A new insight into corrosion inhibition process of mild steel in sulfuric acid medium: a combined experimental and theoretical study

2019 ◽  
Vol 66 (6) ◽  
pp. 835-852 ◽  
Author(s):  
Aziz Boutouil ◽  
My Rachid Laamari ◽  
Ilham Elazhary ◽  
Hafid Anane ◽  
Abdeslem Ben Tama ◽  
...  

Purpose This study aims to investigate the inhibition effect of a newly synthesized1,2,3-triazole containing a carbohydrate and imidazole substituents, namely, 1-((1-((2,2,7,7-tetramethyltetrahydro-5H-bis([1,3]dioxolo)[4,5-b:4′,5′-d]pyran-5-yl)methyl)-1H-1,2,3-triazol-4-yl)methyl)-1H-benzo[d]imidazole (TTB) on the corrosion of mild steel in aerated 1 M H2SO4. Design/methodology/approach The authors have used weight loss measurement, potentiodynamic polarization, electrochemical impedance spectroscopy, FT-IR studies, scanning electron microscopy analysis and energy dispersive X-ray (EDX) spectroscopy techniques. Findings It is found that, in the working range of 298-328 K, the inhibition efficiency of TTB increases with increasing concentration to attain the highest value (92 per cent) at 2.5 × 10−3 M. Both chemisorption and physisorption of TTB take place on the mild steel, resulting in the formation of an inhibiting film. Computational methods point to the imidazole and phenyl ring as the main structural parts responsible of adsorption by electron-donating to the steel surface, while the triazol ring is responsible for the electron accepting. Such strong donating–accepting interactions lead to higher inhibition efficiency of TTB in the aqueous working system. Originality/value This work is original with the aim of finding new acid corrosion inhibitors.

2014 ◽  
Vol 43 (3) ◽  
pp. 127-138 ◽  
Author(s):  
Aida Zaabar ◽  
Razika Aitout ◽  
Laid Makhloufi ◽  
Kamel Belhamel ◽  
Boualem Saidani

Purpose – The aim of this research was to investigate the use of aqueous extracts of nettle plant (NE) as a green corrosion inhibitor of mild steel in hydrochloric acid solution. Design/methodology/approach – The inhibition efficiency was investigated by weight loss measurements, potentiodynamic polarizations, electrochemical impedance spectroscopy, SEM observations and EDX analysis. Findings – The inhibition efficiency increased with an increase in concentration of NE up to a critical concentration of 1.5×10−3 g · cm−3 where the highest inhibition efficiency of 97 percent was obtained. The adsorption of the inhibitor was spontaneous (reflected by the negative value of ΔGads0), supported the mechanism of physical adsorption and obeyed to the Langmuir adsorption isotherm. The inhibition action of the extracts was independent on the storage time; it could be conserved without any specific conditions of time and temperature. Research limitations/implications – The anticorrosion effect can be better understood when the active compound in the extracts is identified and what is the inhibition efficiency of one component in the presence of another in the mixture (synergetic or antagonist effects). Practical implications – Nettle is a healthy plant, without particular toxicity that can find possible applications as environmentally friendly inhibitor of mild steel used as materials in food industry. Originality/value – Aqueous nettle extracts were studied for the first time as corrosion inhibitor and its anticorrosion effect was proven by standard methods.


