Corrosion in oil and gas pipelines remains an ongoing issue, causing significant economic losses, operational disruptions, and environmental hazards. Traditional mitigation methods, such as cathodic protection, alloying, and synthetic chemical inhibitors, are typically associated with high cost, operational complexity, and environmental concern. Recently, environmentally friendly green inhibitors of natural origin have emerged as viable substitutes owing to their biodegradability, low toxicity, and effective adsorption behavior. This review provides a mechanistic overview of the physicochemical properties, adsorption behavior, and inhibition mechanisms of green corrosion inhibitors for ferrous metals. Special attention is paid to their performance in acidic environments, which are among the most widely used in laboratory tests and industrial practices such as acidizing and cleaning operations. According to the reviewed studies, green inhibitors can achieve inhibition efficiencies of over 90% by forming protective films via adsorption, which capture heteroatoms (O, N, S), pi-electrons, and/or polar functional groups (plant extracts; essential oils; biopolymers; derivatives from agro-waste). Nonetheless, the results mainly come from acidic media, and thus their direct relevance to in-situ conditions governed by CO2 (sweet corrosion) and H2S (sour corrosion) must be taken with caution. Thus, this review indicates that further investigations should be conducted in realistic pipeline systems to validate the long-term approaches for improving the stability and long-term performance of green inhibitors for oil and gas applications.
Corrosion and biofouling of metallic materials represent critical challenges in biomedical devices, marine structures, and industrial systems, often leading to material degradation, device failure, and significant economic losses. In recent years, the development of multifunctional protective coatings has emerged as an effective strategy to improve the durability and performance of metallic substrates. This review provides a comprehensive overview of recent advances in anticorrosion and antibacterial coatings, with particular emphasis on nanostructured and multifunctional systems. Various coating materials - including polymeric matrices, ceramic layers, metal-organic frameworks, nanocomposites, and bio-based materials - are discussed in terms of their synthesis strategies, structural characteristics, and protective mechanisms. Special attention is given to nanocontainer-based coatings, self-healing systems, antimicrobial surfaces, and coatings capable of controlled drug release for biomedical implants. The mechanisms of corrosion in medical and marine environments, including microbiologically influenced corrosion and biofilm formation, are also examined. Recent studies demonstrate that integrating antibacterial agents, nanoparticles, graphene-based materials, antimicrobial peptides, and organic corrosion inhibitors significantly enhances the protective performance of coatings. Furthermore, emerging technologies such as smart self-healing polymers, MOF-based coatings, and nanostructured composite systems provide promising approaches for improving corrosion resistance, biocompatibility, and long-term stability. Multifunctional coatings combining anticorrosion, antibacterial, and antifouling properties represent a key direction for the next generation of protective materials in biomedical and industrial applications.
Recent advances in corrosion science and materials engineering have been significantly accelerated by the integration of artificial intelligence (AI), machine learning (ML), and highthroughput experimental techniques. This review and research compilation highlights the development of predictive models for corrosion assessment in metals, reinforced concrete, and biomedical alloys, combining non-destructive testing, electrochemical methods, and convolutional neural networks, and molecular dynamics-have been successfully applied to predict corrosion inhibition efficiency, detect structural degradation, and optimize inhibitor design. Case studies demonstrate the effectiveness of eco-friendly inhibitors such as guava leaf experimental validation confirming high inhibition efficiencies. The integration of theoretical descriptors, imaging data, and deep learning facilitates rapid, accurate, and sustainable corrosion management, offering mechanistic insights into adsorption processes, surface protection, and fatigue behavior. These findings underscore the transformative potential of AI-assisted methodologies in accelerating corrosion research, inhibitor discovery, and structural health monitoring across diverse industrial and biomedical applications.
