Steel Surface In Acidic Medium Research Articles

Adsorption of novel heterocyclic compounds of the purine derivatives as corrosion inhibitors over mild steel surface in acidic medium: Electrochemical, surface characterization and theoretical investigations

In the current study, the adsorption of two new heterocyclic purine derivative compounds is investigated. namely, 7H-purin-6-amine (Adenine) (M2) and 7H-purin-6-amine (Adenine) (2R,3R,4S,5R) −2-(6-amino-9H-purin-9-yl) −5-(hydroxymethyl) tetrahydrofuran-3,4-diol (M3) against the corrosion of mild steel in 1.0 M HCl medium. Weight Loss (WL), Electrochemical Impedance Spectroscopy (EIS), and Potentiodynamic Polarization (PDP) were among the techniques used in the experimental investigation. The respective inhibition efficiencies of M2 and M3 were found to be 89.0% and 96.5%.The Langmuir adsorption model was used to describe how M2 and M3 adsorb on the mild steel substrate. In addition, SEM/EDS, AFM, XRD, contact angle, and FT-IR techniques were employed to analyze the surfaces to support a protective film over the metal surface. Inductively coupled spectroscopy (ICP) was used to examine the WL observations as well. Furthermore, Molecular Dynamics (MD) simulations and DFT calculations were conducted to analyze the interaction of M2 and M3 with the mild steel substrate and their manner of adsorption.

Adsorption Isotherm and Activation Energy of Inhibition of Alkaloids on Mild Steel Surface in Acidic Medium

Alkaloids as green inhibitors were extracted from three different plants Rhynchostylis retusa, Artimesia vulgaris,and Solanum tuberosum. Weight loss measurement in mild steel has been carried out in the presence and absence of green inhibitors individually in an acidic medium. Weight loss measurements at different temperatures are used to calculate thermodynamic parameters. The weight loss measurements at different concentrations are used to find adsorption isotherm and found that it obeys Langmuir adsorption isotherm with R2 values 1, 1, 0.996 for three inhibitors. Activation energy, enthalpy, and entropy of the three inhibitors have been calculated. It is found that the value of all these parameters increased in the addition of inhibitors. The free energy of the system is calculated and found (-17.46 kJ mol-1) indicating that the adsorption process is spontaneous and there is physical adsorption at the MS-Inhibitor interface.

Experimental and computational investigations on the anti-corrosive and adsorption behavior of 7-N,N’-dialkyaminomethyl-8-Hydroxyquinolines on C40E steel surface in acidic medium

Two new 7-N,N’-dialkylaminomethyl-8-Hydroxyquinolines, namely 7-N,N’-dipropylaminomethyl-8-Hydroxyquinoline (DPQ) and 7-N,N’-dimethylaminomethyl-8-Hydroxyquinoline (DMQ), were synthesized and characterized using 1H/13C NMR and Elemental analysis methods. Corrosion inhibition effect of DMP and DPQ for C40E steel in 1 M HCl was evaluated at different concentrations (10−3 to 10−6M) and temperatures (298 to 328 K) using several experimental and computational approaches. Weight loss and electrochemical studies showed that protection efficiencies (ηmax) of DPQ and DMQ increase with increase in concentrations. The DPQ and DMQ showed maximum efficiencies of 96.1% and 94.4%, respectivelyat 10−3 M. Polarization measurements showed that DMQ and DPQ act as mixed type corrosion inhibitors. Adsorption of DPQ and DMQ on C40E steel in 1 M HCl obeyed the Langmuir adsorption isotherm. Variation in surface morphology of corroded metallic surface with and without DMQ and DPQ was demonstrated using scanning electron microscopy. Molecular dynamics (MD) simulations studies showed that DPQ and DMQ acquire the flat or horizontal orientation over the C40E steel. DFT analyses revealed that both DPQ and DMQ interact with the C40E steelusing electron-sharing(donor-acceptor)mechanism. Computational analyses conducted using DFT and MD simulations well corroborate the experimental results.

