Corrosion Inhibition Process Research Articles

Electrochemical Corrosion Inhibition Process, Adsorption Mechanism and Mechanical Effect of Newbouldia laevis Leaf Extract on Aluminum Alloy in Acidic Environment

Electrochemical Corrosion Inhibition Process, Adsorption Mechanism and Mechanical Effect of Newbouldia laevis Leaf Extract on Aluminum Alloy in Acidic Environment

Inhibitory Action of Methanol Leaf Extract of <i>Irvingia Gabonensis</i> on the Corrosion of Mild Steel in H<sub>2</sub>SO<sub>4</sub>

The corrosion inhibition efficiency of methanol leaf extracts of Irvingia gabonensis for mild steel in 0.4, 0.5, 0.6 and 2.5M H2SO4 was investigated using weight loss and gasometric techniques in other to determine the phytochemical components of the crude leaf extract, the corrosion inhibition potential of the leaf extract, the thermodynamic parameters that aided the corrosion inhibition, the adsorption isotherm of the corrosion inhibition of the extracts using the Langmuir and Freundlich models and investigate the kinetics of the corrosion inhibition process. Preliminary phytochemical screening revealed the presence of tannins, saponnins, flavonoids, terpenes and alkaloids. From the results, the corrosion rates decreased with increase in inhibitor concentration. The maximum inhibition efficiency of 58.71% was obtained at extract concentration of 0.6g/L in 0.4M H2SO4 at 303K, 41.83% at extract concentration of 0.6g/L at 303K in 0.5M H2SO4 and 57.33% at extract concentration of 0.6g/L in 0.6M H2SO4 at 303K, for the gravimetric technique. In 2.5M H2SO4, maximum inhibition efficiency for the gasometric technique was 53.53% in 0.6g/L inhibitor concentration at 303K and for the gravimetric technique, the maximum inhibition efficiency was 29.42% in 0.6g/L inhibitor concentration at 303K. The kinetic and thermodynamic studies showed that activation energy (Ea) in the presence of inhibitor is greater than in the absence of inhibitor. From the Ea and ∆Goads values obtained, a physical adsorption mechanism was proposed. The Langmuir isotherm was found to show better correlation (R2) at lower temperature while the Freundlich isotherm had better correlation at higher temperature.

The Synergistic Effect of Chloride Ion and 1,5-Diaminonaphthalene on the Corrosion Inhibition of Mild Steel in 0.5 M Sulfuric Acid: Experimental and Theoretical Insights.

The inhibition efficiency of 1,5-Diaminonaphthalene (1,5DNA) compound was studied by itself as well as in a mixture that included sodium chloride (NaCl), noted [1.5DNA][Cl−], for mild steel in 0.5 M sulfuric acid. Gravimetric, electrochemical techniques and computational chemistry calculations were utilized for the assessment of corrosion inhibition efficiency and explanation of the mechanism involved during the corrosion inhibition process. The results show that inhibition efficiencies on mild steel increase with increase in concentration of the inhibitor and enhancement in inhibition efficiency was observed on addition of sodium chloride due to synergism. This inhibition has been attributed to the stabilization of adsorbed inhibitor film and, consequently, increasing its inhibitive properties. The [1.5DNA][Cl−] acts as mixed type inhibitor and the Nyquist curves show that with the increase in the concentration, the charge transfer resistance Rct increased. In addition, [1.5DNA][Cl−] obeyed Langmuir monolayer adsorption isotherm. Moreover, Molecular Dynamic Simulations and DFT calculations showed that [1.5DNA][Cl−] owned a higher adsorption ability.

4-(2-(2-(2-(2-(Pyridine-4-yl)ethylthio)ethoxy)ethylthio)ethyl)pyridine as New Corrosion Inhibitor for Mild Steel in 1.0 M HCl Solution: Experimental and Theoretical Studies