Water-based polymer resins have emerged as environmentally sustainable alternatives to conventional solvent-borne coatings for corrosion protection of metallic substrates. This comprehensive review examines the classification, corrosion protection mechanisms, performance evaluation, and sustainability aspects of waterborne polymer coatings. The major resin systems include waterborne epoxy, polyurethane, acrylic, alkyd, and hybrid formulations, which provide corrosion protection through barrier formation, inhibitive action, and passivation mechanisms. Advanced formulations incorporating nanofillers such as graphene oxide, hexagonal boron nitride, and silica nanoparticles demonstrate significant performance enhancements, with impedance increases of up to 200-fold and corrosion current reductions by three orders of magnitude compared to unmodified systems. Bio-based feedstocks and conducting polymers further enhance both sustainability and protective performance. Electrochemical impedance spectroscopy, potentiodynamic polarization, and salt spray testing remain the primary evaluation methods, with quantitative metrics demonstrating that optimized waterborne systems can match or exceed the performance of traditional solvent-borne coatings. Environmental benefits include volatile organic compound (VOC) reduction by over 90%, elimination of chromate-based inhibitors, and incorporation of renewable bio-based materials. Key challenges include long-term durability validation under harsh environmental conditions, scalability of nanocomposite formulations, and comprehensive life-cycle assessment. Future directions emphasize the development of self-healing coatings, smart release systems, and fully bio-based formulations with enhanced multifunctional properties. This review synthesizes current knowledge and identifies critical research priorities to advance waterborne polymer coatings toward widespread industrial adoption for sustainable corrosion protection.
In this work, we studied the corrosion inhibition effect of copper metal in 1.0 M H2SO4 solution utilizing the expired Mebeverine drug for human uses, by weight loss technique, electrochemical impedance spectroscopy techniques (EIS), potentiodynamic polarization (PP) and computational methods. The study was done at different temperatures (25, 35, 45, and 55 degrees C) for three hours for weight loss study, in the presence of the inhibitor and the absence of the inhibitor with different concentration. According to the density functional theory (DFT)/P3LYP/6-311G, a number of parameters were determined in this work, including the highest occupied molecular orbital E-HOMO, the lowest unoccupied molecular orbital ELUMO, energy gap (Delta E), dipole moment (mu), hardness (eta), softness (S), electronegativity (chi), and electrons transferred fraction (Delta N). The adsorption of the Mebeverine drug on the copper surface followed Langmuir's adsorption model. The adsorption of the Mebeverine drug on the copper is a physical adsorption type. The results showed that with the increment of the inhibitor concentration, there was an improvement of the inhibition efficiency, and the inhibition efficiency decreases with the rise in the temperature. The inhibition efficiency reached a value of 93.51% at 500 ppm of the inhibitor at 25 degrees C and decreased to a value of 82.41% as the temperature increased to 55 degrees C. Potentiodynamic Polarization (PP), and electrochemical impedance spectroscopy (EIS) results were in good agreement with the results of the weight loss (WL) method. Potentiodynamic polarization indicates a combined-type inhibition strategy, where the compound inhibits both anodic and cathodic reactions. Thermodynamic functions of adsorption and activation were determined and explained. The computational results carried out on the inhibitor agree with the experimental one. The employed techniques explain efficiencies in perfect correspondence, demonstrating the validity of these methods. The density functional theory (DFT) results indicated that the expired drug bound to the copper surface through the lone pair of electrons of the heteroatoms as well as the pi-electrons of the two benzene ring.
A series of alkoxysilanes were studied as chamber inhibitors of zinc corrosion. It was shown by corrosion and electrochemical methods that treatment of zinc in vapors of vinyltrimethoxysilane (VTMS) with proper selection of conditions resulted in the formation of polymolecular adsorption layers which increase the corrosion resistance of the metal. The optimal conditions of treatment are: the temperature was 140 degrees C, while the duration was 1 h. Upon chamber treatment under these conditions, the protective effect of VTMS is provided due to blocking of the metal surface. In terms of the effectiveness of zinc protection, VTMS is comparable to 2ethylhexanoic and neodecanoic acids studied previously.
