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This study investigates the efficacy of newly synthesized inhibitor with a dual function of corrosion inhibition and biocide for control of microbial influenced corrosion (MIC) in carbon steel API 5LX in the cooling tower water (CTW) environment. Four types of N-substituted tetrabromophthalic inhibitor (N-TBI) were synthesized, and the structural characterization was performed via proton nuclear magnetic resonance spectroscopy, thermogravimetric analysis and high-resolution mass spectrometry. These studies revealed the distinctive optical, thermal, and dielectric properties of the synthesized inhibitors. The corrosion inhibition efficiency has been evaluated by the weight loss (WL) analysis and electrochemical measurements (ECM) and biofilm assay. Biofilm assays and WL showed that inhibitor II exhibited the highest inhibition efficiency 74% and 79% respectively than others. Further ECM showed that the higher charge transfer resistance and the lower corrosion current, suggesting a protective film formed on the metal surface which was due to the adsorption of the N-TBI. Fourier transform infrared spectroscopy confirmed the adsorption of the N-TBI as C–O stretching and C–H bending with the Fe complex. X-ray diffractometer revealed that the presence of inhibitors in the corrosion product (Fe3O4, Fe2O3, FeH2O2, FeS) were highly reduced than the control system. Overall, this study highlighted the potential application of N-TBI with dual function of corrosion inhibition and biocide to control the MIC for carbon steel API 5LX used in the CTW environment. [ABSTRACT FROM AUTHOR]

In this investigation, the efficacy of PCA-GLU, a polymer obtained by copolymerizing citric acid and glutamic acid, as a corrosion inhibitor for carbon steel was investigated in a 3.5wt% NaCl solution. Electrochemical impedance spectroscopy (EIS) techniques and potentiodynamic polarization (PDP) measurements were used to evaluate the corrosion inhibition. The findings demonstrate that PCA-GLU has a 96.73% corrosion inhibition efficiency. Additionally, when the inhibitor concentration rises, the corrosion inhibition efficiency rises as well, reaching an ideal concentration of 400 mg/L. Furthermore, PCA-GLU can create an adsorption layer on the surface of Q235. This paper verifies the adsorption mechanism of PCA-GLU through molecular dynamics simulations of the system and quantum chemical calculations of corrosion inhibitors in solution. Ultimately, our research findings validate that PCA-GLU is an efficient corrosion inhibitor in safeguarding carbon steel against corrosion in marine environments. [ABSTRACT FROM AUTHOR]

This study investigates sweet corrosion mitigation methods focusing on the efficacy of inhibitors. Specifically, it examines the performance of two types of inhibitors: water-soluble and oil-soluble. Utilising a Rotating Cylinder Electrode (RCE) setup, turbulence is induced in saline solutions to assess the impact of inhibitors on the corrosion of carbon steel. Scanning Electron Microscopy (SEM) is employed to analyse corrosion degradation patterns and material damage mechanisms. Given the prevalent use of inhibitor injection in the oil sector, it is crucial to evaluate and compare the effectiveness of various inhibitors to recommend optimal options and further studies. The findings contribute to advancing corrosion mitigation strategies, providing insights into the performance of inhibitors in flow environments and aiding in the development of more effective corrosion control measures for carbon steel structures. The inhibitors under study are sourced from local oil company vendors. With a projected duration of six months and a total budget of KD 9850, this investigation aims to provide valuable insights into corrosion mitigation strategies. [ABSTRACT FROM AUTHOR]

In this work, leaves of Silybum marianum (L.) Gaertn were extracted by a one-step extraction method using ethanol as a solvent, and the Silybum marianum (L.) Gaertn extract (SMGE) was firstly employed as a green corrosion inhibitor for carbon steel in 0.5 mol/L H2SO4. The corrosion inhibition performance was studied using weight loss and electrochemical methods, and the anti-corrosion mechanism of SMGE is further analyzed through some surface characterizations and theoretical calculations. The results indicate that SMGE can act as a mixed-type corrosion inhibitor and possess superior corrosion inhibition performance for carbon steel in H2SO4 solution, and the optimum corrosion inhibition efficiency reached 93.06% at 800 ppm SMGE combined with 60 ppm KI. The corrosion inhibition efficiency increased with the rising inhibitor concentration. Surface characterizations illustrated that the inhibitor could physico-chemically adsorb on a metal surface, forming a hydrophobic, protective film. [ABSTRACT FROM AUTHOR]