2014 ◽  
Vol 43 (6) ◽  
pp. 394-404 ◽  
Author(s):  
I.O. Arukalam

Purpose The aim of this paper is to appraise the inhibiting potential of hydroxypropyl methylcellulose (HPMC) on the corrosion of mild steel and aluminium in sulphuric and hydrochloric acid solutions. Design/methodology/approach The effects of two different corrodents on the dissolution of mild steel and aluminium were examined. Corrosion rates were determined using the weight loss technique. Inhibition efficiency was estimated by comparing the corrosion rates in absence and presence of the additive. The kinetics and mechanism of HPMC adsorption were investigated by impedance study while the anodic and cathodic partial reactions were studied by polarization measurements. Findings The results reveal that corrosion rate of mild steel and aluminium decreased with addition of HPMC. The corrosion rate and inhibition efficiency were found to depend on the concentration of the inhibitor. The polarization data indicated that the inhibitor was of mixed-type, with predominant effect on the cathodic partial reaction. electrochemical impedance spectroscopy confirms that corrosion inhibition was by adsorption on the metal surface following Freundlich adsorption isotherm via physisorption mechanism. Originality/value Hydroxypropyl methylcellulose has been studied for the first time as an inhibitor of mild steel and aluminium corrosion and the results suggest that the inhibitor could find practical applications in corrosion control in HCl and H2SO4 acid media. The findings are particularly useful, considering the fact that HPMC is a good film former and viscosity enhancer which could also be used in paint formulation.


2014 ◽  
Vol 61 (5) ◽  
pp. 300-306 ◽  
Author(s):  
B.P. Markhali ◽  
R. Naderi ◽  
M. Sayebani ◽  
M. Mahdavian

Purpose – The purpose of this paper is investigate the inhibition efficiency of three similar bi-cyclic organic compounds, namely, benzimidazole (BI), benzotriazole (BTAH) and benzothiazole (BTH) on carbon steel in 1 M hydrochloric acid (HCl) solution. Organic inhibitors are widely used to protect metals in acidic media. Among abundant suggestions for acid corrosion inhibitors, azole compounds have gained attention. Design/methodology/approach – The inhibition efficiency of the three organic compounds was investigated using potentiodynamic polarization and electrochemical impedance spectroscopy (EIS). Findings – Superiorities of BTH and BTAH corrosion inhibitors were shown by EIS data and polarization curves. Moreover, the results revealed that BTAH and BTH can function as effective mixed-type adsorptive inhibitors, whereas no inhibition behavior was observed for BI. Both BTAH and BTH obeyed Longmuir adsorption isotherm. The results obtained from this isotherm showed that both inhibitors adsorbed on the specimen surface physically and chemically. The difference in inhibition efficiencies of BTAH, BTH and BI was related to the presence of nitrogen and sulfur hetero atoms on their molecular structures. Originality/value – This study evaluated inhibition efficiency of BI, BTAH and BTH using electrochemical methods. In addition, the study attempted to find inhibition mechanism of the inhibitors and to find modes of adsorption of the inhibitors, correlating effects of heteroatoms and inhibition efficiency.


2015 ◽  
Vol 44 (6) ◽  
pp. 371-378 ◽  
Author(s):  
Y. Sangeetha ◽  
S. Meenakshi ◽  
C. Sairam Sundaram

Purpose – The purpose of this paper is to develop an eco-friendly corrosion inhibitor for mild steel in 1 M HCl. Design/methodology/approach – A pharmaceutical drug acetyl G was investigated for its corrosion inhibition efficiency using weight loss method, potentiodynamic polarisation and electrochemical impedance spectroscopy. Findings – The inhibition efficiency increased with increase in inhibitor concentration. Results from polarisation studies revealed mixed type of inhibition. Impedance studies, scanning electron microscopy and Fourier transform spectroscopy confirm the adsorption of inhibitor on the mild steel surface. Research limitations/implications – The drug acetyl G has sulphur and nitrogen atoms which effectively block the corrosion of mild steel and is non-toxic and has good inhibition efficiency. Practical implications – This method provides an excellent, non-toxic and cost-effective material as a corrosion inhibitor for mild steel in acid medium. Originality/value – Application of this drug as a corrosion inhibitor has not been reported yet in the literature. Replacing the organic inhibitors, this green inhibitor shows excellent inhibition efficiency. This is adsorbed excellently on the mild steel surface due to the presence of long chain and hetero atoms. Thus, the drug retards the corrosion reaction.


