Potential Corrosion Inhibitor Research Articles

Carbon dot aggregates: a new strategy to promote corrosion inhibition performance of carbon dots

The corrosion of metal not only produces serious economic losses and environmental pollution but also threatens equipment safety. Carbon dots (CDs) exhibit outstanding inhibition properties to availably retard the corrosion of metal. However, the present CDs-based corrosion inhibitors still fail to fully exert the environmentally friendly and low-cost merits of CDs. To address this issue, CD aggregates (CDAs) prepared by low-cost and eco-friendly CDs are developed as novel corrosion inhibitors for the first time, and their corrosion inhibition mechanism is disclosed. Specifically, CDAs with excellent long-term dispersion stability are synthesized by solvothermal treatment of CDs formed by citric acid and urea. CDAs at only 200 mg/L provide a corrosion inhibition effect of 90.38% for Q235 carbon steel in 1 mol/L HCl solution, approximately 1.53 times higher than that of CDs (59.21%). Moreover, the corrosion inhibition mechanism of CDAs is proposed through the analysis of adsorption isotherm, examination of corrosion morphologies, and theoretical calculations. That is, CDAs physically and chemically adsorb on the carbon steel surface, mainly hindering its anodic reaction, thus retarding the corrosion of carbon steel. This research firstly verifies the corrosion inhibition potential of green and low-cost CDAs and provides a novel strategy to promote the corrosion inhibition performance of CDs, promoting the progress of aggregate-based corrosion inhibitors.

Eggshell waste extract as potential natural corrosion inhibitor for AISI 1020 steel in acidic environment

Eggshell waste extract as potential natural corrosion inhibitor for AISI 1020 steel in acidic environment

Inhibitive Effect of Mangifera Indica Extract on Mild Steel in Hydrochloric Acid Solution

This research investigated the corrosion inhibition potential of Mangifera Indica Peel Extract (MIPE) for mild steel in a 1 M HCl solution. The study explored the effects of extract concentration, solution temperature, and immersion time on the inhibition potential of MIPE using weight loss measurements at extract concentrations of 0, 1.0, 1.5, and 2.0 g/L, temperatures of 303 K and 323 K, and immersion times of 1, 2, 4, 6, and 8 h. Experimental results showed that MIPE significantly reduced the corrosion rate of mild steel, with maximum inhibition efficiency reaching 97.26% and 94.83% at 2.0 g/L MIPE concentration and solution temperatures of 303 K and 323 K, respectively. The uninhibited mild steel experienced increased corrosion rates with rising temperatures and longer immersion times. The inhibition efficiency of MIPE improved with higher extract concentrations and immersion periods. These findings underscore the potential of MIPE as an effective and environmentally friendly corrosion inhibitor in acidic environments.

Imidazole derivative for corrosion protection: A comprehensive theoretical and experimental study on mild steel in acidic environments

The inhibition efficiency derivative imidazole, 2-mercapto-5,5-diphenyl-3,5-dihydro-4 H-imidazol-4-one (AM0), against corrosion in a hydrochloric acid (HCl) environment was studied. The research focused on the compound's ability to adsorb onto mild steel surfaces. Various experimental techniques, including potentiodynamic polarization (PDP), electrochemical frequency modulation (EFM), and impedance spectroscopy (EIS), were employed to analyze the inhibitory effects. Results showed that the effectiveness of AM0 increased with concentration, reaching an inhibitory efficiency of 95.1 %. Polarization studies revealed that the inhibitor displayed mixed-type behavior. The adsorption process was modeled using the Langmuir adsorption model. Surface characterization techniques such as scanning electron microscopy (SEM), energy dispersive X-ray analysis (EDS), and X-ray photoelectron spectroscopy (XPS) were utilized to examine the inhibited corrosion surfaces. Theoretical calculations based on density functional theory (DFT) and density functional tight binding (DFTB) suggested that inhibitors with electron-accepting capabilities exhibited strong interactions with the iron surface, shedding light on specific bond formations that contribute to the stability and interaction dynamics at the molecular interface. This study provides valuable information on the corrosion inhibition potential of the new imidazole compound, offering important pointers for the development of effective corrosion inhibitors in acidic environments.