A green corrosion inhibitor was prepared from the bio‐based platform compound 5‐hydroxymethylfurfural through a green synthetic route, which avoid the use of toxic reagent. The inhibition performance and mechanism of this compound for the corrosion of mild steel in 0.1 M HCl was investigated by using the weight loss experiments, polarization measurements, EIS measurements and quantum chemical calculations. The corrosion inhibition efficiency by weight loss measurement (ηWLM%) of this inhibitor can reach up to 90.3 % at 303 K with 1.2 mM concentration. Moreover, the electrochemical experiments revealed that this corrosion inhibitor acts as a mixed‐type inhibitor. Thermodynamic studies gave the values of the standard Gibbs free energy ΔGads0 ${{\rm \Delta }{G}_{ads}^{0}}$ , fall within the range of −20 kJ/mol to −40 kJ/mol, suggested the adsorption of this compound is a spontaneous process involving both physisorption and chemisorption. In addition, quantum chemical calculations were conducted to further validate the formation of an effective absorption layer by this inhibitor on metal surfaces, which showed that the electron density iso‐surfaces of HOMO was mainly distributed on chloride ions, while LUMO tended to be distributed on furan rings and aldehyde groups. Besides, the other quantum chemical parameters of this inhibitor were also calculated to explore the molecular activity, such as, the molecular volume (ν, 333.105 Å), global hardness (η, 4.706 eV), global softness (σ, 0.2125 eV), electronegativity (χ, 4.93 eV), dipolemoment (μ, 13.1429 D) and vertical ionization energy (VIE, 7.2646 eV). [ABSTRACT FROM AUTHOR]

A new conducting polymer of the cellulose acetate poly acrylonitrile (CAPA)–SiC composite was produced using an in situ oxidative polymerization technique in an aqueous medium. SiC was synthesized from Cinachyrella sp. as a source of carbon and silicon at 1200 °C under an argon atmosphere via a catalytic reduction process. The structure and morphology of the CAPA–SiC composite were characterized using surface area studies (BET), X-ray diffraction (XRD), Fourier transformation infrared spectroscopy (FT-IR), and surface morphology (SEM & TEM). To protect copper, the produced CAPA–SiC composite was mixed with commercial epoxy paint using a casting technique, and the copper surface was coated with the three components of the CAPA–SiC/epoxy paint mixture. The corrosion inhibition improvement of the CAPA–SiC/paint coating was assessed using electrochemical impedance spectroscopy followed by Tafel polarization measurements in a 3.5 wt% NaCl solution. The corrosion protection ability of the CAPA–SiC/epoxy coating was found to be outstanding at 97.4% when compared to that of a CAPA/paint coating. SEM and XRD were used to illustrate the coating on the copper surface. [ABSTRACT FROM AUTHOR]

According to the corrosion problems of the gathering and gas piprlinc, thc pipeline material, cx・ trmal corrosion and internal corrosion were analyzed; the chemical corrosion mechanism and electrochemical corrosion mechanism of pipeline corrasion were summarize*! chemical corrosion was often accompanied by electrochemical corrosion, electrochemical corrosion was more common, and the harm was ako more serious; multi pic protective measures including pipeline material selection, coating protection cathode protection and corrasion inhibitor protection mrasurcs were systematically introduced, and pointed that joint protection technology combined of corrosion technologies was the fiiturc

