scholarly journals The Inhibitory Action of the Extracts ofAdathoda vasica, Eclipta alba,andCentella asiaticaon the Corrosion of Mild Steel in Hydrochloric Acid Medium: A Comparative Study

2012 ◽  
Vol 2012 ◽  
pp. 1-13 ◽  
Author(s):  
M. Shyamala ◽  
P. K. Kasthuri

The Inhibitive action of the extracts ofAdathoda vasica, Eclipta alba,andCentella asiaticaon the corrosion of mild steel in 1N HCl has been studied using weight loss method, electrochemical methods, and hydrogen permeation method. Polarization method indicates that the plant extracts are under mixed control, that is, promoting retardation of both anodic and cathodic reactions. The impedance method reveals that charge-transfer process controls the corrosion of mild steel. The plant extracts obey Langmuir adsorption isotherm. Theoretical fitting of the corrosion data to the kinetic-thermodynamic model was tested to show the nature of adsorption. Physisorption mechanism has been proposed for the inhibition action of these plant extracts. The protective film formed on the surface was confirmed by SEM. From hydrogen permeation method, all the plant extracts were able to reduce the permeation current. Results obtained in all three methods were very much in good agreement in the orderEclipta alba > Adathoda vasica > Centella asiatica,and, among the three plant extracts studied, the maximum inhibition efficiency was found inEclipta albawhich showed 99.6% inhibition efficiency at 8.0% v/v concentration of the extract.

2011 ◽  
Vol 2011 ◽  
pp. 1-11 ◽  
Author(s):  
M. Shyamala ◽  
P. K. Kasthuri

A comparative study of the inhibitory effect of plant extracts,Ocimum sanctum, Aegle marmelos, andSolanum trilobatum, on the corrosion of mild steel in 1N HCl medium was investigated using weightloss method, electrochemical methods, and hydrogen permeation method. Polarization method indicates plant extracts behave as mixed-type inhibitor. The impedance method reveals that charge-transfer process mainly controls the corrosion of mild steel. On comparison, maximum inhibition efficiency was found inOcimum sanctumwith 99.6% inhibition efficiency at 6.0% v/v concentration of the extract. The plant extracts obey Langmuir adsorption isotherm. The SEM morphology of the adsorbed protective film on the mild steel surface has confirmed the high performance of inhibitive effect of the plant extracts. From hydrogen permeation method, all the plant extracts were able to reduce the permeation current. The reason for the reduced permeation currents in presence of the inhibitors may be attributed to the slow discharge step followed by fast electrolytic desorption step. Results obtained in all three methods were very much in good agreement in the orderOcimum sanctum>Aegle marmelos>Solanum trilobatum.


2012 ◽  
Vol 9 (4) ◽  
pp. 1746-1752 ◽  
Author(s):  
J. Wilson Sahayaraj ◽  
A. John Amalraj ◽  
Susai Rajendran ◽  
N. Vijaya

The inhibition efficiency (IE) of sodium molybdate (SM) in controlling corrosion of carbon steel in an aqueous solution containing 120 ppm of Cl-, in the absence and presence of Zn2+has been evaluated by weight-loss method. A synergistic effect exists between SM and Zn2+when the concentration of Zn2+is 25 ppm and above. Inhibition efficiencies obtained are greater than 85%. Antagonistic effect exists between SM and Zn2+when the concentration of Zn2+is 10 ppm and below. The SM-Zn2+system shows excellent IE up to third day. Above third day IE decreases. Acceleration of corrosion takes place. Excellent IE is shown at pH 5,7 and 12. At pH 9, IE decreases since Zn2+is precipitated as Zn(OH)2in the bulk of the solution. Polarization study reveals that SM-Zn2+system functions as a mixed inhibitor. FTIR spectra reveal that the protective film consists of Fe2+-SM complex and Zn(OH)2.


Coatings ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 106
Author(s):  
Akbar Ali Samsath Begum ◽  
Raja Mohamed Abdul Vahith ◽  
Vijay Kotra ◽  
Mohammed Rafi Shaik ◽  
Abdelatty Abdelgawad ◽  
...  