Evaluation of the corrosion inhibition potential of Azadirachta indica leaves on thermo mechanically treated steel rebars using an artificial neural network, electrochemical and spectroscopic approach

Evaluation of the corrosion inhibition potential of <i>Azadirachta indica</i> leaves on thermo mechanically treated steel rebars using an artificial neural network, electrochemical and spectroscopic approach

Schiff base derived from 2-hydroxy napthaldehyde as anti-corrosive for mild steel in acid media: experimental investigation and theoretical modelling

Schiff bases (SBs) have the fundamental characteristics of substances that are mostly eligible for testing as inhibitors of corrosion for various metal/electrolyte systems. Through their electron-rich centres, such as the > C = N– (imine) moiety, SBs adsorb and create a surface coating that mitigates corrosion. Because of its π-acceptor characteristics, the > C = N– (imine) moiety provides a strong bonding with the metallic ions. It's vital to note that SBs with polar substituents at the right locations can form chelates with the central metal ions; as a result, these SBs are anticipated to function better as corrosion inhibitors than SBs without substituents. Two distinct Schiff bases, NL1 and NL2, with naphthalene rings have been synthesised, and their structures have been confirmed by the use of 1H and 13C NMR spectrum methods. The anticorrosion potential of the NL1 and NL2 was further confirmed by quantum chemical calculations such as DFT studies and ESP diagrams. The corrosion inhibition potential of the NL1 and NL2 was investigated using the electrochemical method, demonstrating maximum corrosion inhibition efficiency up to 89.2% and 89.5%, respectively on mild steel in 1 M HCl media. The results are further supported by Scanning Electron microscopic (SEM) images and EDAX studies.

Comprehensive Review of Recent Advances in Nanoparticle-Based Corrosion Inhibition Approaches

Corrosion of metals is a persistent challenge in various industries, leading to significant economic losses and safety hazards. Conventional corrosion inhibitors often face limitations such as environmental toxicity, low efficiency, and short-term protection. Nanoparticle-based corrosion inhibitors have emerged as a promising alternative due to their unique properties and versatile applications. This paper provides a comprehensive review of the recent advances in nanoparticle-based corrosion inhibition strategies from 2015-2024 by harvesting data from secondary sources. The fundamental mechanisms underlying the corrosion inhibition by nanoparticles are discussed, including adsorption processes, passivation mechanisms, and synergistic effects with other inhibitors. Various types of nanoparticles, including metallic nanoparticles, metal oxide nanoparticles, polymer nanocomposites, carbon-based nanoparticles, and organic-inorganic hybrid nanoparticles, are explored for their corrosion inhibition potential. Furthermore, the applications of nanoparticle-based corrosion inhibitors in industries such as oil and gas, aerospace, automotive, marine, and infrastructure are highlighted. Despite significant progress, challenges such as stability, compatibility, and environmental concerns remain to be addressed. Future directions in nanoparticle-based corrosion inhibition research are also discussed, aiming to guide further developments in this promising field.

Combined DFT and Monte Carlo simulation studies of potential corrosion inhibition properties of coumarin derivatives.

