Mild Steel In HCl Solution Research Articles

Chemical, electrochemical and theoretical studies of 3-methyl-5,5′-diphenylimidazolidine-2,4-dione as corrosion inhibitor for mild steel in HCl solution

Abstract Imidazolidine-2,4-dione as derivative namely 3-methyl-5,5′-diphenylimidazolidine-2,4-dione (MPIM) used as a corrosion inhibitor for mild (MS) steel in 1 M HCl solution using gravimetric, electrochemical, scanning electron microscopy (SEM) and theoretical calculations. EIS measurements on carbon steel surface samples with and without inhibitor confirmed the inhibiting action of the studied compounds and the results showed increases in inhibition efficiency with the increase in concentration. It gives a maximum inhibition efficiency of 89% at 10−3 M and inhibits corrosion by adsorbing at the carbon steel surface. Polarization (PDP) studies suggest that MPIM behave as mixed inhibitor. The adsorption of MPIM on the surface of the mild steel obeyed the Langmuir isotherm and the value of the standard Gibbs free energy of adsorption ( Δ G a d s ∘ ) is associated with chemisorption mechanism. The surface morphology has been studied using SEM coupled with EDX. In addition, the theoretical results are well consistent with the experimental results.

New N-Heterocyclic Compounds Based on 8-Hydroxyquinoline as Efficient Corrosion Inhibition for Mild Steel in HCl Solution: Experimental and Theoretical Assessments

Both new benzimidazole derivatives based on 8-hydroxyquinoline, namely 4-(1-((4-hydroxynaphthalen-1-yl)methyl)-5-methyl-1H-benzo[d]imidazol-2-yl)benzoic acid (QN1) and 4-(1-((4-hydroxynaphthalen-1-yl)methyl)-1H-benzo[d]imidazol-2-yl)benzoic acid (QN2), were synthesized and characterized, and their corrosion inhibition behavior as well as the mechanism of inhibition was investigated by different techniques. Structural characterization includes NMR, IR and elemental analysis. The anticorrosive activity of these compounds was evaluated by the potentiodynamic polarization and impedance spectroscopy. Experimental data show that the QN1 and QN2 are effective against corrosion of steel in 1.0 M HCl and that the inhibitory efficiency reached at an optimum value of 97.7% for the QN1 compound at 1 mm. Polarization Tafel curves show that QN11 and QN2 act as a mixed type of inhibitors. After evaluating the anticorrosive activity of these two compounds, we used the surface techniques, namely SEM coupled with EDS and the gravimetric solutions were analyzed by UV–visible spectrometry. Quantum mechanical investigations density functional theory calculations and the Monte Carlo simulation on corrosion behavior of QN1 and QN2 compounds were also conducted, and satisfying correlation was noticed between the results of corrosion measurement methods and quantum mechanical evaluations.

Polar group substituted imidazolium zwitterions as eco-friendly corrosion inhibitors for mild steel in acid solution

Two polar group substituted imidazolium zwitterions have been synthesized and investigated as corrosion inhibitors for the first time on mild steel in HCl solution using chemical and electrochemical methods. Sulphur containing zwitterion (Z-2) gave excellent inhibition efficiency of 94.59% at a concentration of 6.01 μmol L−1 (2 ppm), while hydroxyl-containing zwitterion (Z-1) exhibited 94.86% IE at 150.4 μmol L−1 (50 ppm). Surface analyses supported the formation of inhibitor film on the metallic surface. Adsorption of zwitterions obeyed Langmuir adsorption isotherm. Quantum chemical (QC) calculation and molecular dynamics simulations studies further supported the experimental results.

