Anodic Inhibitor Research Articles

Ajuga orientalis L. Extract as a Green Corrosion Inhibitor of Aluminum in an Acidic Solution: An Experimental and DFT Study

The inhibitory effect of A. orientalis L. extract (AO) on aluminum corrosion in a 1.0 M HCl solution was investigated utilizing weight loss, electrochemical polarization, electrochemical impedance spectroscopy (EIS), and scanning electron microscopy (SEM). The results show that AO is a potent inhibitor in an acidic environment, and that the inhibition potency increases with concentration. Temperature investigations showed that, in an acidic medium, the efficiency decreased, increased, and then decreased as the temperature rose. Adsorption isotherms from Freundlich, Temkin, El Awady, and Redlich–Peterson (R-P) approximated the inhibitor’s adsorption properties. For the inhibitory behavior, a physical and chemical adsorption mechanism is proposed. The adsorption process’s thermodynamic parameters (Ea, ΔH*, and ΔS*) were determined and explained. The inhibitor, AO, was identified as a mixed-type (anodic and cathodic) inhibitor based on polarization studies. According to the SEM findings, the inhibitor partially covers the metal surface, providing it with a respectable level of protection. The weight loss, electrochemical polarization, EIS, scanning electron microscopy (SEM), and quantum chemical calculations show a strong agreement, indicating that the AO extract is a highly effective inhibitor of aluminum in an acidic solution.

Synthesis, characterization and performance of ecofriendly epoxy resin as a highly efficient corrosion inhibition for mild steel in 1m HCl solution

In this study, a novel epoxy resin called tetraglycidyl ether of methyl-α-D-mannopyranoside (TGEMM) was synthesized and investigated for its potential used as a corrosion inhibitor for mild steel in a 1.0 M hydrochloric acid (HCl) solution. The main goal was to evaluate the corrosion inhibition properties of TGEMM using various techniques. The methods used in this research included potentiodynamic polarization, electrochemical impedance spectroscopy (EIS), temperature effect, scanning electron microscopy, energy dispersive X-ray spectroscopy, atomic force microscopy and contact angle measurement. These techniques were chosen to comprehensively assess the corrosion inhibition performance of TGEMM on MS. In this context, the structure of the newly synthesized TGEMM epoxy resin was identified and confirmed using Fourier transform infrared spectroscopy (FTIR) and nuclear magnetic resonance (NMR). The results obtained from the experiments demonstrated that, at a lower concentration of 10−3 M, TGEMM demonstrated a high inhibitory efficacy of 91.49%, assessed via electrochemical impedance spectroscopy (EIS), and 93.84%, measured via potentiodynamic polarization (PDP), in a 1.0 M hydrochloric acid solution. The PDP data indicated that the TGEMM epoxy resin acted as an anodic inhibitor in the acidic environment. In addition to gain insights into the interaction mechanism and adsorption mode, DFT and MD simulations were conducted, revealing valuable information about the interaction of TGEMM with the mild steel surface.

Study on the Scale and Corrosion Inhibition Effect of Curcumin‐Based Novel Polymers

AbstractThe curcumin‐malic acid‐aspartic acid polymer (PCMA) as a new water treatment agent was prepared by solid phase synthesis of curcumin, malic acid and aspartic acid. The static scale inhibition experiments showed that PCMA can inhibit CaCO3 and CaSO4 scale formation by 100.0 % and had excellent scale inhibition effect under various experimental conditions. The mechanism of action of PCMA was obtained by X‐ray diffraction, scanning electron microscope and molecular dynamics simulation. Electrochemical test showed that PCMA is an anodic corrosion inhibitor that achieves 93.1 % corrosion inhibition by forming a protective film on the surface of Q235 carbon steel. Besides, fluorescence spectra proved that PCMA has stable fluorescence intensity.