Corrosion, the degradation of materials due to chemical reactions with their environment presents significant challenges both economically and environmentally. It affects various industries, including construction, transportation, and manufacturing, leading to equipment failures, safety hazards, and increased maintenance costs. Coumarin derivatives have shown promise due to their inherent chemical properties and potential for biodegradability. In this study, a series of the coumarin derivatives were examined in silico to reveal their potential corrosion inhibition properties toward the Fe(110) and Cu(111) surfaces. The compounds investigated include coumarin (2H-chromen-2-one, 1), furanocoumarin (7H-furo[3,2-g]chromen-7-one, 2), dihydrofurano coumarin (2,3-dihydro-7H-furo[3,2-g]chromen-7-one, 3), pyrano coumarin-linear type (8,8-dimethyl-2H,8H-pyrano[3,2-g]chromen-2-one, 4), pyrano coumarin-angular type (8,8-dimethyl-2H,8H-pyrano[2,3-f]chromen-2-one, 5), bicoumarin (3,3'-methylenebis(2H-chromen-2-one), 6), and phenyl coumarin (4-phenyl-2H-chromen-2-one, 7). The findings suggest that the bicoumarin derivative 6 exhibits the lowest adsorption energy with the Fe(110) surface, while the same energy absolute value is about two times lower for the Cu(111) surface. This is due to the formation of a planar configuration of a molecule of 6 on the metal surfaces with the participation of both coumarin fragments upon interacting with the Fe(110) surface, while one coumarin fragment interacts with the Cu(111) surface. Density functional theory (DFT) calculations were employed to study the electronic properties of the coumarin derivatives. The specific computational method used was B3LYP, a hybrid functional that combines with the 6-311 + + G(d,p) basis set. Each coumarin derivative was first subjected to a geometry optimization to find the most stable molecular structure. Electronic properties, dipole moments, and molecular electrostatic potential surfaces were calculated. The Monte Carlo simulations were used to model the adsorption behavior of the coumarin derivatives on metal surfaces, namely, Fe(110) and Cu(111). These simulations allowed to visualize interaction of the studied molecules with the metal surfaces, which is crucial for their function as corrosion inhibitors. The present study provides a comprehensive understanding of the corrosion inhibition potential of the applied coumarin derivatives. The insights gained from these methods can inform the development of effective, sustainable corrosion inhibitors that are both environmentally friendly and highly efficient.

Lawsonia inermis as an Active Corrosion Inhibitor for Mild Steel in Hydrochloric Acid

Corrosion is a pervasive issue affecting metallic materials, with significant economic losses and safety risks in various industries. Mild steel, extensively used in construction and infrastructure, faces corrosion challenges, needing continuous research to effectively tackle them. Natural compounds, because of their eco-friendliness and corrosion inhibition potential, are attracting increasing interest for corrosion control. Lawsonia inermis (LI), or henna, a plant native to North Africa and South Asia, has bioactive compounds exhibiting corrosion inhibitive properties. This study comprehensively explores Lawsonia inermis’s effectiveness as a corrosion inhibitor for mild steel, filling a gap in the existing research. Various concentrations of Lawsonia inermis extract were tested in acidic solutions to evaluate corrosion inhibition. Experimental results indicate a significant reduction in the corrosion rate with increasing inhibitor concentration. Langmuir adsorption isothermal analyses reveal the adsorption mechanism as being an interplay between physisorption and weak chemisorption. Electrochemical measurements demonstrate Lawsonia inermis’s capability to alter both cathodic and anodic reactions, leading to improved corrosion resistance. Scanning electron microscopy reveals a more even surface morphology in the presence of the Lawsonia inermis, indicating corrosion inhibition. Gas chromatography–mass spectrometry (GC-MS) analyses identified organic compounds in Lawsonia inermis extract responsible for corrosion inhibition. Overall, Lawsonia inermis emerges as a promising corrosion inhibitor for mild steel, offering excellent inhibition efficiencies. This study sheds light on its adsorption behaviour and provides insights into its mechanism of action. These findings underscore Lawsonia inermis’s potential as a green corrosion inhibitor, paving the way for its practical application in industrial corrosion protection strategies.

