Inorganic Corrosion Inhibitors Research Articles

An inhibitive system to mitigate the corrosion of AA2024-T3 in 3.5 wt% NaCl solution: Utilizing the synergistic effect of cerium cations and benzimidazole molecules

This study aims to improve the anti-corrosion protection performance of AA2024-T3 using the synergistic effect of organic and inorganic corrosion inhibitors in saline solution. Combining the Ce3+ cations and benzimidazole (BI) molecules was employed as the inhibitive system for the AA2024-T3. Electrochemical properties of the metallic substrate in the presence and absence of the inhibitive system were studied utilizing EIS, PD, and OCP techniques. In addition, GIXRD, ATR-FTIR, XPS, OM, FE-SEM/EDS, water contact angle, and AFM were hired to study the protection mechanism. Based on the results obtained, the inhibitive system has a synergistic effect in improving the anti-corrosion protection performance of AA2024-T3. The synergistic index for the Ce + BI system was calculated to be around 19. Also, the efficiency of the synergistic system in the simultaneous presence of Ce3+ cations and BI molecules as the corrosion inhibitor was 99.3 %, which is higher than that of other inhibitive systems. Finally, the surface analysis outcomes revealed that the inhibitive film forming on the samples' surface during the immersion of the sample in the saline solution in the presence of the inhibitive species is the main factor in boosting the anti-corrosion properties of the aluminum substrate.

Synthesis, characterization and anticorrosion performance of a new corrosion inhibitor based on cobalt- phenanthroline- p-hydroxybenzoic acid ternary complex

In this paper, a new corrosion inhibitor based on cobalt- phenanthroline- p-hydroxybenzoic acid ternary complex was synthesized. Its anti-corrosion effects on carbon steel in 0.5 M HCl were investigated by weight-loss measurements, electrochemical tests, surface analyses, and quantum chemical calculations. The results indicated that the Co-phen-phba ternary complex exhibits excellent anti-corrosion efficiencies of ∼97 % at 298 K and ∼86 % at 328 K. The excellent anti-corrosion performance of Co-phen-phba ternary complex could be attributed to the combination of inorganic and organic corrosion inhibitors. Theoretical calculations established the correlation between the structure and the anti-corrosion effect of corrosion inhibitor.

Development of a Method for Determining the Residual Life of Structural Elements with Cracks Under the Action of Load and Corrosive Environment, as well as the Application of Corrosion Inhibitors to Enhance It

A developed method for determining the lifespan of structural elements with large-scale cracks of complex geometry under the influence of long-term static loads and corrosive environments. The method is based on an appropriate computational model, which relies on the first law of thermodynamics for the elementary act of local failure (crack propagation), some fundamental principles of physical chemistry, as well as the basic principles of fracture mechanics. The advantages of this method over existing ones are substantiated. The application of the method is demonstrated through examples involving the determination of the residual life of such structural elements as torsion and a pipe with small cracks made of 45KhN2MFA steel (tempered at 470 K and 725 K) under the influence of long-term static loading and distilled water. As the cracks are considered small, we have constructed a computational model in terms of deformation parameters, including a well-known counterpart in fracture mechanics, crack opening at the crack tip δt. At the same time, based on available experimental data from the literature, it is substantiated that the application of existing linear fracture mechanics methods in stress intensity factors KI for implementing the mentioned problems, the application of existing linear fracture mechanics methods is inappropriate. To determine the residual life of structural elements using this method, it is necessary to have kinetic diagrams in coordinates of the growth rate of small cracks and the crack opening at the crack tip, which means V ∼ δt. These diagrams are constructed here using the provided formulas for determining δt and diagrams are constructed here using the provided formulas and known experimental data for 45KhN2MFA steel under the influence of distilled water and static tension. Using the mentioned method, the residual lifespans of the torsion and the pipe were calculated under the influence of long-term static loading and distilled water. Additionally, the effectiveness of water solutions of well-known inorganic corrosion inhibitors on the residual lifespan of the mentioned structural elements was verified through calculations. It was found that the residual lifespan effectively characterizes the performance of corrosion inhibitors, which can be applied in engineering practice.