Molybdate and vanadate ions as corrosion inhibitors for clad aluminium alloy 2024-T3

Molybdate and vanadate ions were used as corrosion inhibitors for the clad aluminium alloy 2024-T3 in chloride solution to investigate the differences in their inhibitory effect. Electrochemical measurements in 0.1 M NaCl investigated the influence of inhibitor concentration from 0.5 mM to 250 mM, solution pH from 5 to 9 and immersion time at open circuit potential of up to 12 h. Both compounds act predominantly as anodic inhibitors; however, the effect of molybdate increases significantly at concentrations above 50 mM and leads to a broad passive range. Surface analysis of the samples exposed to inhibitor performed by X-ray photoelectron spectroscopy showed that the inhibitor layers consist of oxides of multiple valences. Scanning electron microscopy with chemical analysis was also used to characterise the inhibitor layers. Equilibrium diagrams of the aqueous species in the selected concentration range were generated to better understand the inhibition mechanism and to correlate the electrochemical data and data on surface properties.

تحضير وتقييم بوليمرات رخيصة كمضادات للبكتريا ،الاكسدة ومثبطات تاكل لسبيكة من نوع N80 في تركيز 0.1N من حامض الفسفوريك

في هذا العمل ، تم تحضير بولي بوتادين (PBD) من نفايات الاطارات . وطعم البولي بوتادين المهلجن باستخدام أحادي وثنائي وثلاثي إيثانول امين ، ودرس التطعيم عن طريق حيود الأشعة السينية والمسح المجهري الإلكتروني. وتشير الخواص الحرارية (TGA, DSC) إلى أن المركبات المحضرة تمتلك ثابتًا حرارياً حتى 202 درجة مئوية. باستخدام تقنيات الاستقطاب الديناميكي الفعال ، تم قياس تأثيرات الامتزاز والتآكل للبوليمرات الثلاثة المطعمة على فولاذ N80 في.0.1N H3PO4 في اربع درجات حرارية مختلفة : 25 و 35 و 45 و 55 درجة مئوية. وقد اظهرت البوليمرات المحضرة كفاءة تثبيط ممتازة عند درجات الحرارة المختلفة. يعتبر pBut-g-mono ethanol amine هو الأكثر فعالية كمثبط للتآكل في جميع درجات الحرارة المختبرة. كما ان سلوك الامتزاز للبوليمرات الثلاث تخضع لمخطط لانجموير ، وقيم الطاقة الحرة المتحصلة توضح ان الامتزاز الذي يحدث على سطح N80هو من النوع المختلط كما تشير منحنيات تافل إلى أن البوليمرات المختبرة تعمل كمثبطات أنوديك وكاثودية مختلطة. من ناحية أخرى ،وجد أن جميع البوليمرات المحورة أظهرت خصائص متميزة كمضادة للأكسدة وللبكتيريا.

Corrosion inhibition performance of RNC-n on aluminum alloy surface in alkaline solution

The corrosion inhibition behavior of glycine surfactants with different carbon chain lengths (RNC-n, n = 8, 12, 14) of AA2024-T3 aluminum alloy in 0.01 mol·L−1 NaOH solution was investigated. The weight loss and electrochemical methods, XPS, SEM/EDS techniques, quantum chemical calculations, and molecular dynamics simulations were used for studying the corrosion inhibition properties, adsorption behavior, and corrosion inhibition mechanism. When the maximum solubility of 0.01 mol·L−1 was achieved, the inhibition effectiveness of RNC-8 reached 90.55 %. Both RNC-12 and RNC-14 exhibited inhibitory efficiencies of 92.81 % at 0.005 mol·L−1 and 91.83 % at 0.0005 mol·L−1. RNC-n was shown to be an anodic corrosion inhibitor, since its impact on the anodic reaction was larger than on the cathodic one. RNC-n was able to successfully adsorb on the aluminum surface and form a protective film, which hindered further corrosion damage of the aluminum by the alkaline solution. In addition, the adsorption sites of RNC-n molecules were analyzed, and it was found that the adsorption sites of the corrosion inhibitor were mainly in the carboxyl group. Therefore, this paper can provide some theoretical support for the protection of aluminum alloys against corrosion in alkaline medium.