Proceedings ◽  
2019 ◽  
Vol 41 (1) ◽  
pp. 27
Author(s):  
Shaimaa B. Al-Bghdadi ◽  
Mahdi M. Hanoon ◽  
Jafer F. Odah ◽  
Lina M. Shaker ◽  
Ahmed A. Al-Amiery

A New benzylidene derivative namely benzylidene-5-phenyl-1,3,4-thiadiazol-2-amine (BPTA), was successfully synthesized and characterized using Fourier Transform Infrared Spectroscopy, Nuclear Magnetic Resonance and elemental analysis (CHN) techniques. The inhibition efficiency of BPTA on mild steel corrosion in 1.0 N HCl was tested at various temperatures. The methodological work was achieved by gravimetric method complemented with morphological investigation. The concentrations of inhibitor were 0.1, 0.2, 0.3, 0.4 and 0.5 mM at the temperatures 303, 313, 323 and 333 K. The BPTA, molecules as become superior corrosion inhibitor with 92% inhibition efficiency of mild steel coupon in the acidic environment. The inhibition efficiency increased with increasing concentrations of BPTA and the excellent efficiency was performed with the 0.5 mM concentration and followed with 0.4 mM. In acidic environment, the 0.5 and 0.4 mM gave the optimum performance with weight loss technique and scanning electron microscopy analysis. On the other hand, the inhibition efficiency decreased with the increase of temperature. Results of BPTA indicated mixed type inhibitor and the adsorption on the mild steels surface obeys the Langmuir adsorption isotherm. It was found that the BPTA performance depend on the concentration and the solution temperature. Quantum chemical calculations have been done to correlate the electronic characteristics of BPTA with the corrosive inhibitive impact. Experimental and theoretical results are in good agreement.


2019 ◽  
Vol 66 (5) ◽  
pp. 583-594
Author(s):  
Esma Sezer ◽  
İpek Öztürk

Purpose Tannic acid (TA) is one of the green corrosion inhibitors for mild steel; its anti-corrosive performance in alkaline water on mild steel when it is used together with polyaspartic acid (PASA) still has not been investigated. The purpose of this study is to develop an effective, biodegradable and environment-friendly novel corrosion inhibitor based on TA and PASA as an alternative to the conventional inorganic inhibitors for mild steel in decarbonised water, which is common in cooling systems. Design/methodology/approach Corrosion inhibition mechanism is investigated by electrochemical techniques such as polarisation measurements and electrochemical impedance spectroscopy, and results were evaluated to determine the optimum inhibitor concentration for industrial applications. Additionally, practice-like conditions are carried out in pilot plant studies to simulate the conditions in cooling systems. Thus, the efficiencies of the inhibitors are evaluated through both weight loss and linear polarisation resistance measurements. Moreover, the corrosion product is characterised by scanning electron microscopy with energy dispersive X-ray spectroscopy (SEM-EDX) and Fourier-transform infrared spectroscopy (FTIR) analysis. Findings TA shows high inhibition efficiency especially towards pitting corrosion for mild steel in decarbonised water. PASA addition in the cooling systems improves the inhibition efficiency of TA, and at lower concentrations of TA + PASA, it is possible to obtained better inhibition efficiency than TA alone at higher inhibitor amounts, which is essential in economic and environmental aspect. Originality/value A blended inhibitor program including TA and PASA with suggested concentrations in this work can be used as an environmental friendly treatment concept for the mild steel corrosion inhibition at cooling systems.


2016 ◽  
Vol 63 (5) ◽  
pp. 369-376 ◽  
Author(s):  
Basak Dogru Mert ◽  
Mehmet Erman Mert ◽  
Gülfeza Kardas ◽  
Birgül Yazici

