scholarly journals Corrosion inhibition of iron in chloride media by the aqueous extract of Curcuma longa rhizome powder

2021 ◽  
Vol 48 (2) ◽  
Author(s):  
Imen AbidlI ◽  
◽  
Nébil Souissi ◽  
X. Ramón Novoa ◽  
◽  
...  
Keyword(s):  
Aqueous Extract ◽  
Electrochemical Impedance ◽  
Curcuma Longa ◽  
Charge Transfer Resistance ◽  
Langmuir Adsorption Isotherm ◽  
Nacl Solution ◽  
Iron Corrosion ◽  
Transfer Resistance ◽  
Time Effects ◽  
Langmuir Adsorption

The effect of the aqueous extract of Curcuma Longa Rhizome Powder and their main constituents involve phenolic compounds, as an iron corrosion inhibitor in 0.1 M NaCl solution was tested. Electrochemical impedance spectroscopy (EIS) was employed as the main experimental technique to assess the electrochemical behavior of iron in different concentrations of Curcuma extract. EIS revealed an increase of the charge transfer resistance with increasing inhibitor concentration. The temperature and immersion time effects on the corrosion behavior of iron without and with the extract of Curcuma were also studied. The inhibition action of the extract was discussed in view of the Langmuir adsorption isotherm.

scholarly journals Electrochemical Behaviourof Some Amino Acids as Corrosion Inhibitors for Mild Steel in Sweet Brine

2021 ◽  
Vol 8 (1) ◽  
pp. 1-14
Author(s):  
León GonzálezJP ◽  
Onofre BustamanteE ◽  
Rodríguez Gómez FJ ◽  
Espinoza Vázquez A
Keyword(s):  
Amino Acids ◽  
Immersion Time ◽  
Corrosion Inhibitors ◽  
Electrochemical Impedance ◽  
Charge Transfer Resistance ◽  
Langmuir Adsorption Isotherm ◽  
Transfer Resistance ◽  
Langmuir Adsorption ◽  
Electronic Microscope ◽  
Resistance Improvement

The effect of concentration and immersion time of phenylalanine (Phe), leucine (Leu) and valine (Val) for AISI 1018 in sweet brine was studied trough Electrochemical Impedance Spectroscopy (EIS), polarization resistance (Rp), Scanning Electronic Microscope (SEM) and Fourier Transform Infrared Spectroscopy (FTIR) as an ecological and biodegradable alternative as corrosion inhibitors. Electrochemical results showed that amino acids are good corrosion inhibitors according to their charge transfer resistance improvement. The effect of immersion time on corrosion behavior was studied trough 24 h with amino acids concentration variation of 0, 10, 100 and 250 ppm. The preliminary results demonstrated that the three amino acids adsorb over metal surface following the Langmuir adsorption isotherm model, and tend to agglomerate in bulk within time. Keywords: Corrosion Inhibitors; Biodegradable; Amino acids; Sweet brine

Effect of Cl- Content, pH Value and CO2 on Electrochemical Corrosion Features of Cr15 Super Martensitic Stainless Steel

2013 ◽  
Vol 738 ◽  
pp. 92-96
Author(s):  
Jin Ming Long ◽  
Quan Bin Liu ◽  
Kun Yu Zhao ◽  
Qi Long Yong ◽  
Jie Su
Keyword(s):  
Stainless Steel ◽  
Martensitic Stainless Steel ◽  
Electrochemical Impedance ◽  
Ph Value ◽  
Charge Transfer Resistance ◽  
Uniform Corrosion ◽  
Nacl Solution ◽  
Transfer Resistance ◽  
Pitting Potential ◽  
Super Martensitic Stainless Steel

