Corrosion Inhibition Efficiency Research Articles

Generation of a lignin-polyester coating for the corrosion protection of steel surfaces applied by atmospheric plasma spraying

The natural process of metal corrosion causes significant losses in a wide range of industries, requiring substantial efforts to contain its effects. An alternative approach to corrosion protection is the use of renewable organic coating materials. This research proposes the use of lignin-polyester blends as coating materials. Due to the abundance of functional groups in the lignin structure, it can act as corrosion inhibition centers in the coating. The coatings are deposited on stainless steel surfaces by a novel process route via atmospheric plasma powder spraying (APPS). To determine the effect of the lignin content on the corrosion performance, the specific amounts of lignin and polyester have been varied in 10 % increments from 0 % to 100 % with constant coating parameters. The as-produced coatings exhibited thicknesses that ranged from 11 μm to 30 μm, respectively for the pure lignin and polyester coatings. Additionally, scanning electron microscopy (SEM) analysis demonstrated the meltability of the lignin and polyester powder through the plasma process. Coatings containing a greater proportion of polyester exhibited superior meltability and better coverage. Furthermore, it was observed that the APPS promoted cross-linking of the lignin particles, as determined by Fourier transform infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS). This, in conjunction with well-balanced lignin-polyester ratios, was instrumental in achieving advanced corrosion resistance as evidenced by Potentiodynamic polarization measurement (PDP). The lignin proportion between 40 % and 60 % produced the highest corrosion inhibition efficiency, with a maximum inhibition of 96 %. Furthermore, pull-off adhesion tests suggest that lignin contributes to the overall cohesive strength of the blend.

Unraveling the corrosion inhibition behavior of prinivil drug on mild steel in 1M HCl corrosive solution: insights from density functional theory, molecular dynamics, and experimental approaches.

The deterioration of mild steel in an acidic environment poses a significant challenge in various industries. The emergence of effective corrosion inhibitors has drawn attention to studies aimed at reducing the harmful consequences of corrosion. In this study, the corrosion inhibition efficiency of Prinivil in a 1M HCl solution through various electrochemical and gravimetric techniques has been investigated for the first time. The results demonstrated that the inhibition efficiency of Prinivil expanded from 61.37% at 50ppm to 97.35% at 500ppm concentration at 298K. With a regression coefficient (R 2) of 0.987, Kads value of 0.935 and Ea value of 43.024kJ/mol at 500ppm concentration of inhibitor, a strong affinity of Prinivil for adsorption onto the metal surface has been significantly found. Scanning electron microscopy (SEM) and contact angle measurement analyses further support the inhibitory behavior of Prinivil, demonstrating the production of a defensive layer on the surface of mild steel. Additionally, molecular dynamics (MD) and Monte Carlo simulations were employed to investigate the stability and interactions between Prinivil and the metallic surface (Fe (1 1 0)) at the atomic level. The computed results reveal strong adsorption of Prinivil upon the steel surface, confirming its viability as a corrosion inhibitor.

BF2 complexes of pyridyl‐isoindoline‐1‐ones as an efficient corrosion inhibitor for mild steel in 1 M HCl and the application for surgical instruments anticorrosion

AbstractIn this study, BF2 complexes of pyridyl‐isoindoline‐1‐ones (BPIO) has been firstly designed and investigated as an excellent corrosion inhibitor for the mild steel in 1 M HCl. The corrosion protection properties of BPIO were studied by using a series of experiments. The results indicated BPIO has excellent inhibition performance, and inhibition efficiency of BPIO reached up to 96.6%. The effects of immersion temperature and time were investigated by weight loss experiments to evaluate the stability of adsorbed BPIO film in protecting steel surface. Based on potentiodynamic polarization studies, BPIO acted as one mixed‐type corrosion inhibitor with predominant anodic effectiveness, and its adsorption on the mild steel follows the Langmuir adsorption isotherm. The values of ΔGads suggested the adsorption of BPIO on the mild steel surface was through a combination of chemisorption and physisorption. The adsorption of BPIO molecules on the steel surface was further identified by the techniques of scanning electron microscopy (SEM) and X‐ray photoelectron spectroscopy (XPS). The quantum chemical calculations based on density functional theory (DFT) and molecular dynamics (MD) simulations were used to optimize the BPIO molecular structure and investigate the inhibitive properties on the theoretical level, which agreed well with the experimental results. Besides, BPIO has been used for the development of water soluble metal antirusting agent.

