scholarly journals Pyrite Passivation by Triethylenetetramine: An Electrochemical Study

2013 ◽  
Vol 2013 ◽  
pp. 1-8 ◽  
Author(s):  
Yun Liu ◽  
Zhi Dang ◽  
Yin Xu ◽  
Tianyuan Xu
Keyword(s):  
Cyclic Voltammetry ◽  
Potentiodynamic Polarization ◽  
Mixed Type ◽  
Open Circuit Potential ◽  
Inhibition Efficiency ◽  
Electrochemical Impedance ◽  
Open Circuit ◽  
Experimental Results ◽  
Coating Agent ◽  
Mixed Type Inhibitor

The potential of triethylenetetramine (TETA) to inhibit the oxidation of pyrite in H2SO4solution had been investigated by using the open-circuit potential (OCP), cyclic voltammetry (CV), potentiodynamic polarization, and electrochemical impedance (EIS), respectively. Experimental results indicate that TETA is an efficient coating agent in preventing the oxidation of pyrite and that the inhibition efficiency is more pronounced with the increase of TETA. The data from potentiodynamic polarization show that the inhibition efficiency (η%) increases from 42.08% to 80.98% with the concentration of TETA increasing from 1% to 5%. These results are consistent with the measurement of EIS (43.09% to 82.55%). The information obtained from potentiodynamic polarization also displays that the TETA is a kind of mixed type inhibitor.

Electrochemical Investigation of Myclobutanil as Corrosion Inhibitor for Copper in Acid Medium

2014 ◽  
Vol 960-961 ◽  
pp. 229-233 ◽  
Author(s):  
Li Zheng ◽  
Ji Liu ◽  
Zhi Hua Tao ◽  
Wei He ◽  
Ding Jun Xiao ◽  
...  
Keyword(s):  
Electrochemical Impedance Spectroscopy ◽  
Corrosion Inhibitor ◽  
Potentiodynamic Polarization ◽  
Mixed Type ◽  
Inhibition Efficiency ◽  
Electrochemical Impedance ◽  
Electrochemical Investigation ◽  
Eis Measurements ◽  
Good Agreement ◽  
Mixed Type Inhibitor

This paper is mainly to discuss that myclobutanil as corrosion inhibitor and its corrosion efficiency were evaluated via electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization. The potentiodynamic polarization measurements showed that the inhibition efficiency increases sharply with the increasing of concentration of myclobutanil, and the highest inhibition efficiency of the myclobutanil reached 84.3% at 3.2×10-4 mol/L in 1 mol/L HCl. The result also indicated that myclobutanil belongs to the mixed type inhibitor. The results obtained from EIS measurements are in good agreement with that obtained from potentiodynamic polarization.

scholarly journals Study of Jatropha Curcas Extract as a Corrosion Inhibitor in Acidic Medium on Mild Steel by Weight Loss and Potentiodynamic Methods

2020 ◽  
Vol 41 (1) ◽  
pp. 87-93
Author(s):  
Dipak Kumar Gupta ◽  
KM Anita Kafle ◽  
Anju Kumari Das ◽  
Shova Neupane ◽  
Anita Ghimire ◽  
...  
Keyword(s):  
Weight Loss ◽  
Mild Steel ◽  
Corrosion Inhibition ◽  
Potentiodynamic Polarization ◽  
Jatropha Curcas ◽  
Acidic Medium ◽  
Open Circuit Potential ◽  
Inhibition Efficiency ◽  
Open Circuit ◽  
Mixed Type Inhibitor

The corrosion inhibition properties of methanol extract of Jatropha curcas (JC) were investigated for mild steel (MS) in acidic medium using weight loss and potentiodynamic methods. Corrosion inhibition of MS in 1MH2SO4 was studied in the absence and presence of various concentrations of the methanolic extract of Jatropha curcas barks. The results showed an increase in corrosion inhibition with increasing concentration of the extract. The inhibition efficiency of 1000 ppm JC extract from the weight loss and potentiodynamic polarization methods were approximately 92.0% after 24 hours immersion in the acidic solution. Open circuit potential (OCP) and potentiodynamic polarization measurements showed that the JC extract acts as a mixed-type inhibitor.