Chloride ion diffusion is an important parameter in the corrosion of reinforcing steel in concrete, exposed to marine conditions. This research study aims to investigate the effects of natural palm and mango fibers on reinforced concrete. Concrete cubes were manufactured and two volume fractions of fiber were tested with 0.2 and 0.4% relative to the weight of the sand and fiber dimensions of 1 cm and 3 cm in length. The samples were cured for 28 days and then submerged in a 3% sodium chloride saline solution simulating an aggressive marine environment. Electrochemical measurements were performed periodically over a period of 365 days. The corrosion rate of steel bars in reinforced concrete with different fiber contents was analyzed using the half-cell potential. electrochemical noise, linear polarization resistance, electrochemical impedance spectroscopy, and visual observation analysis. The results showed an initial positive effect of short mango and palm fibers in delaying the onset of corrosion in reinforced concrete compared to fiber-free control concrete. The values for short fibers (1 & times;10(5) Omega & centerdot; cm(2)) are an order of magnitude higher than those for long fibers (1 & times;10(4 )Omega & centerdot; cm(2)), based on polarization resistance. However, during the final exposure period, the fibers showed a negligible influence on its corrosion resistance compared to fiber-free concrete. The type of corrosion present on the surface of the steel was localized with possible pitting, that is, corrosion developed in small points of the rod. The size, concentration, and type of fiber directly influence the electrochemical processes of reinforcing steel in concrete.
In the last decade, there has been active research of expired drugs as inhibitors of metal corrosion in various aggressive environments. In this work, the inhibitory effect of the expired drug Drotaverine against corrosion of St3 carbon steel in model stratum waters of the oil and gas fields, NACE and M1, saturated with 400 mg/L H2S, was studied. The concentration of the drug varied within the range of 20-80 mg/L. The protective effect of Drotaverine (80 mg/L) amounts to 79% and 76%, according to 24-hour gravimetric tests, in the NACE and M1 environments, respectively. The protective effect approaches 90% when urotropine (1 mM) and KCNS (0.5 mM) are added to the solutions along with Drotaverine (80 mg/L). The mutual influence of the components of the inhibitory mixtures in the environments studied was assessed. Analysis of polarization curves in the environments under study showed that Drotaverine slows down both partial electrode reactions in the NACE+H2S medium and the cathodic process in M1+H2S. In the joint presence of the drug and KCNS, primarily the cathodic process is inhibited, with no effect on the anodic one in both environments. The same pattern is characteristic for the joint presence of Drotaverine and Urotropine. Drotaverine reduces the rate of hydrogen diffusion into the metal in the M1 +H2S media and slows down the growth of sulfate-reducing bacteria in Postgate's "B" medium.
The presence of corrosive agents, such as chlorides, in the atmosphere or water can lead to active pitting corrosion of magnesium-containing aluminum alloys. One of the methods of protecting them is coatings obtained by chemical oxidation in molybdate compounds. To enhance the anticorrosive properties of such coatings, modifying additives are added to the conversion composition and then the coatings are filled with a corrosion inhibitor solution. In this research, ultrathin molybdate conversion coatings and their interaction with a number of modifying additives, which have different effects on oxide film formation, were investigated. It was shown that the best effect is achieved by adding sodium silicate and magnesium nitrate to the conversion composition, as well as their combinations with sodium tetraborate and sodium carbonate. According to X-ray photoelectron spectroscopy data, this may be due to an increase in the proportion of Mo(V) compounds in the coatings. Corrosion tests in a G-4 humidity chamber show that modified molybdate conversion coatings are not inferior to standard chromate coatings in terms of protection properties.
The enhancement of the adsorption, passivation, and protective properties of the pyrimidine derivative 2-methyl-5-phenyl-4,5,6,7-tetrahydro-[1,2,4]triazolo[1,5-alpha]pyrimidin-7-ol (MPTTP) by polyethylene glycol (PEG-115), 3-amino-1,2,4-triazole, and its 5-fluoromethyl derivative on copper in neutral borate buffer and chloride solutions were studied. It was shown that PEG-115 can act as a copper surface modifier for subsequent adsorption of MPTTP on it. Adsorption isotherms of PEG-115 on the oxidized copper surface and MPTTP on the electrode surface preliminarily modified with PEG-115 were obtained using the ellipsometric method. The adsorption kinetics of PEG-115 on copper was studied, and the thicknesses of conventional MPTTP monolayers on copper and on a PEG-115-modified copper surface were calculated. Corrosion tests of copper in a chloride solution containing PEG-115, MPTTP, and their mixture were conducted. The results of these experiments demonstrated the possibility of complete copper protection at lower concentrations of the PEG-115 + MPTTP mixture than with its individual components.