Copper corrosion inhibition in acidic aqueous media through tolyltriazole application: performance analysis

Tolyltriazole (TTA) is recognized as an effective copper corrosion inhibitor in cooling systems due to its low toxicity and versatile properties. With the increasing focus on sustainable development, the employment of compounds of this nature has become increasingly widespread, driving the search for environmentally responsible alternatives. In this context, the aim of this work was to evaluate the efficiency of a corrosion inhibitor formulated with TTA on copper specimens in HCl 0.1 mol L−1 medium. The samples were exposed to the corrosive electrolyte with inhibitor concentrations ranging from 0 to 20 ppm. Electrochemical methods, including open circuit potential, potentiodynamic polarization, and electrochemical impedance spectroscopy were employed for corrosion monitoring. Overall, the results revealed that TTA behaves as a predominantly anodic inhibitor. Additionally, polarization curves demonstrated that within the Tafel region, the inhibitor adsorbs to the copper surface, following the Langmuir isotherm model. Regarding inhibitory effectiveness, the observed values ranged between 81.3 and 96.1%, while morphological analyses indicated the presence of nitrogen on the surface of the copper specimens after electrochemical tests, confirming the formation of a protective TTA film. In conclusion, this study highlights TTA's efficacy as a corrosion inhibitor, demonstrating its significant potential in safeguarding copper against acidic environments.

Eco-friendly methanolic Ajuga orientalis extract as corrosion inhibitor for aluminium in 1.0 M NaOH

The inhibitory impact of the methanolic Ajuga orientalis (MAO) extract on Al corrosion in 1.0 M NaOH solution was examined using weight loss with electrochemical polarisation and scanning electron microscopy (SEM) techniques. According to the findings, the extract was an effective inhibitor in basic condition, as well as inhibition effectiveness increased with concentration. Furthermore, temperature studies revealed a loss in efficiency followed by a rise when temperature rose, followed by an increase and a fall in the fundamental media when the temperature increased from 30 °C to 50 °C. Frumkin, Freundlich and El Awady isotherms were used to mimic the inhibitor's adsorption properties. For the inhibitory behaviour, physical and chemical adsorption mechanisms are proposed. The adsorption process's thermodynamic parameters (ΔH*, ΔS* and Ea) were determined and explained. The inhibitor was examined as a mixed-type (anodic and cathodic) inhibitor based on polarisation studies. The inhibitor, according to the SEM data, is partially coating the metal surface, providing it with a reasonable amount of protection. The findings from weight loss, electrochemical polarisation, SEM and quantum chemical calculations collectively demonstrate a strong consensus, indicating that the MAO extract exhibits high effectiveness as an inhibitor for aluminium in a basic solution.

Three anionic surfactants for corrosion inhibition in cobalt CMP: Research on validity and mechanism

Inhibitors are introduced into the slurry to avoid excessive metal corrosion during the chemical mechanical polishing (CMP) process. The anti-corrosion effect of surfactants in CMP was not investigated systematically in past studies. In this paper, three eco-friendly anionic surfactants, potassium laurate, potassium oleate, and dodecyl benzenesulfonic acid, were studied in depth as cobalt CMP inhibitors. Electrochemical experiments demonstrated that the three inhibitors act as anodic inhibitors. Static etching tests and surface morphology analysis proved that they can effectively inhibit the corrosion rate of cobalt and improve surface morphology. XPS results demonstrated that the inhibitor reduces corrosion by inhibiting cobalt oxidation. DFT calculations demonstrated that inhibitors adsorb on the cobalt surface through the O atoms in hydrophilic groups, while the CC double bond and benzene ring can significantly enhance the adsorption. Molecular dynamics simulations showed that the inhibitors are adsorbed on the cobalt surface in parallel. Additionally, all three surfactants improved the solution's wettability on cobalt. This report provides critical insights into the corrosion inhibition specific to cobalt CMP and offers an approach to realize the multi-functionality of a single agent in slurries.

