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Article
Publication date: 16 January 2007

E.E. Oguzie, G.N. Onuoha and E.N. Ejike

This paper aims to appraise the effectiveness of Gongronema latifolium extract as an environmentally friendly corrosion inhibitor for aluminium in strong acid (2 M HCl) and…

345

Abstract

Purpose

This paper aims to appraise the effectiveness of Gongronema latifolium extract as an environmentally friendly corrosion inhibitor for aluminium in strong acid (2 M HCl) and alkaline (2 M KOH) environments.

Design/methodology/approach

Corrosion rates were determined using the gas‐volumetric technique. The efficiency of inhibition was estimated by comparing corrosion rates in absence and presence of the additive, while the mechanism of inhibition was assessed by considering temperature effects on corrosion and inhibition processes.

Findings

The results show that the extract was well adsorbed on the metal surface and significantly repressed aluminium corrosion in both environments. Inhibition efficiency generally increased with concentration up to maximum values of 97.54 and 90.82 per cent in 2 M HCl and 2 M KOH, respectively. Temperature dependence studies revealed that the extract was chemically adsorbed on the aluminium surface at all concentrations in 2 M HCl and physically adsorbed in 2 M KOH, with likely tendency to become chemisorbed at higher concentration.

Originality/value

Gongronema latifolium has been studied for the first time as an inhibitor of aluminium corrosion and the results suggest that the extract could find practical application in corrosion control in aqueous acidic and alkaline environments. The findings are particularly useful, considering the scarcity of reports on the effective inhibition of aluminium corrosion in strong alkaline solutions.

Details

Pigment & Resin Technology, vol. 36 no. 1
Type: Research Article
ISSN: 0369-9420

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Article
Publication date: 17 August 2018

Alexander I. Ikeuba and Peter C. Okafor

This paper aims to appraise the inhibitory effect of saponins extracted from Gongronema latifolium (SEGL) on mild steel in acid media. This is in a bid to conserve our environment…

231

Abstract

Purpose

This paper aims to appraise the inhibitory effect of saponins extracted from Gongronema latifolium (SEGL) on mild steel in acid media. This is in a bid to conserve our environment and maintain the integrity of engineering structures and materials.

Design/methodology/approach

The corrosion inhibition of SEGL and ethanolic extracts of the leaves of G. latifolium (EEGL) on mild steel was studied by hydrogen evolution technique within a temperature range of 30-60°C in tetraoxosulphate (VI) acid solutions.

Findings

The extracts inhibit the corrosion of mild steel, and the inhibition efficiency depends on the concentration of the plant extract, temperature and the period of immersion. SEGL was comparatively more efficient than EEGL. Optimum values of the inhibition efficiency for both the EEGL and SEGL (93.7 and 96.5 per cent, respectively) were obtained at extract concentration of 10 g/L, whereas the least values were obtained at extract concentration of 0.5 g/L.

Originality/value

This paper provides new information on the possible application of isolated SEGL as an environmentally friendly corrosion inhibitor. The possible mechanism of the inhibitive action is also given.

Details

Pigment & Resin Technology, vol. 48 no. 1
Type: Research Article
ISSN: 0369-9420

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Article
Publication date: 3 November 2014

I.O. Arukalam

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…

123

Abstract

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.

Details

Pigment & Resin Technology, vol. 43 no. 6
Type: Research Article
ISSN: 0369-9420

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Article
Publication date: 25 May 2018

Khaoula Nasr, Michele Fedel, Khaled Essalah, Flavio Deflorian and Nebil Souissi

This study aims to investigate the inhibition performance of an aqueous extract of Matricaria recutita chamomile on the corrosion of S235JR steel in 0.5 M NaCl by using…

180

Abstract

Purpose

This study aims to investigate the inhibition performance of an aqueous extract of Matricaria recutita chamomile on the corrosion of S235JR steel in 0.5 M NaCl by using electrochemical impedance spectroscopy (EIS) and polarization measurements.

Design/methodology/approach

The inhibition performance was investigated using EIS and polarization measurements. Surface analysis demonstrates the presence of a protective layer on the steel surface in the presence of the extract. Quantum chemical parameters calculated for the molecules contained in the aqueous extract are interpreted to predict the corrosion inhibition efficiency of the considered extract.

Findings

The inhibition efficiency of chamomile aqueous extract for S235JR steel increases with increasing amounts of plant concentration and with an increase in the immersion time. The optimal inhibition efficiency of chamomile extract, 98.90 per cent, was achieved for S235JR steel when immersed in 15 per cent v/v of extract concentration for 2 h. The surface analysis in the absence and presence of the chamomile extract confirmed the formation of a protective layer on steel surface. The quantum chemical calculations allowed to explain the great inhibition efficiency values by interpreting the calculated quantum parameters.