Anticorrosive action of eco-friendly plant extracts on mild steel in different concentrations of hydrochloric acid

Abstract The extracts of different parts of plants (leaf, stem, and flower) act as a green, environmentally friendly, economical, and safe corrosion inhibitors. The eco-friendly extracts of plant material provide an excellent alternative that substitutes toxic traditional (organic and inorganic) corrosion inhibitors. The plant extracts are renewable and readily available; thus, they occupy a unique position in the family of green inhibitors. The plant extract contains several bioactive compounds, such as flavonoids, tannins, polyphenols, phenolic acids, glycosides, flavonols, etc., which possess experienced significant interest as anti-corrosive agents. These plant extracts contain several heteroatoms like phosphorus, nitrogen, sulfur, oxygen, etc., which are adsorbed on the metallic surface and form an inert protective layer that protects metal from a corrosive environment. Thus, this article aims to shed light on the efficiency of plant extract in protecting steel in an acidic environment.

Current and emerging trends of inorganic, organic and eco-friendly corrosion inhibitors.

Effective corrosion control strategies are highly desired to reduce the fate of corrosion. One widely adopted approach is the use of corrosion inhibitors, which can significantly mitigate the detrimental effects of corrosion. This systematic review provides a thorough analysis of corrosion inhibitors, including both inorganic and organic compounds. It explores the inhibition mechanisms, highlighting the remarkable inhibitive efficiency of organic compounds attributed to the presence of heteroatoms and conjugated π-electron systems. The review presents case studies and investigations of corrosion inhibitors, shedding light on their performance and application potential. Moreover, it compares the efficacy, compatibility, and sustainability of emerging environmentally friendly corrosion inhibitors, including biopolymers from natural resources as promising candidates. The review also highlights the potential of synergistic impacts between mixed corrosion inhibitors, particularly organic/organic systems, as a viable and advantageous choice for applications in challenging processing environments. The evaluation of inhibitors is discussed, encompassing weight loss (WL) analysis, electrochemical analysis, surface analysis, and quantum mechanical calculations. The review also discusses the thermodynamics and isotherms related to corrosion inhibition, further improving the understanding of inhibitor's behavior and mechanisms. This review serves as a valuable resource for researchers, engineers, and practitioners involved in corrosion control, offering insights and future directions for effective and environmentally friendly corrosion inhibition strategies.

A Review Paper on the Research Status and Development Trend of Corrosion Inhibitors

With the widespread use of metals in various industrial sectors, corrosion has become a serious challenge, affecting the life and performance of equipment. As a key technical means, corrosion inhibitors have made significant progress in the past few decades. This paper aims to summarize the research status of corrosion inhibitors and discuss their future development trends. In terms of research status, the research status of corrosion inhibitors at home and abroad was reviewed, and the application of corrosion inhibitors in different application fields was discussed. In addition, we discussed the inhibition mechanism of different types of corrosion inhibitors, such as organic corrosion inhibitors and inorganic corrosion inhibitors.

Electrochemical and DFT studies of Terminalia bellerica fruit extract as an eco-friendly inhibitor for the corrosion of steel

It is well known that metal corrosion causes serious economy losses worldwide. One of the most effective ways to prevent corrosion is the continuous development of high-efficient and environment-friendly corrosion inhibitors. Among the widely used organic and inorganic corrosion inhibitors, plant extracts are top candidates due to their nontoxic nature. The present study reports a novel application of the methanolic extract of Terminalia bellerica fruits as an environment friendly corrosion inhibitor for steel in sulphuric acid medium. The phytochemicals of the extract, namely Ellagic, Gallic, and Malic acids, play a key role of the anti-corrosive behavior of the extract. The corrosion prevention activity was studied on the steel in 1 M H2SO4 using a variety of approaches including weight loss analysis (WL), scanning electron microscope (SEM), electrochemical impedance spectroscopy (EIS), density functional theory (DFT), natural bond orbital analysis (NBO), Fukui function and Monte Carlo simulations (MC). In 1 M H2SO4 solution, the maximum electrochemical inhibition efficiency of 91.79% was observed at 4000 mg/L concentration of the extract. The NBO analysis showed that the charge density of the double bonds and the oxygen atoms of carbonyl and hydroxyl groups of the phytochemicals lies on the top of the natural bond orbitals which promotes the anticorrosive properties of the investigated inhibitors. The surface coverage of steel was validated by SEM measurements. According to DFT studies, numerous nucleophilic regions were present in the active phytochemical constituents of the inhibitor, demonstrating their favorable nucleophilicity. The computed electronic structure of the phytochemicals revealed band gaps of 4.813, 5.444, and 7.562 eV for Ellagic, Gallic, and Malic acids respectively suggesting effective metal-inhibitor interactions. A good correlation between experimental and theoretical findings was addressed.