Forming of Corrosion Inhibitor Film during Turbulent Flow

2011 ◽  
Vol 66-68 ◽  
pp. 540-544 ◽  
Author(s):  
Ahmed Y. Musa ◽  
Abdul Amir H. Kadhum ◽  
Abu Bakar Mohamad ◽  
Mohd Sobri Takriff
Keyword(s):  
Turbulent Flow ◽  
Potentiodynamic Polarization ◽  
Flow Condition ◽  
Open Circuit Potential ◽  
Electrochemical Impedance ◽  
Steel Corrosion ◽  
Film Structure ◽  
Open Circuit ◽  
Mild Steel Corrosion ◽  
Scanning Electron

The organic material named 4-amino-5-phenyl-4H-1, 2, 4-trizole-3-thiol (APTT) was studied as inhibitor for mild steel corrosion in 1.0 M HCl at 30 °C. The effects of turbulent flow on the inhibition process were characterized using open circuit potential (OCP), potentiodynamic polarization, electrochemical impedance spectroscopy (EIS) and scanning electron microscopy (SEM). Turbulent flow condition experiments were simulated by Rotating Cylinder Electrode (RCE). Results obtained from changes of open circuit potential (OCP) with immersion time, potentiodynamic polarization, and impedance measurements all are in good agreement and indicated that the formation and the development of the inhibitor film were flow rate dependence. The scanning electron micrograph confirmed film structure is dependence of flow condition.

scholarly journals Effect of Nd3+ Ion Concentration on the Corrosion Resistance of API X70 Steel in Chloride-Rich Environments

2018 ◽  
Vol 2018 ◽  
pp. 1-15 ◽  
Author(s):  
D. M. Martinez de la Escalera ◽  
J. J. Ramos-Hernandez ◽  
E. Porcayo-Palafox ◽  
J. Porcayo-Calderon ◽  
J. G. Gonzalez-Rodriguez ◽  
...  
Keyword(s):  
Open Circuit Potential ◽  
Inhibition Efficiency ◽  
Electrochemical Impedance ◽  
Electrochemical Techniques ◽  
Protective Layer ◽  
Open Circuit ◽  
Chloride Ions ◽  
Ion Concentration ◽  
Linear Polarization Resistance ◽  
Potentiodynamic Polarization Curves

In this study, the effect of the addition of Nd3+ ions as a corrosion inhibitor of the API X70 steel in a medium rich in chlorides was evaluated. The performance of the Nd3+ ions was evaluated by means of electrochemical techniques such as potentiodynamic polarization curves, open circuit potential measurements, linear polarization resistance, and electrochemical impedance spectroscopy, as well as by means of scanning electron microscopy and EDS measurements. The results showed that Nd3+ ions reduce the corrosion rate of steel at concentrations as low as 0.001 M Nd3+. At higher concentrations, the inhibition efficiency was only slightly affected although the concentration of chloride ions was increased by the addition of the inhibitor. The adsorption of the Nd3+ ions promotes the formation of a protective layer of oxides/hydroxides on the metal surface, thereby reducing the exchange rate of electrons. Nd3+ ions act as a mixed inhibitor with a strong predominant cathodic effect.

scholarly journals Metolazone compound as corrosion inhibitor for API 5L X-52 steel in hydrochloric acid solution

2020 ◽  
Vol 34 (2) ◽  
pp. 407-418
Author(s):  
F. E. Abeng ◽  
M. E. Ikpi ◽  
V. C. Anadebe ◽  
W. Emori
Keyword(s):  
Potentiodynamic Polarization ◽  
Inhibition Efficiency ◽  
Electrochemical Impedance ◽  
Reaction System ◽  
Electrochemical Corrosion ◽  
Electrochemical Impedance Spectra ◽  
Maximum Inhibition ◽  
System Temperature ◽  
Hcl Solution ◽  
Mixed Type Inhibitor