Phytochemicals as eco-friendly corrosion inhibitors for mild steel in sulfuric acid solutions: a review

Abstract Plant extracts represent abundant sources of biomolecules distributed throughout various plant parts. These biomolecules are extracted using diverse solvents and methods. Within these plant extracts lie bioactive compounds, known for their antioxidant properties and anticorrosive capabilities. Detecting and isolating these active biomolecules from plant extracts necessitates analytical techniques such as gas chromatography-mass spectrometry and liquid chromatography-mass spectrometry. The active biomolecules within plant extracts contain heteroatoms within their structures, facilitating their adsorption on steel surfaces and conferring corrosion inhibition properties. The advantages of plant extracts as green corrosion inhibitors include ready availability, ease of application, eco-friendly characteristics, and cost-effectiveness. These extracts adhere to steel surfaces, blocking their active sites and effectively reducing the corrosion rate. This review consolidates the findings on the corrosion inhibition potential of plant extracts from various plant parts, elucidating their performance in different concentrations of sulfuric acid.

Verbena officinalis (VO) leaf extract as an anti-corrosion inhibitor for carbon steel in acidic environment

In the present work, Verbena Officinalis (VO) leaf extract was used as potential corrosion inhibitor for the corrosion of carbon steel (CS) in 0.5 M H2SO4 medium. Further, the corrosion inhibiting nature of VO leaf extract towards the CS was evaluated using mass loss (ML), potentiodynamic polarization (PDP), electrical impedance spectroscopy (EIS) and surface morphological analyses using atomic force microscope (AFM) and X-ray photoelectron spectroscopy (XPS) techniques. Calculation of activation energy Ea∗\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\left( {{\ ext{E}}_{{\ ext{a}}}^{*} } \\right)$$\\end{document} using Arrhenius equation shows the increase in activation energy when adding the VO leaf extract in 0.5 M H2SO4 medium and the maximum activation energy (Ea∗\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$${\ ext{E}}_{{\ ext{a}}}^{*}$$\\end{document} = 49.9 kJ mol−1) was observed for 1000 mg L−1 VO leaf extract in acid medium. The negative free energy values suggested the spontaneous and the stability of the adsorbed layer of VO leaf extract on the CS surface. Using EIS measurements, high percent inhibitory effectiveness of 91.1% for 1000 ppm solutions was achieved. With an increase in VO leaf extract dose, the double layer capacitance (Cdl) values fall while the values of charge transfer (Rct) increase. This showed that a protective layer of VO leaf extract on CS surface was formed. The polarization curves showed that the VO leaf extract acts as a mixed-type inhibitor. It is discovered that the adsorption of VO leaf extract molecules adhering to the CS surface followed the Langmuir isotherm. The anti-corrosion action of VO leaf extract is fully demonstrated by some surface techniques.

Experimental accompanied with computational (atomic/electronic)-level simulation investigations of Polygonum cuspidatum root extract as sustainable corrosion inhibitor for mild steel in aggressive corrosive media.

This study investigates the corrosion inhibition potential of Polygonum cuspidatum root extract (PCRE) on mild steel in a 0.5M HCl acidic environment. Herein, various techniques including electrochemical and gravimetric measurements were employed, along with scanning electron microscopy (SEM) and contact angle (CA) measurements for surface morphology analysis. The impedance study revealed a concentration-dependent enhancement in corrosion resistance, classifying PCRE as a mixed-type inhibitor (i.e., inhibits both anodic and cathodic reactions). The highest efficiency, 96.71% at 298K, was observed at a 1000-ppm PCRE concentration. Langmuir model computations suggested chemisorption and physisorption of PCRE on the electrode substrate. Increased Rp (from 28.648 to 174.01 Ω) and Rct (185.74 Ω cm2) at 1000ppm demonstrated improved corrosion resistance. Additionally, SEM analysis displayed a uniform, protective surface, reducing metal degradation. Theoretical calculations highlighted strong interactions between PCRE and mild steel, with a low energy gap (ΔE), as follows: 1-O-methylemodin (2.267eV) < emodin (2.288eV) < emodin-1-O-glucoside (2.343eV) < piceid (2.931eV) < resveratrol (2.952eV), confirming PCRE's excellent micro-level anti-corrosion capabilities. This eco-benign corrosion inhibitor offers sustainable, low-toxicity protection, cost-effectiveness, and versatile performance, surpassing commercial counterparts while aligning with sustainability goals.