Self-formation of the protective film on mild steel surface in hydrochloric acid medium containing Papaya resin extract

Plant extracts have been considered to be an effective corrosion inhibitor due to their high inhibition performance, huge amount, regeneration, and nature, as well as biological sources. However, several steps in the plant extract processes and extracted solvents are still questionable. Therefore, Papaya resin - extract (PRE) was recommended, produced, and characterized as a mixed-type inhibitor for corrosion of mild steel in 0.1 M hydrochloric acid medium. The results indicated that the 2000 ppm of PRE inhibitor has significant effects on the inhibition efficiency, reaching a remarkable value of 98.08% for mild steel in the investigated solution. The potentiodynamic polarization results showed that the PRE inhibitor acts as a mixed-type inhibitor with a dominant anodic inhibitor for mild steel. Moreover, electrochemical impedance spectroscopy and linear polarization resistance results demonstrated that PRE molecules can form protective film, and increase charge transfer and polarization resistances, suggesting the improved steel corrosion resistances. The scanning electron microscope results indicated less occurrence of corrosion on the steel surface exposed to the inhibitor system. Meanwhile, X-ray photoelectron spectroscopy results demonstrated that PRE’s molecules were absorbed and created reactions with iron products to form a protective film on the steel surface. Furthermore, density functional theory (DFT) and molecular dynamics simulation were used to calculate, suggesting that the conjugation effect of two double bonds in PRE’s molecules creates an electron-withdrawing effect on the reactive space around. Moreover, the results revealed the good adhesion and thermal stability of the absorbent protective layer, indicating an agreement with experimental characteristics. Therefore, this result suggests a contemporary design for developing the self-corrosion inhibitor based on natural products with less steps in the synthetic process.

Synthesis and investigation of two new compounds (2-(methoxymethyl)−1- phenyl-2-propen-1-one and 2-(methoxymethyl)−1-(4-methoxyphenyl) - 2-Propen-1-one) as corrosion inhibitors for mild steel in acidic solutions at elevated temperature.

This study evaluated the performance of two newly synthesized organic corrosion inhibitors using the gravimetric weight loss method in hydrochloric acid (HCl), methanesulphonic acid (MSA), and a combination of HCl and MSA in the presence of different corrosion inhibitor (CI) concentrations at temperatures of 30 °C to 90 °C. Potentiodynamic polarization (PDP) and electrochemical impedance spectroscopy (EIS) studies were carried out for an in-depth study of corrosion mechanisms. Following the weight loss study, the percentage inhibition efficacies of C1 and C2 at 300 ppm concentrations were found to be ≈ 100% at 30 °C, 40 °C and 60 °C in 15 wt% HCl, 10 wt% MSA, and a combination of both acids (15 wt% HCl and 10 wt% MSA). The performances of C1 and C2 deteriorated slightly when tested in 10 wt% MSA at 90 °C. The synthesized CIs still showed a very high inhibition efficiency in the presence of 15 wt% HCl and a mixture of acids (HCl and MSA) at 90 °C. PDP studies indicated that both C1 and C2 act as anodic inhibitors. The inhibition efficiencies obtained from the PDP and EIS studies agreed with the weight loss study. The high value of Kads and the negative ∆Gads value suggests that C1 and C2 corrosion inhibitors have a strong and spontaneous tendency to chemisorb onto the mild steel surface. SEM-EDX studies proved the formation of a uniform, protective corrosion inhibitor film on the metal surface. Both C1 and C2 have been proven suitable for high-temperature corrosion applications.