The aim of this research is to evaluate the inhibitive effect of metolazone on API 5L X-52 steel in 2 M HCl solution using electrochemical impedance spectroscopy (EIS), potentiodynamic polarization techniques within a temperature range of 303 to 323 K. Scanning electron microscopy (SEM) was also employed to study the morphology of the corroded coupons in 2 M HCl solution and in the presence of the inhibitor. The efficiency of the inhibition depends on the concentration of metolazone and reaction system temperature. The maximum inhibition efficiency values were 92.7 and 90.7%, respectively, for both EIS and polarization techniques at the temperature of 303 K. The electrochemical impedance spectra (EIS) studies reveal that the process of inhibition is through charge transfer. Potentiodynamic polarization (PDP) studies showed that metolazone is mixed-type inhibitor.  The metolazone adsorption characteristics on API 5L X-52 steel surface was found to be spontaneous and obeyed Langmuir adsorption isotherm and the mechanism of adsorption suggest chemisorptions. The inhibition efficiency of metolazone drug obtained by electrochemical methods was in good relationship with each other.                     KEY WORDS: Metolazone drug, API 5L X-52 Steel, SEM, Electrochemical, Corrosion inhibition   Bull. Chem. Soc. Ethiop. 2020, 34(2), 407-418 DOI: https://dx.doi.org/10.4314/bcse.v34i2.16

scholarly journals Inhibition Effect of Glycerol on the Corrosion of Copper in NaCl Solutions at Different pH Values

2014 ◽  
Vol 2014 ◽  
pp. 1-10 ◽  
Author(s):  
Santos Lorenzo Chi-Ucán ◽  
Andrea Castillo-Atoche ◽  
Pedro Castro Borges ◽  
José Antonio Manzanilla-Cano ◽  
Gerardo González-García ◽  
...  
Keyword(s):  
Open Circuit Potential ◽  
Inhibition Efficiency ◽  
Electrochemical Impedance ◽  
Electrochemical Techniques ◽  
Impedance Analysis ◽  
Inhibitory Effect ◽  
Open Circuit ◽  
Copper Corrosion ◽  
Inhibition Effect ◽  
Ph Values

The inhibitory effect of glycerol on copper corrosion in aerated NaCl (0.5 M) solutions at three pH values (4, 7, and 10) was evaluated. Inhibition efficiency was assessed with conventional electrochemical techniques: open circuit potential, potentiodynamic polarization, and electrochemical impedance analysis. Glycerol reduced the corrosion rate of copper in NaCl solutions. The best inhibition effect (η≈83%) was produced in alkaline (pH 10) chloride media. This effect can be ascribed to increased viscosity and the presence of copper-glycerol complexes.

scholarly journals Investigation of Akuamma Seed Extract on Corrosion Inhibition of Aluminum in Hydrochloric Acid Pickling Environment

2019 ◽  
pp. 115-138
Author(s):  
J. O. Ezeugo ◽  
O. D. Onukwuli ◽  
K. O. Ikebudu ◽  
V. C. Ezechukwu ◽  
L. O. Nwaeto
Keyword(s):  
Corrosion Inhibition ◽  
Mixed Type ◽  
Inhibition Efficiency ◽  
Electrochemical Impedance ◽  
Seed Extract ◽  
Aluminum Surface ◽  
Inhibition Concentration ◽  
Inhibition Process ◽  
Anodic Reactions ◽  
Mixed Type Inhibitor

Inhibitive impact of Akuamma seed (AS) extract toward 1.0M HCl corrosion of aluminum was examined using response surface methodology (RSM). Gravimetric (weight loss), potentiodynamic polarization and electrochemical impedance spectroscopy techniques were used in the corrosion inhibition process. In all the method used, the seed extract acted as good corrosion inhibitor of aluminum in 1.0M HCl solution. Optimal inhibition efficiency of 72.6% was obtained at optimum inhibition concentration of 1.2g/l, temperature of 304.19k and maximized time of 11.53hrs. It showed that the plant extract has excellent inhibitive properties for the corrosion inhibition process. The values of kads are relatively small indicating that the interaction between the adsorbed extract molecules and aluminum surface is a physical process. The (AS) extract protects aluminum against pitting corrosion. The level of protection increases with increase extract concentrations. The extract inhibited both cathodic and anodic reactions and acted as mixed-type inhibitor.