تثبيط التآكل للصلب المقوى في كلوريد الصوديوم بنسبة 3.5 % باستخدام عقار بنتوكسيفيلين منتهي الصلاحية: دراسة فقدان الكتلة

Corrosion is a major issue affecting the durability and performance of various metallic materials, leading to substantial economic losses and safety hazards. The corrosion of reinforced steel in sodium chloride environment poses a significant concern for various industrial applications. This study aims to investigate the corrosion inhibition properties of expired pentoxifylline drug on reinforced steel in a 3.5% NaCl solution. The mass loss method was utilized to quantify the corrosion rate and assess the efficiency of the expired pentoxifylline drug as a potential corrosion inhibitor. The results indicate that the corrosion rate of steel in the 3.5% NaCl solution decreased significantly in the presence of expired drug. Higher concentrations of expired drugs have shown a greater impact on corrosion inhibition. Investigation of the effects of temperature on corrosion inhibition efficacy. The inhibition efficiency increased with increasing concentrations of the inhibitor and decreased with increasing immersion time. The experimental data were tested according to the Langmuir adsorption isotherm, through which the equilibrium adsorption constant (Kads) was calculated and found to be 4.38 litres mol-1 as the maximum value when immersed for one day. The standard free energy of adsorption (∆G_ads^o) ranged from 45 to 30.5 kJ mol-1. Keywords: Reinforced steel, sodium chloride medium, inhibition, expired drugs, pentoxifylline

Multi-faceted investigation: DFT studies and corrosion inhibition potential of 4-(2-((2-methyl-1H-indol-3-yl)methylene)hydrazinyl)- phenol for mild steel in 0.5 M HCl medium

Multi-faceted investigation: DFT studies and corrosion inhibition potential of 4-(2-((2-methyl-1H-indol-3-yl)methylene)hydrazinyl)- phenol for mild steel in 0.5 M HCl medium

Methanol extract of Murraya koenigii stem as green inhibitor for mild steel corrosion in 1 M HCl solution

In this work, methanol extract of Murraya koeginii stem has been studied as an ecofriendly inhibitor against mild steel corrosion in 1 M hydrochloric acid medium. Ultraviolet–visible and Fourier transform infrared spectroscopic tools were employed to characterize the extract. Corrosion inhibition efficacy of the extract against mild steel was studied in terms of weight loss method and electrochemical measurement method. Weight loss measurement shows the inhibition efficiency of 94.95 % for the first 6 h of immersion time and maximum efficiency of 96.39 % for 24 h immersion time using 1000 ppm inhibitor solution. Electrochemical measurement shows that for the same concentration of inhibitor, inhibition efficiency is 81.54 % in as-immersed condition whereas it is 85.76 % in 1 h immersed condition. Free energy of the adsorption reflected the physisorption followed by chemisorption. Similarly, thermodynamic parameters revealed the feasibility and spontaneity of the adsorption. Obtained results showed that the methanol extract of Murraya koeginii stem can be a potential corrosion inhibitor.

Influence of Soda and Kraft lignin in polyurethane coatings for the corrosion protection of mild steel in 3.5 % NaCl solution

This study highlights the potential of coconut shell biomass waste-derived lignins (CSL) as corrosion inhibitors to reinforce the coating properties of polyurethane. The utilization of CSL involves a green approach to prepare eco-friendly metallic coatings. Herein, lignin was extracted via Kraft and Soda pulping processes. The present findings indicated that the percentage yield of Soda lignin (SL) (26.43 ± 0.75 %) was significantly higher than that of Kraft lignin (KL) (8.52 ± 0.39 %). Electrochemical impedance spectroscopy and potentiodynamic polarization corrosion monitoring techniques were used to evaluate the anticorrosive performance of modified polyurethane coatings on mild steel exposed to 3.5 % NaCl solution. In this study, doping concentration of 5 wt% KL and SL into polyurethane attained the optimum anticorrosion performance. The surface conditions of uncoated and coated mild steel substrates were investigated through scanning electron microscopy/energy dispersive X-ray (EDX) analysis, salt spray and adhesion tests. EDX analysis demonstrated that polyurethane added with 5 wt% doping concentration of SL contained the highest content of Fe (86.05 wt%) compared to 5 wt% KL which contained 79.64 wt% of Fe, whereas neat polyurethane coating contained 75.43 wt% of Fe. Hence, enhanced corrosion protection of polyurethane through the addition of CSL, particularly SL, possesses a viable and an effective green approach to utilize coconut shell biomass waste for the application as a potential corrosion inhibitor in organic coatings.