Experimental and computational mediated illustration of effect of different substituents on adsorption tendency of phthalazinone derivatives on mild steel surface in acidic medium

Four 1-(2H)-phthalazinone substituted compounds were investigated for their anticorrosion potentials on mild steel in 1 M HCl using electrochemical techniques, namely Tafel polarization and impedance spectroscopy. Fourier Transform Infrared (FTIR) spectroscopic technique was used to substantiate the interaction of the phthalazinone molecules with mild steel. Potentiodynamic polarization study suggested that inhibitor compounds exhibited mixed-type corrosion inhibition activities by repressing both oxidative steel dissolution and reductive hydrogen evolution reactions. Adsorption of the phthalazinone molecules on mild steel surface was modeled in Monte Carlo simulations. AC impedance spectroscopy measurements revealed that the corrosion of mild steel in the studied electrolytes is driven by single charge transfer mechanism and the studied phthalazinone molecules reduced the steel dissolution by forming adsorbed pseudo-capacitive film on the steel surface. Scanning electron microscopy plates showed the protective effects of the inhibitor molecules. The inhibition efficiencies of the studied phthalazinone molecules followed the order, P3 (78.25%) > P1 (77.24%) > P2 (76.60%) > P4 (67.86%) at 500 ppm. Both quantum chemical calculations and Monte Carlo simulations corroborated experimental results.

5-Methyl-1H-Benzotriazole as an Effective Corrosion Inhibitor for Ultra-Precision Chemical Mechanical Polishing of Bearing Steel

5-methyl-1H-benzotriazole was used as an effective corrosion inhibitor in acidic H2O2-based slurries for ultra-precision chemical mechanical polishing (CMP) of a high carbon chromium GCr15 bearing steel (AISI 52100). The CMP performance of GCr15 steel and the corresponding corrosion inhibition mechanism of 5-methyl-BTA were thoroughly investigated. The CMP results reveal that, compared with 1,2,4-triazole, 1,2,3-triazole and BTA, 5-methyl-BTA achieves the best corrosion inhibition performance, and the surface roughness Ra of GCr15 steel greatly improves, which can be attributed to the triazole and hydrophobic methyl functional groups. In synergy with H2O2, 5-methyl-BTA can be both chemically and physically adsorbed on the GCr15 steel surface in acidic medium. Specifically, the chemical adsorption mainly occurs by chemical reactions between 5-methyl-BTA and iron of GCr15 steel to form a surface complex. In the presence of 1.0 wt% H2O2 and 20 mM 5-methyl-BTA, the sparse corrosion inhibition film formed by 5-methyl-BTA together with the dense oxide film constitutes a complete passivation film, eventually resulting in the nanoscale planarization. The results can provide a guide for the selection of appropriate nitrogen-containing corrosion inhibitors for bearing steels CMP.

Phytochemical screening, total phenolic and flavonoid methanolic extract of pomegranate bark (Punica granatum L): Evaluation of the inhibitory effect in acidic medium 1 M HCl

The evaluation of the polyphenolic chemical composition in the methanolic extract of Punica granatum L. bark considered as a waste, using phytochemical screening (phenols, flavonoids, saponosides, sterols and polyterpenes), quantitative tests and UV analysis, which indicate an important amount of total phenolic content (272.82 ± 3.05 µg/mg GAE/g sample) while the minor fraction of total flavonoids (38.26 ± 1.78 µg/mg QE/g sample). The inhibition effect of the methanolic extract on the mild steel corrosion in 1 M HCl at 298 K has been investigated using the following tools and methods: electrochemical impedance spectroscopy (EIS), potentiodynamic polarization and weight loss measurements. After varying different concentrations of the extract, the optimal inhibition efficiency (88%) was correlated to the concentration of 1 g/L. The adsorption phenomenon of the extract on mild steel surface in acidic medium has been studied showing the follow-up of the Langmuir adsorption model. The polarization curves indicated that the extract might be classified as a mixed type inhibitor. The waste generated by Punica granatum L. bark could be valorized and explored as a very efficient new corrosion inhibitor, eco-friendly to the environment with low cost.

Adsorption characteristics of hydantoin derivatives on mild steel surface in acidic medium: An experimental approach

AbstractHydantoin compounds tagged 3‐(3,3‐diethylureido)‐N‐(4‐hydroxyphenyl)‐2,4‐dioxoimi dazolidine‐1‐carbothioamide (3a) and N‐(4‐aminophenyl)‐3‐(3,3‐diethylureido)‐2,4‐dioxoimidazolidine‐1‐carbothioamide (3d) were studied for their ability to inhibit mild steel corrosion in 0.5 M HCl using gravimetric, potentiodynamic polarization, and electrochemical impedance techniques. Various thermodynamic parameters for the adsorption of these inhibitors on mild steel was computed and discussed. Scanning Electron Microscopy (SEM) analysis were carried out to characterize the surface film.

