Experimental, quantum chemical and Monte Carlo simulation studies on the corrosion inhibition of some alkyl imidazolium ionic liquids containing tetrafluoroborate anion on mild steel in acidic medium

An electrochemical, and surface studies of synthesized Gemini ionic liquid as corrosion inhibitor for carbon steel in petroleum field

In this work, we study the efficiency of N1, N3-dibenzyl-N1, N1, N3, N3-tetramethylpropane-1,3-diaminium chloride, as anticorrosion. This compound exhibits potential as a prospective remedy to stop the deterioration of carbon steel caused by corrosion in 1.0 M HCl. The synthesis of this compound is described in a comprehensive manner, and its composition is supported by a range of precise analytical approaches such as elemental analysis, and mass spectroscopy. Based on the findings of the investigation, the synthesized Gemini ionic liquid demonstrates a robust capacity to slow down the rate at which the metal corrodes. The Prepared compound was evaluation by electrochemical and morphology study. Our results revealed that elevating the inhibitor concentration led to an augmentation in inhibition effectiveness, reaching up to 94.8% at 200 ppm of the synthesized compound at 298 K. It is crucial to emphasize that the recently prepared Gemini ionic liquid is consistent with the Langmuir adsorption model and function as a mixed inhibitor, participating in the physio-chemisorption process of adsorption.

Synthesis and Characterization of New Polymeric Ionic Liquids as Corrosion Inhibitors for Carbon Steel in a Corrosive Medium: Experimental, Spectral, and Theoretical Studies

A novel series of polymeric ionic liquids (ILs) based on benzimidazolium chloride derivatives, namely, 1,3-diheptyl-2-(2-phenyl-propyl)-3H-benzimidazol-1-ium chloride (IL1), 1,3-dioctyl-2-(2-phenyl-propyl)-3H-benzimidazol-1-ium chloride (IL2), and 1,3-Bis-decyl-2-(2-phenyl-propyl)-3H-benzoimidazol-1-ium chloride (IL3), were synthesized and chemically elucidated by Fourier transform infrared spectroscopy, 1H NMR, 13C NMR, and elemental analysis. Their influence as corrosion suppressors were investigated for C-steel corrosion in 1 M HCl, by weight loss (WL), potentiodynamic polarization (PDP), and electrochemical impedance spectroscopy (EIS) methods, revealing that their exclusive addition decreased corrosion with mounting concentrations. These assays demonstrated that novel ILs are efficient inhibitors at relatively low dosages. The efficacy of the synthesized ILs reached 79.7, 92.2 and 96.9%, respectively, at 250 ppm and 303 K. Parameters for activation and adsorption were calculated and are discussed. The Tafel polarization results demonstrated that the investigated ILs support the suppression of both cathodic and anodic reactions, acting as mixed type inhibitors. Langmuir's adsorption isotherm was confirmed as the best fitted isotherm, describing the physical-chemical adsorption capability of used ILs on the C-steel surface with the change in the free energy of adsorption, ΔG°ads = 32.6-37.2 kJ mol-1. The efficacy of the synthesized ILs was improved by increasing the doses, and the temperature reached 86.6, 96.1, and 98.4%, respectively, at 318 K. Surface morphology was proved by Fourier Transform Infrared spectroscopy, X-ray photoelectron spectroscopy, and atomic force microscopy (AFM), and then, changes in test solutions were checked by Ultraviolet-visible spectroscopy. Theoretical modeling (density functional theory and Monte Carlo) revealed the correlation between the IL's molecular chemical structure and its anticorrosive property.