In the present study, the corrosion inhibition effect of Spilanthes acmella aqueous leaves extract (SA-LE) on mild steel was investigated in 1.0 M HCl solution at different temperature using weight loss, Tafel polarization, linear polarization resistance (LPR), and electrochemical impedance (EIS) measurements. Adsorption of inhibitor on the surface of the mild steel obeyed both Langmuir and Temkin adsorption isotherms. The thermodynamic and kinetic parameters were also calculated to determine the mechanism of corrosion inhibition. The inhibition efficiency was found to increase with an increase in the inhibitor concentration i.e., Spilanthes acmella aqueous leaves extract, however, the inhibition efficiency decreased with an increase in the temperature. The phytochemical constituents with functional groups including electronegative hetero atoms such as N, O, and S in the extract adsorbed on the metal surface are found responsible for the effective performance of the inhibitor, which was confirmed by Fourier-transform infrared spectroscopy (FT-IR) and ultraviolet–visible spectroscopic (UV-Vis) studies. Protective film formation against corrosion was confirmed by scanning electron microscopy (SEM), atomic force microscopy (AFM), and contact angle studies. The result shows that the leaves extract acts as corrosion inhibitor and is able to promote surface protection by blocking active sites on the metal.


2009 ◽  
Vol 6 (3) ◽  
pp. 887-897 ◽  
Author(s):  
P. Manjula

The inhibition efficiency of a phosphonic acid, Diethylene Triamine Pentamethylene Phosphonic acid (DTPMP) in controlling corrosion of carbon steel immersed in an aqueous solution containing 60 ppm of Cl-has been evaluated by weight loss method in the absence and presence of Zn2+. The formulation consisting of DTPMP and Zn2+has excellent inhibition efficiency (IE). A synergistic effect is noticed between Zn2+and DTPMP. Addition of sodium gluconate (SG) enhances the IE of Zn2+and DTPMP system. The DTPMP-Zn2+-SG system function as a mixed inhibitor as revealed by polarization study. AC impedance spectrum, optical and atomic force micrographs reveal the formation of a protective film on the metal surface. FTIR spectra reveal that the protective film consists of Fe2+-DTPMP complex, Fe2+-SG complex and Zn(OH)2.


2019 ◽  
Vol 7 (2) ◽  
pp. 72-77
Author(s):  
M.B. Geetha ◽  
◽  
J. Sathish ◽  
S. Rajendran ◽  
◽  
...  

The formulation consisting of 100 ppm Thiourea, 25 ppm Zn2+ and 250 ppm of L-Phenylalanine has 95% corrosion inhibition efficiency with a synergistic effect among Thiourea, L-Phenylalanine and Zn2+ ions. Polarization study shows that this formulation as a mixed inhibitor. FTIR spectra exposed the presence of Fe2+-Thiourea, Fe2+-L-Phenylalanine complex and Zn(OH)2 in protective film. AFM study confirmed the metal surface smoothness following engrossed in the inhibitor and the presence of formed protective film on the metal surface.


2021 ◽  
Vol 32 (1) ◽  
pp. 40-45
Author(s):  
Christiana Agbenu Adah ◽  
Sylvester Obaike Adejo ◽  
Joeseph Aondoaver Gbertyo ◽  
Andrew Adah Ogwuche

Abstract The menace of corrosion of steel in industries has been widely acknowledged. Analysis of oil pipeline failures in oil and gas industries in the Niger Delta area of Nigeria showed corrosion as one of the major causes of failure. Eco-friendly, cheap and renewable materials such as plant extracts have been investigated as alternative to the use of expensive synthetic chemicals which are often hazardous. In this study inhibitive properties of ethanol extracts of Ficus polita and Ficus platyphylla leaves as eco-friendly inhibitors of mild steel in 2 M sulfuric acid solution were investigated by weight loss method at temperatures of 301, 305, 309 and 313 K. The study has shown that both plant extracts inhibited the corrosion of mild steel in the acid medium. The inhibition efficiency (IE) and surface coverage (θ) for both extracts increased with increase in concentration and temperature. This trend is suggestive of chemical adsorption. However, the leaf extract of Ficus polita showed higher IE compared to F. platyphylla. Thermodynamic parameters and apparent activation energy obtained from the studies revealed the inhibition by both plant extracts to be spontaneous, exothermic and chemisorptive, while the adsorption mechanism of both plant extracts on the steel surface aligned with the Freundlich isotherm model, F. polita fits well to Temkin and Adejo-Ekwenchi isotherm models in addition.