This paper continues a series of publications dealing with HAENYTEX Protectoseal CI, a migrating corrosion inhibitor for steel reinforcement in concrete. A combination of corrosionelectrochemical and mechanical methods demonstrated that HAENYTEX Protectoseal CI is efficient in protecting steel reinforcement covered with corrosion products, as well as reinforcement embedded in carbonated concrete. Exposure to alternating temperatures and grinding of concrete surface do not affect the protection of steel reinforcement by HAENYTEX Protectoseal CI inhibitor. Surface treatment of reinforced concrete elements with this inhibitor does not adversely affect the adhesion of paint materials or the strength of concrete.
This study reports the synthesis, characterization, and corrosion inhibition performance of a novel inhibitor, EDFS-1, prepared from ethylenediaminetetraacetic acid (EDTA), sodium metasilicate, and phosphoric acid. The optimal molar ratio of 1:3:1 was determined by gravimetric screening, providing the highest inhibition efficiency. EDFS-1 was evaluated for St20 steel in industrial water containing CO2, H2S, and their mixture, showing 84.6-94.2% inhibition at 100 mg/L, depending on the gas environment. In acidic media (0.5-1 M HCl), inhibition efficiency increased with concentration and temperature, reaching 92.98% in 0.5 M HCl and 93.75% in 1 M HCl at 333 K and 150 mg/L. Electrochemical measurements indicated that EDFS-1 significantly reduced corrosion current density while minimally affecting corrosion potential. Surface analyses (SEM and AFM) demonstrated smoother, less pitted steel surfaces in the presence of EDFS-1, confirming the formation of a protective adsorbed film. These results highlight EDFS-1 as an effective and thermally stable inhibitor for steel in CO2-H2S-containing waters and strongly acidic environments.
Teeth that are properly aligned are considered appealing; however, some individuals naturally have misaligned teeth. To address this issue, orthodontists utilize wires. Following the placement of the wires, patients consume a variety of foods, drinks, and medications orally, which may affect the longevity of the wires. Additionally, the wires are susceptible to corrosion when exposed to saliva. This study examined the corrosion resistance of orthodontic wires made from SS 18/8 alloy in artificial saliva, both with and without the inclusion of specific candies, using a polarization analysis. The corrosion characteristics of the SS 18/8 alloy were evaluated for the following systems: Artificial Saliva (AS) system and Artificial Saliva combined with candies 1 to 7. The study involved measuring Linear Polarization Resistance (LPR) and corrosion current values. The results of the research produced the following findings. The ranking of corrosion resistance in SS 18/8 alloy orthodontic wire is as follows: AS+candy 6 > AS+candy 4 > AS+candy 2 > AS+candy 1 > AS+candy 7 > AS+candy 3 > AS+candy 5 > AS. This indicates that individuals using SS 18/8 alloy Orthodontic wire can consume all the candies (1 to 7) under examination. For the system with greater corrosion resistance (AS+candy 6) and the system with the smallest corrosion resistance (AS+candy 5), SEM images and contact angle measurements were recorded.
The protective effectiveness of a superhydrophobic (SHP) coating on a steel electrode obtained by electrodeposition of nickel followed by treatment in a solution of myristic acid was studied for 240 hours in different media. The SHP coating is characterized by a contact wetting angle of 154 +/- 1 degrees. Corrosion gravimetric tests of steel samples with the SHP coating, carried out under conditions of 100% humidity and in distilled water, showed the absence of mass losses with an almost unchanged contact angle. Tests in the gas phase of NaCl (50 g/L) + CO2 and NACE+ CO2 solutions showed a high protective effect of the coating (Z = 98-99%). In this case, the contact angle decreases by 4-6 degrees with the loss of superhydrophobicity, but subsequent exposure to air contributes to its restoration. After the liquid phase, the coating remains hydrophobic. Tests in the gas and liquid phases of 1 and 3% SO2 solutions showed that the protective effect of the coating is close to 90% in the gas phase and 70% in the liquid phase. After testing, the samples lose superhydrophobicity but remain hydrophobic, with contact angles only by 10-16 degrees smaller than 150 degrees. Electrochemical studies in NaCl solution (50 g/L) for 168 hours showed a high protective effect of the SHP coating.