Effective corrosion inhibition of mild steel using novel 1,3,4-oxadiazole-pyridine hybrids: Synthesis, electrochemical, morphological, and computational insights

An easy synthesis of two 1,3,4-oxadiazole derivatives, namely, 2-phenyl-5-(pyridin-3-yl)-1,3,4-oxadiazole (POX) and 2-(4-methoxyphenyl)-5-(pyridin-3-yl)-1,3,4-oxadiazole (4-PMOX), and their corrosion-inhibition efficacy against mild steel corrosion in 1 N HCl, is evaluated using weight loss from 303 to 323 K, Electrochemical Impedance Spectroscopy (EIS), Potentiodynamic Polarization (PDP), Scanning Electron Microscopy (SEM), Energy Dispersive X-ray (EDX), UV-Vis spectroscopy, along with theoretical evaluation. Both POX and 4-PMOX exhibit excellent inhibition efficiency, with values reaching 97.83% and 98% at 500 ppm, respectively. The PDP analysis reveals that both derivatives act as mixed-type inhibitors. The Langmuir adsorption isotherm provides insights into the adsorption phenomena, demonstrating that 4-PMOX exhibits superior adsorption behavior on the mild steel surface compared to POX. This finding is further supported by SEM, DFT, RDF, and MSD analyses. Quantum mechanical parameters, including EHOMO, ELUMO, dipole moment (μ), energy gap (ΔE), etc., are in good agreement with the effectiveness of inhibition performance revealing ΔE values of 3.10 and 2.75 for POX and 4-PMOX, respectively. The results obtained from this study hold significant implications for researchers aiming to design more efficient organic inhibitors to combat metal corrosion.

1-Butyl-3-methylimidazolium methane sulfonate ionic liquid corrosion inhibitor for mild steel alloy: Experimental, optimization and theoretical studies

The current research reports the performance of 1-butyl-3-methylimidazolium methane sulfonate ([C4MIM][OMs](IL)) as effective corrosion inhibitor for mild steel in 1 M H2SO4 electrolyte. For proper evaluation, weight loss, electrochemical study, theoretical modeling and optimization techniques were used. Weight loss and electrochemical methods shows that the inhibition performance of [C4MIM][OMs] on the metal surface strengthens as the concentration increases. Maximum inhibition efficiency of 85.71%, 92.5% and 91.1% at 0.8 g L-1 concentration of [C4MIM][OMs] were obtained from the weight loss, polarization and impedance studies, respectively. In addition, response surface methodology (RSM) a statistical tool was used for modeling and optimization of the empirical data. The RSM model validates the empirical findings. Also, DFT/MD-simulation investigations evidenced that [C4MIM][OMs] forms a barrier film on the mild steel surface. The result shows that the synthesized [C4MIM][OMs] could open up opportunities in corrosion and materials protection for sustainability.

Novel Corrosion Inhibitor for Carbon Steel in Acidic Solutions Based on α-Aminophosphonate (Chemical, Electrochemical, and Quantum Studies)

α-aminophosphonate (α-AP) is used as a novel corrosion inhibitor for carbon steel. The aggressive media applied in this study are HCl and H₂SO₄ acid solutions. The findings indicate that the morphology of the α-AP compound is cubic, with particles ranging in size from 17 to 23 μm. FT-IR, ¹HNMR, ³¹PNMR, and ¹³CNMR analysis confirmed the synthesis of the α-AP molecule. It has been discovered that the compound α-AP plays an important role in inhibiting the corrosion of carbon steel in both HCl and H₂SO₄ acids. This was identifiably inferred from the fact that the addition of α-AP compound decreased the corrosion rate. It is important to report that the maximum inhibition efficiency (92.4% for HCl and 95.7% for H₂SO₄) was obtained at 180 ppm. The primary factor affecting the rate at which steel specimens corrode in acidic electrolytes is the tendency of α-AP compounds to adsorb on the surface of steel through their heteroatoms (O, N, and P). This was verified by SEM/EDX results. The adsorption actually occurs through physical and chemical mechanisms via different active centers which are matched with the calculated quantum parameters. In addition, the adsorption of α-AP follows the Langmuir isotherm.