The corrosion behavior of a Cr15 super martensitic stainless steel (Cr15 SMSS) was investigated in NaCl solutions by means of potentiodynamic polarization and electrochemical impedance spectroscopy (EIS). Effects of Cl-content, pH value and saturated CO2on corrosion were sdudied. It was found that the parameters of maintaining passivity current density (ip), the critical pitting potential (Eb) and charge transfer resistance (Rt) of Cr15 SMSS varied widely under different conditions. The corrosion resistance of Cr15 SMSS decrease with increasing Cl-concentration and lowering pH value. BothipandEbincrease for Cr15 SMSS in CO2-saturated NaCl solution, which verified that the CO2in NaCl solution can result in lower pitting sensitivity and higher uniform corrosion rate to Cr15 SMSS.

scholarly journals Electrochemical Investigation of Corrosion Behavior Heat Treated Al-6Si-0.5Mg-xCu (x = 0, 0.5, 1, 2, and 4 wt%) Alloys

2014 ◽  
Vol 2014 ◽  
pp. 1-6
Author(s):  
A. Hossain ◽  
F. Gulshan ◽  
A. S. W. Kurny
Keyword(s):  
Charge Transfer ◽  
Potentiodynamic Polarization ◽  
Corrosion Potential ◽  
Electrochemical Impedance ◽  
Charge Transfer Resistance ◽  
Nacl Solution ◽  
Transfer Resistance ◽  
Cu Content ◽  
Cu Alloy ◽  
Heat Treated

The corrosion behaviour of heat treated Al-6Si-0.5Mg-xCu (x=0.5, 1, 2, and 4 wt%) alloys in 0.1 M NaCl solution was investigated using potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) techniques. The potentiodynamic polarization curves reveal that 2 wt% Cu (Alloy-4) and 4 wt% Cu (Alloy-5) content alloys are more prone to corrosion than the other alloys investigated. But the EIS test results showed that charge transfer resistance (Rct) increases with increasing Cu content into Al-6Si-0.5Mg. Maximum charge transfer resistance (Rct) is reported with the addition of 2 wt% Cu and minimumRctvalue is for 4 wt% Cu content Al-6Si-0.5Mg alloy. Due to additions of Cu into Al-6Si-0.5Mg alloy, the magnitudes of open circuit potential (OCP), corrosion potential (Ecorr), and pitting corrosion potential (Epit) in NaCl solution were shifted to the more noble direction.

scholarly journals Electrochemical Corrosion Behavior of Ni-Fe-Co-P Alloy Coating Containing Nano-CeO2 Particles in NaCl Solution

Materials ◽  
2019 ◽  
Vol 12 (16) ◽  
pp. 2614 ◽  
Author(s):  
Xiuqing Fu ◽  
Wenke Ma ◽  
Shuanglu Duan ◽  
Qingqing Wang ◽  
Jinran Lin
Keyword(s):  
Composite Coating ◽  
Corrosion Behavior ◽  
Electrochemical Impedance ◽  
Electrochemical Corrosion ◽  
Alloy Coating ◽  
Charge Transfer Resistance ◽  
Corrosion Mechanism ◽  
Nacl Solution ◽  
Transfer Resistance ◽  
Electrochemical Corrosion Behavior

In order to study the effect of nano-CeO2 particles doping on the electrochemical corrosion behavior of pure Ni-Fe-Co-P alloy coating, Ni-Fe-Co-P-CeO2 composite coating is prepared on the surface of 45 steel by scanning electrodeposition. The morphology, composition, and phase structure of the composite coating are analyzed by means of scanning electron microscope (SEM), energy dispersive spectroscopy (EDS), and X-ray diffraction (XRD). The corrosion behavior of the coatings with different concentrations of nano-CeO2 particles in 50 g/L NaCl solution is studied by Tafel polarization curve and electrochemical impedance spectroscopy. The corrosion mechanism is discussed. The experimental results show that the obtained Ni-Fe-Co-P-CeO2 composite coating is amorphous, and the addition of nano-CeO2 particles increases the mass fraction of P. With the increase of the concentration of nano-CeO2 particles in the plating solution, the surface flatness of the coating increases. The surface of Ni-Fe-Co-P-1 g/L CeO2 composite coating is uniform and dense, and its self-corrosion potential is the most positive; the corrosion current and corrosion rate are the smallest, and the charge transfer resistance is the largest, showing the best corrosion resistance.