Potential role of a novel green eco-friendly inhibitor in corrosion inhibition of mild steel in HCl solution: Detailed macro/micro-scale experimental and computational explorations

Ziziphora leaves extract was utilized as a new eco-friendly green inhibitor for acidic-induced corrosion of mild steel (MS). The inhibition activity of various phytochemicals present in the Ziziphora leaves aqueous extract, e.g., acacetin, chrysin, and thymonin were probed by electrochemical examinations. The influence of Ziziphora leaves extract on HCl aggressiveness reduction was inspected via several surface experiments. Moreover, the structure of extract phytochemicals was characterized by Fourier transform infrared spectroscopy (FT-IR) spectroscopy and ultraviolet–visible (UV–Vis) spectroscopy. The electrochemical impedance spectroscopy (EIS) analysis evidences that by increasing the concentration of Ziziphora leaves extract (up to 800 ppm) the inhibition performance raises to 93% (after 2.5 h). The polarization curves reveals that through mixed inhibition control the corrosion of steel was retarded by Ziziphora leaves extract. The surface studies ensure the Ziziphora leaves extract effectiveness in MS surface damage/roughness reduction. Also, the Ziziphora leaves extract molecules adsorption on the steel surface occurs according to the Langmuir isotherm model. Alongside experimental explorations, theoretical tools including classical simulations (molecular dynamics, MD connected with Mote Carlo, MC) and quantum chemical computations (density functional theory, DFT) were chosen for obtaining basic electronic/atomic-scale details about the extract compounds adsorption on target metal and their active sites. The results of molecular simulations the adsorption tendency of green extract molecules on the steel, which supports the experimental outcomes.

Adsorption and corrosion inhibition performance of some environmental friendly organic inhibitors for mild steel in HCl solution via experimental and theoretical study

In this study, two organic compounds were synthesized: N-[(2E)-3-phenylprop-2-en-1-yl]aniline (PPA-1) and 4-{[(2E)-3-phenylprop-2-en-1-yl]amino}phenol (PPAP-2). Their structures were confirmed by DRIFT, 1H and 13C NMR spectroscopy analyses. The two organic molecules were inspected as corrosion inhibitors of mild steel in HCl medium. The experimental studies such as electrochemical impedance spectroscopy, potentiodynamic polarization and surface analysis were conducted in order to prove the corrosion inhibition of these molecules and to confirm the presence of the organic film on the mild steel surface. Furthermore, theoretical studies by density functional theory and molecular dynamic simulation were used to corroborate the electrochemical results and to establish the adsorption mechanism and the orientation of the two organic molecules at the interface mild steel-aggressive solution. Langmuir adsorption isotherm model was used to explain the adsorption of the two molecules in HCl solution. Mulliken charges, Fukui functions, proton affinity and gas-phase basicity indicate that the nitrogen and oxygen heteroatoms are the most basic active site. Molecular dynamics simulation showed that the two inhibitors were adsorbed almost parallel on the Fe (110) surface attesting the high inhibition performances.

Inhibition effect of 4,4′-thio bis{N-[(E)-phenol-3-ylmethylidene]aniline} on the corrosion of mild steel in HCl solution under stagnant condition and hydrodynamic flow

The inhibition effect of a new Schiff base, namely, 4,4′-thio bis{N-[E-phenol-3-ylmethylidene]aniline}(SB), on the corrosion of mild steel (MS) in a 1M HCl solution was investigated under both hydrodynamic flow and a stagnant environment at different temperatures and concentrations. To assess the inhibition effect, different characterization techniques have been used including the measurement of weight loss, potentiodynamic polarization, and electrochemical impedance spectroscopy (EIS). It was found that the inhibition efficiency increases with the increase of the inhibitor concentration and decreases when the temperature increases. The adsorption of the inhibitor on the surface of MS obeys the Langmuir isotherm. The surfaces of MS, after being exposed to test solutions, were examined by atomic force microscopy (AFM).

Electrochemical and Theoretical Studies of 2-Acetyl Pyridine and Acetophenone Derivatives as Corrosion Inhibitors for Mild Steel in HCl Solution

2-Acetyl pyridine nicotinic hydrazone and acetophenone nicotinic hydrazone have prepared and their corrosion inhibition properties for mild steel in 1 M HCl were studied using weight loss, electrochemical and density functional theory (DFT) methods. Both inhibitors showed good inhibition ability and their adsorption on mild obeyed Langmuir adsorption isotherm. Polarization measurements show that they can be classified as inhibitors of mixed type. The inhibition efficiencies of 2-acetyl pyridine nicotinic hydrazone and acetophenone nicotinic hydrazone at 2 mM optimum concentration are 96.5% and 87.7% respectively.