This work introduces a newly synthesized triazole derivative, 5-([(2-furanyl)methyl]thiomethyl)-4-(naphtha-2-yl)-3-hydroxyl-4H-1,2,4-triazole (FTNT), as an effective corrosion inhibitor for carbon steel A106 G/B in 0.1 M HCl solution. The structure of the novel derivative was confirmed by FTIR, H-1 NMR, and C-13 NMR spectra. Potentiodynamic polarization measurements reveal that FTNT markedly suppresses corrosion, with inhibition efficiency reaching 81.6% at 600 ppm. Thermodynamic analysis indicates spontaneous, physisorption/chemisorption-augmented adsorption of FTNT on the steel surface, best described by the Freundlich isotherm. Atomic force microscopy (AFM) surface examination demonstrated that a protective FTNT coating precipitated on the metal surface. The experimental findings are corroborated by complementary density functional theory calculations at the B3LYP/6-311++G (d, p) level, which demonstrate advantageous electronic properties and adsorption propensity that are correlated with high inhibitory efficiency. The results provide molecular-level insight into the rational design of triazole-based corrosion inhibitors, and FTNT represents a focused, well-characterized inhibitor with practical potential to reduce carbon steel corrosion in acidic settings.
The protective effect of sunflower oil diethanolamide (DEAS), Kaptax, phenylthiourea (PTU), diphenylthiourea (DPTU) and sodium diethyldithiocarbamate (DEDTC), as well as mixtures of DEAS with sulfur-containing organic substances during the corrosion of steel 3 in a 0.5 M sulfuric acid solution was studied using gravimetry, polarization curve recording and impedance spectroscopy. It was found that at the highest studied concentration of DEAS, Kaptax, DPTU, PTU and DEDTC provide protection of steel from corrosion in sulfuric acid by 93.0; 99.9; 98.7; 98.7, and 96.3% at a temperature of 25 degrees C, respectively. A mixture of DEAS (0.5%) with organic sulfur-containing substances (5.10(-5)...10(-3) M) protects steel at the specified temperature by 85.0-99.6%. As temperature increases, the effectiveness of most individual compounds decreases. Increased inhibition with a temperature increase to 60 degrees C is observed for inhibitor mixtures with the highest concentrations of the sulfur-containing component. The influence of the components and their mixtures on specific electrode reactions of the corrosion process was determined. The degree of surface coverage by inhibitors and the free energy of adsorption were determined.
This study systematically evaluates the corrosion inhibition potential of 3-benzylsulfanyl-4H-(1,2,4) triazole (BST) on mild steel in a 1.0 M HCl environment. The investigation utilized a multi-faceted approach combining weight loss analysis, potentiodynamic polarization (PDP), scanning electron microscopy (SEM), and density functional theory (DFT). Gravimetric results indicated that inhibition efficiency is temperature-and concentration-dependent, peaking at 93.0% with a 0.5 mM concentration after 5 hours at 303 K. Adsorption analysis confirmed the data fits the Langmuir isotherm, suggesting a mechanism driven by both physisorption and chemisorption. PDP measurements corroborated these findings, showing a mixed-type inhibition behavior that suppresses both anodic and cathodic reactions, achieving a maximum efficiency of 96.3%. Surface analysis via SEM revealed that a protective layer was formed by the inhibitor, significantly reducing surface damage compared to the uninhibited acid solution. Furthermore, DFT calculations provided molecular-level evidence of strong interaction between the inhibitor and the steel surface, characterized by favorable HOMO-LUMO energy levels. These findings establish BST as a highly effective corrosion inhibitor that performs comparably to or better than existing triazole derivatives.
