Corrosion inhibitory effect of mixed cocoa pod-Ficus exasperata extract on MS in 1.5 M HCl: optimization and electrochemical study

2021 ◽  
Vol 39 (2) ◽  
pp. 109-122
Author(s):  
Lekan Taofeek Popoola

Abstract This paper investigated optimization of corrosion inhibitory attributes of mixed cocoa pod-Ficus exasperata (CP-FE) extracts towards mild steel in 1.5 M HCl using central composite design. Potentiodynamic polarization, linear polarization resistance and electrochemical impedance spectroscopy measurements were used for the electrochemical study. The result revealed maximum inhibition efficiency of 91.52% at temperature, inhibitor concentration, time and acid concentration of 50 °C, 5 g/L, 144 h and 0.2 M, respectively with R 2 value of 0.9429. Central composite design predicted optimum point of 70.37 °C, 3.81 g/L, 127.37 h and 0.22 M. Potentiodynamic polarization revealed extract to be mixed-type inhibitor with anodic prevalence. Electrochemical impedance spectroscopy showed that corrosion inhibition occurred via adsorption of CP-FE molecules on active sites of MS surface. Scanning electron microscopy images revealed protection of mild steel surface by adsorbed molecules of CP-FE extracts. Fourier transform infrared revealed presence of carboxyl (–COOH), unsaturated (–C-C–) and hydroxyl (–OH). Energy dispersive spectroscopy revealed presence of high iron composition on mild steel surface in the presence of mixed CP-FE extract proving its corrosion inhibition efficiency in 1.5 M HCl. Atomic adsorption spectroscopy revealed loss of Fe2+ into free HCl solution. Generally, extract from mixed CP-FE was found as effective corrosion inhibitor for mild steel in 1.5 M HCl solution.

2014 ◽  
Vol 2014 ◽  
pp. 1-6 ◽  
Author(s):  
Nimmy Kuriakose ◽  
Joby Thomas Kakkassery ◽  
Vinod P. Raphael ◽  
Shaju K. Shanmughan

The corrosion inhibition efficiency of thiophene-2-carbaldehyde tryptophan (T2CTRY) on mild steel (MS) in 1 M HCl solution has been investigated and compared using weight loss measurements, electrochemical impedance spectroscopy, and potentiodynamic polarization analysis. The Schiff base exhibited very good corrosion inhibition on mild steel in HCl medium and the inhibition efficiency increased with the increase in concentration of the inhibitor. The adsorption of the inhibitor on the surface of the corroding metal obeys Freundlich isotherm. Thermodynamic parameters (Kads, ΔG ads0) were calculated using adsorption isotherm. Polarization studies revealed that T2CTRY acts as a mixed type inhibitor. A maximum of 96.2% inhibition efficiency was achieved by EIS studies at a concentration of 1 mM.


2020 ◽  
Vol 32 (8) ◽  
pp. 2043-2050
Author(s):  
Phattarasuda Manantapong ◽  
Nattanon Chaipunya ◽  
Suttipong Wannapaiboon ◽  
Prae Chirawatkul ◽  
Worawat Wattanathana ◽  
...  

The inhibiting action of Thai-bael fruit extract at room temperature on hot-rolled steel in 1M HCl solution was studied. The chemical functional groups of the green inhibitors were characterized by Fourier-transformed infrared spectroscopy. The electrochemical activities of steel surface were investigated through linear polarization measurements, electrochemical impedance spectroscopy, surface assessment techniques based on optical microscopy and X-ray absorption spectroscopy. Electrochemical testing samples have been prepared in the form of square plates with the size 1 × 1 cm2. The organic corrosion inhibitor extract from Thai-bael fruit has shown the smallest corrosion current density (Icorr) of 114.8 μA cm-2 and corrosion potential (Ecorr) of -424.6 mV, compared with standard Ag/AgCl electrode potential. In comparison, similar tests in the bare HCl solutions yielded Icorr = 882.4 mA cm-2 and Ecorr = -445.8 mV. The mixed-type corrosion inhibiting behaviour was evidenced in the results of the polarization measurements. Electrochemical impedance spectroscopy reveals that the resistance to charge transfer due to the presence of the extracts has been increased by about four times that of the same test on the bare HCl solution, indicating the formation of a protective layer. The adsorption of the organic molecules near the steel-electrolyte interface is evident in the decreasing double-layer capacitance with the enhancing concentration levels of the extract. This latter finding supports the displacement of the water molecules by means of the adsorption of the inhibitors on the steel surface. The optical images of steel surface before and after being immersed in HCl solution also showed pieces of evidence of corrosion retardation. XANES study as well as the linear combination fitting revealed that the samples immersed in HCl solutions with Thai-bael fruit extract possess less Fe3+ compositions. All tendencies across the four examinations indicate that Thai-bael fruit extract could potentially inhibit the corrosion reaction of steel electrodes in the acidic solution.