The inhibition effect of 4-(2-(2-(2-(2-(pyridine-4-yl)ethylthio)ethoxy)ethylthio)ethyl)pyridine (P4E4P) on mild steel corrosion in 1.0 M HCl solution was investigated by quantum chemical calculations, electrochemical techniques, and weight loss measurements. The experimental results reveal that this compound has a good inhibiting effect and the inhibition efficiency, increased with the inhibitor concentration to reach 97% at 1 mM. The effect of temperature on the corrosion behavior of mild steel has been examined in the temperature range of 308–353 K. The inhibition efficiency increases with increasing inhibitor concentration, but decreases with increasing temperature. The adsorption of the inhibitor on mild steel surface obeyed the Langmuir adsorption isotherm. The kinetic and thermodynamic parameters for mild steel corrosion and inhibition adsorption, respectively, were determined and discussed. Potentiodynamic polarization suggested that it is a mixed type of inhibitor. Data obtained from EIS measurements were analyzed to model the corrosion inhibition process through the appropriate equivalent circuit model. Quantum chemical calculations were employed to study the electronic properties of P4E4P to ascertain the correlation between the inhibitory effect and the molecular structure. Both the experimental and theoretical results are in good agreement with each other in this regard and confirm that P4E4P is an effective inhibitor.

Interaction of water soluble polyacrylic acid with mild steel / hydrochloric acid interface

Many of the polymers such as polyanilines, polyanthranilic acids have been reported as one of the efficient corrosion inhibitors for mild steel in acidic media. In view of the major limitation of insolubility of polymers, we have taken water soluble polyacrylic acid for the corrosion inhibition process. The corrosion inhibition property of polyacrylic acid is demonstrated for mild steel in 0.5 M hydrochloric acid using electrochemical impedance spectroscopy, Tafel polarization and weight loss methods. All the results are found to be in well correlation and the inhibition efficiency shows upto 94% in 0.5 M hydrochloric acid for 3hrs duration. Surface studies are also done by scanning electron microscopy

Inhibition of Mild Steel Corrosion in Acidic Medium by Telfairia occidentalis Rind Extract

Telfairia occidentalis rind extract has been studied as a potential green inhibitor for mild steel corrosion in 1 M H2SO4 using weight loss and hydrogen evolution methods. The results of the investigation reveal that Telfairia occidentalis rind extract is a good inhibitor of mild steel corrosion in sulphuric acid solution. The inhibition efficiency increases with increase in rind extract concentration but decreases with increase in temperature. The calculated thermodynamic parameters reveal that the corrosion inhibition process was endothermic and spontaneous. Physical adsorption has been proposed for the adsorption of Telfairia occidentalis rind extract onto mild steel surface. The adsorption of the extract on mild steel surface obeys the Langmuir adsorption isotherm.

Experimental and Theoretical Investigation of Thiazolyl Blue as a Corrosion Inhibitor for Copper in Neutral Sodium Chloride Solution

The anticorrosion effect of thiazolyl blue (MTT) for copper in 3% NaCl at 298 K was researched by electrochemical methods, scanning electron-microscopy (SEM), and atomic force microscopy (AFM). The results reveal that MTT can protect copper efficiently, with a maximum efficiency of 95.7%. The corrosion inhibition mechanism was investigated by X-ray photoelectron spectroscopy (XPS), Fourier transform infrared spectral (FT-IR), and theoretical calculation. The results suggest that the MTT molecules are adsorbed on metal surface forming a hydrophobic protective film to prevent copper corrosion. It also indicates that the MTT and copper form covalent bonds. The molecular dynamic simulation further gives the evidence for adsorption. The adsorption isotherm studies demonstrate that a spontaneous, mixed physical and chemical adsorption occurs, which obeys Langmuir adsorption isotherm. The present research can help us better understand the corrosion inhibition process and improve it.

Glycolipid biosurfactant as an eco-friendly microbial inhibitor for the corrosion of carbon steel in vulnerable corrosive bacterial strains