In the present work, a study was performed on the prevention of carbon steel corrosion in desalinated water systems using natural honey NH and Fenugreek (Trigonella foenum gracum, TFG) aqueous extracts as a novel green corrosion inhibitor for carbon steel. Depending upon the concentration ratio, these inhibitors' ability to mitigate corrosion was examined both individually and in combination. This study employed potentiodynamic strategies together with the weight loss approach. Results revealed that as inhibitor concentrations rise, so do the inhibitors' capacities for reducing corrosion rate. The addition of a solution containing 800 ppm NH to various concentrations of TFG significantly improved the inhibitor performance of (TFG). It was found that the optimum concentration was mixture of [800 ppm NH and 60 ppm TFG] yielding a maximum inhibition efficiency value of 93.1% weight loss and 87.2% electrochemical. These mixtures were found to affect both the anodic and cathodic polarization curves. Results demonstrated that the inhibitor's effects on the anodic polarization are stronger than those on the cathodic polarization and show synergistic behavior. These findings inferred that the studied inhibitors served as mixed-type inhibitors with anodic predominance. The potentiodynamic tests show that the primary cause of the inhibition mechanism is the adsorption of inhibitor species on the metal surface, as evidenced from SEM studies of the corroded and inhibited steel specimens. It's important to notice how much better steel will be protected in desalinated water systems when this form of inhibitor is used.
In the presented work, the conductive polymer, poly[1-(4-chlorophenyl)-5-styryl-1-tetrazole] (PCPST), was successfully synthesized by the electro polymerization of the 1-(4-chlorophenyl)5-styryl-1-tetrazole (CPST) monomer. The resulting polymer was characterized using Fourier with the use of the potentiostatic method, the corrosion behavior regarding uncoated and coated low carbon steel (L-CS) has been determined with the use of Tafel plots in a corrosion medium of 3.5 wt.% NaCl solution across a temperature range of 293 degrees to 323 degrees K. The protective efficiency of the polymeric coating was remarkably enhanced by incorporating nanoscale metal oxides: magnesium oxide (MgO) and zinc oxide (ZnO). When nano ZnO and nano MgO were present, the polymer's protection efficiency increased from 75.852% to 80.759% and 91.512%, respectively. Furthermore, kinetic and thermodynamic parameters (the enthalpy of activation Delta H*, the activation energy Ea, the Gibbs free energy Delta G, and the entropy of activation Delta S*) were calculated for both the uncoated and coated L-CS specimens. The AFM was utilized to examine the surface morphology of the coating.
Certain regularities of corrosion of metallic copper M1 in freely aerated H3PO4solutions have been revealed; the media under study included solutions containing Cu(II) phosphate as a corrosion product, and Fe(III) phosphate as an additional oxidizing agent. Useful information about the possibility of chemical reactions occurring during copper corrosion in these media and the reaction products was obtained by analyzing the E-pH diagram of the Cu-H2O-phosphate anion system. Using the data on the mass loss of metal samples in the aggressive medium, the corrosion rates of copper in H3PO4 solutions (20 +/- 2 degrees C) were obtained for various exposure times of the metal in the corrosive medium and at various acid concentrations in solutions. The maximum average corrosion rate of the metal was 0.11 g/(m2 center dot h) in 2 M H3PO4 over 8 days of testing. Upon prolonged contact of copper with 2 M H3PO4 (12 days), the mass loss of the metal due to the corrosion was 25 g/m2. The addition of Cu(II) phosphate to 2 M H3PO4 solution does not significantly affect the corrosion rate of metallic copper in this medium. As a result, the accumulation of Cu(II) phosphate, the product of metallic copper corrosion in this aggressive medium, does not have a noticeable effect on copper corrosion. In contrast, copper corrosion increases significantly in the presence of Fe(III) phosphate in H3PO4 solutions. According to the data obtained for 6 h of testing, the corrosion rate of copper in 2 M H3PO4 in the presence of 0.01 M Fe(III) phosphate is 6.5 times higher than without it. This effect is slightly reduced with an increase in the duration of contact between the metal samples and the acid solution, and is enhanced with an increase in the concentration of Fe(III) phosphate in the aggressive medium. This regularity should be taken into account for industrial conditions in order to prevent accelerated corrosion of copper when technological H3PO4 solutions, contaminated with Fe(III) phosphate, come into contact with copper equipment.