Tolyltriazole (TTA) is recognized as an effective copper corrosion inhibitor in cooling systems due to its low toxicity and versatile properties. With the increasing focus on sustainable development, the employment of compounds of this nature has become increasingly widespread, driving the search for environmentally responsible alternatives. In this context, the aim of this work was to evaluate the efficiency of a corrosion inhibitor formulated with TTA on copper specimens in HCl 0.1 mol L−1 medium. The samples were exposed to the corrosive electrolyte with inhibitor concentrations ranging from 0 to 20 ppm. Electrochemical methods, including open circuit potential, potentiodynamic polarization, and electrochemical impedance spectroscopy were employed for corrosion monitoring. Overall, the results revealed that TTA behaves as a predominantly anodic inhibitor. Additionally, polarization curves demonstrated that within the Tafel region, the inhibitor adsorbs to the copper surface, following the Langmuir isotherm model. Regarding inhibitory effectiveness, the observed values ranged between 81.3 and 96.1%, while morphological analyses indicated the presence of nitrogen on the surface of the copper specimens after electrochemical tests, confirming the formation of a protective TTA film. In conclusion, this study highlights TTA's efficacy as a corrosion inhibitor, demonstrating its significant potential in safeguarding copper against acidic environments. [ABSTRACT FROM AUTHOR]

In this study, a new type of green corrosion inhibitor, namely, sodium humate (SH), was extracted from humus soil, which is a natural humus plant, by dissolution‐neutralization, and then used for corrosion inhibition of low carbon steel in seawater. The corrosion inhibition performance of SH on low carbon steel EH40 in seawater was tested by weight loss method and electrochemical technology. The surface and corrosion products of low carbon steel were observed and analyzed by scanning electron microscope (SEM), atomic force microscope (AFM), contact angle and X‐ray photoelectron spectroscopy (XPS). The results show that SH is a mixed corrosion inhibitor, and the optimum concentration is 2 g L−1. At this concentration, the inhibition rate can reach 93.6%. It mainly affects the semi‐reaction of cathodic corrosion. By forming a corrosion protection layer with uniform adsorption on the surface of EH40 steel, EH40 steel becomes more resistant to seawater corrosion. [ABSTRACT FROM AUTHOR]

The inhibitory effect of Rosemary oil on the corrosion of aluminum alloy EN AW-2011 in 1M H2SO4 solution was studied by weight loss and electrochemical methods such as open circuit potential (OCP), linear sweep voltammetry (LSV) and linear polarization resistance (LPR). The inhibition efficiency increases with increasing the concentration and shows maximum inhibition efficiency (70.7 %) at optimum concentration (0.05 g.L-1). The linear polarization resistance measurements show that the presence of Rosemary oil in 1M H2SO4 solution influences polarization resistance increasing and corrosion current decreasing. The voltammetric curve shows that Rosemary oil reduces the anodic process. Open circuit potential results confirmed that organic compounds present in Rosemary oil can form a protective layer on aluminum surfaces. The inhibitive effect was probably caused by the adsorption of organic compounds such as 1,8-cineole, α-pinene, borneol, limonene, and myrcene on aluminum surfaces which are non-toxic and environmentally friendly. This study showed that the essential oil of Rosemary could be used as an environmentally friendly inhibitor of the corrosion of alloy EN AW-2011 in an acidic medium. [ABSTRACT FROM AUTHOR]

Abstract This study investigates the efficacy of newly synthesized inhibitor with a dual function of corrosion inhibition and biocide for control of microbial influenced corrosion (MIC) in carbon steel API 5LX in the cooling tower water (CTW) environment. Four types of N-substituted tetrabromophthalic inhibitor (N-TBI) were synthesized, and the structural characterization was performed via proton nuclear magnetic resonance spectroscopy, thermogravimetric analysis and high-resolution mass spectrometry. These studies revealed the distinctive optical, thermal, and dielectric properties of the synthesized inhibitors. The corrosion inhibition efficiency has been evaluated by the weight loss (WL) analysis and electrochemical measurements (ECM) and biofilm assay. Biofilm assays and WL showed that inhibitor II exhibited the highest inhibition efficiency 74% and 79% respectively than others. Further ECM showed that the higher charge transfer resistance and the lower corrosion current, suggesting a protective film formed on the metal surface which was due to the adsorption of the N-TBI. Fourier transform infrared spectroscopy confirmed the adsorption of the N-TBI as C–O stretching and C–H bending with the Fe complex. X-ray diffractometer revealed that the presence of inhibitors in the corrosion product (Fe3O4, Fe2O3, FeH2O2, FeS) were highly reduced than the control system. Overall, this study highlighted the potential application of N-TBI with dual function of corrosion inhibition and biocide to control the MIC for carbon steel API 5LX used in the CTW environment.