In the present studies, glycolipid type of biosurfactant was used as a microbial inhibitor for corrosive bacterial strains (Bacillus subtilis A1, Streptomyces parvus B7, Pseudomonas stutzeri NA3 and Acinetobacter baumannii MN3). Biosurfactant was produced by using the bacterial strain, Pseudomonas mosselii F01 and characterized by using Fourier transform infrared spectroscopy and thin layer chromatography. Weight loss experiment and electrochemical analysis (Tafel polarization and AC-impedance) were used to confirm the corrosion reaction. X-ray diffractometer analysis was carried out to confirm the nature of the corrosion product formed during the corrosion reactions. Microdilution methods confirm that biosurfactant has higher antibacterial activity in the range of 1280–2560μg/mL in presence of those corrosive bacterial strains. Further, lower corrosion rate of carbon steel (0.0215mm/y) was recorded in presence of the mixed consortia included with biosurfactant as inhibitor/biocide compared to the mixed bacterial system (0.1653mm/y). The inhibition efficiency was found about 87% for mixed consortia included with biosurfactant system. The decreased level of corrosion current and potential was also recorded in the biosurfactant added system, similarly higher resistant capacity was found in the mixed consortia included with biosurfactant system. The XRD analysis supports other analysis that biosurfactant play a key role in the corrosion inhibition process in presence of the indigenous corrosive bacterial consortia. Anti-biofilm properties of the biosurfactant over the wide range of the bacterial strains make them as an efficient microbial corrosion inhibitor for the diverse environment.

Computational, Monte Carlo simulation and experimental studies of some arylazotriazoles (AATR) and their copper complexes in corrosion inhibition process

The inhibition properties of three synthesized 3-(-arylazo)-l, 2, 4-triazole (AATR) derivatives were investigated for copper corrosion in aerated 0.5M HNO3 acid using potentiodynamic polarization, cyclic voltammetry, and spectrophotometric measurements. DFT calculations and Monte Carlo simulation are applied to further explain the anti-corrosion mechanism. Quantum chemical indexes, are performed using DFT/B3LYP methods with SDD, 6-31++G (d,p) and 6-31 G basis sets in gas and aqueous phase. The inhibitors can be adsorbed onto surfaces by both physical and chemical means obeys Langmuir and that of El-Awady adsorption isotherm. Potentiodynamic polarization curves revealed that AATRs behave as mixed-type inhibitors. Both thermodynamic and kinetic: (Kads, ∆G°ads, A, 1/y, Ea, ∆H°a and ∆S°a) parameters were determined and discussed. The adsorption behaviour of the AATR derivatives on Cu (111) surface was investigated by Monte Carlo simulation in the presence of water to verify their corrosion inhibition efficacies. The results showed that AATRs were good inhibitors and the inhibition efficiency increased with increasing of their concentration but decreased with rising temperature. The high IE (%) is due primarily to the adsorption behaviour of both free ligand inhibitor, together with overlapping chelate [Cu (I) and Cu (II)-AATR] complex molecules in the ratio (1:1) and/or (1:2) depending on concentration. DFT calculations and Monte Carlo simulation indicate that the order of IE (%) is: AATR_3≅AATR_2>AATR_1. The theoretical results were found to be consistent with the experimental data reported.

Experimental and theoretical studies on corrosion inhibition performance of an environmentally friendly drug on the corrosion of copper in acid media

PurposeThe purpose of this paper is to study the corrosion inhibition performance of an eco-friendly drug clozapine on the corrosion of copper in 1.0 M nitric acid and 0.5 M sulfuric acid solutions.Design/methodology/approachThe corrosion inhibition nature of inhibitor molecule was evaluated by weight loss, electrochemical impedance spectroscopy and potentiodynamic polarization studies. An attempt was made to correlate the molecular properties of neutral and protonated forms of inhibitor molecule using quantum chemical calculations. The effect of temperature on the corrosion inhibition efficiency was also studied using electrochemical impedance spectroscopy. The potential of zero charge was determined to explain the mechanism of corrosion inhibition.FindingsThe studies on corrosion inhibition performance of clozapine showed that it has good corrosion inhibition efficiency on the corrosion of copper in 1.0 M nitric acid and 0.5 M sulfuric acid solutions. The adsorption of clozapine molecules onto the copper surface obeyed the Langmuir adsorption isotherm. The value of free energy of adsorption calculated is very close to −40 kJmol−1, indicating that the adsorption is through electrostatic coulombic attraction and chemisorption. The decrease in the value of energy of activation with the addition of inhibitor also shows the chemisorption of the inhibitor on the metal surface. The potential of zero charge and quantum chemical studies confirmed that the protonated molecules also get involved in the corrosion inhibition process through physisorption.Originality/valueThe present work indicates that clozapine can act as a good corrosion inhibitor for the corrosion of copper in acid media.