Effect of Na2SiO3 and TEA Electrolyte Additives on the Corrosion Inhibition of Zinc Electrodes and Electrochemical Performance of Rechargeable Alkaline Manganese Batteries

To inhibit hydrogen evolution corrosion, passivation, and zinc dendrite growth during the charging and discharging of the zinc negative electrode of rechargeable alkaline manganese battery containing ultra-fine zinc powders, the effects of the single addition amounts of inorganic corrosion inhibitor Na2SiO3 and organic corrosion inhibitor TEA and their compounding ratio on the corrosion inhibition effect and the charging and discharging performance of alkaline manganese battery were systematically investigated in this paper. SEM and XPS were used to observe the microscopic morphology of the zinc anode, and the inhibition mechanisms of the relevant inhibitors were explored. The results show that, the addition of Na2SiO3 and TEA can synergistically improve the coverage of the protective film, thereby inhibiting hydrogen evolution corrosion, passivation and dendrites of zinc electrodes. Compared to blank electrolyte, when the composite concentration of Na2SiO3 and TEA is 1 g l−1 Na2SiO3+56.25 mg l−1 TEA, the hydrogen evolution corrosion inhibition efficiency can reach 70.56%, the initial specific capacity and the specific capacity after 50 cycles can increase from 160.7 mAh g−1, 58 mAh g−1 to 198.4 mAh g−1, 74 mAh g−1, respectively. This study has great theoretical and engineering value for guiding the design of electrolytes for rechargeable alkaline manganese batteries.

Multifunctional liquid-like magnetic nanofluids mediated coating with anticorrosion and self-healing performance

The long-term protective efficacy of organic coatings against corrosion can be diminished by the presence of micropores/cracks and poor self-healing capabilities. To address these issues, Ti3C2 MXene was subjected to liquefaction-like treatment to maintain a two-dimensional lamellar structure in water and polymer matrix for a long time, as well as improve the dispersion stability and loading capacity of MXene. The inorganic corrosion inhibitor ferroferric oxide (Fe3O4) was then electrostatically loaded onto MXene nanofluids to obtain a hybrid material. Through hydrogen bonding, polyvinyl alcohol (PVA) molecular chains were bridged to the hybrid material, resulting in a self-healing anti-corrosion coating. The coating exhibited excellent corrosion protection, as well as self-healing properties attributed to the labyrinth effect and corrosion inhibition of MXene@Fe3O4 hybrids. Notably, electrochemical testing demonstrated outstanding corrosion resistance of this coating on diverse substrate surfaces. In addition, the anti-corrosion coating will strongly coalesce on the surface of B-NdFeB under magnetic stimulation, realizing the localized corrosion protection of metal materials. The anti-corrosion coating can be quickly repaired under the stimulation of water as well as recovery, the anti-corrosion repair efficiency on the surface of permanent magnets is up to 92%, and the mechanical properties after recovery can be restored to 97% of the original sample. This innovative coating offers a convenient, green synthesis strategy for the construction of self-healing coatings with superior anti-corrosion properties.

Corrosion Inhibition in CO2-Saturated Brine by Nd3+ Ions.

This study reports the use of an inorganic corrosion inhibitor to mitigate dissolved CO2-induced corrosion. Using electrochemical techniques (polarization curves, open circuit potential, polarization resistance, and electrochemical impedance), the effect of adding Nd3+ ions on the corrosion resistance of X52 steel immersed in CO2-saturated brine at 20 °C and 60 °C was evaluated. The polarization curves showed that the Icorr values tend to decrease with increasing Nd3+ ion concentration, up to the optimal inhibition concentration, and that the corrosion potential increases at nobler values. Open circuit potential measurements showed a large increase in potential values immediately after the addition of the Nd3+ ions. Similarly, polarization resistance measurements showed similar trends. It was observed that regardless of temperature, Nd3+ ions can reduce the corrosion rate by more than 97% at doses as low as 0.001 M. Electrochemical impedance measurements confirmed the formation of a protective layer on the steel surface, which caused an increase in the magnitude of the impedance module and phase angle, which indicates an increase in the resistance to charge transfer and capacitive properties of the metallic surface. The characterization of the metallic surface showed that the protective layer was formed by Nd carbonates, whose formation was due to a CO2 capture process.