A New Imidazole Derivative for Corrosion Inhibition of Q235 Carbon Steel in an Acid Environment

Q235 carbon steel is a commonly used engineering material, but its application in marine environments is limited by its susceptibility to corrosion, especially localized corrosion that can lead to material perforation. Effective inhibitors are crucial to addressing this issue, particularly in acidic environments where localized areas become increasingly acidic. This study reports the synthesis of a new imidazole derivative corrosion inhibitor and evaluates its effectiveness in corrosion inhibition performance using potentiodynamic polarization curve and electrochemical impedance spectroscopy techniques. High-resolution optical microscopy and scanning electron microscopy were employed for surface morphology analysis. Fourier-transform infrared spectroscopy was used to explore the protection mechanisms. The results demonstrate that the self-synthesized imidazole derivative corrosion inhibitor offers an excellent corrosion protection performance for Q235 carbon steel in a 3.5 wt. % NaCl acidic solution. This inhibitor can provide a new strategy for carbon steel corrosion protection.

A Review of Trends in Corrosion-Resistant Structural Steels Research-From Theoretical Simulation to Data-Driven Directions

This paper provides a review of models commonly used over the years in the study of microscopic models of material corrosion mechanisms, data mining methods and the corrosion-resistant performance control of structural steels. The virtual process of material corrosion is combined with experimental data to reflect the microscopic mechanism of material corrosion from a nano-scale to macro-scale, respectively. Data mining methods focus on predicting and modeling the corrosion rate and corrosion life of materials. Data-driven control of the corrosion resistance of structural steels is achieved through micro-alloying and organization structure control technology. Corrosion modeling has been used to assess the effects of alloying elements, grain size and organization purity on corrosion resistance, and to determine the contents of alloying elements.

The inhibitive action of 2-mercaptobenzothiazole on the porosity of corrosion film formed on aluminum and aluminum-titanium alloys in hydrochloric acid solution

2-Mercaptobenzothiazole (2-MBT) in a solution of 0.5 M HCl is an effective corrosion inhibitor for aluminum and aluminum-titanium alloys. Tafel polarization and electrochemical impedance spectroscopy (EIS) were employed to assess this heterocyclic compound's anticorrosive potential and complementary by scanning electron microscope (SEM) and calculating porosity percentage in the absence and presence of various inhibitor concentrations. Inhibition efficiency (IE%) was strongly related to concentration (10^-6-10^-3 M). Temperature's effect on corrosion behavior was investigated. The data exhibited that the IE% decreases as the temperature increases. An increase in activation energy (E_a) with increasing the inhibitor concentration and the decrease in the IE% value of the mentioned compound with raising the temperature indicates that the inhibitor molecules are adsorbed physically on the surface. Thermodynamic activation parameters for Al and Al-Ti alloy dissolution in both 0.5 M HCl and the inhibited solution were calculated and discussed. According to Langmuir's adsorption isotherm, the inhibitor molecules were adsorbed. The evaluated standard values of the enthalpy ([Formula: see text], entropy ([Formula: see text] and free energy changes ([Formula: see text] showed that [Formula: see text] and [Formula: see text] are negative, while [Formula: see text] was positive. The formation of a protective layer adsorbed on the surfaces of the substrates was confirmed with the surface analysis (SEM). The porosity percentage is significantly reduced in the inhibitor presence and gradually decreased with increasing concentration. Furthermore, the density functional theory (DFT) and Monte Carlo (MC) simulations were employed to explain the variance in protecting the Al surface from corrosion. Interestingly, the theoretical findings align with their experimental counterparts. The planarity of 2-MBT and the presence of heteroatoms are the playmakers in the adsorption process.

Adsorption and Surface Analysis of Sodium Phosphate Corrosion Inhibitor on Carbon Steel in Simulated Concrete Pore Solution

Corrosion of steel-reinforced concrete exposed to marine environments could lead to structural catastrophic failure in service. Hence, the construction industry is seeking novel corrosion preventive methods that are effective, cheap, and non-toxic. In this regard, the inhibitive properties of sodium phosphate (Na3PO4) corrosion inhibitor have been investigated for carbon steel reinforcements in 0.6 M Cl- contaminated simulated concrete pore solution (SCPS). Different electrochemical testing has been utilized including potentiodynamic polarization, electrochemical impedance spectroscopy (EIS), and Mott-Schottky plots to test Na3PO4 at different concentrations: 0.05, 0.1, 0.3, and 0.6 M. It was found that Na3PO4 adsorbs on the surface through a combined physicochemical adsorption process, thus creating insoluble protective ferric phosphate film (FePO4) and achieving an inhibition efficiency (IE) up to 91.7%. The formation of FePO4 was elucidated by means of Fourier-transform infrared spectroscopy (FT-IR) and X-ray photoelectron spectroscopy (XPS). Quantum chemical parameters using density functional theory (DFT) were obtained to further understand the chemical interactions at the interface. It was found that PO43- ions have a low energy gap (ΔEgap), hence facilitating their adsorption. Additionally, Mulliken population analysis showed that the oxygen atoms present in PO43- are strong nucleophiles, thus acting as adsorption sites.

