated that NOLE acts as a mixed type of inhibit or. The changes in charge transfer resistance (Rt) with increasing inhibitor (i.e. NOLE) concentrati on assured the adsorption of the inhibitor onto the metal surface. The results of ηw, ηp (inhibition efficiency obtained from polarisation study) and ηR (inhibition efficiency obtained from impedance analysis) are in par with each other. Sur face morphology study uncovered the coating of the inhibitor molecule on the metal surface. The phenomenon of physical adsorption has been established based on the inhibi t on efficiency of the inhibitor with change in temperature.","PeriodicalId":20334,"journal":{"name":"Portugaliae Electrochimica Acta","volume":"38 1","pages":"387-400"},"PeriodicalIF":1.2,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70918342","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":"Comparative Study of Pure Mg and AZ91D as Sacrificial Anodes for Reinforced Cement Concrete Structures in a Chloride Atmosphere","authors":"Y. Murthy, S. Gandhi, A. Kumar","doi":"10.4152/pea.202004243","DOIUrl":"https://doi.org/10.4152/pea.202004243","url":null,"abstract":"","PeriodicalId":20334,"journal":{"name":"Portugaliae Electrochimica Acta","volume":"38 1","pages":"243-252"},"PeriodicalIF":1.2,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70917798","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}
A. Batah, A. Anejjar, L. Bammou, M. Belkhaouda, R. Salghi
Natural oil extracted from apricot seeds was evaluated as carbon steel corrosion inhibitor in 1 M hydrochloric acid, using potentiodynamic polarization, electrochemical impedance spectroscopy (EIS) and weight loss measurements. The measurements show that apricot seed oil is a good inhibitor for carbon steel corrosion in a hydrochloric environment, and this inhibitive action was mainly due to its adsorption onto the carbon steel surface, and active sites blocking. The above results showed that apricot seed oil acted as a mixed-type corrosion inhibitor, and that its adsorption onto the carbon steel surface obeyed the Langmuir adsorption isotherm. The inhibition effectiveness increased with the inhibitor concentration, and reached 83.49% at 0.5 g/L, in a 1 M HCl medium. Some thermodynamic parameters of the studied inhibitor were calculated and discussed.
采用动电位极化、电化学阻抗谱(EIS)和失重测量等方法，对杏籽天然油在1 M盐酸中作为碳钢缓蚀剂进行了评价。结果表明，杏籽油在盐酸环境下对碳钢具有良好的缓蚀作用，其缓蚀作用主要是由于杏籽油在碳钢表面的吸附和活性位点的阻断作用。上述结果表明，杏籽油作为混合型缓蚀剂，其在碳钢表面的吸附服从Langmuir吸附等温线。随着缓蚀剂浓度的增加，缓蚀剂的缓蚀效果逐渐增强，在1 M HCl介质中，当浓度为0.5 g/L时，缓蚀效果达到83.49%。对所研究缓蚀剂的热力学参数进行了计算和讨论。
{"title":"Effect of Apricot Almond Oil as Green Inhibitor for Steel Corrosion in Hydrochloric Media","authors":"A. Batah, A. Anejjar, L. Bammou, M. Belkhaouda, R. Salghi","doi":"10.4152/pea.202004201","DOIUrl":"https://doi.org/10.4152/pea.202004201","url":null,"abstract":"Natural oil extracted from apricot seeds was evaluated as carbon steel corrosion inhibitor in 1 M hydrochloric acid, using potentiodynamic polarization, electrochemical impedance spectroscopy (EIS) and weight loss measurements. The measurements show that apricot seed oil is a good inhibitor for carbon steel corrosion in a hydrochloric environment, and this inhibitive action was mainly due to its adsorption onto the carbon steel surface, and active sites blocking. The above results showed that apricot seed oil acted as a mixed-type corrosion inhibitor, and that its adsorption onto the carbon steel surface obeyed the Langmuir adsorption isotherm. The inhibition effectiveness increased with the inhibitor concentration, and reached 83.49% at 0.5 g/L, in a 1 M HCl medium. Some thermodynamic parameters of the studied inhibitor were calculated and discussed.","PeriodicalId":20334,"journal":{"name":"Portugaliae Electrochimica Acta","volume":"38 1","pages":"201-214"},"PeriodicalIF":1.2,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70917352","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}
Mohammed Barbouchi, B. Benzidia, M. E. Idrissi, M. Choukrad
In the present paper, the methanol extract from the leaves of Pistacia terebinthus L. (PT) was characterized by GC/MS analysis. It was tested as a corrosion inhibitor for iron in a 3% NaCl solution, using gravimetric measurements and electrochemical methods (potentiodynamic polarizations and electrochemical impedance spectroscopy). Fourteen compounds were identified; the major compounds are palmitic acid (31.5%), stearic acid (25.7%) and oleic acid (11.3%). The data showed that the tested extract offers good corrosion resistance. The constituents of the PT extract affected polarization resistance (Rp) and corrosion current density (icorr), demonstrating that the proposed inhibitor hinders corrosion reactions. The results obtained at 200 ppm are very interesting, and reach maximum values of 96.96%, 89% and 64.82%, respectively, which were confirmed by scanning electron microscopy (SEM), coupled with energy scattering of X-ray spectroscopy (EDX).