Physisorption and corrosion inhibition of mild steel in 1 M HCl using a new pyrazolic compound: Experimental data & quantum chemical calculations

The adsorption and corrosion inhibition of mild steel in 1 M HCl solution by 1,5-dimethyl-1H-pyrazolo[3,4-d]pyrimidin-4(5H)-one were investigated by the electrochemical measurements. This organic compound has been found to have a high inhibitory efficiency against corrosion of mild steel in HCl solution. This compound is classified as a mixed type corrosion inhibitor. Corrosion rate at high temperature and some thermodynamic parameters were studied and calculated. The studied inhibitor is adsorbed on the metal surface according to the model of the Langmuir adsorption isotherm. Finally, we conclude our study by the correlation between the inhibitory efficiency of and its electronic structural parameters. For this reason, quantum chemistry is called.

Inhibition effect of ethanolic extract of Ipomoea batatas peel on the corrosion of Mild steel in hydrochloric acid medium

The corrosion inhibition of mild steel in HCl solution in the presence of Ipomoea batatas peel extract (IBPE) at a temperature range of 30°C to 60°C was studied using the chemical weight loss method. The IBPE acts as an inhibitor in the acid environment. The inhibition efficiency (IE) increases with increase in inhibitor concentration but decreases with an increase in temperature and concentration of acid. 93.96%, 89.99% and 85.61% IE were obtained at 6.67 g/L extract in 0.5, 1.5 and 2.5M acid media respectively at temperature of 30°C. 84.86%, 83.99% and 81.13% IE were obtained at 6.67 g/L extract in 0.5, 1.5 and 2.5M acid media respectively at temperature of 40°C. Also 78.92%, 76.21% and 75.73% IE were obtained at 6.67 g/L extract in 0.5, 1.5 and 2.5M acid media respectively at temperature of 50°C, while 71.45%, 69.87% and 66.00% IE were obtained at 6.67g/L extract in 0.5, 1.5 and 2.5M acid media respectively at temperature of 60°C. The inhibitive effect of the IBPE could be attributed to the presence of some compound in the peel which is adsorbed on the surface of the mild steel. The peel extract was found to conform to the Langmuir adsorption isotherm and Freundlich adsorption isotherm at all the concentration levels and temperature studied.

Green production of bioactive components from herbal origins through one-pot oxidation/polymerization reactions and application as a corrosion inhibitor for mild steel in HCl solution

Abstract Biopolymers such as polydopamine and polyserotonin are effective corrosion inhibitors for the acidic-induced corrosion of steel. Despite the excellent corrosion inhibition activity of these compounds, they are not cost-effective and readily available in a large scale. In this study, for the first time, a cheap and easy methodology was followed for obtaining the modified Nettle extract including the oxidized/dimerized bio-active products such as serotonin and histamine. The Nettle extract (NTE) and oxidized Nettle extract components (ONTE) were characterized by Fourier transform infrared spectroscopy (FT-IR), scanning electron microscope (SEM), UV-visible spectroscopy, and thermal gravimetric analysis (TGA). The NTE was oxidized under the alkaline condition at an ambient temperature. Finally, 600 ppm NTE and ONTE were separately added to 1 mol L−1 HCl solution to reduce the steel corrosion rate. The corrosion inhibition activity of the utilized inhibitors was assessed by electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization (PDP) techniques. The surface features were examined by SEM, atomic force microscope (AFM), and water contact angle test. The obtained results displayed that the ONTE inhibitor resulted in the higher inhibition efficiency than the NTE. The maximum inhibition efficiency, i.e. 93.40%, was obtained in the case of the acidic solution inhibited by 600 ppm ONTE after 1.5 h. Results of the polarization test and surface analyses proved the ONTE inhibitor components adsorption on the active metal sites, especially on the anodic areas. In studying of effects of temperature on the corrosion rate of mild steel the positive effect of ONTE on the mild steel corrosion mitigation was noticed. It was shown that the adsorption of the inhibitor on the metal surface obeyed the Langmuir isotherm in both physisorption and chemisorption forms.