Investigation of the inhibition behavior of an octacalcium phosphate as a green corrosion inhibitor against carbon steel in 3 % NaCl medium

The development of new corrosion inhibitors constitutes a significant endeavor for researchers. In this study, the efficacy of octacalcium phosphate (OCPa), an inorganic green corrosion inhibitor for carbon steel in a 3% NaCl solution, was evaluated. This investigation marks the first application of this compound in a saline environment. The phosphate inhibitor was synthesized through a double aqueous decomposition process in an equimolar solution of water and ethanol, and subsequently characterized using X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), chemical analysis, and SEM/EDX to ascertain its properties and morphology. Meanwhile, the electrochemical behavior was investigated using techniques such as potentiodynamic polarization (PDP) and electrochemical impedance spectroscopy (EIS) to assess the anticorrosive performance of the studied phosphates. Analysis of the carbon steel surface morphology of the resultant layer was conducted using SEM/EDX and FTIR. According to the electrochemical results, OCPa demonstrated an impressive inhibitory effect, with an efficiency reaching 93.1% at an optimal concentration of 50 ppm, exhibiting a cathodic type of inhibition. Moreover, the charge transfer resistance was found to be 2450 Ω.cm2 in the presence of 50 ppm of the inhibitor, as compared to 161.0 Ω.cm2 in the uninhibited solution. The thermodynamic parameters indicated an endothermic nature for the adsorption process in the presence of OCPa. Examination of the carbon steel surface morphology by SEM revealed the formation of a protective layer, serving to shield the metal from corrosion. The experimental findings underscore the potential of octacalcium phosphate as a promising inorganic green corrosion inhibitor for carbon steel in saline environments, opening new avenues for the exploration and development of environmentally benign anti-corrosive substances.

Optimization and understanding of corrosion inhibitors for cooling water system

PurposeTwo corrosion inhibitors for closed cooling water systems, nitrite-based and mixture of nitrite and molybdate corrosion inhibitor, are often compared to each other. This study aims to optimize these two inhibitors in terms of concentration and pH for carbon steel protection, with insights into the double layer structure on surface and its impact on corrosion inhibition.Design/methodology/approachElectrochemical analysis including electrochemical impedance spectroscopy and potentiodynamic test are carried out for quick assessment of corrosion inhibition efficiency and optimization, which is confirmed by immersion test and microscopic analysis. The electronic properties of the surface film are analyzed through Mott–Schottky method which provides new insights into the inhibition mechanism and the role of each component in mixture inhibitor.FindingsMixture of nitrite and molybdate is shown to present higher inhibition efficiency, owning to the double layer structure. Nitrite alone can form a protective surface film, whereas molybdate leads to an n-type semiconductive film with lower donor density, hence giving rise to a better inhibition effect.Research limitations/implicationsSurface after inhibitor treatment has been carefully characterized to the microscopic scale, implying the effect of micro-structure, chemical composition and electronic properties on the corrosion resistance. Inorganic corrosion inhibitors can be tuned to provide higher efficiency by careful design of surface film structure and composition.Originality/valueAlmost every study on corrosion inhibitor applies such method for quick assessment of corrosion inhibition effect. Mott–Schottky test is one of electrochemical methods that reveals the electronic properties of the surface film. Previous works have studied the surface layer mainly through X-ray photoelectron spectroscopy. This study provides another insight into the surface film treated by nitrite and molybdate through Mott–Schottky analysis, and relates this structure to the corrosion inhibition effect based on multiple analysis including electrochemistry, microscopic characterization, thermodynamics and interface chemistry.

A Review of Inorganic Corrosion Inhibitors: Types, Mechanisms, and Applications

A Review of Inorganic Corrosion Inhibitors: Types, Mechanisms, and Applications

Cysteine as an Alternative Eco-Friendly Corrosion Inhibitor for Absorption-Based Carbon Capture Plants.