{"title":"Iron Corrosion Green Inhibition in a 3% NaCl Solution, by Leaves Extract from Pistacia Terebinthus L. Growing Wild in Morocco","authors":"Mohammed Barbouchi, B. Benzidia, M. E. Idrissi, M. Choukrad","doi":"10.4152/pea.202003175","DOIUrl":"https://doi.org/10.4152/pea.202003175","url":null,"abstract":"In the present paper, the methanol extract from the leaves of Pistacia terebinthus L. (PT) was characterized by GC/MS analysis. It was tested as a corrosion inhibitor for iron in a 3% NaCl solution, using gravimetric measurements and electrochemical methods (potentiodynamic polarizations and electrochemical impedance spectroscopy). Fourteen compounds were identified; the major compounds are palmitic acid (31.5%), stearic acid (25.7%) and oleic acid (11.3%). The data showed that the tested extract offers good corrosion resistance. The constituents of the PT extract affected polarization resistance (Rp) and corrosion current density (icorr), demonstrating that the proposed inhibitor hinders corrosion reactions. The results obtained at 200 ppm are very interesting, and reach maximum values of 96.96%, 89% and 64.82%, respectively, which were confirmed by scanning electron microscopy (SEM), coupled with energy scattering of X-ray spectroscopy (EDX).","PeriodicalId":20334,"journal":{"name":"Portugaliae Electrochimica Acta","volume":"38 1","pages":"175-184"},"PeriodicalIF":1.2,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70917697","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 paper, we report on the preparation of an amorphous and nanocrystalline structure of titanium dioxide, by cathodic electrodeposition on fluorine doped tin dioxide (FTO) coated glass, from an aqueous peroxo-titanium complex solution. Structural X-ray analysis shows anatase phase for heated deposits, and an amorphous form for non-heated deposits. Scanning electron microscopy (SEM) allowed investigating the morphological aspect of the deposits which exhibited nano-particulate grain size. AFM results exhibited the different roughness values of both kinds of films. The crystalline deposits have been used as catalysts for the photocatalytic oxidation of methyl orange dye, under an irradiation source (UV lamp of 365 nm). The results revealed that the dye has undergone a slight degradation under UV illumination. Using spectrophotometer measurements, the decolourisation rate was estimated from residual concentration.
{"title":"Elaboration of Amorphous and Crystalline Titanium Dioxide on FTO: its Characterization and Photocatalytic Effect on Orange Methyl","authors":"R. Foudil, A. Djamila","doi":"10.4152/pea.202005331","DOIUrl":"https://doi.org/10.4152/pea.202005331","url":null,"abstract":"In this paper, we report on the preparation of an amorphous and nanocrystalline structure of titanium dioxide, by cathodic electrodeposition on fluorine doped tin dioxide (FTO) coated glass, from an aqueous peroxo-titanium complex solution. Structural X-ray analysis shows anatase phase for heated deposits, and an amorphous form for non-heated deposits. Scanning electron microscopy (SEM) allowed investigating the morphological aspect of the deposits which exhibited nano-particulate grain size. AFM results exhibited the different roughness values of both kinds of films. The crystalline deposits have been used as catalysts for the photocatalytic oxidation of methyl orange dye, under an irradiation source (UV lamp of 365 nm). The results revealed that the dye has undergone a slight degradation under UV illumination. Using spectrophotometer measurements, the decolourisation rate was estimated from residual concentration.","PeriodicalId":20334,"journal":{"name":"Portugaliae Electrochimica Acta","volume":"38 1","pages":"331-341"},"PeriodicalIF":1.2,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70917826","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}
M. Sahrane, T. Ghailane, M. Galai, A. Souizi, Ebn Touhami, R. Ghailane, R. Touir
{"title":"Experimental and Theoretical Studies for Mild Steel Corrosion Inhibition in 1.0 M HCl by Two Stereoisomers of Benzothiazinone Derivatives","authors":"M. Sahrane, T. Ghailane, M. Galai, A. Souizi, Ebn Touhami, R. Ghailane, R. Touir","doi":"10.4152/pea.202001001","DOIUrl":"https://doi.org/10.4152/pea.202001001","url":null,"abstract":"","PeriodicalId":20334,"journal":{"name":"Portugaliae Electrochimica Acta","volume":"38 1","pages":""},"PeriodicalIF":1.2,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70916959","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}
Biomaterials are being used in implants as metallic supports, to restructure bone and tissue in biomedical applications, and so forth. In this study, the assessment of films from the Chitosan-Gelatin system in detached condit ions was carried out, in order to evaluate the effect of the electrolyte over the mem brane, to simulate a physiological solution. An equivalent circuit is proposed, so as to interpret the process of biopolymer degradation using electrochemical parameters, as we ll as a reaction mechanism for the membrane’s cathodic areas. The gathered information may be associated with the biodegradability ionic diffusion behavior, also in its application as a temporary coating for metal protection control during the corrosion p rocess of biomaterials, such as magnesium, in bone regeneration.