Machine learning insight into inhibition efficiency modelling based on modified graphene oxide of diaminohexane (DAH-GO) and diaminooctane (DAO-GO)

The effective prediction of corrosion inhibition efficiency (%IE) of modified graphene oxides (GOs); diaminohexane-modified graphene oxide (DAH-GO) and diaminooctane-modified graphene oxide (DAO-GO) is vital for advanced material applications. This study employs a dual-modelling scheme to predict the %IE, for this purpose, four stand-alone machine learning (ML) models (Multivariate Regression (MVR), Gaussian Process Regression (GPR), Adaptive Neuro-Fuzzy Inference System (ANFIS), and Neural Network (NN)), and five simple averaging (SA) ensemble paradigms (MVR-SA, GPR-SA, ANFIS-SA, NN-SA, and Decision Tree-SA (DT-SA)). Feature selection processes were carried out to develop three distinct models, leading to a comprehensive comparative analysis. The results demonstrated that the non-linear stand-alone models (GPR, ANFIS, NN) significantly outperform the linear MVR model, with the M2 model configuration yielding the highest performance across all models. Remarkably, GPR-M2 achieved perfect model tuning with zero error rates, indicating its superior predictive capabilities. Ensemble techniques further improved performance, reflecting the experimental data's complexities in %IE modelling. The hierarchical order of performance in the training phase in the testing phase is DT-SA < MVR-SA < ANFIS-SA < NN-SA < GPR-SA. The GPR-SA ensemble emerged as the most accurate technique, substantially enhancing the predictive accuracy of the ensemble models by up to 67.73% in the training phase and 50.71% in the testing phase. These findings suggest the potential of GPR-SA in boosting the performance of ensemble approaches in material science applications. The study recommended a promising future for ML in the development and application of corrosion-inhibitors.

Corrosion inhibition of stainless steel through the formation of hydrophobic nanoporous oxide layer

This study investigates anti-corrosion properties of anodized and hydrophobically modified anodized SUS 304 stainless steel (SS 304). Utilizing electrochemical anodization and subsequent annealing, a well-ordered hexagonally closed-packed nanoporous oxide layer on the SS 304 surface, designated as AAS, was successfully developed. Then, a self-assembled monolayer of silane molecules, namely, octadecyltrimethoxysilane (ODTS) and 1 H,1 H,2 H,2 H-perfluorooctyltriethoxysilane (PFTS), was formed on the nanoporous oxide layer of annealed-anodized SS 304. The FTIR study confirmed the formation of the self-assembly of silane molecules on nanoporous oxide surface. The self-assembled monolayers exhibited hydrophobic surface where hydrophobicity increases with increase of silane molecule concentration and gives a water contact angles measure of 127.60° and ∼ 128.83° for 0.50 wt% ODTS and 0.50 wt% PFTS, respectively. The potentiodynamic polarization study revealed a corrosion rate of 1.485 × 10−3 mm year−1 for AAS, 0.614 × 10−3 mm year−1 for 0.50 wt% ODTS-AAS, and 0.348 × 10−3 mm year−1 for 0.50 wt% PFTS-AAS. This represents a significant reduction in corrosion rate compared to bare stainless steel (4.385 × 10−3 mm year−1) when exposed to a simulated sea water environment. The AAS, 0.50 wt% ODTS-AAS and 0.50 wt% PFTS-AAS exhibited corrosion inhibition efficiency of 66.13 %, 85.97 % and 92.06 %, respectively. Electrochemical impedance analysis revealed that PFTS exhibits roughly double the effective charge transfer resistance of ODTS and 7.4 times higher than that of annealed anodized stainless steel, confirming superior corrosion inhibition capability. Overall, this research illuminates the mechanism behind self-assembled monolayer formation, resulting in the development of hydrophobic surfaces and the inhibition of corrosion on nanoporous oxide layers on stainless steel surfaces.

