Inhibition of acid corrosion of mild steel by aqueous nettle extracts

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.

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.


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 (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.


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. 


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.


2018 ◽  
Vol 65 (2) ◽  
pp. 146-151 ◽  
Author(s):  
Mohd Rashid ◽  
Umesh S. Waware ◽  
Afidah A. Rahim ◽  
A.M.S. Hamouda

Purpose The purpose of this study is to compare the inhibitive effect of polyaniline (PAni) and N-cetyl-N,N,N trimethyl ammonium bromide (CTAB)-stabilized PAni in a hydrochloric acid (HCl) medium. Design/methodology/approach PAni has been deposited potentiodynamically on mild steel in the presence of CTAB as a stabilizing agent to achieve high corrosion inhibition performance by the polymer deposition. The corrosion inhibition studies of CTAB-stabilized PAni inhibitor in 0.1 M HCl acidic solution was carried out by electrochemical methods, namely, open-circuit potential, potentiodynamic polarization and electrochemical impedance spectroscopy technique. Findings The results of electrochemical studies have shown that the CTAB-stabilized PAni inhibitor has higher corrosion efficiency than PAni on mild steel in 0.1 M HCl solution. The maximum per cent efficiency evaluated using the potentiodynamic polarization method is approximately 91.9. Originality/value CTAB-stabilized PAni has never been studied as a corrosion inhibitor for mild steel in an acidic medium. The investigations demonstrate relatively the better corrosion inhibition efficiency and high dispersion of the polymer in the acidic medium.


2016 ◽  
Vol 63 (4) ◽  
pp. 275-280
Author(s):  
Yao Ding ◽  
Zhengtang Luo ◽  
Dong Liu

Purpose The purpose of this paper is to use Dextrofosfomysin levophenethylamine salt to prepare HEHSPN-(Na)2 (HSPN), a new corrosion inhibitor containing sulfur. Design/methodology/approach The inhibition efficiency for Q235 steel in hydrochloric acid has been evaluated by weight-loss test, potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) techniques. Surface studies were performed by Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM). Findings The results show that inhibition efficiency of HSPN increases with an increase in concentration. Adsorption conforms to Flory–Huggins uniform temperature equation, which is multi-molecular layer adsorption and belongs to physical adsorption. Originality/value This paper is intended to be added to the family of papers that deal with green corrosion inhibitors which are highly efficient and can be used in the area of corrosion prevention and control.


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.


2014 ◽  
Vol 43 (5) ◽  
pp. 299-313 ◽  
Author(s):  
S.A. Umoren ◽  
U.M. Eduok ◽  
M.M. Solomon

Purpose – The purpose of this paper is to investigate the effect of polyethylene glycol (PEG), polyvinylpyrrolidone (PVP) and blended formulations on the corrosion inhibition of aluminium in HCl solutions at 30-60°C and to study the mechanism of action. Design/methodology/approach – The inhibitive effect of the homopolymers and polymer blend was assessed using weight loss and hydrogen evolution methods at 30 and 60°C. The morphology of the corroding aluminium surface without and with the additives was visualized using atomic force microscopy. The trend of inhibition efficiency with temperature was used to propose the mechanism of inhibition and type of adsorption. Findings – Results obtained show that inhibition efficiency (η%) increases with increase in concentration of the polymers but decreases with increase in temperature. The inhibition efficiency of the homopolymers and their blends decreased with rise in temperature. Inhibition efficiency was found to be synergistically enhanced on blending the two homopolymers with highest inhibition efficiency obtained for (PEG:PVP) blending ratio of 1:3. The phenomenon of physical adsorption is proposed from the trend of inhibition efficiency with temperature. Research limitations/implications – The mechanistic aspect of the corrosion inhibition can be better understood using electrochemical studies such as potentiodynamic polarization and electrochemical impedance spectroscopy. Originality/value – Studies involving the use of polymer blends/mixtures as corrosion inhibitor for metals in corrosive environments are scarce. The results suggest that the mixture could find practical application in corrosion control in aqueous acidic environment. The data obtained would form part of database on the use of polymer–polymer mixtures to control acid-induced corrosion of metal.


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