The Effectiveness of Na<sub>2</sub>CrO<sub>4</sub> to Inhibit Corrosion Rate of a A106 Grade Pipe in the Furnace Circulating Cooling Water with the Weight Loss Method on Pipe Lifetime Determining

Pipes from industrial process flow diagrams have a predictable risk of failure or damage, so that periodic inspections are carried out. Corrosion that occurs in the pipe can cause a risk of leakage or blockage of the pipe flow which can be fatal to the fluid distribution process. This damage can be anticipated by inhibitors adding and predicting the corrosion rate. This research was conducted to determine the effective concentration of Na2CrO4 inhibitor to inhibit the corrosion rate and predict the lifetime of the furnace cooling water circulation pipe using the weight loss method. Na2CrO4 inhibitor is a type of anodic inhibitor that works by passively the anode by inhibiting corrosion on a whole metal surface. The study begins with the preparation stage, cutting the pipe into specimens of a certain size, smoothing the surface and weighing the initial weight. The testing phase was carried out by immersing the specimens at various times of 120 h, 240 h and 360 h with Na2CrO4 inhibitor variations concentration was 0%; 0,3%; 0,6%; and 0,9%. The corrosion rate was calculated by re-weighing the specimen after the immersion process. The results showed that the most effective inhibitor concentration was 0.6% with a corrosion rate of 0.3021 mmpy and the Remaining Service Lifetime (RSL) was 9.399 years.

A computational and experimental investigation of novel synthesis fused pyrazolopyrimidine as zinc corrosion inhibitor in 1 M HNO3

Two compound derived from fused Pyrazolo-Triazolo-Pyrimidine (C1 and C2), have inhibitory action against corrosion of Zinc in 1 M HNO3 examined experimentally by electrochemical tests and theoretically by density functional theory (DFT). The findings demonstrate that zinc corrodes in acidic conditions with greater corrosion resistance than C1 and C2. Concentration and corrosion inhibition directly relate to one another. The two Pyrazolopyrimidine-derived compounds had optimum inhibition efficiency of 92.06 and 79.36% for C1 and C2, respectively, at 700 ppm. In accordance to the polarization curves, the antagonists feature a mixed but primarily anodic inhibitor and a Langmuir process. DFT computations validated the compounds apparent antagonistic response. SEM also show the development of a barrier on the zinc surface. In conclusion, these two antagonists, C1 and C2, are successful in avoiding zinc dissolution in HNO3.

An Investigation on the Inhibition Behavior of Anodic Inhibitors on St37 Carbon Steel in Closed-Circuit Cooling Water

An Investigation on the Inhibition Behavior of Anodic Inhibitors on St37 Carbon Steel in Closed-Circuit Cooling Water

Study the Corrosion Inhibition on the Iraqi Fuel Tanks using Cefoperazone Drug

Corrosion is one of the most important problems that face the petroleum industry, both production and refining, and cause damage to petroleum equipment, tanks, and transmission lines, and increasing maintenance costs. in this study , was adding six concentrations of the drug expired Cefoperzone (Exp CEF) (50, 100, 200, 300, 400, and 500 ppm) to a Simulated Oil Well Water (SOWW), the inhibitive role of (Exp CEF) drug was investigated to Reduce the corrosion risk of carbon steel. Four different temperatures were used to conduct electrochemical tests (303, 313, 323 and 333 K) to achieve the study. The study was then supported by an examination of the inhibited surface using field emission scanning electron microscopy with energy dispersive (FESEM) and (AFM). The results indicated occurring the inhibition by an anodic inhibitor that controls the dissolution of iron from steel gave the highest inhibition efficiency (IE%) by adding 500 ppm, while the calculation of polarization resistance (Rp) gave the highest resistance by 400 ppm through adsorption the added drug to show flakes shaped structures with decreasing surface roughness (Ra ) from 307.1 to 83.15 after inhibition. The calculation of adsorption isotherm confirmed the obeying of Langmuir adsorption isotherm by giving the coefficient of linear regression was about one in the range of 0.999 > R^2 > 0.995, with the spontaneous adsorption that estimated from the negative values of 〖∆H〗_ads^o and variation in the type of adsorption to be physically or chemically according to the added concentration because of the differential sign of 〖∆H〗_ads^o . The sign of 〖∆H〗_ads^o was positive that reflecting the increase in randomness at the metal/solution interface.