{"title":"Electrochemical Evaluation of the Chitosan-Gelatin Biopolymer as a Detached Film with a Body Simulated Physiological Solution","authors":"J. Ramírez, H. Quintana, G. Galicia, T. Hernández","doi":"10.4152/pea.202001059","DOIUrl":"https://doi.org/10.4152/pea.202001059","url":null,"abstract":"Biomaterials are being used in implants as metallic supports, to restructure bone and tissue in biomedical applications, and so forth. In this study, the assessment of films from the Chitosan-Gelatin system in detached condit ions was carried out, in order to evaluate the effect of the electrolyte over the mem brane, to simulate a physiological solution. An equivalent circuit is proposed, so as to interpret the process of biopolymer degradation using electrochemical parameters, as we ll as a reaction mechanism for the membrane’s cathodic areas. The gathered information may be associated with the biodegradability ionic diffusion behavior, also in its application as a temporary coating for metal protection control during the corrosion p rocess of biomaterials, such as magnesium, in bone regeneration.","PeriodicalId":20334,"journal":{"name":"Portugaliae Electrochimica Acta","volume":"38 1","pages":"59-68"},"PeriodicalIF":1.2,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70917430","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}
Harish Mudila, P. Prasher, Himanshu Kapoor, S. Rana, M. Zaidi
Carbonaceous materials are used to generate composites for numerous purposes, due to their extraordinary properties. In this context, we have carried out a study on the modified properties, viz. thermal stability and specific capacitance of the composites fabricated by the introduction of a carbonaceous material (graphite and graphene oxide) into the Polyvinyl Butyral matrix. Since it has excellent adhesibility and dielectric permittivity, and it can be employed as an electrode in sensors, polyvinyl butyral is used in the current investigation, along with carbonaceous materials, for electrochemical and bandgap properties (HOMO-LUMO) studies. Spectroscopic FT-IR, XRD and SEM analyses remark the comprehensive entanglement of the two components. Various fabricated composites show an increased thermal stability, with a percentage of carbonaceous filler, as suggested by TGA. Cyclic voltammetry studies reveal that PVB acts as an excellent binder, and as a good matrix for the charge movement through it, because it has a good level of dielectric permittivity, thus enabling fabricated materials to be developed as good candidates for supercapacitive batteries.
{"title":"Electrochemical Characterization and HOMO-LUMO Studies on Fabricated PVB/Graphite and PVB/GO Nanocomposites","authors":"Harish Mudila, P. Prasher, Himanshu Kapoor, S. Rana, M. Zaidi","doi":"10.4152/pea.202002069","DOIUrl":"https://doi.org/10.4152/pea.202002069","url":null,"abstract":"Carbonaceous materials are used to generate composites for numerous purposes, due to their extraordinary properties. In this context, we have carried out a study on the modified properties, viz. thermal stability and specific capacitance of the composites fabricated by the introduction of a carbonaceous material (graphite and graphene oxide) into the Polyvinyl Butyral matrix. Since it has excellent adhesibility and dielectric permittivity, and it can be employed as an electrode in sensors, polyvinyl butyral is used in the current investigation, along with carbonaceous materials, for electrochemical and bandgap properties (HOMO-LUMO) studies. Spectroscopic FT-IR, XRD and SEM analyses remark the comprehensive entanglement of the two components. Various fabricated composites show an increased thermal stability, with a percentage of carbonaceous filler, as suggested by TGA. Cyclic voltammetry studies reveal that PVB acts as an excellent binder, and as a good matrix for the charge movement through it, because it has a good level of dielectric permittivity, thus enabling fabricated materials to be developed as good candidates for supercapacitive batteries.","PeriodicalId":20334,"journal":{"name":"Portugaliae Electrochimica Acta","volume":"38 1","pages":"69-78"},"PeriodicalIF":1.2,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70917487","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}
Y. E. Aoufir, Y. E. Bakri, A. Chaouiki, H. Lgaz, H. Oudda, R. Salghi, A. Guenbour, E. Essassi
{"title":"Potentiodynamic Polarization Behavior and Microscopic Examination of Tungsten Carbide Hard Metal Materials in Supported Ammoniacal Medium","authors":"Y. E. Aoufir, Y. E. Bakri, A. Chaouiki, H. Lgaz, H. Oudda, R. Salghi, A. Guenbour, E. Essassi","doi":"10.4152/pea.202004253","DOIUrl":"https://doi.org/10.4152/pea.202004253","url":null,"abstract":"","PeriodicalId":20334,"journal":{"name":"Portugaliae Electrochimica Acta","volume":"1 1","pages":""},"PeriodicalIF":1.2,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70917865","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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