Characterization, inhibition efficiency and DFT simulation of 1,2-bis(2-bromobenzylidene)hydrazine towards aluminum 1050 in H2SO4 1M

In this study, 1,2-bis(2-bromobenzylidene)hydrazine (BBBH) has been synthesized and for the first time its corrosion inhibition efficiency was studied for pure aluminum corrosion in 1M sulfuric acid using polarization curve technique. After treatment of experimental data at 298 K, the results revealed that the compound is a good inhibitor and the efficiency increase with its concentration, to attain 83.23 % for 600 ppm. The adsorption process of this Schiff base on aluminum surface obeys Langmuir isotherm. To complete the inhibition study, thermodynamic parameters including activation energy, Gibbs free energy, were discussed. In order to characterize the Aluminum surface, scanning electron microscopy (SEM), DRX and X-ray photoelectron XPS were used to demonstrate the effect of the inhibitor and the formation of a protective layer. The molecular electronic structure of the title compound was established using the density functional theory (DFT) approach to understand molecular geometry, stability, and chemical reactivity. The FTIR, UV, 1H-NMR and Raman spectroscopy were further applied to examine its purity.

Performance of anionic dimeric surfactant on AZ31 Magnesium alloy in neutral medium unveiled through experimental and theoretical investigation

The synthesis of a novel eco-friendly anionic Gemini surfactant, pursuing three parameters of green chemistry: economic, environmental factor, and mass reaction efficiency is developed as a corrosion inhibitor for AZ31 Mg alloy. Herein, the corrosion inhibition ability of novel EDTA-based dimeric surfactant on AZ31 Mg alloy in corrosive media with varying concentrations of NaCl and Na2SO4 at temperatures between 30–50 °C were studied. The surfactant’s molecular structure is affirmed by FT-IR, NMR, and LC–MS techniques. Electrochemical techniques and surface morphology were employed to evaluate the corrosion inhibition efficiency. The inhibitor studied exhibited appreciable corrosion inhibition at 30 °C. The surfactant shows physical adsorption as per the data obtained in the Gibbs free energy and enthalpy of adsorption studies. The adsorption of the inhibitor was found to be a film-like layer on the surface of AZ31 Mg alloy and, is confirmed by SEM–EDX and XPS techniques. In addition, theoretical simulations were performed to compare with experimental results. Conclusively, the work provides a deeper understanding of the intricacies involved in the development of a new anionic dimeric surfactant as an effective corrosion inhibitor.

Thiol-ene Click Chemistry Synthesis of L-Cysteine-Grafted Graphene Oxide As a New Corrosion Inhibitor for Q235 Steel in Acidic Environment.

l-cysteine, as an eco-friendly and nontoxic corrosion inhibitor, was directly covalently linked to the carbon/carbon double bonds of the GO flakes by a thiol-ene click reaction to avoid decreasing the number of hydrophilic oxygen-containing polar functionalities. The corrosion inhibition performances of Cys-GO toward Q235 steel (QS) in diluted hydrochloric acid were studied by electrochemical methods. The corrosion was a charge transfer-controlled process, and Cys-GO manifested as a mixed-type corrosion inhibitor. The corrosion inhibition efficiency (η) for QS showed a first-increase-and-then-decrease trend with increasing Cys-GO concentrations. The optimum concentration of Cys-GO was 15 mg L-1, and the according η value was up to 90%. The Cys-GO adsorbed on the QS surface to form a protective barrier was responsible for the efficient corrosion inhibition. Langmuir adsorption isotherm model was fitted well with the experiment data, indicating a monolayer adsorption. Furthermore, the coordinate covalent bonds, π-back-donation effect, and electrostatic attraction were responsible for the Cys-GO adsorption on the QS surface.