Corrosion inhibition mechanism of vitamins on steel bars in chloride environments: Experimental analysis and quantum chemical calculation

The inhibition potency of thiamine (VB1), nicotinic acid (VB3), pyridoxine (VB6) and ascorbic acid (VC) against the reinforcement corrosion and their adsorption behavior on the surface of steel bars in chloride environments are studied using potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) tests. Based on the density functional theory (DFT), quantum chemical calculation is also performed to further reveal the corrosion inhibition mechanism of vitamins at the electronic level. The results indicate that these four kinds of vitamins are proven to be potentially applied as corrosion inhibitors to effectively reduce the risk of chloride-induced reinforcement corrosion in a simulated concrete pore solution with 0.05 M NaCl, and VB6 shows the best corrosion inhibition effect since the bonding stability between its highest occupied molecular orbital (HOMO) and the 3d-orbital of iron is the strongest among these vitamins. Under the experimental conditions of this study, there is a specific concentration value for each vitamin to achieve the optimum corrosion inhibition efficiency (IE%). At this time, VB1 and VB3 act as anodic corrosion inhibitors, while VB6 and VC act as mixed-type corrosion inhibitors. With the increase of vitamin concentration, IE% shows a fluctuating value, which is ascribed to the further aggravated imbalance between the cathode and the anode when the cathodic reaction is inhibited due to the adsorption of polar groups on the steel surface.

Improved corrosion resistance of permanganate-phosphate conversion coat on steel surface by surfactants

In the present work, we studied the effect of the presence of different concentrations of each of Triton-X-100 and Tween-80 surfactants in the bath of permanganate-phosphate conversion coating (PPC) on the corrosion resistance and the microstructure of the prepared coats. The coats were investigated using a scanning electron microscope (SEM), an energy dispersive X-ray spectrometer (EDX), X-ray photoelectron spectroscopy (XPS), electrochemical impedance spectroscopy (EIS), and potentiodynamic polarization techniques. The SEM results show that, on addition of the surfactants to the PPC bath, the porosity of the coat decreases and the coating layer becomes more compact. EIS results indicated that the presence of 0.01 M Triton-X-100 or 0.01 M Tween-80 in the coating solution caused an increase in the protection efficiency of the coat up to 93.7% and 84.1%, respectively. The potentiodynamic polarization results indicated that the two surfactants mainly act as anodic inhibitors due to the adsorption of their molecules at the anodic sites of the surface of steel and retard its oxidation reaction. The EDX and XPS results confirmed the results of the other techniques. A mechanism for the role of the surfactants in the coating process was proposed using the results of XPS and the other techniques.

Electrochemical, surface and theoretical investigations of a new tri-tolyl imidazole designed for corrosion inhibition of carbon steel in normal hydrochloric acid medium

Throughout this work, it is intended to evaluate the effect of a new ((4RS,5SR)-2,4,5-tri-p-tolyl-4,5-dihydro-1H-imidazole (4T-C) on Carbon Steel (C-steel) corrosion inhibition in 1 M HCl medium. For this purpose, potentiodynamic polarization measurements and Electrochemical Impedance Spectroscopy (EIS) were realized. It could be perceived that the inhibitor concentration increase led to substantial corrosion level drop of C-steel in the harsh medium, with inhibitive efficiency value reaching 96 % at 10−3 M inhibitor concentration. The polarization curves showed that the inhibitor 4T-C operated as a mixed cathodic and anodic type inhibitor. The Nyquist diagrams illustrated that increasing 4T-C’s amount in solution occasioned an increase in polarization resistance values, implying an increase of the inhibitory efficiency and a decrease of the double layer capacity. SEM and UV–Vis. spectroscopy have been utilised to specify the impact of the inhibitor’s existence on the superficial condition of the C-steel in the harsh solution. Temperature impact of the 4T-C molecule on the corrosion conducts of C-steel in 1 M HCl at the inhibitor’s optimal amount of 10−3 M has been explored in the T range of 303–333 K. It could be stated that inhibitive efficiency was not significantly affected by the temperature rise. The Langmuir isotherm model was found to govern 4T-C adsorption on C-steel surface. Energy, enthalpy and entropy of activation were calculated and discussed. The Arrhenius law was used to calculate the adsorption free energy. The chemisorption of 4T-C on the C-steel surface was confirmed by a free adsorption energy of −44.04 kJ/mol. To support the experimental results, the investigated inhibitor molecule was optimized using B3LYP/6–31+ G(d,p) level of theory and Molecular Dynamic Simulation (MDS). The calculation was apprehended in aqueous medium. The global and local chemical reactivity describing parameters were determined and analysed.

