Z. Faska, L. Majidi, R. Fihi, A. Bouyanzer and B. Hammouti
This paper seeks to evaluate the effect of natural menthols and their synthesised epoxy‐allylmenthols as a non‐toxic inhibitor on the corrosion of steel in HCl media at various…
Abstract
Purpose
This paper seeks to evaluate the effect of natural menthols and their synthesised epoxy‐allylmenthols as a non‐toxic inhibitor on the corrosion of steel in HCl media at various temperatures.
Design/methodology/approach
Epoxy‐allylmenthols were synthesised and characterised. Gravimetric technique was used to measure the efficiency of corrosion inhibition.
Findings
Modified allylmenthol (to epoxy‐allylmenthol) exhibited a good inhibition. But its efficiency decreases with temperature.
Research limitations/implications
The inhibition efficiency increases with the concentration of inhibitor to attain 74 percent at 0.8 g/l.
Practical implications
The efficiency of menthol derivatives increases with the concentration but decreases with rise of temperature in the 303‐328 K range. Natural inhibitor can be used in chemical cleaning and pickling processes.
Originality/value
The originality of this work is to find a safe and cheap eco‐friendly inhibitor from natural plants.
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The effects of natural Artemisia oil on the corrosion of steel in molar hydrochloric acid were studied by the measurements of weight loss, electrochemical and EIS polarisation…
Abstract
The effects of natural Artemisia oil on the corrosion of steel in molar hydrochloric acid were studied by the measurements of weight loss, electrochemical and EIS polarisation. The results obtained revealed that Artemisia oil reduced the rate of corrosion. The corrosion inhibition efficiency increased with the increase of inhibitor concentration. Potentiodynamic polarisation studies clearly revealed that the presence of the natural Artemisia oil did not alter the mechanism of the hydrogen evolution reaction and acted essentially as a cathodic inhibitor. Good agreement between gravimetric and electrochemical polarisation results was noted. The effect of temperature on the corrosion behaviour of steel in 1M HCl, with and without the oil in the temperature range of 308‐353 K, indicated that inhibition efficiency increased with temperature. The adsorption of Artemisia oil on the steel is followed by Frumkin adsorption isotherm.
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The purpose of this paper is to make people aware of organic corrosion inhibitors.
Abstract
Purpose
The purpose of this paper is to make people aware of organic corrosion inhibitors.
Design/methodology/approach
As it is a literature review paper, no specific method is used.
Findings
It has been found that plant extracts and oils show inhibition efficiency up to 98 percent, so it is certain that plant extracts and oils are effective corrosion inhibitors and can be successfully used at the industrial level.
Research limitations/implications
Plant extracts and oils are also found to be non‐toxic, highly efficient, renewable and cheap. But less effort has been given towards the identification of which compound is active in the extract.
Originality/value
The paper shows detailed account of the inhibitors obtained from plants, which are used as natural corrosion inhibitors.
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S.A. Umoren, I.B. Obot, L.E. Akpabio and S.E. Etuk
To investigate the adsorption behaviour and inhibitive effect of Vigna unguiculata (VU) extract (agricultural waste material) for aluminium corrosion in 0.5 M NaOH and H2SO4.
Abstract
Purpose
To investigate the adsorption behaviour and inhibitive effect of Vigna unguiculata (VU) extract (agricultural waste material) for aluminium corrosion in 0.5 M NaOH and H2SO4.
Design/methodology/approach
The inhibitive effect of the plant extract was assessed using weight loss method at 30 and 60oC. The trend of inhibition efficiency with temperature was used to propose the mechanism of inhibition and type of adsorption.
Findings
VU extract effectively inhibited aluminium corrosion in both alkaline and acidic media. Inhibition efficiency (I %) of the extract increased with increase in concentration of the extract and temperature. Inhibitor adsorption characteristics were approximated by Freunlich and Temkin adsorption isotherms at all the concentrations and temperatures studied. The phenomenon of chemical adsorption is proposed from the activation parameters obtained.
Research limitations/implications
The mechanistic aspect of the corrosion inhibition can be better understood using electrochemical studies such as polarization and AC impedance spectra.
Practical implications
The findings may be useful in metal surface anodizing and metal coating.
Originality/value
This paper provides new information on the possible application of VU extract as eco‐friendly inhibitor. It has not been reported elsewhere.
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Uchenna Luvia Ezeamaku, Innocent Eze, Nkiru Odimegwu, Angela Nwakaudu, Amarachukwu Okafor, Okechukwu Dominic Onukwuli and Ikechukwu Abuchi Nnanwube
The purpose of this study is to investigate starch mucor (SM) in potassium iodide (KI) as corrosion inhibitor of aluminium in hydrochloric acid (HCl) medium.
Abstract
Purpose
The purpose of this study is to investigate starch mucor (SM) in potassium iodide (KI) as corrosion inhibitor of aluminium in hydrochloric acid (HCl) medium.
Design/methodology/approach
The SM in KI was characterized by gravimetric, scanning electron microscopy, electrochemical impedance spectroscopy measurements, potentiodynamic polarization and gas chromatography-mass spectrometer techniques. The inhibition efficiency was optimized using response surface methodology.