Data from Chemical, electrochemical and quantum chemical studies for interaction between Cephapirin drug as an eco-friendly corrosion inhibitor and carbon steel surface in acidic medium

The influence of Cephapirin drug on the corrosion of carbon steel (CS) in 2 M HCl solutions has been examined by mass loss (ML), and electrochemical methods. The results demonstrated that Cephapirin drug acts as good inhibitor for CS corrosion. The inhibition efficiency increased as the concentration of the drug increases. Potentiodynamic polarization (PDP) studies showed that Cephapirin is mixed-type inhibitor. The electrochemical impedance spectra (EIS) studies reveal that the process of inhibition is through charge transfer. The adsorption of the drug on metal surface obeyed Temkin adsorption isotherm. The surface analysis of the CS was investigated using Attenuated total reflectance spectroscopy (ATR-FTIR) and UV–visible reflectance spectroscopy. Surface analysis of CS confirmed the existence of a protective adsorbed film of the drug on the metal surface. The quantum chemical calculations of the drug molecule in aqueous phase were done using density functional theory (DFT) method and discussed to correlate the theoretical and experimental data. The inhibition efficiency of Cephapirin drug obtained by chemical and electrochemical methods was in good correlation with each other.

Electrochemical kinetics, molecular dynamics, adsorption and anticorrosion behavior of melatonin biomolecule on steel surface in acidic medium

Electrochemical, anticorrosion and adsorption behaviour of bio-based melatonin (MEL) in 5% HCl solution was investigated by experimental and theoretical approaches. MEL was found to possess high adsorptive capacity for steel surface and inhibits the acid corrosion. With a concentration of 10 mM, inhibition efficiency of 98.3% and 88.6% were obtained at 30 °C and 60 °C respectively. Langmuir associative and dissociative models describe simultaneous physisorption and chemisorption. FTIR, SEM/EDS and quantum molecular dynamics simulations using DFT provide evidences that MEL forms adsorbed surface complex film (in the protonated form) coordinated mainly by indole ring, N(9) and O(10). The biomolecule is a promising alternative anticorrosion additive for acid wash solutions.

Anticorrosive property of Spiraea Cantoniensisis extract as an eco-friendly inhibitor on mild steel surface in acid medium

The inhibitive performance of methanolic extract of eco-friendly green inhibitor Spiraea cantoniensis (S. cantoniensis) on inhibiting corrosion of mild steel (MS) in 1 M HCl was studied by weight loss, AC-impedance, Fourier transform infrared spectroscopy (FT-IR), Raman, x-ray diffraction (XRD), ultraviolet-visible (UV-Vis), atomic absorption spectroscopy (AAS), and scanning electron microscopy (SEM) analysis. The results showed that the corrosion rate significantly decreased in the presence of the S. cantoniensis inhibitor with a gradual increase in inhibition efficiency at an increased inhibitor concentration. The temperature studies were conducted which included activation energy (Ea), change in enthalpy (ΔH°ads), change in entropy (ΔS°ads), change in free energy (ΔG°ads) and heat of adsorption (Qads). These calculations were helpful to determine the reaction mechanism and proved it as a physisorption type following the Langmuir adsorption isotherm. The analysis of the protective film using FT-IR, Raman, XRD, and SEM analysis clearly showed the potentiality of S. cantoniensis in blocking the MS surface to prevent corrosion by 1 M HCl. The solution analysis via AAS and UV-Vis showed the inhibitive effect of the inhibitor (S. cantoniensis) in both inhibitive and the uninhibitive solution exhibiting the adsorption of the phytochemical molecules on the MS surface.

Experimental, density functional theory and molecular dynamics supported adsorption behavior of environmental benign imidazolium based ionic liquids on mild steel surface in acidic medium