Synthesis and characterization of novel dicarbohydrazide derivatives with electrochemical and theoretical approaches as potential corrosion inhibitors for N80 steel in a 3.5% NaCl solution

Two novel ethanoanthracene-11,12-dicarbohydrazide derivatives N'11,N'12-bis((Z)-4-hydroxybenzylidene)-9,10-dihydro-9,10-ethanoanthracene-11,12-dicarbohydrazide (H2HEH) and N'11,N'12-bis((Z)-4-methoxybenzylidene)-9,10-dihydro-9,10-ethanoanthracene-11,12-dicarbohydrazide (H2MEH) were synthesized and characterized by FT-IR spectroscopy, electronic spectra, and NMR spectroscopy. These two derivatives as novel anticorrosion inhibitors for N80 steel in a 3.5% NaCl solution were studied using electrochemical techniques including potentiodynamic polarization (PP), electrochemical impedance spectroscopy (EIS), and electrochemical frequency modulation (EFM). Corrosion parameters and adsorption isotherms were determined from current-potential diagrams (i.e., Tafel slopes). The impact of temperature and inhibitor concentration on the corrosion performance was studied using the PP method. The PP results suggested mixed-type inhibitors. The inhibition prohibition increased and decreased when the dose was increased and the temperature was increased, respectively. The adsorption of the hydrazides on the N80 exterior followed the Langmuir isotherm. The maximum inhibition proficiency for H2MEH and H2HEH were 93.3% and 92.2%, respectively, at 1 × 10-4 M. Moreover, the investigated surface was studied with the synthesized compounds through X-ray photoelectron spectroscopy (XPS) to confirm the construction of an adsorbed shielding barrier. An evident association was established between the corrosion inhibition proficiency and theoretical variables acquired using the density functional theory (DFT) method and Monte Carlo (MC) simulations. The experimental data were in good agreement with the theoretical results.

Effectiveness of Some Novel Ionic Liquids on Mild Steel Corrosion Protection in Acidic Environment: Experimental and Theoretical Inspections

Three ionic liquids (ILs)-1-butyl-1-methyl-pyrrolidinium Imidazolate (BMPyrIM), 1-butyl-3-methyl-imidazolium Imidazolate (BMImIM), and bis(1-butyl-3-methyl-imidazolium Imidazolate) (BBMImIM)-were synthesized and examined experimentally and theoretically as potential inhibitors for mild steel corrosion in HCl (1.0 M) solution. To our knowledge, two of the ILs successfully synthesized in our laboratory named BMPyrIM and BBMImIM are novel. Different electrochemical (potentiodynamic polarization (PDP), electrochemical impedance spectroscopy (EIS)), surface and structural (scanning electron microscopy (SEM), Energy-dispersive X-ray spectroscopy (EDS), Atomic force microscopy (AFM) and Fourier Transform Infrared Spectroscopy (FTIR)) and theoretical (Density functional theory (DFT)) techniques were utilized to confirm their use as efficient environmentally safe inhibitors. These ionic liquids were designed to study the cation effect (imidazolium and pyrrolidinium) and the dimeric effect of the imidazolium-based IL. A pronounced inhibiting effect was recorded using the optimum concentration (5 × 10^-3 M) of BBMImIM with protection efficiency of 98.6% compared to 94.3% and 92.4% for BMImIM and BMPyrIM, respectively. The investigated ILs act as a mixed-type corrosion inhibitors and their protection obeys Langmuir adsorption isotherm. The results obtained by SEM, EDS and AFM confirmed the mild steel protection by the formation of protective film of the ILs on the steel surface resulted in less damaged surfaces compared with the blank solution. Furthermore, quantum chemical calculations illustrated the electronic structure of the investigated ILs and their optimized adsorptiοn configurations on mild steel surface. The findings from the different techniques helped to provide a supported interpretation of the inhibition mechanism.