Originality/value

This is the first study carrying out an experimental and theoretical investigation on M. recutita chamomile as a green corrosion inhibitor, with interesting potential industrial applications.

Details

Anti-Corrosion Methods and Materials, vol. 65 no. 3
Type: Research Article
ISSN: 0003-5599

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Article
Publication date: 3 November 2014

P.C. Okafor and E.A. Apebende

This paper aims to evaluate the inhibitive action of the corrosion of mild steel in sulphuric acid solutions by ethanol extracts of Thymus vulgaris (TYV), Xylopia aethiopica (XYA…

182

Abstract

Purpose

This paper aims to evaluate the inhibitive action of the corrosion of mild steel in sulphuric acid solutions by ethanol extracts of Thymus vulgaris (TYV), Xylopia aethiopica (XYA) and Zingiber officinale (ZGO) as eco-friendly and non-toxic mild-steel corrosion inhibitors in H2SO4 solutions.

Design/methodology/approach

Ethanol extracts of TYV leaves, XYA fruits and ZGO roots were used as inhibitors in various corrosion tests. Gravimetric and gasometric techniques were used to characterize the mechanism of inhibition.

Findings

Results indicate that the extracts inhibit the corrosion process efficiently. Inhibition efficiency was found to increase with an increase in extract concentration and decrease with an increase in temperature. Inhibition efficiencies followed the trend TYV > ZGO > XYA. Thermodynamic considerations revealed that the energy of activation increased in the presence of the plant extracts. Adsorption of the plant extracts on mild steel surface occurred spontaneously, and Ea and ΔGads values confirm a physical adsorption processes. Phytochemical studies showed the presence of saponoids, flavonoids and polyphenols whose attachment to adsorption sites on the metal surface is responsible for the inhibition process. Experimental data fit the Langmuir adsorption isotherm.

Practical implications

The plant extracts can be used in chemical cleaning and picking processes.

Originality/value

The research provides information on the possible use of the ethanol extracts from TYV leaves, XYA fruits and ZGO roots as sources of cheap, eco-friendly and non-toxic corrosion inhibitors.

Details

Pigment & Resin Technology, vol. 43 no. 6
Type: Research Article
ISSN: 0369-9420

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Article
Publication date: 7 March 2016

Divya Ladha, Nisha Shah, Suresh Thakur, Mohsin Lone and Prakash Jha

– The purpose of this paper is to investigate the inhibitive properties of black pepper extract (BPE) for aluminium in 1M hydrochloric acid (HCl) medium.

277

Abstract

Purpose

The purpose of this paper is to investigate the inhibitive properties of black pepper extract (BPE) for aluminium in 1M hydrochloric acid (HCl) medium.

Design/methodology/approach

Gravimetric, electrochemical impedance spectroscopy, galvanostatic polarization, scanning electron microscopy with energy dispersive X-ray examinations (SEM-EDX) techniques were used to study the corrosion inhibitive study.

Findings

The gravimetric measurement indicates that inhibition efficiency shows direct proportional relation with concentration of inhibitor. The impedance results illustrates that there was a presence of protective layer of inhibitor adsorbed on the metal/solution interface. Polarization outcome showed that BPE is mixed type inhibitor. The existence of adherent layer of inhibitor on the Al surface was confirmed by SEM-EDX. Quantum chemical calculations were performed using the density functional theory at B3LYP/6-31G(d) level of theory to evaluate the activity of inhibitor molecules present in extract towards the corrosion inhibition of Al.

Research limitations/implications

Due to the presence of large number of compounds in the extract, it becomes difficult to understand the most active compound responsible for inhibition. However, from gas chromatography mass spectrometry and quantum data, the approximation has been made that the major compound piperine present in the extract can be most probable component responsible for the inhibition activity. Further calculation of binding energy between Al and inhibitor molecules can be performed using Material Studio software.

Practical implications

The extract can be used in cleaning and etching solutions. It can be used to limit the loss of Al metal during etching process.

Originality/value

BPE can be used as a potential source of eco-friendly corrosion inhibitor for Al in HCl medium.

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Article
Publication date: 2 January 2018

Aisha H. Al-Moubaraki

This paper aims to evaluate the inhibitive potential of borage flowers’ aqueous extract (BFAE), Borago officinalis L., against the corrosion of mild steel in 1.0 M phosphoric acid.

131

Abstract

Purpose

This paper aims to evaluate the inhibitive potential of borage flowers’ aqueous extract (BFAE), Borago officinalis L., against the corrosion of mild steel in 1.0 M phosphoric acid.

Design/methodology/approach

Evaluation was carried out by chemical hydrogen evolution (HE), mass loss (ML) and electrochemical potentiodynamic polarization (PDP) measurements. SEM-EDX analysis also was used to confirm the existence of the adsorbed film.