2017 ◽  
Vol 5 (3) ◽  
pp. 800-809
Author(s):  
L. Bazzi ◽  
E Azzouyahar ◽  
M Essahli

The inhibition effect of eugenol oil (EO) on the corrosion of tin in 0.1 M Na2CO3 has been studied by electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization technics. The effect of temperature on the corrosion behavior of tin in 0.1 M Na2CO3 with and without addition of eugenol oil was studied in the temperature range 278-308 K. This compound inhibits the corrosion of tin at low concentration. At 4g/L eugenol oil the inhibition efficiency calculated by potentiodynamic polarization and EIS techniques is 70% and 82%, respectively. The inhibition efficiency increased with increase of the inhibitor concentration and decreased with increase of medium temperature. Electrochemical impedance spectroscopy was used to investigate the mechanism of corrosion inhibition. Polarization curves reveal that EO acts as a mixed-type inhibitor in corrosive solution. The results obtained from the different corrosion evaluation techniques are in good agreement.


2017 ◽  
Vol 6 (4) ◽  
pp. 108-116 ◽  
Author(s):  
Imane Hamdou ◽  
Mohamed Essahli ◽  
Abdeslam Lamiri

The study was carried out using potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) technique. The inhibition efficiency was found around 87 % with 1600 ppm of inhibitor. The efficiency was accentuated with the increase of the concentration while it decreased with the rise of the temperature. Analysis of the polarization curves revealed that the Ricinus communis oil is considered as a mixed inhibitor. The Influence of the temperature was also studied, the values of the activation energy showed that the inhibition occurred by physisorption. 


2011 ◽  
Vol 66-68 ◽  
pp. 817-821
Author(s):  
Abdul Amir H. Kadhum ◽  
Ahmed Y. Musa ◽  
Abu Bakar Mohamad ◽  
Mohd Sobri Takriff ◽  
Long Lynnyen

The production of polyaniline films on mild steel from sulfuric acid was carried out using cyclic voltammetry. Corrosion protection of the coating was observed in 3.5% NaCl using electrochemical impedance spectroscopy, (EIS) and potentiodynamic polarization measurements. Results showed that the polyaniline layer has the potential to protect mild steel by stabilizing the oxide layer formed on the steel surface and thus prevent the metal dissolution process.


2021 ◽  
Vol 37 (4) ◽  
pp. 779-790
Author(s):  
G. Pandimuthu ◽  
P. Muthukrishnan ◽  
S. Rameshkumar ◽  
K. Paramasivaganesh ◽  
A. Sankar

In the present work, Pyrrole derivatives containing oxygen, nitrogenand aromatic rings namely,N-(1H-Pyrrol-2-ylmethylidene)-2,3-dihydro-1,4-benzodioxin-6-amine (BPS) was synthesized and its anticorrosion potential was studied applying the gravimetric, polarization and AC impedance methods on the mild steel (MS) corrosion in corrodent (0.5M H2SO4 and 1 M HCl). It is observed that in the acidic environments, the inhibition efficiency (IE) of the BPS raised with the enhance in the concentration and it resulted in greater inhibition efficiency in1 M HCl solution than in 0.5M H2SO4 solution. The inhibition efficiency assessed by Electrochemical Impedance Spectroscopy reaches about 81.6% in 0.5 M H2SO4 and 84.2% in 1.0 M HCl solutions at 600 ppm of BPS.The studied BPS being mixed type inhibitor was shown by the Tafel polarization curves. And it was noticed that over the MS surface, the adsorption of the BPS obeyed Langmuirisotherm. In order to ascertain the inhibitor mechanism, the potential of zero charge (PZC) was measured. Electrochemical Impedance spectroscopy was applied to assess the influence of temperature on corrosion inhibition.The surface morphology of MS surface was analyzed using SEM and AFM techniques. The anti-bacterial activity for the BPS was studied as a divergent analysis.


RSC Advances ◽  
2021 ◽  
Vol 11 (41) ◽  
pp. 25314-25333
Author(s):  
Mai A. Khaled ◽  
Mohamed A. Ismail ◽  
Ahmed. A. El-Hossiany ◽  
Abd El-Aziz S. Fouda

This study targets the investigation of three pyrimidine derivatives (MA-1230, MA-1231, MA-1232) for the prevention of corrosion on copper in 1 M HNO3via weight loss (WL), potentiodynamic polarization (PDP), and electrochemical impedance spectroscopy (EIS) techniques.


2019 ◽  
Vol 7 (4.14) ◽  
pp. 168
Author(s):  
N Z. Nor Hashim ◽  
K Kassim ◽  
F H. Zaidon

Two N-substituted thiosemicarbazone derivatives namely as 2-(4-chlorobenzylidene)-N-phenylhydrazinecarbothioamide and 2-benzylidene-N-phenylhydrazinecarbothioamide (L1 and L2, respectively) have been tested as corrosion inhibitors on mild steel in 1 M HCl. The ligands were synthesized and investigated using potentiodynamic polarization (PD) and electrochemical impedance spectroscopy (EIS).  The obtained results indicated that inhibition efficiency, (IE, %) L1 increased with increasing inhibitor concentrations which behaved as a good corrosion inhibitor compared to L2. The synthesized ligands were successfully characterized by melting point, elemental analysis (C, H, N, and S), Fourier-transform infrared spectroscopy (FT-IR) and NMR (1H and 13C) spectroscopy. The excellent inhibition effectiveness for both compounds on mild steel before and after immersion in 1 M HCl solution containing 40 ppm of L1 and L2 were also verified by scanning electron microscope (SEM). Based on potentiodynamic polarization results, it can be concluded that all investigated compounds are mixed-type inhibitors and obey the Langmuir adsorption isotherm. 


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