Organic Compounds as Corrosion Inhibitors for Carbon Steel in HCl Solution: A Comprehensive Review

Most studies on the corrosion inhibition performance of organic molecules and (nano)materials were conducted within "carbon steel/1.0 M HCl" solution system using similar experimental and theoretical methods. As such, the numerous research findings in this system are sufficient to conduct comparative studies to select the best-suited inhibitor type that generally refers to a type of inhibitor with low concentration/high inhibition efficiency, nontoxic properties, and a simple and cost-economic synthesis process. Before data collection, to help readers have a clear understanding of some crucial elements for the evaluation of corrosion inhibition performance, we introduced the mainstay of corrosion inhibitors studies involved, including the corrosion and inhibition mechanism of carbon steel/HCl solution systems, evaluation methods of corrosion inhibition efficiency, adsorption isotherm models, adsorption thermodynamic parameters QC calculations, MD/MC simulations, and the main characterization techniques used. In the classification and statistical analysis section, organic compounds or (nano)materials as corrosion inhibitors were classified into six types according to their molecular structural characteristics, molecular size, and compound source, including drug molecules, ionic liquids, surfactants, plant extracts, polymers, and polymeric nanoparticles. We outlined the important conclusions obtained from recent literature and listed the evaluation methods, characterization techniques, and contrastable experimental data of these types of inhibitors when used for carbon steel corrosion in 1.0 M HCl solution. Finally, statistical analysis was only performed based on these data from carbon steel/1.0 M HCl solution system, from which some conclusions can contribute to reducing the workload of the acquisition of useful information and provide some reference directions for the development of new corrosion inhibitors.

Adsorption and inhibition behavior of imidazolium tetrafluoroborate derivatives as green corrosion inhibitors for carbon steel

The adsorption and inhibition mechanism of chain length increase and group substitution of imidazole tetrafluoroborate derivatives for the corrosion inhibition of carbon steel in HCl solution was revealed in detail via the density functional theory, molecular dynamics (MD) simulation, and quantitative structure-activity relationship (QSAR) methods. The main reactive site of an ionic liquid is located on its imidazolium ring. With alkyl chain lengthening or the introduction of methyl groups onto the imidazolium ring, its molecular reactivity and electron-donating ability increase the interaction between the ionic liquid and the Fe (110) surface. Therefore, the imidazolium rings of four IL inhibitors are more likely to lie on the Fe (110) surface in parallel through chemical adsorption. The interactions between N atoms in ionic liquids and the Fe (110) surface are stronger than those between the C atoms on the imidazolium rings of the four ionic liquid, and coordination bonds can be formed between N atoms and the Fe (110) surface. Therefore, ionic liquids can hinder the interaction between corrosion particles and the Fe (110) surface, hinder the diffusion of corrosion particles, and effectively reduce the number density of corrosion particles on the Fe (110) surface. A methyl substituent on the C2 atom of the imidazolium ring can enhance the electron-donating ability and adsorption tendency much more than an increase in the alkyl chain on the N3 atom. The four inhibitors are ordered in terms of corrosion inhibition efficiency as [C₁₂DMIM]BF₄ > [C₁₀DMIM]BF₄ > [C₁₂MIM]BF₄ > [C₁₀MIM]BF₄, which agrees well with the experimental results. A good correlation between experimental inhibition efficiency, concentration and microscopic structures parameters of ILs such as energy gap ΔE, polarizability P, electronegativity χ, hardness η, softness σ, number of electrons transferred ΔN, and electrophilicity ω was achieved.