scholarly journals Electrochemical, Thermodynamic, Surface, and Spectroscopic Study in Inhibition of Iron Corrosion with Turmeric Root Extract (TRE)

2020 ◽  
Author(s):  
Khuloud Almzarzie ◽  
Ayman Almassri ◽  
Ahmad Falah ◽  
Hassan Kellawi
Keyword(s):  
Charge Transfer ◽  
Inhibition Efficiency ◽  
Electrochemical Impedance ◽  
Corrosion Current ◽  
Charge Transfer Resistance ◽  
Root Extract ◽  
Iron Corrosion ◽  
Transfer Resistance ◽  
Corrosion Reaction ◽  
Capacitive Loop

Turmeric root extract was tested as corrosion inhibitor for iron in 0.5 M HCl, using potentiodynamic polarization and electrochemical impedance spectroscopy, scanning electron microscope, and energy dispersive X-ray analysis. The inhibition efficiency increases as the time of immersion rises but decreases with temperature rise. The Nyquist plots showed that the charge transfer resistance increases and the double-layer capacitance decreases as the time of immersion increases. Tafel results show that both corrosion current and corrosion speed are reduced with time of immersion. All impedance spectra of EIS tests exhibit one capacitive loop, which indicates that the corrosion reaction is controlled by charge transfer process. Inhibition efficiency increases with the concentration of the inhibitor reaching its maximum value, 88.90%, at 8 g/100 mL. Thermodynamic parameters, Ea, ∆H*, and ∆S*, were estimated, and the mechanism of corrosion and inhibition was discussed. The adsorption of turmeric root extract followed Langmuir adsorption isotherm.

IMMERSION AND ELECTROCHEMICAL TESTS STUDY ON CORROSION RESISTANCE OF CHROME-FREE CHEMICAL CONVERSION FILM ON AZ91D Mg ALLOY IN 5 wt% NaCl SOLUTION

2005 ◽  
Vol 12 (03) ◽  
pp. 417-424
Author(s):  
X. P. ZHANG ◽  
G. CHEN
Keyword(s):  
Corrosion Resistance ◽  
Corrosion Protection ◽  
Electrochemical Impedance ◽  
Chemical Conversion ◽  
Alloy Coating ◽  
Charge Transfer Resistance ◽  
Mg Alloy ◽  
Nacl Solution ◽  
Transfer Resistance ◽  
Electrochemical Tests

Immersion and electrochemical tests have been applied to study corrosion protection of AZ91D Mg alloy coating with chrome-free chemical conversion (CCC) coat in 5wt% NaCl solution. The immersions tests include weight-loss measurements after full or partial immersion with whole coating and full immersion with damaged coating. The electrochemical tests include electrochemical impedance spectroscopy (EIS) and polarization curves measurement. The results of immersion and electrochemical tests show that chrome-free chemical conversion (CCC) surface treatment can significantly improve the corrosion resistance of AZ91D Mg alloy in 5% NaCl solution, and that the corrosion protection effect of CCC coating is not sensitive to pores or cracks. The equivalent circuit models are fitted from Nyquist plots for the uncoated specimens and the CCC-coated specimens. The charge transfer resistance, R ct , increases from about 1.669 Ω cm2 for the uncoated alloy to about 210 Ω cm2 after the alloy is coated with CCC coating.

