DFT and experimental studies on the inhibition potentials of expired Tramadol drug on mild steel corrosion in hydrochloric acid

An Evaluation of the Corrosion Inhibition Performance of Chitosan Modified by Quaternary Ammonium Salt for Carbon Steel in Stone Processing Wastewater

Chitosan was used as the raw material. A quaternization reaction was carried out between 2,3-epoxypropyltrimethylammonium chloride and water-soluble chitosan to prepare quaternary ammonium salt water-soluble chitosan (QWSC), and its corrosion inhibition performance against the corrosion of carbon steel in stone processing wastewater was evaluated. The corrosion inhibition efficiencies of QWSC on carbon steel in stone processing wastewater were investigated through weight loss, as well as electrochemical and surface morphology characterization techniques. The results show that QWSC has superior corrosion inhibition performance for A3 carbon steel. When an amount of 60 mL·L-1 is added, the corrosion inhibition efficiency can reach 59.51%. Electrochemical research has shown that a QWSC inhibitor is a mixed-type corrosion inhibitor. The inhibition mechanisms of the QWSC inhibitor revealed that the positive charge on the surface of carbon steel in stone wastewater was conducive to the adsorption of Cl- in the medium, which produced an excessive negative charge on the metal's surface. At the same time, the quaternary ammonium cation and amino cation formed in QWSC in stone processing wastewater can be physically absorbed on the surface of A3 carbon steel, forming a thin-film inhibitor to prevent metal corrosion.

Experimental Studies on the Effect of Expired Amiodarone Drug (EAD) as a Corrosion Inhibitor on Mild Steel in 1 M HCl

In the present investigation, the corrosion tendency of mild steel under acidic pH was studied by employing unused expired amiodarone (EAD) drug as a potential corrosion inhibitor by adopting the weight loss measurement method. The corrosion inhibition efficiency (IE) of the formed protective film (EAD) on the steel surface was analyzed using potentiodynamic polarization and AC-impedance spectroscopy studies. The surface morphology of the mild steel before and after corrosion (in 1.0 M HCl) was analyzed via scanning electron microscopy-energy dispersive X-ray spectroscopy (SEM-EDAX), atomic force microscopy (AFM), and thermodynamic studies. The weight loss measurement under different concentrations of EAD indicated that an excellent inhibition was displayed at a concentration of 0.001 M, and the IE was found to depend on both the concentration and molecular structure of EAD. A potentiodynamic polarization study revealed that EAD predominantly acted as a cathode inhibitor, and electrochemical impedance spectroscopy (EIS) confirmed the adsorption of EAD on the surface of mild steel, which obeyed Temkin's adsorption isotherm model. The calculated thermodynamic parameters revealed that adsorption was spontaneous and exothermic.

Efficiency of Expired Drugs Used as Corrosion Inhibitors: A Review

Corrosion inhibitors represent one of the most commonly used methods for significantly reducing the corrosion rate of metals and alloys. Adsorption inhibitors have a wide range of applications in cooling water systems, deicing solutions for aircrafts, airports and ways, etching and degreasing solutions, oil pipelines, paints and coatings and metal processing solutions. Adsorption corrosion inhibitors of metals and alloys are generally organic compounds that contain structures with heteroatoms (N, P, S, As, O) in their molecules, having lone pair electrons or π electrons in aromatic rings or multiple bonds. They enable relatively strong interactions between the metal atoms and organic molecules, resulting in a protective layer of organic molecules adsorbed at the metal-corrosive solution interface. Most molecules of active substances from drugs contain similar structures, which is why many drugs have been already tested as corrosion inhibitors. One of the major disadvantages of using drugs for this purpose is their particularly high price. To overcome this impediment, the possibility of using expired drugs as corrosion inhibitors has been investigated since 2009. The present paper is an exhaustive compilation of the scientific published papers devoted to the use of expired drugs as corrosion inhibitors in various aggressive solutions. The inhibitory efficiencies of expired drugs are presented as a function of the studied metal or alloy and the nature of the aggressive solution, as well as the concentration of the inhibitor in such a solution. Research has especially been focused on mild and carbon steel and less on stainless steel, as well as on some metals such as copper, zinc, nickel, tin and aluminum and its alloys. The experimental methods used to assess the inhibitory efficiencies of expired drugs are briefly discussed. Also, the available information on the stability of the active substances in the drugs is presented, although most authors were not concerned with this aspect. Finally, several actions are revealed that must be undertaken by researchers so that the results obtained in the study of the anticorrosive action of expired drugs can be applied at the industrial level and not remain only an academic concern.