2-Benzylsulfanyl-1H-benzimidazole and its mixture as highly efficient corrosion inhibitors for carbon steel under dynamic supercritical CO2 flow conditions

2-Benzylsulfanyl-1H-benzimidazole(2B1BI) was synthesized and used to inhibit the corrosion of carbon steel in supercritical CO2 brine at various rotation speeds. Thiourea (TU) can improve the inhibition of 2B1BI. The corrosion inhibition mechanism and adsorption process were investigated by electrochemical techniques and theoretical calculations. The results show that 2B1BI-TU mixed corrosion inhibitors exhibit increased adsorption with strong bonds on steel, forming a denser and more persistent protective film. This film can effectively inhibit corrosive particles, slowing down both general and localized corrosion. This study explores the potential of the new inhibitor as an efficient corrosion inhibitor in challenging environmental conditions.

Influence of sorbitol as a green and inexpensive corrosion inhibitor for Al-air batteries: An experimental and theoretical study

The Al-air battery (AAB) is a promising new energy source as an effective supplement to existing energy sources. However, hydrogen evolution reaction (HER) severely limits their application and development. In this paper, an inexpensive green additive, sorbitol, is introduced, and its inhibition effect on HER and its inhibition principle is investigated in experiments, quantum chemistry calculations and molecular dynamics (MD) simulations. The electrochemical experimental results show that the corrosion inhibition efficiency of sorbitol to pure Al anode significantly increases with increasing concentration of sorbitol, which is up to 54.2 % and 90.16 % with 20 % and 30 % sorbitol, respectively. It is calculated that, in the 4 mol/L NaOH solution with 20 % sorbitol, the capacity density and energy density of AAB significantly increase by 171.4 % and 147.4 %, respectively. This work demonstrates that sorbitol can form a strong hydrogen bond (H-bond) network with water molecules, which can reduce the activity of water and the hydrogen evolution of Al anode. Compared with glycerol and inositol, which possesses the same number of hydroxyl (–OH) groups, sorbitol presents the highest comprehensive HER resistance and battery performance, indicating that molecular backbone length of inhibitor can effectively influence the inhibition properties.

Preparation of efficient hydrochloric acid corrosion inhibitor from natural grease

Abstract To alleviate the metal corrosion problem caused by incomplete acid discharge during pickling or acidification, a corrosion inhibitor, long chain fatty hydrazides (LCFH), with a significant corrosion inhibition effect was synthesized from natural grease. The corrosion inhibition and adsorption properties of LCFH on carbon steel in 1 M HCl solution were studied by static sample weight loss test, electrochemical impedance spectroscopy, and potentiodynamic polarization curve. The results showed that LCFH exhibits excellent corrosion inhibition performance in HCl solution. The inhibition efficiency increases with the increase of inhibitor concentration. When the concentration of LCFH is 40 mg/L, the inhibition efficiency can reach 97.9%. The potentiodynamic polarization curve shows that LCFH is a corrosion inhibitor that mainly inhibits the cathodic reaction. The corrosion inhibitor is spontaneously adsorbed on the surface of low-carbon steel in physical form, which conforms to the Langmuir isothermal adsorption model.

Study of the Corrosion Inhibition Efficiency by Using New Azo Compounds from Thiazole Derivatives

Azo compounds were prepared by reacting thiazole derivatives with 2-naphthol, o-vanillin, 4-(dimethyl amino) pyridine, and 4-bromo aniline with thiazole derivatives. The molar conductivity of the azo compounds prepared in this study was measured using (ethanol) as a solvent and at room temperature, all compounds showed non-electrolytic behavior. The compounds were characterized by TGA/DTA, studying the thermal stability and calculating the activation energy of azo compounds, where the thermal analyses of the prepared compounds were measured to identify the temperature at which the compound disintegrates, as the compound has more than one degree of disintegration, and this variation in the degrees of disintegration and the remaining materials depends on the nature of the compound and the type of groups present in it, as well as the efficiency of their use as materials. Resistant to corrosion by weight loss method with different concentrations at constant temperature. The higher the concentration, the greater the inhibition efficiency.