CORROSION PROTECTION OF AZ91D Mg ALLOY COATING WITH MICRO-ARC OXIDATION FILM EVALUATED BY IMMERSION AND ELECTROCHEMICAL TESTS

2005 ◽  
Vol 12 (02) ◽  
pp. 279-287 ◽  
Author(s):  
X. P. ZHANG ◽  
G. CHEN
Keyword(s):  
Corrosion Protection ◽  
Electrochemical Impedance ◽  
Alloy Coating ◽  
Charge Transfer Resistance ◽  
Mg Alloy ◽  
Nacl Solution ◽  
Transfer Resistance ◽  
Electrochemical Tests ◽  
Micro Arc Oxidation ◽  
Eis Measurements

This paper describes the preliminary results of corrosion protection of AZ91D Mg alloy coated with a micro-arc oxidation (MAO) coating. The corrosion behavior of coated substrates was evaluated by means of immersion and electrochemical tests in 5 wt.% NaCl solution. The immersions tests include weight loss measurement after full or partial immersion with the whole coat and full immersion with the damaged coat. The electrochemical tests include polarization curves and electrochemical impedance spectroscopy (EIS) measurements. The results of immersion and electrochemical tests show that micro-arc oxidation (MAO) surface treatment can significantly improve the corrosion resistance of the AZ91D Mg alloy in 5% NaCl solution, and the corrosion protection effect of the MAO coating is not sensitive to pores or cracks in the coating. The charge transfer resistance R ct , increases from about 1.669Ωcm2 for the uncoated alloy to about 1113Ωcm2 after being coated with MAO coat.

Effectiveness of Myrmecodia Pendans Extract as Eco-Friendly Corrosion Inhibitor for Material API 5L Grade B in 3,5% NaCl Solution

2013 ◽  
Vol 789 ◽  
pp. 484-491 ◽  
Author(s):  
Atria Pradityana ◽  
Sulistijono ◽  
Abdullah Shahab
Keyword(s):  
Corrosion Inhibitor ◽  
Electrochemical Impedance ◽  
Charge Transfer Resistance ◽  
Antioxidant Compounds ◽  
Effective Inhibitor ◽  
Nacl Solution ◽  
Potentiodynamic Polarization Curve ◽  
Transfer Resistance ◽  
Initial Hypothesis ◽  
Wood Extract

The main objective of this research is to investigate the effectiveness of Myrmecodia Pendans (MP) wood extract as Eco friendly Corrosion Inhibitor on corrosion of material API 5L Grade B in 3,5% NaCl solution using potentiodynamic polarization curve, Gas Chromatography-Mass Spectrometer (GC-MS) and Electrochemical Impedance spectroscopy (EIS). MP usually called as sarang semut in Indonesia. We analyzed MP in different concentration of extract. By 500, 1000, 1500, 2000 and 2500 ppm. The experiment was started by extraction of the MP. According to the polarization potensiodynamic data, the rate corrosion could be decrease about 90,36% by concentration 500 ppm. In accordance with the data of the EIS, the same concentration of inhibitor produced 92.3% with charge transfer resistance of 595.6 Ω.cm2. It means MP extract could serve as an effective inhibitor for the corrosion. This is consistent with the initial hypothesis that MP contains antioxidant compounds that can inhibit oxidation thereby reducing the corrosion rate.

Improvement of Ti/RuO2–IrO2 Anode Lifetime and Electrocatalytical Properties by Using an Eco-Friendly Thermal Decomposition Method Using Polyvinyl Alcohol as Solvent

2019 ◽  
Author(s):  
Charlys Bezerra ◽  
Géssica Santos ◽  
Marilia Pupo ◽  
Maria Gomes ◽  
Ronaldo Silva ◽  
...  
Keyword(s):  
Thermal Decomposition ◽  
Polyvinyl Alcohol ◽  
High Efficiency ◽  
Electrochemical Impedance ◽  
Pechini Method ◽  
Low Cost ◽  
Charge Transfer Resistance ◽  
Transfer Resistance ◽  
Calcination Temperatures ◽  
Service Lifetime