Rollinia occidentalis extract as green corrosion inhibitor for carbon steel in HCl solution

An extract of Rollinia occidentalis as well as pure solutions of two acetogenins isolated from this extract, namely Rolliniastatin-1 and Motrilin, were tested as corrosion inhibitors for carbon steel in acidic solutions. Weight loss measurements were performed in the 298–328K temperature range and the obtained data were used to calculate corrosion rate and inhibition efficiency. It was found that the extract and the acetogenins solutions act as good corrosion inhibitors for the tested C-steel in 1M HCl media. Moreover, results from potentiodynamic polarization measurements indicate that R. occidentalis and the two tested acetogenins act as mixed-type inhibitors. Data collected from EIS studies were modeled with an equivalent circuit containing a single time constant what can be understood in terms of a corrosion inhibition process resulting from the geometric blocking effect of the carbon steel surface by an adsorbed inhibitor species. Inhibitor adsorption follows a Langmuir adsorption isotherm. The inhibition efficiency decreases with increasing temperature and extract concentration. Spectroscopic analysis points to the formation of a complex between metal cations and compounds present in the R. occidentalis extract. This additional aspect is considered in the proposed inhibition mechanism of C-steel.

Ficus racemosaas corrosion inhibitor for mild steel in acid medium

Corrosion inhibitors significantly retard the rate of attack of a corrosive medium on a metal or an alloy when they are added in small concentrations. Their effect on human health and the environment is a very important criterion to be considered when dealing with corrosion inhibitors. Plants are non-toxic, environment-friendly and rich reserves of naturally occurring organic compounds which can aid the corrosion inhibition process. The inhibition effect of Ficus racemosa (FR) leaf extract on the corrosion of mild steel in 0·5 M sulfuric acid solution was investigated by potentiodynamic polarisation and electrochemical impedance spectroscopy. The inhibition efficiency increases with an increase in the concentration of the FR leaf extract, attaining the maximum value at the highest inhibitor concentration of 2500 parts per million. The effect of temperature on the corrosion behaviour of mild steel in 0·5 M sulfuric acid with and without addition of leaf extract was studied in the temperature range of 298–328 K. A decrease in inhibition efficiency was observed with the rise in temperature. Potentiodynamic polarisation data revealed a mixed mode of inhibition. The adsorption process was found to be consistent with Langmuir adsorption isotherm.

Evaluation of pawpaw leaves extract as anti-corrosion agent for aluminium in hydrochloric acid medium

Pawpaw leaves extract was examined as anti-corrosion agent for aluminium in hydrochloric acid medium. The extract and corrosion product were analyzed using Fourier transform infrared spectrophotometer (FTIR). Thermometric, gravimetric, potentiodynamic polarization and scanning electron microscopic methods were employed in the study. The inhibition efficiency was optimized using Response Surface Methodology (RSM) of Design Expert Software 9. Inhibitor concentration (0.2 g/l – 1.0 g/l), temperature (303 K – 333 K) and time (1hour - 5 hours) were the considered factors. It was revealed that stretched C-H and O-H functional groups were predominantly responsible for the corrosion inhibition process. The adsorption of the extract on the aluminium surface adhered to the mechanism of physical adsorption. A quadratic model adequately described the inhibition process. Optimum inhibition efficiency of 80.58% was obtained at inhibitor concentration of 0.961 g/l, temperature of 311.459 K and time of 3.932 hrs. The extract is a mixed-type inhibitor that can control both cathodic and anodic corrosion. http://dx.doi.org/10.4314/njt.v36i2.241

Synthesis and characterisation of composite nanoparticles of mesoporous silica loaded with inhibitor for corrosion protection of Cu-Zn alloy

A new type of composite nanoparticles (CNPs) was prepared by loading a typical inhibitor 1-hydroxybenzotriazole (HOBT) for corrosion protection of copper alloy in mesoporous silica nano-containers. The release kinetics of HOBT from CNPs in 3.5% NaCl solution was in conformity with the first order kinetic model. The open circuit potential monitoring, the morphology observation and the scanning Kelvin probe measurement of the Cu-Zn alloy in 3.5% NaCl solution with CNPs proved that a uniformly protective film was formed on the surface. Electrochemical impedance spectroscopy was employed to analyse the corrosion inhibition process of CNPs on the Cu-Zn alloy.