Corrosion inhibition and the structure-efficiency relationship study of two cationic surfactants

Purpose As an example of structure-efficiency relationship study, this paper aims to evaluate the corrosion inhibition effect of two cationic surfactants, cetyl-trimethyl ammonium chloride (CTAC) and cetyl-dimethyl-hydroxyethyl ammonium chloride (CDHAC), and to discuss the effect of structure on the performance by thermodynamics methods. Design/methodology/approach The effect of the two cationic surfactants, CTAC and CDHAC, on the corrosion of the mild steel in HCl solution was investigated by using weight loss measurements, and the activation energies of CTAC and CDHAC involved in the corrosion inhibition were calculated and discussed. Findings The weight loss measurements showed that the corrosion inhibition efficiency of CDHAC was higher than that of CTAC in any case. The effects of the structure on performance were discussed, and the following data are available from the results, all of ΔS are positive, the values of ΔG are both close to −40 kJ·mol-1 and the values of ΔH are 10.960 and 36.996 kJ·mol-1, which indicate that the surfactant molecules are spontaneously adsorbed on the surface of the steel surface, and the adsorption on the steel plate is endothermic chemical adsorption. Originality/value The available data show that most organic inhibitors undergo physisorption on the metal surface, while in the presence of non-bonded and p-electrons, the inhibitor molecules may undergo chemisorption. This work showed that the two surfactant molecules are spontaneously adsorbed on the surface of the steel surface, and the adsorption on the steel plate is endothermic chemical adsorption.

Eriobotrya japonica Lindl leaves extract application for effective corrosion mitigation of mild steel in HCl solution: Experimental and computational studies

The feasibility of using Eriobotrya japonica Lindl (EJL) extract as a green inhibitor towards mild steel corrosion retardation in 1 M HCl solution was evaluated through integrated experimental and computational perspective. By utilizing electrochemical and surface analyses benefits, including EIS, potentiodynamic polarization, SEM, AFM and contact angle test, the protection function of EJL extract was studied. In addition, the EJL extract itself was examined by means of FT-IR and UV–Vis analysis. EIS results revealed the increase in mild steel corrosion resistance in the presence of EJL extract by increasing the extract concentration. The highest resistance was achieved at 800 ppm concentration. A mixed type behavior of EJL extract with dominant anodic dissolution reduction was proved by DC polarization. The lowest current density was obtained at 800 ppm concentration. SEM and AFM images indicated the protective layer growth on steel surface having intact surface morphology and more homogeneity in the presence of inhibitor. Contact angle test results confirmed the steel surface wettability enhancement by addition of EJL extract. The presence of functional groups, which make the inhibitors molecule adsorption possible, was verified by FT-IR and UV–Vis tests results. Furthermore, the computational methods (i.e., quantum mechanics and molecular simulations) evidenced the binding of EJL extract compounds onto steel substrate, affirming the inhibition action of EJL extract.

Experimental Study of 2-Amino-5-(4- nitrophenyl)-1, 3, 4-Thiadiazole for MS in HCl Solution

The present work aims to study the inhibition performance of new organic inhibitor namely ANTD “2-amino-5-(4-nitrophenyl)-1,3,4- thiadiazole” on corrosion of mild steel (MS) in HCl environment at the concentration of 1.0 M through using weight loss techniques. Weight lost measurements demonstrates the presence of a film on MS surface in existence of organic substance. The inhibition performance of ANTD at various concentrations for mild steel increases with increasing concentration and with an increased in the immersion time and decreased with raising temperatures degrees. The optimal inhibition efficiency of (ANTD), 82%, was achieved for mild steel when immersed with the highest utilized concentration for 6 hrs.