Functionalization Strategies for Electropolishing Process of Carbon Steel Using Novel Quinazoline-4-one Derivatives: Synthesis, Spectroscopic Characterization, and DFT Studies.

A novel class of organic electropolishing (EP) inhibitors, entitled quinazoline-4-one derivatives (benzylidene oxoquinazolineyl acetohydrazide (BOA)), has laid a solid foundation for the creation of a new efficient inhibitor platform for the dissolution of carbon steel (C-steel) in 8 M H3PO4. Fourier-transform infrared (FTIR), 1H NMR, and elemental analyses have all been employed to identify BOA's functional groups, components, and active centers. The inhibition strength of BOA derivatives (m-NBOA, p-HBOA, and p-BBOA) on C-steel was assured by galvanostatic polarization measurements. Within the range of concentrations (0.33-3.43 × 10-3 mol/L) and temperatures (298-313 K) evaluated, the tested derivatives exhibit extraordinarily high gloss and low roughness, and improved the corrosion resistance of the electropolished surface with the lowest negative environmental impact. The dissolution rate (IL) decreases with increasing BOA concentration, supporting a mass transport-controlled technique and demonstrating that BOA is appropriate for anodic inhibitors. Activation energy indicates physical adsorption. Thermodynamic parameters were calculated for further investigation of the heat involved and the mechanism of the EP process. Adsorption isotherm and adsorption thermodynamics parameters were discussed using three models: Langmuir, Flory-Huggins, and kinetic adsorption isotherms, to study the inhibition of EP of the steel surface. The free energy of adsorption was calculated to assert the physisorption process. A scanning electron microscope (SEM) was utilized to inspect the morphology of the metal surface before and after the inclusion of BOA under different conditions. In contrast, the surface roughness was identified using an atomic force microscope (AFM) and reflectance. Eventually, practical results have been proved through computational calculations using the LYP correlation functional by the density functional theory (DFT) method.

Amino acid imidazole ionic liquids as green corrosion inhibitors for mild steel in neutral media: Synthesis, electrochemistry, surface analysis and theoretical calculations

The corrosion inhibition properties of three amino acid imidazole ionic liquids ([CyVIm][AA]) as corrosion inhibitors for mild steel in a 3.5 wt% NaCl corrosion medium were evaluated by electrochemical measurements. The polarization experiments show that [CyVIm][AA] influences anode reaction processes, demonstrating that [CyVIm][AA] is an anodic inhibitor type corrosion inhibitor. [CyVIm]Try outperforms [CyVIm]His and [CyVIm]Pro in terms of corrosion inhibition. The results of surface analysis and quantum chemical calculations show that [CyVIm]Try can form a protective film on the surface of mild steel and inhibit surface corrosion. Furthermore, by applying molecular dynamics simulations, after investigating the corrosion inhibitor adsorption trends on the Fe (110) surface, the interaction order between the molecular framework of the Fe corrosion inhibitor and the Fe (110) surface for entanglement was determined. According to the radial distribution function, the corrosion inhibitor adsorption mode on the metal surface is composite adsorption with chemisorption as the major mode and physical adsorption as the secondary mode.