Chemical and Electrochemical Studies on the Areca Fat as a Novel and Sustainable Corrosion Inhibitor for Industrially Important Materials in Hostile Fluid Environments

In the present study, the influence of the constituents of Areca fat as a sustainable green corrosion inhibitor for copper and mild steel, metals in both hydrochloric acid and sodium hydroxide solutions was evaluated with the aid of weight loss and Tafel plot techniques. Results of gravimetric (weight loss) study depicted that the protection efficiency enhanced with increment in the concentration of Areca fat in test solutions. Inhibitive modality of Areca fat is acknowledged due to adsorption of their organic moieties on metal surfaces, which effectively boost the corrosion-resisting nature of study metals in both acid and base systems. Solution temperature and immersion periods are an important parameter in the studies of dissolution of metals. The effect of test solution temperature and contact time on protection efficiency of inhibitor was also thoroughly assessed. Thermodynamic (K ads, and $$\Delta G_{\text{ads}}^{{^\circ }}$$ ) and kinetic ( $$E_{\text{a}}^{ *}$$ , $$\Delta H^{*}$$ and $$\Delta S^{*}$$ ) parameters for adsorption process were evaluated and discussed, which provided further insight into the corrosion protection efficiencies determined experimentally. Functional groups accountable for corrosion inhibition process were identified via Fourier transform infrared spectroscopy technique. The probable inhibitory mechanism was further corroborated by results obtained from polarization (Tafel plots) studies, which confirms the blockage of electrode surfaces by Areca fat constituents via adsorption mechanism. Scanning electron microscopy (SEM) technique was applied to confirm the protective role of Areca fat on mild steel and copper metal surfaces. The chemical and electrochemical (Tafel plot) results were also being supplemented by SEM studies.

Phase transfer synthesis of novel based surfactants: Role of biocorrosion inhibition and corrosion of steel

Four novel aziridinium, pyrrolium and azepanium bis-quaternary ammonium salts joined within similarly aromatic spacer have been synthesized. The phase transfer synthesized cycloadduct as a selective and startreaction material is a positive indicator for the corrosion inhibition process. The structures of the desired heterocyclic surfactants were confirmed by using elemental analysis, FT-IR and 1H NMR spectral analysis. The adsorption of these compounds on the metal surface is found to obey Tafel adsorption isotherm. Furtheron, the dilution method need to be included to evaluate their biocorrosion inhibition. This study explores the corrosion resistance of the prepared bisquats in 1 M HCl and SRB corroded medium. The growth of the reference SRB (Desulfomonas pigra) was shown to be completely inhibited by bisquaternary ammonium surfactants, In1- In3, and also the inhibition efficiency was found to increase with increasing inhibitor concentration and decreased with increasing surface tension which is due to the fact, that the rate of corrosion of carbon steel is higher than the rate of adsorption and therefore indicates that the joint adsorption of these compounds and chloride ions by the addition of HCl is due to the increase of the surface coverage. On the other hand, opposite cases were found where the presence of certain cations decreased the protective effect, for example, towards the corrosion of In4. Additionally, the thermodynamic parameters for adsorption and activation processes were determined; the following formulation properties are considered: the surface tension at cmc (γcmc), critical micelle concentration (cmc) of the surfactants in aqueous solutions, saturated adsorption amount of the surfactant (Г∞) and the minimum average area per surfactant molecule (Amin) at the air–water interface. On the bases of the result of small saturated adsorption amount and the large minimum average area per surfactant molecule, it is indicated that the minimum average area of surfactant decreases with the enhanced hydrophilic character of the molecule. A direct relationship has found between the corrosion efficacy (% IE) and Г∞. The galvanostatic polarization curves showed that, the inhibitor behaves as mixed type. The observed corrosion data indicate that, the inhibition of carbon steel corrosion is due to the adsorption of the inhibitor molecules on the surface, which follow Langmuir adsorption isotherm. By fitting the obtained experimental data with Langmuir adsorption model, some thermodynamic and kinetic parameters such as adsorption free energy, Gads, equilibrium constant, Kads, were estimated.