Findings
The result revealed that the inhibitor inhibited corrosion at a low concentration with the rate of inhibition increasing as the concentration of the inhibitor increased. The inhibition efficiency increases as the temperature was increased with slight incorporation of the inhibitor (SM in KI). This indicates that the corrosion control is both inhibitor (SM in KI) and temperature dependent.
Originality/value
The research results can provide the basis for using SM in KI as corrosion inhibitor of aluminium in HCL medium. Mixed-type inhibitor nature of SM was proved by cathodic and anodic nature of the polarization curves.
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Y. Sangeetha, S. Meenakshi and C. Sairam Sundaram
– The purpose of this paper is to develop an eco-friendly corrosion inhibitor for mild steel in 1 M HCl.
Abstract
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.
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M. Bendahou, M. Benabdellah and B. Hammouti
To evaluate the effect of natural rosemary oil as non toxic inhibitor on the corrosion of steel in H3PO4 media at various temperatures.
Abstract
Purpose
To evaluate the effect of natural rosemary oil as non toxic inhibitor on the corrosion of steel in H3PO4 media at various temperatures.
Design/methodology/approach
The oil was hydro‐distilled. The oil was used as inhibitor in various corrosion tests. Gravimetric and electrochemical techniques were used to characterise the corrosion mechanism.
Findings
Chromatographic analysis by GC showed that the oil was rich in 1,8‐cineole. The oil was a good inhibitor. But, its efficiency decreased with temperature.
Research limitations/implications
The inhibition efficiency increased with the concentration of the natural oil to attain 73 per cent at 10 g/l. Good agreement between the various methods explored was observed. Polarisation measurements showed that rosemary oil acted essentially as a cathodic inhibitor.
Practical implications
The efficiency of the oil increased with the concentration but decreased with the rise of temperature in the 298‐348 K range. The natural oil could thus be used in chemical cleaning and pickling processes.
Originality/value
The originality of this work is the finding of a safe and cheap inhibitor from natural plants.
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Okechukwu Okechukwu Onukwuli, Benson Chinweuba Udeh, Monday Omotioma and Ikechukwu Abuchi Nnanwube
The purpose of this study was to investigate cimetidine as corrosion inhibitor of aluminium in hydrochloric acid medium.
Abstract
Purpose
The purpose of this study was to investigate cimetidine as corrosion inhibitor of aluminium in hydrochloric acid medium.
Design/methodology/approach
Cimetidine was characterized by gas chromatography mass spectrophotometer and Fourier transform infrared spectroscopy to determine its chemical composition and functional groups, respectively. Gravimetric, potentiodynamic polarization and electrochemical impedance spectroscopic techniques were used in the corrosion inhibition process. Thermodynamic and adsorption parameters were evaluated. And response surface methodology was used to optimize the corrosion inhibition process.
Findings
Analysis of the results revealed that major constituents of cimetidine include metronidazole, n-hexadecanoic acid cyclohexane and methyl ester. It has C-H stretch, C = N stretch, CH3C-H bend, ring C = C stretch, -C-O-O stretch, N-H bend, C-O stretch and C-H bend as predominant functional groups. Adsorption of molecules of the inhibitor on the aluminium surface was spontaneous, and it followed mechanism of physical adsorption. Response surface methodology revealed that quadratic model adequately described the inhibition efficiency of cimetidine as function of inhibitor concentration, temperature and time. Chemical and electrochemical results are in agreement that the cimetidine is a viable corrosion inhibitor. Cimetidine was revealed as mixed-type inhibitor because it controlled both cathodic and anodic reactions.
Originality/value
Empirical and optimization studies of cimetidine drug as corrosion inhibitor of aluminium in hydrochloric acid medium were carried out. The research results can provide the basis for deploying drugs (with mucosal protective and antacid properties) for corrosion control of metallic structures.
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Aida Zaabar, Razika Aitout, Laid Makhloufi, Kamel Belhamel and Boualem Saidani
– 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.
Abstract
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.
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Pawin Wongkhamprai and Manthana Jariyaboon
The aim of this work was to investigate how Andrographis paniculata (Burm.f.) Wall.ex Nees extract affected the corrosion of low-carbon (C) steel in 0.1M HCl.
Abstract
Purpose
The aim of this work was to investigate how Andrographis paniculata (Burm.f.) Wall.ex Nees extract affected the corrosion of low-carbon (C) steel in 0.1M HCl.
Design/methodology/approach
The Andrographis paniculata (Burm.f.) Wall.ex Nees was extracted into distilled water at 70°C for 1 h. The corrosion inhibition efficiency of the extract was determined in 0.1M HCl using weight loss measurements, potentiodynamic polarization and electrochemical impedance spectroscopy. The effects of extract concentrations and of temperature were investigated.
Findings
The Andrographis paniculata (Burm.f.) Wall.ex Nees extract could inhibit the corrosion process of low-C steel in 0.1M HCl. With the extract concentration of 1 g/l, an inhibition efficiency of 96.3 per cent was obtained. The extract acted as an anodic inhibitor. The adsorption process of the extract was physisorption and it followed the Langmuir adsorption isotherm.
Originality/value
This paper revealed that Andrographis paniculata (Burm.f.) Wall.ex Nees cultivated in Thailand, which was extracted using a simple and environmentally friendly method, could act as a very good green corrosion inhibitor for low-C steel in 0.1M HCl solution.