This study describes the adsorption behavior of three 1-butyl-3-methyl-imidazolium ionic liquids namely, 1-butyl-3-methylimidazolium chloride ([bmim][Cl]), 1-butyl-3-methylimidazolium acetate ([bmim][Ac]) and 1-butyl-3-methylimidazolium trifluoromethanesulphonate ([bmim][CF3SO3]) at mild steel/1 M HCl interface using experimental and computational studies. Electrochemical and gravimetric measurements revealed that the inhibition efficiency of the studied ionic liquids increases with increase in concentrations, such that [bmim][Cl], ([bmim][CF3SO3] and [bmim][Ac]) gave the maximum inhibition efficiencies of 93.18%, 96.02% and 97.15%, respectively at a concentration as low as 8.67 × 10−4 mol L−1. The studied ionic liquids act as interfacial corrosion inhibitors and their adsorption at mild steel/electrolyte interface obeyed the Temkin adsorption isotherm. Polarization study suggested that the ionic liquids are mixed-type corrosion inhibitors. SEM and AFM analyses were undertaken to support the adsorption of the ionic liquid molecules on mild steel surface in 1 M HCl solution. Orientation and adsorption mode of 1-butyl-3-methyl-imidazolium molecules on mild steel surface was investigated using molecular dynamic (MD) simulations, which revealed that 1-butyl-3-methyl-imidazolium molecules adsorb on mild steel surface in flat orientations. Quantum chemical parameters for the neutral and protonated forms of the ionic liquids as well as the binding energies and radial distribution function indices obtained from molecular dynamic simulations corroborate the experimental results.

Choline based ionic liquids as sustainable corrosion inhibitors on mild steel surface in acidic medium: Gravimetric, electrochemical, surface morphology, DFT and Monte Carlo simulation studies

The adsorption tendency of choline based ionic liquids namely, 2-hydroxyethyl-trimethyl-ammonium chloride [Chl][Cl], 2-hydroxyethyl-trimethyl-ammonium iodide [Chl][l] and 2-hydroxyethyl-trimethyl-ammonium acetate [Chl][Ac] on mild steel surface in 1 M HCl has been demonstrated using experimental and theoretical approaches. Weight loss analysis showed that inhibition efficiencies of [Chl][Cl], [Chl][I] and [Chl][Ac] increases with their concentrations. The maximum efficiencies of are in the order; [Chl][Cl] (92.04%) < [Chl][I] (96.02%) < [Chl][Ac] (96.59%) at 17.91 × 10−4 M concentration. Electrochemical analyses (OCP, PDP and EIS) data provide good support to the weight loss study and showed that investigated ionic liquids behaved as interfacial and mixed type corrosion inhibitors. The adsorption of [Chl][Cl], [Chl][I] and [Chl][Ac] at mild steel/1 M HCl (electrolyte) interfaces obeyed the Temkin adsorption isotherm. The adsorption of studied ionic liquids on the metallic surface was further supported by SEM-EDX and AFM methods. DFT and Monte Carlo (MC) Simulations based computational approaches were undertaken to support the experimental findings. DFT studies revealed that [Chl][Cl], [Chl][I] and [Chl][Ac] interact with metallic surface through donor-acceptor interactions in which the anionic parts act as electron donor (HOMO) and cationic parts behaved as electron acceptor (LUMO). The MC simulations study showed that studied ionic liquids adsorb spontaneously on mild steel surface and their effectiveness depends upon nature of anionic moieties. The experimental and theoretical analyses show that the investigated inhibition efficiencies of studied ionic liquids followed the order: [Chl][Cl] < [Chl][I] < [Chl][Ac].

Adsorption characteristics of green 5-arylaminomethylene pyrimidine-2,4,6-triones on mild steel surface in acidic medium: Experimental and computational approach

Abstract The effect of electron withdrawing nitro (–NO2) and electron releasing hydroxyl (–OH) groups on corrosion inhibition potentials of 5-arylaminomethylenepyrimidine-2,4,6-trione (AMP) had been studied. Four AMPs tagged AMP-1, AMP-2, AMP-3 and AMP-4 were studied for their ability to inhibit mild steel corrosion in 1 M HCl using experimental and theoretical methods. Gravimetric results showed that inhibition efficiency of the studied inhibitors increases with increasing concentration. The results further revealed that that electron withdrawing nitro (–NO2) group decreases the inhibition efficiency of AMP, while electron donating hydroxyl (–OH) group increases the inhibition efficiency of AMP. SEM and AFM studies showed that the studied compounds inhibit mild steel corrosion by adsorbing at the metal/electrolyte interface and their adsorption obeyed the Temkin adsorption isotherm. Potentiodynamic polarization study revealed that studied inhibitors act as mixed type inhibitors with predominant effect on cathodic reaction. The inhibitive strength of the compounds might have direct relationship electron donating ability of the molecules as revealed by quantum chemical parameters. The order of interaction energies derived from Monte Carlo simulations is AMP-4 > AMP-3 > AMP-2 > AMP-1, which is in agreement with the order of inhibition efficiencies obtained from experimental measurements.