Experimental and surface morphological studies of corrosion inhibition on carbon steel in HCl solution using some new hydrazide derivatives

The corrosion inhibition of C-steel in 1 M HCl was assessed using three newly synthesized hydrazide derivatives (H1, H2 and H3) using weight loss (WL), potentiodynamic polarization (PDP) and electrochemical impedance spectroscopy (EIS) techniques. Also, the adsorption of these compounds was confirmed using several techniques such as atomic force microscopy (AFM), Fourier-transform infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS). High inhibition efficiencies were obtained resulting from the constitution of the protective layer on the C-steel surface, which increased with increasing concentration and temperature and reached 91.7 to 96.5% as obtained from the chemical method at 20 × 10-6 M at 45 °C. The polarization curves refer to these derivatives belonging to mixed-type inhibitors. The adsorption of (H1, H2 and H3)on the CS surface follows the Temkin adsorption isotherm. Inhibition influence of hydrazide derivatives at the molecular level was greatly proven using quantum chemical calculations and Monte Carlo simulation methods. Furthermore, the molecular simulation results evidenced the adsorption of these derivatives on the carbon steel surface.

Effect of phosphonate functional group on corrosion inhibition of imidazoline derivatives in acidic environment

In the present study, ({2-[2-(7-Isopropyl-1,4-dimethyl-9,10-octahydro-phenanthren-1-yl)-4,5-dihydro-1-yl]-ethylamino}-methyl)-phosphonicimidazole (GSIM) was synthesized by introducing phosphonate (-PH₂O₃) group into imidazoline derivatives and its corrosion inhibition performance was studied for Q345 steel in acidic medium along with SIM using potentiodynamic polarization, EIS and SECM analysis. Surface analysis of steel samples was also performed by optical microscopy and SEM-EDS analysis after polarization tests. XPS was used to detect chemical composition of the surface passive films. It was observed that introducing -PH₂O₃ group not only improved the adsorption capacity on the metal surface by coordinating with iron ions, but also inhibited the interference of hydrogen bond formed by -NH₂ group and water molecules on the adsorption. GSIM not only inhibited intercrystalline corrosion and pitting corrosion, but also reduced uniform corrosion. Thermodynamics studies demonstrated that GSIM followed the Langmuir adsorption isotherm and had a larger adsorption equilibrium constant than SIM, which indicated that it had a stronger adsorption capacity. XPS and UV confirmed that the coordination between GSIM and Fe³⁺ and hydrogen bonding between SIM and water molecules. The quantum chemical study further clarified that the site and strength of hydrogen bond between SIM and H₂O and the dominant configuration and coordination stability of GSIM with Fe³⁺.

Synthesis of two supramolecular coordination polymers and electrochemical evaluation of their corrosion inhibition performance on corrosion of carbon steel in acidic medium

The effect of the SCPs-[CuII(en)2] [CuI (CN)2]2. H2O] (SCP1) and {[H2DAB] [Cu4(CN)6].2H2O} (SCP2) as corrosion inhibitors for carbon steel (CS) was studied in 1.0M HCl solution. As the synthesized inhibitor dose increases, the inhibition productivity (%e) increases reaching to 90.3% and 89.9% at 21x10-6M dose for SCP2 and SCP1, respectively. This result evidenced by mass loss (ML) investigated at three different temperatures 25-35-45oC, while potentiodynamic polarization (PP), electrochemical impedance spectroscopy (EIS), and electrochemical frequency modulation technique (EFM) were tested at 25°C. The synthesized inhibitors adsorbed on the CS surface physically allowing Henry isotherm. The results displayed that the synthesized inhibitors are excellent and their (%e) was significantly increased by raising the dose and decreased by raising the temperature. Polarization curves revealed that the synthesized inhibitors act as mixed type. The thermodynamic parameters were calculated and discussed. The protection was confirmed by the creation of the thin film of inhibitors precipitated on the surface of CS.

Adlay seed hull polysaccharide as a green corrosion inhibitor for mild steel in acid solution: surface analyses and theoretical calculations

Adlay seed hull polysaccharide was developed here as a green corrosion inhibitor for mild steel in 1 M HCl solution, and its inhibition effect was studied with electrochemical experiments, theoretical calculations, etc.