Experimental and computational chemistry studies of two imidazole-based compounds as corrosion inhibitors for mild steel in HCl solution

Two imidazole-based corrosion inhibitors, namely thiazole-4-carboxylic acid (TCA) and 2-methyl-1,3-thiazole-4-carboxylic acid (MTCA), were synthesized and their corrosion inhibition performance on mild steel in 0.1mol·L−1 HCl solution at 25°C was investigated using electrochemical measurements. Corrosion inhibition efficiency increased with increasing inhibitor concentration in solution and at a concentration of 150ppm, both MTCA and TCA exhibited similar corrosion inhibition efficiencies of ~90%. Adsorption of both inhibitors on steel followed the Langmuir adsorption isotherm. Theoretical quantum chemical calculation and Monte Carlo simulation were employed to determine the most stable configuration, the adsorption sites, and the interaction energies of TCA and MTCA on the steel surface. The simulation results demonstrated that the competitive adsorption of inhibitors and water molecules, proton, and chloride ions has a large impact on the adsorption configuration of inhibitors.

Chromenes as efficient corrosion inhibitor for mild steel in HCl solution

The Chromene derivatives having heteroatoms as active sites were investigated for scaling downthe corrosion process in mild steel (MS). The effectiveness of the inhibitors was monitored by gravimetric potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) methods. Observations suggested that the mechanism of inhibition is mainly due to the adsorption of the inhibitor molecules on the MS surface. Adsorption of both inhibitors follows the Langmuir adsorption isotherm. Tafel curve shows that both inhibitors act as mixed type inhibitor. Morphological studies were done by FESEM and AFM instruments. These images indicated the formation of a protective layer on the MS surface which slows down the process of corrosion. DFT calculation provides the valuable quantum chemical parameters for both inhibitors which are supportive of the results obtained from gravimetric and EIS methods.

Novel cost-effective and high-performance green inhibitor based on aqueous Peganum harmala seed extract for mild steel corrosion in HCl solution: Detailed experimental and electronic/atomic level computational explorations

Traditional corrosion inhibitors have been frequently used for metal protection against strong acids. However, most of them are hazardous/toxic compounds with high cost. Therefore, due to the strict environmentally friendly regulation the green and low-cost compounds from renewable sources like plant extracts have gained high consideration in recent applications. In the present study, the aqueous Peganum harmala seed extract, commonly called Esfand, a cost-effective and green source of amine-rich molecules like harmaline, harmalol, harmane, harmol, vasicine and vasicinone, was selected to inhibit mild steel corrosion in 1 mol·L−1 HCl media. The Peganum harmala seed extract composition was investigated by FT-IR and UV–Visible analysis. The Peganum harmala seed extract corrosion inhibition behavior on mild steel in HCl solution was examined through electrochemical methods (EIS and polarization), surface analyses (AFM, SEM and contact angle) and theoretical studies (MD, DFT and MC). The presence of many electron donor atoms based on nitrogen and oxygen in the molecules of Peganum harmala seed extract is responsible for its effective adsorption behavior on metal surface through chelation with iron atoms. Experimental exploration declared that with the increase in Peganum harmala seed extract concentration and time of immersion the inhibition power increased and reached the high value of 95%. Peganum harmala seed extract behaved as a mixed type inhibitor and properly obeyed an adsorption isotherm of Freundlich. Results of AFM and SEM analyses clearly proved that Peganum harmala molecules adsorption on the metallic surface considerably reduced its dissolution rate and resulted in clean and smooth surface. The use of water instead of ethanol for extraction of major organic compounds of Peganum harmala seed, being non-toxic and cost-effective and exhibiting inhibition efficiency much greater than other green inhibitors (which are almost in the range of 80–90%), propose the Peganum harmala seed as a unique green corrosion inhibitor. Furthermore, the detailed theoretical observations elucidated from molecular simulations and density functional theory affirmed the Peganum harmala compounds adhesion via reactive sites.

The Electrochemical Variation of a Kind of Protein Staining and Food Dye as a New Corrosion Inhibitor on Mild Steel in Acidic Medium

In this study, the relevance of a food dye, namely, Fast Green-FCF (FG-FCF), was surveyed as a new inhibitor for mild steel in HCl solution. This effect was specified by electrochemical impedance spectroscopy (EIS), one of the most widely used measurement techniques. As a result of the increment of the inhibitor concentration, it was seen that the values ​​of polarization resistance increased and covered the metal surface of FG-FCF like a blanket. Tests endorse that the FG-FCF is chemically adsorbed on mild steel surface, according to the Langmuir isotherm. With surface characteristic analyses, such as field emission scanning electron microscope (FESEM) and atomic force microscope (AFM), it was further determined that the metal surface in HCl of FG-FCF was protected. By applying the hydrogen gas evolution technique, FG-FCF has been proven to provide the lowest surface area with all inhibited solutions from the blank due to its strong adsorption to the metal surface. Finally, it has been clarified that FG-FCF can be practically used as a good corrosion inhibitor for mild steel with the supported results.