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.

PTFE/EP Reinforced MOF/SiO2 Composite as a Superior Mechanically Robust Superhydrophobic Agent towards Corrosion Protection, Self-Cleaning and Anti-Icing

Organic resin cross-linking ZIF-67/SiO₂ superhydrophobic (SHPB) multilayer coating was successfully fabricated on metal substrate. The perfluoro-octyl-triethoxy silane (POTS) modified ZIF-67 and SiO₂ coating was applied on primary coated polytetrafluoroethylene (PTFE) and epoxy resin (EP) via spray coating method. Here, we present that the robust superhydrophobicity can be realized by structuring surfaces at two different length scales, with a nanostructure design to provide water repellence and a microstructure design to provide durability. The as-fabricated multilayer coating displayed superior water-repellence (CA=167.4°), chemical robustness (pH=1-14) and mechanical durability undergoing 120th linear abrasion or 35th rotatory abrasion cycle. By applying different acidic and basic corrosive media and various weathering conditions, it can still maintain superior-hydrophobicity. To get a better insight of interaction between inhibitor molecules and metal surface, density functional theory (DFT) calculations were performed, showing lower energy gap and increased binding energy of ZPS/SiO₂ /PTFE/EP (ZPS=ZIF-67+POTS) multilayer coating compared to the ZIF-67/SiO₂ /PTFE/EP, thereby supporting the experimental findings. Additionally, such coatings may be useful for applications such as anti-corrosion, self-cleaning, and anti-icing multi-functionalities.

Diaryl Sulfide Derivatives as Potential Iron Corrosion Inhibitors: A Computational Study

The present work aimed to assess six diaryl sulfide derivatives as potential corrosion inhibitors. These derivatives were compared with dapsone (4,4′-diaminodiphenyl sulfone), a common leprosy antibiotic that has been shown to resist the corrosion of mild steel in acidic media with a corrosion efficiency exceeding 90%. Since all the studied compounds possess a common molecular backbone (diphenyl sulfide), dapsone was taken as the reference compound to evaluate the efficiency of the remainder. In this respect, two structural factors were examined, namely, (i) the effect of replacement of the S-atom of diaryl sulfide by SO or SO₂ group, (ii) the effect of the introduction of an electron-withdrawing or an electron-donating group in the aryl moiety. Two computational chemical approaches were used to achieve the objectives: the density functional theory (DFT) and the Monto Carlo (MC) simulation. First, B3LYP/6-311+G(d,p) model chemistry was employed to calculate quantum chemical descriptors of the studied molecules and their geometric and electronic structures. Additionally, the mode of adsorption of the tested molecules was investigated using MC simulation. In general, the adsorption process was favorable for molecules with a lower dipole moment. Based on the adsorption energy results, five diaryl sulfide derivatives are expected to act as better corrosion inhibitors than dapsone.

Arylamino Substituted Mercaptoimidazole Derivatives as New Corrosion Inhibitors for Carbon Steel in Acidic Media: Experimental and Computational Study

Two arylamino substituted mercaptoimidazole derivatives namely 4,5-dimethyl-1-(phenylamino)-1H-imidazole-2(3H)-thione (I1) and 4,5-dimethyl-1-((p-chlorophenyl)amino)-1H-imidazole-2(3H)-thione (I2) were synthesized and investigated as corrosion inhibitors for carbon steel in 0.5 M HCl solution by means of electrochemical impedance spectroscopy (EIS), potentiodynamic polarization, ATR-FTIR spectroscopy and SEM. The results showed that the investigated mercaptoimidazole derivatives act as mixed type inhibitors and inhibition efficiency follows the I2>I1 order. Adsorption of inhibitors on metal surface was found to obey the Langmuir adsorption isotherm. Thermodynamic parameters revealed that adsorption of the inhibitors has both physisorption and chemisorption adsorption mechanism. Electrochemical test results were supported by quantum chemical parameters obtained from DFT calculations.