Regio- and chemoselective synthesis of new isoxazolyl-linked benzimidazolones via 1,3-dipolar cycloaddition: Characterization, corrosion studies, density functional theory, and Monte Carlo simulations

In this study, novel compounds, isoxazolyl-benzimidazolone (AE1) and isoxazolinylbenzimidazolone (AE2), were synthesized and characterized using various spectroscopic methods. This involved employing 1,3-dipolar cycloaddition techniques with 2,4,6-trimethoxylbenzonitrile N-oxide and mesitonitrile-oxide in combination with “1-cyclohex-1-en-1-yl-3-propargyl-benzimidazolone” or “1-cyclohex-1-en-1-yl-3-allylbenzimidazolone”. The structural identification of these newly formed cycloadducts was achieved through comprehensive analytical and spectral analyses. The two heterocyclic compounds, AE1 and 2, have been investigated into their corrosion inhibition potential of mild steel (MS) in 1.0 M HCl, utilizing diverse analysis methods such as Potentiodynamic Polarization (PDP), Electrochemical Impedance Spectroscopy (EIS), Scanning Electron Microscopy (SEM), and Energy Dispersive X-ray (EDX) techniques. The outcomes revealed significant corrosion inhibition, with AE1 displaying the highest effectiveness (97.2 %), followed closely by AE2 (95.8 %) at 10−4M. The inhibitors were observed to adhere to the MS surface following Langmuir isotherms, and their adsorption and thermodynamic characteristics were thoroughly assessed. Moreover, Density Functional Theory (DFT) and Monte Carlo (MC) simulations corroborated the robust adsorption capability of these organic chemicals on the MS surface.

Kopsia terengganensis’ alkaloids as potential green inhibitors for mild steel corrosion in CO2-saturated 3.5% NaCl medium

The corrosion inhibition potential of alkaloids from Kopsia terengganensis bark extract (KTBE) in mitigating the mild steel corrosion in a CO2-saturated 3.5% NaCl medium was evaluated. Standard corrosion evaluation methods, including weight loss test, electrochemical impedance spectroscopy (EIS), and potentiodynamic polarization (PD) were employed, which revealing a concentration-dependent enhancement in KTBE's inhibition efficiency. At 500 ppm, the corrosion inhibition efficiency recorded the highest value of 90.63% based on the weight loss study and 87.38% based on electrochemical analysis. Tafel slopes in PD studies affirmed that KTBE functioned as an anodic-type inhibitor. The adsorption of the inhibitor is in accordance with the Langmuir adsorption isotherm with an adsorption free energy (ΔG°ads) of −26.47 kJ/mol, suggesting the binding of KTBE molecules by means of physisorption. Surface analysis conducted through scanning electron microscopy (SEM), energy dispersive X-ray (EDX) spectroscopy, and Fourier transform infrared spectroscopy (FTIR) confirmed the formation of a protective inhibitive layer on the surface of mild steel. The proposed corrosion inhibition mechanism involves electrostatic interactions between KTBE molecules and the mild steel surface. This comprehensive investigation underscores KTBE's potential as an effective corrosion inhibitor in corrosive environments.