Schiff Bases as Corrosion Inhibitors: A Mini-Review

Corrosion, a ubiquitous and economically burdensome phenomenon, poses a persistent challenge across various industries. As the search for effective corrosion inhibitors intensifies, Schiff bases have emerged as promising candidates due to their versatile chemical structures and unique reactivity. This mini-review provides a comprehensive overview of the role of Schiff bases in corrosion inhibition. Beginning with an introduction to corrosion and the imperative for corrosion inhibitors, the paper delves into the structural features and synthesis methods of Schiff bases. The mechanism of corrosion inhibition by Schiff bases is elucidated, emphasizing their interactions with metal surfaces. Recent advances in the field are highlighted, shedding light on novel Schiff base modifications that exhibit enhanced corrosion inhibition efficiency. The review also addresses characterization techniques employed to study the interaction between Schiff bases and metal surfaces. Furthermore, the practical applications of Schiff bases as corrosion inhibitors in diverse industries are explored, taking into account their compatibility with various metals and environments. Despite the promising prospects, challenges and limitations associated with Schiff bases as corrosion inhibitors are discussed, providing insights into future research directions. In conclusion, this mini-review consolidates current knowledge, offering a succinct yet comprehensive overview of Schiff bases as effective corrosion inhibitors and outlining avenues for further exploration in this dynamic field.

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.

Evaluation of adsorption behaviour of benzylidene chitosan derivatives at mild steel/ 0.5 M H2SO4 solution interface

Four green benzylidene chitosan derivatives (BCs) were synthesized and evaluated as anti-corrosive substances for the first time against mild steel corrosion in 0.5 M H2SO4 solution. The synthesized BCs were laid to infrared spectroscopy and proton resonance spectroscopy for structural confirmation. Gravimetric and electrochemical experiments were accustomed to appraise the effectiveness of inhibitors, however, Scanning Electron Microscopy-Electron Dispersive Spectroscopy (SEM-EDS), Atomic Force Microscopy (AFM), and X-ray Photoelectron Spectroscopy (XPS) were exploited to evaluate the protective mechanism offered by benzylidene chitosan derivatives. Experimental results demarcate the synthesized inhibitors; Anisaldehyde modified Chitosan (CMB), 2-Hydroxy-4-methoxybenzaldehyde modified Chitosan (CHMB), 2,4-Dimethoxybenzaldehyde modified Chitosan (CDMB) and 2-Bromo-4-methoxybenzaldehyde modified Chitosan (CBMB) exhibiting praising inhibitory properties for mild steel corrosion and CDMB was seen possessed preferable inhibition potential at the finest concentration of 500 mgL-1 owing to the proximity of two electron-donating OCH3 groups. Furthermore, the inhibitors have been recorded to behave mixed type with pronounced impact on hydrogen evolution kinetics. The order of inhibition efficacy obtained was CDMB (98.8 %) > CHMB (95.4 %) > CMB (92.8 %) > CBMB (89.2 %) which was further validated by quantum chemical calculations which later opened up about the mechanistic approach involved in electron transfer from inhibitors to metallic vacant orbitals. Additionally, the effect of molecular structure possessed by synthesized inhibitors has been correlated with observed variation in their corrosion inhibition efficiency.

Okra leaves extract as green corrosion inhibitor for steel in sulfuric acid: Gravimetric, electrochemical, and surface morphological investigations

Utilizing plant extracts as an alternative source for corrosion inhibitors holds significant promise in minimizing the risk of corrosion. In this study, an okra leaf extract (OLE) was employed as a corrosion inhibitor for N80 steel in 1.0 M H2SO4. The corrosion rate was assessed concerning temperature (30, 40, 50, and 60 °C) and inhibitor concentrations (blank, 25, 50, 75, and 100 ml/l) through weight loss and electrochemical polarization techniques. The results indicated that OLE functions as a mixed-type corrosion inhibitor, with corrosion rates increasing with temperature and decreasing with inhibitor concentration. The maximum corrosion inhibition efficiency reached 96 % at 30 °C and 100 ml/l. Adsorption studies revealed that OLE physically adsorbed onto the mild steel surface, following the Langmuir adsorption isotherm. Gravimetrical and electrochemical techniques were confirmed by FTIR and UV measurements, which showed the presence of a protective layer on the metal surface. Optical microscopy, AFM, and SEM images demonstrated the formation of a protective layer on the metal surface. Thermogravimetric analysis (TGA) highlighted the thermal stability exhibited by inhibitor molecules, which showed that OLE was thermally stable up to 85 °C.