Electrochemical and Computational Insights on the Application of Expired Metformin Drug as a Novel Inhibitor for the Sweet Corrosion of C1018 Steel

An expired metformin drug (MET) was used as a corrosion inhibitor for C1018 carbon steel in a CO2-saturated 3.5 wt % NaCl + 340 ppm acetic acid solution under static conditions. The inhibitor was evaluated using electrochemical methods complemented with surface analytical measurements and computational modeling. The drug displayed a high inhibition efficiency of ∼90% at 200 ppm. Impedance analyses revealed a rise in the charge transfer resistance at the steel-solution interface upon the addition of the inhibitor. Polarization measurements suggested that MET acted more like a cathodic-type corrosion inhibitor and significantly reduced the corrosion current density. The adsorption of MET on the steel substrate followed the Langmuir isotherm, showing a mixed type of physical and chemical modes of adsorption. The thermodynamic parameters revealed strong and spontaneous adsorption on the steel surface. The surface analysis using SEM supported the inhibitor adsorption on the steel substrate. Based on the DFT simulation, inhibition by MET is mainly achieved by its protonated form, which leads to the formation of a thin film on the steel surface rather than the modification of the work function of the steel surface. The experimental and theoretical estimations of pKa complemented the DFT results, both agreeing that the monoprotonated form of MET is the dominant form in which the inhibitor adsorbs on the steel surface to form a thin film rather than modify the work function of the steel surface.

The effect of regional selectivity on the corrosion inhibition properties of synthetic ionic liquid via the synergistic action of the cation and anion

By adding different proportions of N-butylimidazole and carboxyethylthiosuccinic acid (CETSA), three hybrid systems of ionic liquids were synthesized and named ILHS1, ILHS2 and ILHS3.

Plant Extracts as Green Corrosion Inhibitors for Different Metal Surfaces and Corrosive Media: A Review

Natural extracts have been widely used to protect metal materials from corrosion. The efficiency of these extracts as corrosion inhibitors is commonly evaluated through electrochemical tests, which include techniques such as potentiodynamic polarization, electrochemical impedance spectroscopy, and weight loss measurement. The inhibition efficiency of different extract concentrations is a valuable indicator to obtain a clear outlook to choose an extract for a particular purpose. A complementary vision of the effectiveness of green extracts to inhibit the corrosion of metals is obtained by means of surface characterizations; atomic force microscopy, scanning electron microscopy, and X-ray photoelectron spectroscopy analysis are experimental techniques widely used for this purpose. Moreover, theoretical studies are usually addressed to elucidate the nature of the corrosion inhibitor—metal surface interactions. In addition, calculations have been employed to predict how other organic substances behave on metal surfaces and to provide experimental work with fresh proposals. This work reports a broad overview of the current state of the art research on the study of new extracts as corrosion inhibitors on metal surfaces in corrosive media. Most constituents obtained from plant extracts are adsorbed on the metal, following the Langmuir adsorption model. Electron-rich regions and heteroatoms have been found to be responsible for chemisorption on the metal surface, whereas physisorption is due to the polar regions of the inhibitor molecules. The plant extracts compiled in this work obtained corrosion inhibition efficiencies above 60%, most of them around 80–90%. The effect of concentration, extraction solvent, temperature, and immersion time were studied as well. Additional studies regarding plant extracts as corrosion inhibitors on metals are needed to produce solutions for industrial purposes.

Coupling of chemical, electrochemical and theoretical approach to study the corrosion inhibition of mild steel by new quinoxaline compounds in 1 M HCl

The corrosion inhibition displays of two quinoxaline derivatives, on the corrosion of M-steel (M-steel) in 1 M HCl was studied by gravimetric, electrochemical, scanning electron microscopy (SEM), functional density theory (DFT) and molecular dynamic simulation (MD). The inhibitory efficacy increases with decreasing temperature and increases with inhibitor concentration and reached to 96 % (NSQN) and 92 % (CSQN) at 303 K and the optimum concentration (1×10-3 M). Ultraviolet-visible (UV-vis) spectroscopic analyses confirmed the presence of chemical interactions between the inhibitors and MS surface. The adsorption of NSQN & CSQN on the metallic surface obeys the Langmuir isotherm. A potentiodynamic polarization study confirmed that the inhibitors are of mixed-kind inhibitors. Theoretical computation (DFT) and molecular dynamics simulation (MD) are utilized to understand the mechanism of inhibition.