Inorganic corrosion inhibitors are commonly applied to mitigate severe corrosion in absorption-based carbon capture plants. They are, however, not environmentally friendly, posing a health risk, harming the environment, and making chemical handling and disposal costly. Therefore, this study evaluated the corrosion inhibition performance of an amino acid, namely cysteine, with the aim of providing an eco-friendly alternative to the commercial inorganic corrosion inhibitors. Electrochemical and weight loss corrosion measurements showed that cysteine was effective in protecting carbon steel at all process operating conditions. At 80 °C, a 500 ppm cysteine could provide up to 83% and 99% inhibition efficiency under static and dynamic flow conditions, respectively. Its inhibition efficiency could be improved when the cysteine concentration, solution temperature, and flow condition were altered. Cysteine was an anodic corrosion inhibitor and underwent spontaneous, endothermic, and combined physical and chemical adsorption that followed the Langmuir adsorption isotherm model. The quantum chemical analysis indicated that cysteine had a high reactivity with metal surfaces due to its low energy gap and high dipole moment. The EDX analysis revealed a significant sulphur content on the metal substrate, indicating that cysteine's mercapto group played an integral role in forming an effective adsorption layer on the metal interface.

EFFECT OF CORROSION INHIBITORS ON REINFORCED CONCRETE PROPERTIES—A REVIEW

Over recent decades, considerable effort has been made to discover new and efficient corrosion inhibitors for reinforced concrete in corrosive media. Organic, inorganic, and green corrosion inhibitors have been used to inhibit the corrosion of reinforcing bars in contaminated concrete structures. Despite the efficacy of corrosion inhibitors, an evaluation of the effect of inhibitors on other concrete properties plays a prominent role in assessing the industrial use of these effective materials. A comprehensive study of improvements in concrete properties such as workability, setting time, air content, fresh density, compressive strength, tensile strength, flexural strength, consistency, elasticity, water absorption, and water permeability after the addition of a corrosion inhibitor allows for effective reduction of reinforcement steel corrosion. Hence, this study summarizes all corrosion inhibitors used for concrete reinforcement during the last decade (2010–2020), as well as their effects on the properties of contaminated concrete.

Insight on the corrosion inhibition of nanocomposite chitosan/boron nitride integrated epoxy coating system against mild steel

Research in the field of organic and inorganic corrosion inhibitors has become prominent in recent years whereas its applicability is limited owing to the toxicity, non-biodegradability, low inhibition efficiency, etc. Polymer nanocomposites have high mechanical strength, stiffness, toughness, and thermal stability. They act as barriers against moisture and gases which enhance their applicability to various fields. The present study focuses on the synthesis of nanocomposite of chitosan/boron nitride (CS-BN) by sol-gel process and incorporated into epoxy matrix. The composite is then characterized by Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD). XRD results show that nano hexagonal boron nitrides are finely scattered in the chitosan matrix. The thermal stability of the CS-BN composite was studied with TGA. The study depicts that boron nitride increases the thermal stability of chitosan. The corrosion protection features of biocompatible chitosan/boron nitride nanocomposite on mild steel (MS) substrate in 1 mol/L HCl solution were monitored by potentiodynamic polarization studies (Tafel), electrochemical impedance spectroscopy (EIS), and linear polarization studies (LPS). X-ray photoelectron spectroscopy (XPS) analysis was adopted to propose the mechanism of corrosion and also used to compare the corrosion inhibition behavior of BN in composite on MS surface.

Waterborne Eco-Sustainable Sol-Gel Coatings Based on Phytic Acid Intercalated Graphene Oxide for Corrosion Protection of Metallic Surfaces.