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.

Exploring Ginkgo biloba extract's green corrosion inhibition effects on Q235 steel in H2SO4 environments

The corrosion inhibition properties of Ginkgo biloba extract on Q235 steel in 0.5 M H2SO4 solution were comprehensively investigated using weight loss measurements, electrochemical techniques, surface characterization, and quantum chemical calculations. The results demonstrate that Ginkgo biloba extract acts as an effective green corrosion inhibitor, with inhibition efficiencies reaching up to 96.54% at a concentration of 0.7 g/L. The inhibition efficiency increased with increasing extract concentration and temperature. FTIR and LC/MS analyses revealed that the extract contains various phytochemical constituents, including flavonoids, terpenoids, and other polyphenolic compounds, which contribute to its corrosion inhibition properties. The adsorption of the extract compounds on the steel surface followed the Langmuir adsorption isotherm, with a negative value of the standard free energy of adsorption, indicating a spontaneous and stable adsorption process involving both physisorption and chemisorption. SEM and XPS analyses confirmed the formation of a protective film by the adsorbed extract compounds, which acts as a barrier, preventing the direct contact between the aggressive solution and the steel substrate. The film also alters the wettability of the metal surface, making it more hydrophobic and further enhancing the corrosion inhibition efficiency. Quantum chemical calculations showed that flavonoids, particularly quercetin, contribute significantly to the corrosion inhibition performance due to their high reactivity, strong dipole moment, and stable adsorption on the Fe(110) surface. These findings provide valuable insights into the development of sustainable and eco-friendly corrosion inhibitors for the protection of metal structures in acidic environments.

Relation of alkyl chain length and corrosion inhibition efficiency of N-Acylated Chitosans over mild steel in acidic medium

The present investigation is focussed on unveiling the potential of ecologically safe Chitosan derived N-Acylated products (N-ACs) as anti-corrosive agents for mild steel in 0.5 M H2SO4. Electrochemical Impedance Spectroscopy (EIS) including potentiodynamic polarization (PDP) and potentiostatic electrochemical impedance were deployed to evaluate their anti-corrosive performance and the results of the same reported N-acylated chitosan derivatives project remarkable inhibition efficiency with the most effective performance of 96.80% at 250 mgL-1. The pronounced inhibition efficiency reported was conclusively accredited to the availability of heteroatoms in modified chitosan which further aid in the formation of a protective barrier over mild steel counterparts. The final acylated products were reported to be mixed type as demarcated by PDP results. Further, the prevention ability of modified chitosan was obtained via adsorption and the Langmuir adsorption model was best seen as suitable in this regard. Surface studies and theoretical modeling including Global Reactivity results, molecular Dynamic Modelling (MD), and Density Functional Bond Tight Binding Results (DFBT) were incorporated to gain insights into the molecular level of interactions between metal and N-ACs.

Experimental and computational studies of novel cyclic ammonium based ionic liquids as corrosion inhibitors for carbon steel in acid medium

The challenge of corrosion posed as a result of acidic sittings is considered as a major industrial concern, wherein ionic liquids serve as crucial in addressing the corrosive impacts on metals. In this study, five selected cyclic ammonium based ionic liquids were synthesized; IL-1MPyrBr, IL-1MPipBr, IL-2PyBr, IL-3MPyBr and IL-4MPyBr and their chemical structures were characterized using a variety of spectroscopic techniques (FT-IR, IH-NMR, 13C-NMR, Elemental analysis and thermal gravimetric analysis (TGA). Their corrosion inhibition efficiency was studied on carbon steel in 1 M HCl via different concentrations at 298 K using chemical and electrochemical parameters (PDP and EIS). DFT quantum parameters were computed, and the noted results were in complete compatible with the experimental. The synthesized ILs recorded excellent inhibition on the carbon steel corrosion in acidic media with increasing efficiency by increasing the inhibitor concentrations from 20 to 100 ppm. Different cations in the synthesized ILs affect the anti-corrosion effect and IL-3MPyBr showed the highest inhibition (ηR); 96.12% using the lowest concentration. Kinetic and thermodynamic considerations were studied and illustrated.