Synergistic inhibition between the gemini surfactant and bromide ion for steel corrosion in sulphuric acid

The inhibitive synergistic effect between a cationic gemini surfactant, 1,3-propane-bis(dimethyl dodecylammonium bromide) (12-3-12), and bromide ion for the corrosion inhibition of cold rolled steel in 0.5 mol L−1 H2SO4 was investigated by weight loss, potentiodynamic polarization method and electrochemical impedance spectroscopy (EIS). The inhibition system composed by 12-3-12 and bromide ion is efficient. The adsorption mechanism of the 12-3-12 and bromide ion on steel in acidic medium is discussed on the basis of experimental data and an adsorption model is proposed. Adsorption of inhibitor system on the mild steel surface in acidic medium obeys Langmuir’s adsorption isotherm. In addition, potentiodynamic polarization studies show that the system acts as a mixed-type inhibitor. Electrochemical impedance spectroscopy also suggests the formation of a protective layer on the steel surface by the adsorption of surfactant molecules and bromide ions.

Synergistic effect between cationic gemini surfactant and chloride ion for the corrosion inhibition of steel in sulphuric acid

Corrosion inhibition of cold rolled steel in 0.5 mol L −1 sulphuric acid by a quaternary ammonium gemini surfactant, l,3-propane-bis(dimethyl dodecylammonium bromide) (designated as 12-3-12), in the absence and presence of chloride ions was investigated at different temperatures. The results revealed significant synergistic effect between gemini 12-3-12 and chloride ions for the corrosion protection of cold rolled steel in sulphuric acid, and that the novel composite inhibitor system containing cationic gemini surfactant and chloride ions was efficient and low-cost for steel corrosion inhibition in sulphuric acid medium, even when concentration of 12-3-12 was as low as 1 × 10 −6 mol L −1. By fitting the obtained experimental data with Langmuir adsorption model and Arrhenius equation, some thermodynamic and kinetic parameters such as adsorption free energy, the apparent activation energy, and the pre-exponential factor were estimated. The adsorption mechanism of the gemini surfactant onto steel surface in acid medium in the absence and presence of chloride ions was also discussed, respectively.

A novel triazole-based cationic gemini surfactant: synthesis and effect on corrosion inhibition of carbon steel in hydrochloric acid

A triazole-based cationic gemini surfactant, 3,5-bis(methylene octadecyl dimethylammonium chloride)-1,2,4-triazole (18-triazole-18) has been synthesized, and its effect on corrosion inhibition of A 3 steel in 1 M HCl has been studied using the weight-loss method. The result showed that 18-triazole-18 acted as an excellent inhibitor in 1 M HCl. It was found that the adsorption mechanism of 18-triazole-18 on the steel surface in acid medium was quite different from that of cationic gemini surfactants containing dimethylene as a spacer, as well as that of conventional cationic single-chained surfactants, which is due to unique molecular structure of 18-triazole-18. 18-Triazole-18 may be adsorbed on the steel surface in acid medium through a maximum of four atoms or groups, i.e., the two nitrogen atoms of triazole ring and two quaternary ammonium head groups. Four regions of surfactant concentration could be divided to illustrate the adsorption of 18-triazole-18 on the steel surface, and four different adsorption mechanisms may take place in different regions of surfactant concentration.

Understanding the effect of the spacer length on adsorption of gemini surfactants onto steel surface in acid medium

Corrosion inhibition of carbon steel in 1 M hydrochloride acid by gemini surfactants alkanediyl-α,ω-bis(dimethyl dodecylammonium bromide) with different spacer lengths (designated as 12- s-12, s = 2, 3 or 6) was studied using the weight loss method. When monolayer forms on the metal surface below or near critical micelle concentrations (CMCs) of the gemini surfactants, it can be found that gemini surfactant with long spacer (12-6-12) tends to be adsorbed with two hydrophilic ionic groups onto the metal surface site, while gemini surfactants with short spacer (12-2-12 and 12-3-12) tend to be adsorbed with one hydrophilic group onto the meta surface site and the other hydrophilic group is free in solution phase, and further increase in surfactant concentration results in the formation of multilayer. Possible adsorption mechanisms of these gemini surfactants with different spacer lengths above and below their CMCs were discussed in detail, respectively.