CORROSION INHIBITION BEHAVIOUR OF CUSTARD APPLE LEAVES AND ACACIA CONCINNA EXTRACT ON MILD STEEL IN ACIDIC MEDIA: ADSORPTION AND THERMODYNAMIC STUDY

Custard apple leaves extract (CALE) was tested to evaluate corrosion inhibition efficiency for mild steel under acidic medium. The test metal substrate was collected over a period of 24 hr of contacting with acid to determine the corrosion inhibition efficiency (CIE) and corrosion rate (CR) using the Gravimetric analysis. The findings of the study were applied to examine the adsorption behavior and thermodynamic characteristics for CALE as a potential corrosion inhibitor in acidic environment. Mild steel exhibited the highest corrosion rate in the absence of a corrosion inhibitor in a 0.5 M sulphuric acid solution. However, the rate of corrosion was observed to decrease gradually with increase in CALE concentration (0.4–2.0 g/l). The similar trend was noted at the experimental temperature range of 298-328 K. Adsorption behavior was investigated using the Langmuir, Temkin, Freundlich, and Flory Huggins adsorption isotherm models. The Temkin adsorption isotherm model provides the best fit to the experimental data. Besides, the negative values of Gibb’s free energy of adsorption (ΔGad) reveal strong evidence for the spontaneous nature of CALE adsorption on mild steel surface. The increase in activation energy (Ea) from 35.05 kJ/mol in the blank test solution to 68.03 kJ/mol at 2.0 g/l concentration of CALE indicates the formation of a protective film of inhibitor molecules on the metal surface. Adsorption enthalpy values (∆H=31.28-73.79 kJ/mol) over the concentration range (0-2.0g/l of CALE) implies physical adsorption, whereas negative entropy values (ΔS) suggests free movement of inhibitor molecules in the bulk solution. Additionally, a synergistic effect was demonstrated in lowering the corrosion rate by combining Acacia concinna extract (ACE, 0.1-0.3 g/l) with CALE, thereby enhancing the overall corrosion inhibition efficiency. For citation: Jitendra Kisan Shinde, Ravindra Gulab Puri, Pawan Devidas Meshram, Rajkumar Shankarrao Sirsam Corrosion inhibition behaviour of Custard apple leaves and Acacia concinna extract on mild steel in acidic media: adsorption and thermodynamic study. ChemChemTech [Izv. Vyssh. Uchebn. Zaved. Khim. Khim. Tekhnol.]. 2024. V. 67. N 7. P. 119-126. DOI: 10.6060/ivkkt.20246707.7038.

Corrosion inhibition potential of new oxo-pyrimidine derivative on mild steel in acidic solution: Experimental and theoretical approaches

Through electrochemical impedance testing and potentiodynamic polarisation, it was investigated how a material at ambient temperature might prevent corrosion. 1-(5-(4-Methoxybenzoyl)-4-(4-methoxyphenyl)-2-oxopyrimidin-1(2H)-yl)-3-(4-chlorophenyl) urea (MMOP) was used as a corrosion inhibitor on mild steel samples in 1 M HCl. With a maximum inhibition efficacy of 97.6 % (at immersion period of 72 h and concentration of 5 × 10-4 M), the inhibitor used was shown to be an exceptional corrosion inhibitor. Based on the findings of potentiometric polarization, this substance falls within the category of mixed inhibitors since corrosion inhibition was accomplished by the inhibitor adhering to the metal. Adsorption of investigated MMOP completely followed Langmuir adsorption isotherm and adsorption can be categorized as physisorption–chemisorption, with a value of ΔGads of -35.6 kJ.mol-1. In order to confirm the effectiveness of the protective coating applied to the mild steel surface, we analysed the protective layer through the utilization of Atomic Force Microscopy (AFM) and Scanning Electron Microscope (SEM) / Energy Dispersive X-ray spectrometry (EDX). The density functional theory (DFT) and Monte Carlo simulation (MCS) approaches were used to investigate the relationship between molecular structure and inhibitory efficacy. The results suggest that the inhibitor in issue could be a new approach to reducing mild steel corrosion under harsh circumstances and long immersion times.