2020 ◽  
Vol 13 (4) ◽  
pp. 347-356
Author(s):  
S. Manimegalai

The aquatic plant kingdom is a treasure of potential bioactive compounds. Aquatic plants contain some organic compounds that provide definite physiological actions on the human body. In the present study deals with the synergistic effect of Trisodium citrate (TSC)on the inhibition efficiency of methanolic extract of Sargassum swartzii (SS) and Zn2+ system on mild steel in aqueous environment. The corrosion monitoring techniques adopted in the study were weight-loss methods, electrochemical measurements, FT-IR and surface morphological techniques namely SEM and EDX. It has proved the formulation consisting of 100 ppm of Zn2+, 120 ppm of SS and 100 ppm of TSC has 95.77% IE. The high performance of SS - Zn 2+- TSC system could be due to synergistic effect that covers a wide surface coverage area on the metal surface and thus retarding the corrosion. Polarization study reveals that this formulation functions as a mixed inhibitor. AC impedance spectra suggest the presence of protective film on the metal surface. FT-IR spectra reveals that the protective film consists of Fe2+-SS complex, Fe2+-TSC complex and Zn (OH)2. SEM and EDX provide a pictorial representation on the nature of surface film in the absence and presence of inhibitors. Thus, it concluded that Sargassum swartzii - Zn 2+- TSC inhibitor system acted as a good inhibitor in aqueous medium.


2006 ◽  
Vol 2 (2) ◽  
pp. 82-90
Author(s):  
Petchiammal A.p ◽  
P.Deepa Rani ◽  
S.Seetha Laks ◽  
S. Selvaraj

The inhibition effect of Cassia alata leaves extract on corrosion of mild steel in 1N HCl was investigated through mass loss measurements with various time and temperature. The observed result indicated that the corrosion inhibition efficiency and degree of surface coverage were increased with increase of inhibitor concentration and temperature. The thermodynamic parameters (Ea, ∆Hads, ∆Gads, ∆Sads) were evaluated for corrosion inhibition process which suggests that the adsorption is endothermic, spontaneous and chemisorptions and also the inhibitor follows Langmuir adsorption isotherm. The protective film formed on metal surface was analyzed using spectroscopic studies viz, UV, FT-IR and EDX techniques.


Author(s):  
Dr. Abhay Singh

Abstract: DL-methionine has been investigated as inhibitor for the corrosion of mild steel in 1.0M hydrochloric acid solution using weight loss method and Scanning Electron Microscope (SEM) analysis. The investigated results showed that the inhibition efficiency increases with the increase in concentration of the inhibitor and decreases with the increase in temperature. SEM analysis indicated that the metal surface was in a better condition in the presence of inhibitor than the specimen exposed in the absence of the inhibitor. DL-methionine acted as a very good inhibitor and is also environmentally friendly, non -toxic, biodegradable and relatively cheap. Keywords: DL-methionine, mild steel, SEM, Corrosion inhibitor.


2019 ◽  
Vol 40 ◽  
pp. 25-29
Author(s):  
Bishal Thapa ◽  
Dipak Kumar Gupta ◽  
Amar Prasad Yadav

The bark extract of Euphorbia royleana as a green corrosion inhibitor was studied in 1M HCl using weight-loss method and potential measurement. The results show that the bark extract of Euphorbia royleana is an effective anti-corrosion inhibitor of mild steel in acidic media. The corrosion rate decreases with the time of immersion. Weight loss experiment shows that the loss in weight decreases with the time of immersion and inhibition efficiency increases with the concentration of extract. It was observed that maximum inhibition efficiency is 99.60% in 100% concentration of extract. Potential measurement study shows that bark extracts act as a mixed type of inhibitor i.e. inhibits both anodically as well as cathodically. 


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