scholarly journals Corrosion Resistance of Mild Steel in Hydrochloric Acid Solutions by Clinopodium acinos as a Green Inhibitor

2020 ◽  
Vol 11 (2) ◽  
pp. 9786-9803
Keyword(s):  
Mild Steel ◽  
Mixed Type ◽  
Inhibition Efficiency ◽  
Electrochemical Impedance ◽  
Acid Solutions ◽  
Green Inhibitor ◽  
Electrochemical Tests ◽  
Hydrochloric Acid Solutions ◽  
Surface Examination ◽  
Mixed Type Inhibitor

Study of corrosion inhibition for mild steel in 1M HCl by Clinopodium acinos (CA) extract was evaluated by altered methods. These methods are WL, electrochemical tests (Electrochemical frequency modulation (EFM), potentiodynamic polarization (PP), and electrochemical impedance spectroscopy (EIS)) and surface examination performances (AFM, ATR- FTIR and XPS). The CA extract concentrations are (50, 100, 150, 200, 250,300 ppm) at altered temperatures 25, 30, 35, 40, 45 0C.WL curves showed raising the inhibition efficiency of M-S by increasing CA concentration and lowering the temperature. PP curves explained that CA extract act as a mixed type inhibitor. The green inhibitor was utilized because of its lower price and not affect the environment.

scholarly journals Corrosion Inhibition Effect of Acidic Extract of Bark of Eucalyptus Globulus on Mild Steel

2020 ◽  
Vol 35 (1) ◽  
pp. 1-10
Author(s):  
Dipak Kumar Gupta ◽  
Laxmi Awasthi ◽  
Anju Kumari Das ◽  
Brahamdeo Yadav ◽  
Anita Ghimire ◽  
...  
Keyword(s):  
Mild Steel ◽  
Corrosion Inhibition ◽  
Eucalyptus Globulus ◽  
Open Circuit Potential ◽  
Inhibition Efficiency ◽  
Acidic Solution ◽  
Open Circuit ◽  
Weight Loss Method ◽  
Loss Method ◽  
Mixed Type Inhibitor

The corrosion inhibition properties of the acidic extract of Eucalyptus globulus (EG) was investigated for mild steel (MS) using the weight loss method and open circuit potential (OCP) measurement. Corrosion inhibition of MS in 0.1M HCl was studied in the absence and presence of various concentrations of the acidic extract of EG barks. The results showed an increase in corrosion inhibition with increasing concentration of the extract. The inhibition efficiency of 100% EG extract was approximately 98.0% after 24 hours immersion in the acidic solution. FTIR spectrum showed the presence of compounds containing oxygen and nitrogen functional groups responsible for forming barrier layers onto MS surface. Open circuit potential (OCP) measurements showed that the EG extract acts as a mixed type inhibitor.

scholarly journals Open Circuit Potential, Polarization and Thermometric Study of Guar Gum as Corrosion Inhibitor on Mild Steel by in Acidic Media

2020 ◽  
pp. 55-60 ◽  
Author(s):  
Rupesh Kushwah ◽  
R. K. Pathak
Keyword(s):  
Mild Steel ◽  
Corrosion Inhibitors ◽  
Open Circuit Potential ◽  
Inhibition Efficiency ◽  
High Efficiency ◽  
Guar Gum ◽  
Open Circuit ◽  
Maximum Efficiency ◽  
Electrochemical Tests ◽  
Mixed Type Inhibitor

The influence of guar gum as inhibitors for mild steel (MS) dissolved in 1.0 M H2SO4 had been investigated via various electrochemical tests at 298 K. Open circuit (OC), Tafel plots had been examined. At first OCP shift found to be more negative values which clarify that guar gum having high efficiency as corrosion inhibitors. The inhibition efficiency (IE%) can be improved with improvement of concentration of inhibitor reaching maximum efficiency up to 89.37% at 298 K. The Tafel plots had been illustrated that a maximum difference of Ecorr 68 mV, that shows that the guar gum worked as mixed type inhibitor. Thermometry investigation shows maximum IE is found to be 86.99.

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