Findings

It was found that the inhibition efficiency of BFAE increases with the increase in its concentration, but decreases with the increase in temperature. The potentiodynamic polarization curves indicated that BFAE acts as a mixed-type inhibitor with a predominantly anodic action. The adsorption of BFAE on mild steel surface was found to obey Langmuir and thermodynamic-kinetic adsorption isotherms by forming a thin film on the metal surface. SEM-EDX analysis confirms the corrosion inhibition ability of BFEA in 1.0 M H3PO4 by forming a thin film on mild steel surface. In this study, the inhibitive action of BFAE components is discussed on the basis of the physical adsorption mechanism. The same results were obtained for both the freshly prepared extract and the one that kept in a refrigerator for one year.

Originality/value

This paper indicates that BFAE can act as a good inhibitor for the corrosion of mild steel in 1.0 M H3PO4 even after one year of preparation.

Details

Anti-Corrosion Methods and Materials, vol. 65 no. 1
Type: Research Article
ISSN: 0003-5599

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Article
Publication date: 23 March 2010

N.O. Eddy and E.E. Ebenso

The purpose of this paper is to study the inhibitive and adsorptive characteristics of ethanol extract of Gongronema latifolium (GL) as a corrosion inhibitor for mild steel in H2SO…

340

Abstract

Purpose

The purpose of this paper is to study the inhibitive and adsorptive characteristics of ethanol extract of Gongronema latifolium (GL) as a corrosion inhibitor for mild steel in H2SO4.

Design/methodology/approach

The inhibition efficiencies were evaluated using thermometric and hydrogen evolution techniques.

Findings

The inhibition efficiency of ethanol extract of GL vary with concentration of the extract, period of immersion and with temperature. The extract acts as an inhibitor because of its phytochemical and amino acid composition. The extract is adsorbed spontaneously on the surface of mild steel according to Langmuir adsorption isotherm. The mechanism of physical adsorption is proposed from the trend of the inhibition efficiency with temperature and the values of some kinetic and thermodynamic parameters obtained.

Research limitations/implications

The study provides information on the use of ethanol extract of GL as a corrosion inhibitor. Electrochemical studies such as polarisation and alternating current impedance spectra will throw more light on the mechanistic aspects of the corrosion inhibition.

Practical implications

Ethanol extract of GL can be used as an environmentally friendly inhibitor for the corrosion of mild steel in H2SO4.

Originality/value

This environmentally friendly inhibitor could find possible applications in metal surface anodising and surface coatings.

Details

Pigment & Resin Technology, vol. 39 no. 2
Type: Research Article
ISSN: 0369-9420

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Article
Publication date: 17 April 2023

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.

67

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.

Details

Pigment & Resin Technology, vol. 53 no. 6
Type: Research Article
ISSN: 0369-9420

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Article
Publication date: 7 May 2020

Chinyere Elizabeth Agiriga, Emeka Oguzie, Arinzechukwu Chidiebere, Nnaemeka John Okorocha and Reginald Ndubuisi Chikwe

This paper aims to investigate the corrosion inhibition efficiency of Landolphia heudelotii (LH) on mild steel in 1 M HCl and 0.5 M H2SO4 using weight loss and potentiodynamic…

96

Abstract

Purpose

This paper aims to investigate the corrosion inhibition efficiency of Landolphia heudelotii (LH) on mild steel in 1 M HCl and 0.5 M H2SO4 using weight loss and potentiodynamic polarization techniques.

Design/methodology/approach

Water extract of LH was used as corrosion inhibitor on mild steel in acidic media at room temperature and elevated temperatures (30-60°C). Various concentrations of the plant extract were prepared from the stock solution obtained after solvent extraction. The inhibition efficiency of LH extract was evaluated and mechanism of adsorption was deduced.

Findings

LH extract showed significant corrosion inhibition on mild steel in both acidic media, with inhibition efficiency increasing with extract concentration. Potentiodynamic polarization measurements revealed mixed inhibition mechanism. Optimum inhibition efficiency was recorded at 2500 mg/L after 288 h. Mechanism of adsorption was mainly of physisorption. The inhibitor exhibited good inhibition efficiency even at elevated temperature.

Research limitations/implications

This study provides new data on the anticorrosion characteristics of LH extract under the specified conditions. Further studies could expand the experimental variables and use advanced surface probe techniques.

Practical implications

The developed inhibitor provides an alternative method of inhibiting corrosion on mild steel using eco-friendly materials from natural products which are less toxic, safer, cost-effective and readily available.

Originality/value

The method used was effective and the inhibitor developed can be incorporated in surface coatings where mild steel is used as construction materials, as tube sheets, rods and bars.

Details

Pigment & Resin Technology, vol. 49 no. 5
Type: Research Article
ISSN: 0369-9420

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