Corrosion Control of Cu-10Al-10Ni and Cu-10Al-10Zn Alloys in Seawater Environment by Some Ethoxylated Tolyltriazole Derivatives

Abstract Protection of metals from being damaged under the effect of corrosion occurs by several methods like the addition of alloying elements or inhibitors. A new family of some nonionic surfactants based on tolyltriazole derivatives (TTAs) having various ethoxyl chain lengths were prepared and their chemical structure was elucidated by using different spectroscopic techniques (FTIR and 1H-NMR). The corrosion inhibition capability of these surfactants [TTA, TTA (12) and TTA (24)] was investigated on two Cu-ternary alloy surfaces (Cu-10Al-10Ni and Cu-10Al-10Zn) in seawater by potentiodynamic polarization and electrochemical impedance spectroscopy measurements. The results revealed that ethoxylated tolyltriazole compounds, TTAs, inhibited corrosion of Cu-ternary alloys in the investigated sea water environment, yielding maximum inhibition efficiencies of 92% and 91% for Cu-10Al-10Ni and Cu-10Al-10Zn, respectively. The corrosion and corrosion inhibition behavior of the Cu alloy specimens were influenced by the metal composition and microstructure. The presence of inhibitors and increase of concentration greatly decreases corrosion rate, parameters determined from polarization curves and EIS plots show that inhibitors decrease both cathodic and anodic current densities, suppressing charge transfer processes by adsorption on alloy surface. The corrosion inhibition process is based on the adsorption of the TTAs molecules on the alloy surface, and the adsorption follows the Langmuir adsorption isotherm. The free energy of adsorption of the different tolyltriazole derivatives on the alloy surfaces was in the range of ≈−38 kJ mol−1, which reveals a strong physical adsorption of the inhibitor molecules on the metallic surface. SEM/EDX studies confirmed that TTA inhibitors could protect Cu alloys by adsorption on the alloy surface.

Effect of clozapine on inhibition of mild steel corrosion in 1.0 M HCl medium

In this work, an eco-friendly antipsychotic, namely clozapine (CZP) was used to investigate the mild steel (MS) corrosion inhibition process in 1M HCl, using weight loss (WL) measurements, potentiodynamic polarization (PDP), electrochemical impedance spectroscopy (EIS). The performance of the CZP on the corrosion inhibition of MS was also evidenced by scanning electron microscopy (SEM). Results show that the CZP is a good inhibitor and inhibition efficiency (IE%) reach 96% at an optimum concentration of 10−3M. Potentiodynamic polarization curves showed that the CZP affects both cathodic and anodic current and may be classified as mixed type inhibitor in HCl medium. In addition, the IE% increased with a rise in CZP concentration. While the adsorption of tested compound on MS surface was found to follow the Langmuir isotherm. Furthermore, the molecular dynamic (MD) simulations, radial distribution function (RDF) and quantum chemical parameters have been calculated and discussed in view of the results earlier reported.

Experimental evaluation of quinolinium and isoquinolinium derivatives as corrosion inhibitors of mild steel in 0.5 M H2SO4 solution

The 1-methylquinolinium iodide (I) Qui+, I– and 2-methylisoquinolinium iodide isoQui+, I– were investigated as a corrosion inhibitors for mild steel in sulfuric acid using electrochemical impedance spectroscopy and potentiodynamic polarization techniques. The results indicated that the corrosion inhibition efficiency and extent of surface coverage were increased with increase in inhibitors concentrations. Polarization curves revealed that both inhibitors acted as a mixed-type inhibitor. The thermodynamic parameters were evaluated for corrosion inhibition process. The adsorption of both inhibitors on mild steel surface obeyed Langmuir adsorption isotherm.

Computational study of some triazole derivatives (un- and protonated forms) and their copper complexes in corrosion inhibition process

Three triazoles compounds used as corrosion inhibitors for copper in acidic medium, namely: 1,2,4 triazole (TR), 3-amino 1,2,4 triazole (3 ATR) and 3,5-diamino 1,2,4 triazole (3,5 DATR) have been studied theoretically in aim to investigate the correlation between its molecular reactivity indicators and the corresponding inhibition efficiency. All quantum chemical calculations at the B3LYP/6-31+G(d,p) method were performed with and without solvent effect. In the present paper, not only the neutral inhibitors has been studied, but also the first and the second protonation forms. A good correlation between theoretical and experimental data has been obtained both in gas and aqueous phases, notably for unprotonated inhibitors. Also, the interaction energy between inhibitors and copper has been calculated.