<p>Electrochemical oxidation processes are promising solutions for wastewater treatment due to their high efficiency, easy control and versatility. Mixed metal oxides (MMO) anodes are particularly attractive due to their low cost and specific catalytic properties. Here, we propose an innovative thermal decomposition methodology using <a>polyvinyl alcohol (PVA)</a> as a solvent to prepare Ti/RuO<sub>2</sub>–IrO<sub>2</sub> anodes. Comparative anodes were prepared by conventional method employing a polymeric precursor solvent (Pechini method). The calcination temperatures studied were 300, 400 and 500 °C. The physical characterisation of all materials was performed by X-ray diffraction and scanning electron microscopy coupled with energy dispersive spectroscopy, while electrochemical characterisation was done by cyclic voltammetry, accelerated service lifetime and electrochemical impedance spectroscopy. Both RuO<sub>2</sub> and IrO<sub>2</sub> have rutile-type structures for all anodes. Rougher and more compact surfaces are formed for the anodes prepared using PVA. Amongst temperatures studied, 300 °C using PVA as solvent is the most suitable one to produce anodes with expressive increase in voltammetric charge (250%) and accelerated service lifetime (4.3 times longer) besides reducing charge-transfer resistance (8 times lower). Moreover, the electrocatalytic activity of the anodes synthesised with PVA toward the Reactive Blue 21 dye removal in chloride medium (100 % in 30 min) is higher than that prepared by Pechini method (60 min). Additionally, the removal total organic carbon point out improved mineralisation potential of PVA anodes. Finally, this study reports a novel methodology using PVA as solvent to synthesise Ti/RuO<sub>2</sub>–IrO<sub>2</sub> anodes with improved properties that can be further extended to synthesise other MMO compositions.</p>

scholarly journals Electrochemical Immunosensor for the Quantification of S100B at Clinically Relevant Levels Using a Cysteamine Modified Surface

Sensors ◽  
2021 ◽  
Vol 21 (6) ◽  
pp. 1929
Author(s):  
Alexander Rodríguez ◽  
Francisco Burgos-Flórez ◽  
José D. Posada ◽  
Eliana Cervera ◽  
Valtencir Zucolotto ◽  
...  
Keyword(s):  
Frequency Analysis ◽  
Surface Characterization ◽  
Electrochemical Impedance ◽  
Limit Of Detection ◽  
Neuronal Damage ◽  
Charge Transfer Resistance ◽  
Single Frequency ◽  
Response Analysis ◽  
Transfer Resistance ◽  
Therapeutic Decisions

Neuronal damage secondary to traumatic brain injury (TBI) is a rapidly evolving condition, which requires therapeutic decisions based on the timely identification of clinical deterioration. Changes in S100B biomarker levels are associated with TBI severity and patient outcome. The S100B quantification is often difficult since standard immunoassays are time-consuming, costly, and require extensive expertise. A zero-length cross-linking approach on a cysteamine self-assembled monolayer (SAM) was performed to immobilize anti-S100B monoclonal antibodies onto both planar (AuEs) and interdigitated (AuIDEs) gold electrodes via carbonyl-bond. Surface characterization was performed by atomic force microscopy (AFM) and specular-reflectance FTIR for each functionalization step. Biosensor response was studied using the change in charge-transfer resistance (Rct) from electrochemical impedance spectroscopy (EIS) in potassium ferrocyanide, with [S100B] ranging 10–1000 pg/mL. A single-frequency analysis for capacitances was also performed in AuIDEs. Full factorial designs were applied to assess biosensor sensitivity, specificity, and limit-of-detection (LOD). Higher Rct values were found with increased S100B concentration in both platforms. LODs were 18 pg/mL(AuES) and 6 pg/mL(AuIDEs). AuIDEs provide a simpler manufacturing protocol, with reduced fabrication time and possibly costs, simpler electrochemical response analysis, and could be used for single-frequency analysis for monitoring capacitance changes related to S100B levels.

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