Chitosan-cinnamaldehyde Schiff base: A bioinspired macromolecule as corrosion inhibitor for oil and gas industry

A Schiff base of chitosan with cinnamaldehyde (Cinn-Cht) was synthesized in a single step using microwave irradiation and characterized using spectroscopic techniques. The synthesized Schiff base was used for the mitigation of carbon steel corrosion in 15% HCl. The corrosion evaluation was performed using weight loss tests, electrochemical impedance measurements, and polarization studies. The corrosion inhibition efficiency increased with inhibitor dosage and achieved a high value of 85.16% at 400 mgL-1. The inhibitor adsorption followed the Langmuir isotherm and displayed a mixed physical and chemical adsorption behavior. To further improve the corrosion inhibition efficiency, potassium iodide (KI) was incorporated in the corrosive solution, which increased the inhibition efficiency further to 92.45% at a concentration of 10 mM. Surface studies carried out via SEM analyses indicated the inhibitor adsorption and protective film formation on the steel surface. The computational studies carried out via DFT revealed that mainly the protonated form of inhibitor adsorbs on the metal surface. Monte Carlo simulation studies also showed that the protonated form of the inhibitor molecule exhibited higher adsorption energy than the neutral inhibitor.

Microwave-assisted synthesis of a new Piperonal-Chitosan Schiff base as a bio-inspired corrosion inhibitor for oil-well acidizing

A new Schiff base of chitosan, namely Piperonal-chitosan (Pip-Cht), was synthesized for the first time, using a microwave irradiation method and characterized using spectroscopic techniques. The corrosion inhibition behavior of the new Schiff base was evaluated on carbon steel in 15% HCl medium via gravimetric and electrochemical techniques. This is the first work on the application of chemically functionalized chitosan as a corrosion inhibitor in the oil-well acidizing environment. The Pip-Cht inhibitor exhibited a high corrosion inhibition efficiency of 85.16% at a moderate dose of 600 mg L-1. Further, the addition of potassium iodide as a synergistic agent to the corrosive electrolyte produced a significant improvement in the inhibition efficiency to 91.15% at a low dosage of 10 mM of KI. At a higher temperature of 65 °C, the combination of both the inhibitor and KI yielded a high inhibition efficiency. The results of the gravimetric and electrochemical experiments were corroborated using AFM and SEM studies. The DFT calculations indicated that corrosion inhibition behavior of the Schiff base mainly occurs in the protonated form.

Surface protection of X80 steel using Epimedium extract and its iodide-modified composites in simulated acid wash solution: a greener approach towards corrosion inhibition

The pure extract of Epimedium (EPM) was investigated as an alternative anticorrosion additive for acid wash and descaling solution simulated using 5% HCl.

Triazole-modified chitosan: a biomacromolecule as a new environmentally benign corrosion inhibitor for carbon steel in a hydrochloric acid solution

In this work, a new inhibitor, triazole modified chitosan, was synthesized for the first time following chemical modification of chitosan using 4-amino-5-methyl-1,2,4-triazole-3-thiol. The newly synthesized biopolymer (CS–AMT) was characterized using FTIR and NMR, and then it was evaluated as an inhibitor against corrosion of carbon steel in 1 M hydrochloric acid. The corrosion testing and evaluation were performed thoroughly employing the weight loss method, electrochemical measurements and surface analysis. A maximum corrosion inhibition efficiency of >95% was obtained at 200 mg L⁻¹ concentration of inhibitor. The adsorption of inhibitor obeyed the Langmuir isotherm and showed physical and chemical adsorption. The electrochemical study via impedance analysis supported the adsorption of the inhibitor on the surface of carbon steel, and the potentiodynamic polarization indicated a mixed type of inhibitor behavior with cathodic predominance. To get a better insight on the interaction of inhibitor molecules with the metal surface, a detailed theoretical study was performed using DFT calculations, Fukui indices analysis and molecular dynamics (MD) simulation. The DFT study showed a lower energy gap of CS–AMT and the MD simulations showed an increased binding energy of CS–AMT compared to the parent chitosan and triazole moieties thereby supporting the experimental findings.

A novel derivative of chitosan is evaluated as an environment-friendly corrosion inhibitor for carbon steel in hydrochloric acid solution.

Hexamethylene-1,6-bis(N-d-glucopyranosylamine) as a novel corrosion inhibitor for oil and gas industry: electrochemical and computational analysis

Experimental and theoretical studies on hexamethylene-1,6-bis(N-d-glucopyranosylamine) as a novel inhibitor against sweet corrosion useful for oil and gas industry.