A combined experimental and theoretical study of green corrosion inhibition of mild steel in HCl solution by aqueous Citrullus lanatus fruit (CLF) extract

The potentiality of Citrullus lanatus fruit (CLF) extract containing several phytochemicals (e.g., citrulline, hesperetin, resveratrol and riboflavin) for mitigating the corrosion of mild steel specimens in subjection to 1 M HCl was assessed from integrated experimental and electronic/atomic level theoretical perspectives. The corrosion inhibition characteristics were examined applying electrochemical (EIS and polarization) and surface morphological (SEM, AFM, contact angle) techniques. Additionally, the presence of major phytochemicals in CLF extract was explored by FT-IR spectroscopy combined with UV–Visible analyses. Based on electrochemical results, with the use of 800 ppm CLF extract 91% inhibition capacity was derived. The potentiodynamic polarization clarified the mixed inhibition effect of CLF extract with prevalence cathodic inhibition. Also, the graphical SEM/AFM results disclosed that the interactions of CLF extract molecules with steel surface greatly influenced the prevention of surface damage. The outcomes resulted from molecular simulation and quantum mechanics analyses further reflected the CLF extract compounds adsorption on steel surface.

Novel oxazole and imidazole based on 8-hydroxyquinoline as a corrosion inhibition of mild steel in HCl solution: Insights from experimental and computational studies

Hydrochloric acid pickling treatment is used to remove mill scales from mild steel (MS) surface at diverse temperatures up to 328 ± 5 K. In order to minimize the metal dissolution newly multifunctional heterocycles based on 8-hydroxyquinoline derivatives, have been synthesized and characterized. These compounds have been tested as corrosion inhibitors of mild steel in 1 M HCl at 298 ± 5 K was studied using mass-loss, hydrogen evolution and electrochemical methods combined with DFT calculations. It is found also that these heterocycles based on 8-hydroxyquinoline compounds acted as excellent inhibitors and their inhibition efficiencies depend on the type of the substituent and which acted as mixed type inhibitors. In addition, UV−visible studies reveal the formation of a complex that may also be responsible for the observed inhibition. Furthermore, the Scanning Electron Microscope (SEM) images of the corrosion product confirmed the protection offered by both synthesized compounds on the surface of the mild steel immersed in molar HCl media. It is found that the theoretical parameters confirmed those obtained by experimental studies.

Casein as a natural protein to inhibit the corrosion of mild steel in HCl solution

In this research, the effects of casein on the corrosion behavior of mild steel in 0.1 M HCl were investigated by different analytical techniques. According to weight loss measurements, an increase in the concentration of casein from 50 ppm to 400 ppm resulted in a decrease in the corrosion rate of mild steel, for example, from 34.3 mpy to 3.9 mpy as compared to 98.1 mpy calculated for the casein-free solution at 298 K. However, increasing the temperature from 298 K to 343 K had adverse effects on the surface coverage, and the corrosion inhibition efficiency of casein. Based on thermodynamic calculations, in the presence of 400 ppm casein the corrosion activation energy and the enthalpy of activation increased from 8.61 kJ·mol−1 to 45.89 kJ·mol−1 and from 5.95 kJ·mol−1 to 43.23 kJ·mol−1, respectively.Potentiodynamic polarization experiments revealed a considerable decrease in the corrosion current density when casein was dissolved in the corrosive solution. This is in accordance with the observed increase in the charge transfer resistance from 121.4 Ω·cm2 to 917.9 Ω·cm2 measured by EIS. ATR-FTIR and EDS analyses confirmed the surface adsorption of casein on mild steel. AFM also illustrated an improvement in the surface properties of the samples in the presence of casein.