Purpose The purpose of this paper is to investigate the adsorption and corrosion inhibition of two isomeric compounds (C4H5N3) as aminopyrazine (AP) and 2-amino-pyrimidine (2AP) on mild steel (MS) in 0.5 M HCl. The study was a trial to combine experimental and modelling studies and research effect of molecular geometry on inhibition effect of inhibitor molecules. Design/methodology/approach The thermodynamic, kinetic and quantum parameters were determined. The electrochemical impedance spectroscopy and anodic polarisation measurements were obtained. The scanning electron microscope was used for monitoring electrode surface. The highest occupied molecular orbital, energy of the lowest unoccupied molecular orbital, Mulliken and natural bonding orbital charges on the backbone atoms, absolute electronegativity, absolute hardness were calculated by density functional theory (DFT)/B3LYP/6-311G (++ d,p). Findings Results showed that AP and 2AP suppressed the corrosion rate of MS. The corrosion current values were 0.530, 0.050 and 0.016 mA cm-2 in HCl, AP and 2AP containing HCl solutions, respectively. It was illustrated with the blocked fraction of the MS surface by adsorption of inhibitors which obeyed the Langmuir isotherm. The inhibition efficiency follows the order: 2AP > AP which is in agreement with experimental and quantum results. Originality/value This paper provides lay a bridge on the molecular geometry and inhibition efficiency by electrochemical tests and modelling study. The inhibition effect of AP and 2AP has not been compared with each other, neither experimentally nor theoretically. This study put forward possible application of 2AP as corrosion inhibitor especially for closed-circuit systems.


2017 ◽  
Vol 64 (5) ◽  
pp. 563-572 ◽  
Author(s):  
Asmae Bouoidina ◽  
Mehdi Chaouch ◽  
Abdelfattah Abdellaoui ◽  
Amal Lahkimi ◽  
Belkheir Hammouti ◽  
...  

Purpose The inhibition effect of Foeniculum vulgare seeds’ (FVS) extract on the corrosion of mild steel in acidic medium was studied using weight loss, electrochemical impedance spectroscopy and Tafel polarization, as well as the surface morphology of the mild steel. Design/methodology/approach Weight loss measurements, potentiodynamic tests, electrochemical impedance spectroscopy studies and gas chromatography/mass spectrometry and scanning electron microscopy analysis of FVS extract were performed. Findings FVS extract acts as a good inhibitor for the corrosion of mild steel in 1.0 M HCl. The inhibition efficiency increases with the increase in inhibitor concentration but decreases with the increase of temperature. Practical implications FVS extract was observed to play an important role in the corrosion inhibition of mild steel in acidic solution. Originality/value This paper is intended to be added to the family of green inhibitors which are highly efficient inhibitors and can be used in the area of corrosion prevention and control.


2015 ◽  
Vol 44 (5) ◽  
pp. 322-329 ◽  
Author(s):  
Shabnam Ashhari ◽  
Ali Asghar Sarabi

Purpose – This paper aims to investigate the corrosion inhibition effects of indole-3-carbaldehyde and 2-methylindole on mild steel in 1 M HCl solution. Design/methodology/approach – Indole-3-carbaldehyde and 2-methylindole as corrosion inhibitors of mild steel in 1 M HCl solution were investigated by polarisation and electrochemical impedance spectroscopy (EIS). Adsorption isotherm and mechanism were calculated. Quantum chemical calculations were used to find out a correlation between electronic structure of inhibitors and inhibition efficiency. Changes in the properties of metal surface in HCl solution in the presence of inhibitors were studied by contact angle measurements. Findings – Polarisation results revealed inhibitors could reduce cathodic and anodic reactions rates on metal surface. EIS analysis showed that inhibition efficiency of indoles increases by increasing the inhibitors’ concentration; maximum inhibition efficiency was 95 and 94 per cent in solutions containing 1 mM indole-3-carbaldehyde and 2-methylindole, respectively. Inhibitors’ adsorptions on metal surface were confirmed by analysing the exposed metals’ surface through contact angles measurements. The adsorption of inhibitors was found to follow Langmuir isotherm. Quantum chemical calculations showed that a more positively charged benzene ring in the structure of two indole-based inhibitors would lead to higher adsorption to metal. Originality/value – This research was carried out to understand the effects of two different functional groups (-C=O, -CH3) with different induction effects on the indole structure and on inhibition efficiency of corrosion inhibitors with the purpose of using these components in industrial application as acid wash solutions to etch and remove rusts from metal surfaces.


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.


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