scholarly journals Synergistic Effect of KI on Corrosion Inhibition of Mild Steel by Polynuclear Schiff Base in Sulphuric Acid

2012 ◽  
Vol 2012 ◽  
pp. 1-8 ◽  
Author(s):  
K. S. Shaju ◽  
K. Joby Thomas ◽  
Vinod P. Raphael ◽  
Aby Paul

Synergistic effect of KI on the corrosion inhibition efficiency of polynuclear Schiff base, anthracene-9(10H)-one-3-aminopropanoic acid (A9O3AP), on mild steel (MS) in 0.5 M sulphuric acid solution has been investigated using weight loss measurements, electrochemical impedance spectroscopy (EIS), and potentiodynamic polarization studies. The results show that inhibition efficiencies on MS increase with increase in concentration of the inhibitor and enhancement in inhibition efficiency was observed on addition of potassium iodide due to synergism. The adsorptions, of inhibitor and inhibitor + KI on the surfaces of the corroding metal obey Freundlich and Langmuir isotherms, respectively. Polarization studies revealed that A9O3AP acts as a mixed type inhibitor. Thermodynamic parameters (; ) were calculated using the adsorption isotherms. A probable synergismtic mechanism is proposed.

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.


2021 ◽  
pp. 67-80
Author(s):  
K. Ragi ◽  
Joby Thomas Kakkassery ◽  
Vinod P. Raphael ◽  
Binsi M. Paulson ◽  
Reeja Johnson

The corrosion inhibition efficiency of the Schiff base N,N’-(5,5-dimethylcyclohexane-1,3-diylidene)dianiline (DmChDa) on mild steel in 1M HCl and 0.5M H2SO4 was evaluated using gravimetric, electrochemical impedance spectroscopy, potentiodynamic polarization and electrochemical noise measurement. Experimental results established that DmChDa possess relatively high corrosion inhibition capacity. Langmuir and El-Awady adsorption isotherms were obeyed by the Schiff base in 1M HCl and 0.5M H2SO4 respectively. SEM analysis showed that DmChDa was adsorbed on the steel surface during corrosion inhibition. The variation of metal dissolution with temperature was also examined using gravimetric study.


2018 ◽  
Vol 25 (02) ◽  
pp. 1850050
Author(s):  
V. SHANMUGA PRIYA ◽  
C. UMA RANI ◽  
S. VELRANI

The synergistic effect of halide ions such as KCl, KBr and KI on the corrosion inhibition of mild steel in 1 N sulphuric acid by [Formula: see text]-2,c-6-diphenyl-t-3-methyl piperdin-4-ones with semicarbazone (01[Formula: see text]SC), [Formula: see text]-2,c-6-diphenyl-N-methyl-t-3-ethyl piperdin-4-ones with semicarbazone (02[Formula: see text]SC) and 2,6-diphenyl-t-3-ethyl piperdin-4-one with semicarbazone (03[Formula: see text]SC) has been examined by weight loss method, potentiodynamic polarization measurements and electrochemical AC impedance spectroscopy. Results show that substituted [Formula: see text]-2,c-6-diphenyl piperidin-4-ones with semicarbazone act as the perfect corrosion inhibitors and their inhibition efficiency increases with the addition of halide ions. The inhibitor (01[Formula: see text]SC) shows the inhibition efficiency of 78.28% (0.2[Formula: see text]mM) by using a weight loss method. The influence of I[Formula: see text], Br[Formula: see text] and Cl[Formula: see text] anions raises the inhibition efficiency of the substituted 2,6-diphenyl piperidin-4-ones with semicarbazone due to the synergistic effect. The synergistic effect of halide ions was formed in the following order: KI [Formula: see text] KBr [Formula: see text] KCl.


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.


2020 ◽  
Vol 7 (1) ◽  
Author(s):  
Kashmitha Muthamma ◽  
Preethi Kumari ◽  
M. Lavanya ◽  
Suma A. Rao

Abstract Mild steel (a low carbon steel) is an affordable engineering material used for many purposes in various environments including mild acidic environment with some precautions. The corrosion behaviour of mild steel (MS) in 0.5 M H2SO4 and 0.5 M HCl, in the temperature range (303–323 K) without and with the inhibitor N-[(3,4-dimethoxyphenyl) methyleneamino]-4-hydroxy-benzamide (DMHB), was investigated using Potentiodynamic polarization and Electrochemical impedance spectroscopy (EIS) techniques supplementing with surface characterization study using scanning electron microscope (SEM) and atomic force spectroscopy (AFM). Experimental observations were found to be in agreement with Density functional theory (DFT) calculations. The inhibition efficiency increases with increase in DMHB concentration and showed maximum inhibition efficiency of 86% in 0.5 M H2SO4 and 81% in 0.5 M HCl, respectively, at concentration of 3 × 10─3 M at 303 K. The inhibition efficiency of DMHB obtained relatively at its lower concentration (3 × 10─3 M) compared to other reported related compounds confirms its potential towards corrosion inhibition. The variation in the kinetic and thermodynamic parameters indicated physisorption of DMHB on MS and its mixed type inhibitive action followed Langmuir’s isotherm model. DFT calculations go along with the experimental results, signifying the potential corrosion inhibition behaviour of DMHB for MS in both the acid media.


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