In the past few years, corrosion protection of metal materials has become a global challenge, due to its great economic importance. For this reason, various methods have been developed to inhibit the corrosion process, such as surface treatment approaches, by employing corrosion inhibitors through the deposition of opportunely designed functional coatings, employed to preserve from corrosion damages metallic substrates. Recently, among these techniques and in order to avoid the toxic chromate-based pre-treatment coatings, silane-based coatings and films loaded with organic and inorganic corrosion inhibitors have been widely used in corrosion mitigation water-based surface treatment. In this study, the synthetic approach was devoted to create an embedded, hosted, waterborne, and eco-friendly matrix, obtained by use of the sol–gel technique, through the reaction of functional alkoxysilane cross-linking precursors, namely (3-glycidyloxypropyl)trimethoxysilane (GPTMS) and (3-aminopropyl)triethoxysilane (APTES), in the presence of graphene oxide (GO) intercalated with natural and non-toxic phytic acid (PA) molecules. As a matter of fact, all experimental results from FT-IR spectroscopy, UV–Vis analysis, and SEM confirmed that PA molecules were successfully decorated on GO. Furthermore, polarization measurements and a neutral salt spray test were used to evaluate the anticorrosive performance on aluminum and steel substrates, thus showing that the GO-PA nanofiller improved the barrier and corrosion protection properties of the developed functional silane-based coatings.

The effect of Tetracycline drug as a green corrosion inhibitor for carbon steel in HCl media

Corrosion protection of metals, and alloys is a prime activity of technical, economic, environmental, and aesthetical significance. The use of inhibitors is oneof the best choice of combating metals, and alloys against detoriation against environmental impact. The toxicity of organic, and inorganic corrosion inhibitors to the environment has provoked the search for eco-friendly corrosion inhibitors like green corrosion inhibitors as other more environmental friendly corrosion inhibitors. This research demonstrates the anti-corrosion effect of Tetracycline drug on carbon steel alloy (ck45) in 1 M hydrochloric acid using electrochemical measurements (Tafel polarization and impedance spectroscopy (EIS) techniques). Also, the activation energy, the thermodynamic parameters and adsorption isotherm were derived from the electrochemical results. The highest inhibition yield for ck45 alloy in 1.0 M hydrochloric acid using 300 ppm of the drug is about 82% and 78% by polarization and EIS method, respectively. The potentiodynamic polarization measurement result shows that Tetracycline is a mixed-type inhibitor. The adsorption of drug molecules on the alloy surface obeying the Langmuir adsorption isotherm model and the ΔG°ads value calculated, suggested that the drug molecules adsorbed on the alloy surface via a physisorption mechanism. Also, optical microscopy and scanning electronic microscopy (SEM) studies, confirmed the formation of a protective film over the metal surface.

Assessment of Inhibitive Drugs for Corrosion Inhibition Applications in Petrochemical Plants – A Review

The world is paying more attention and trying to eliminate the use of substance that are toxic to human and the environment. The use of some organic and inorganic corrosion inhibitors exhibit toxicity and research has been ongoing on the use of eco-friendly substitutes. Plant extract, dyes and drugs have shown good corrosion inhibitive capabilities and this work gives a summary of several works that have been done on the use of drugs as efficient corrosion inhibitors for mild steel which is mostly used in the petroleum and petrochemical industry in acidic media such as HCl and H2SO4.

Use of Lawsonia Inermis and Sodium Nitrite as Surface Applied Corrosion Inhibitors

This research provides an investigation to measure the rate of corrosion of steel bars coated with organic corrosion inhibitor Lawsonia inermis (Henna) and inorganic corrosion inhibitor Sodium Nitrite (NaNO2) embedded in concrete. Presence of corrosion on the reinforcement bars reduces the bond strength between steel and concrete over a while and excessive corrosion on reinforcement bar can lead to loss of ductility, strength and in extreme cases collapse. Structures like marine structures, sewage pipes, which are prone to damage due to presence of excessive salts, acidic environment, the corrosion rate is accelerated when compared to normal structures, therefore there is need of protecting such type of structures. In previous researches, the corrosion inhibitors were added directly into the mix while preparing the concrete mix and inhibition efficiency was analysed. However, in this case, the corrosion inhibitors are applied to the reinforcing bars itself as the corrosion occurs on the bars and which has proven to be effective. In the present study, the reinforcement bars are coated with Henna paste and Sodium Nitrite paste as corrosion inhibitors. Inhibitors in the form of 2 layers, 4 layers and a combination were used. The beams specimens were cured for 58 days in saline environment. The difference in the corrosion potential is measured by half-cell potentiometer. Results suggested that the specimen with 4 layers of Henna coating had reduced the rate of corrosion by 46% when compared to original sample. Also, specimens with 2 coats of Henna and 4 coats of Henna and sodium nitrite showed better corrosion inhibition efficiency.