Abstract The increasing demand for corrosion prevention strategies that are both effective and sustainable is part of the research the background. Nonionic surfactants offer a potential replacement for traditional corrosion inhibitors. These surfactants are well-known for their low toxicity and biodegradability. The research involved conducting experimental tests (such as weight loss, polarization and impedance spectroscopy) and theoretical computations to investigate the role of nonionic surfactant (polyoxyethylene (7) tribenzyl phenyl ether) (PETPE) in controlling the corrosion of mild steel in hydrochloric acid (1.0 M HCl) environment. The results of the study demonstrated that PETPE exhibited significant corrosion inhibition properties for mild steel in HCl solution. The inhibition efficiency of PETPE was found to increase with increasing PETPE concentration. PETPE is an excellent corrosion inhibitor because it significantly reduces the rate of corrosion, as seen by the notable inhibition efficiency result (95.4%) at a relatively low dose of PETPE (100 ppm). Thermodynamic studies were used to discuss the fundamental mechanisms that control PETPE-acid interactions. The adsorption process followed Langmuir adsorption isotherm, indicating a monolayer adsorption of the PETPE on the mild surface. Theoretical computations confirm the strong inhibition behavior of PETPE. The innovative feature of this research is its comprehensive strategy, which integrates experimental studies and theoretical simulations to evaluate the impact of PETPE on the corrosion control of mild steel in hydrochloric acid. The combined effort has the ability to supply valuable knowledge into the mechanisms of corrosion that will lead to the establishment of powerful corrosion control strategies.

Abstract A new conducting polymer of the cellulose acetate poly acrylonitrile (CAPA)–SiC composite was produced using an in situ oxidative polymerization technique in an aqueous medium. SiC was synthesized from Cinachyrella sp. as a source of carbon and silicon at 1200 °C under an argon atmosphere via a catalytic reduction process. The structure and morphology of the CAPA–SiC composite were characterized using surface area studies (BET), X-ray diffraction (XRD), Fourier transformation infrared spectroscopy (FT-IR), and surface morphology (SEM & TEM). To protect copper, the produced CAPA–SiC composite was mixed with commercial epoxy paint using a casting technique, and the copper surface was coated with the three components of the CAPA–SiC/epoxy paint mixture. The corrosion inhibition improvement of the CAPA–SiC/paint coating was assessed using electrochemical impedance spectroscopy followed by Tafel polarization measurements in a 3.5 wt% NaCl solution. The corrosion protection ability of the CAPA–SiC/epoxy coating was found to be outstanding at 97.4% when compared to that of a CAPA/paint coating. SEM and XRD were used to illustrate the coating on the copper surface.

Salvia Miltiorrhiza, extensively distributed and commonly employed as a traditional Chinese medicinal herb, has garnered significant attention. In this study, the Salvia Miltiorrhiza extract (SME) was prepared by one-step water extraction method, and was firstly used as a novel corrosion inhibitor for Q235 steel in 1 mol/L HCl solution. As identified via liquid chromatography-mass spectrometry, the findings reveal that Salvianic acid A, tanshinone II A, danshenxinkun D, dihydrotanshinone, and methylene tanshinquinone are the primary constituents of SME. The optimum corrosion inhibition efficiency reached 92.8 % at 200 mg/L and maintained at 90.4 % after 72 h. Based on in-situ scanning vibration electrode technology (SVET) monitoring, the adsorption of inhibitor molecules on metal surface greatly retarded the propagation of localized corrosion. AFM examination of the corroded surface reveals that the samples supplemented with SME exhibit a smoother surface compared to the blank group. The force curve graph for the SME-added group demonstrates a more evenly distributed point array and an elevated average adhesion force, indicating that the addition of SME improves the corrosion resistance of the metal surface. XPS characterization illustrated that SME interacted with iron ions to form insoluble precipitate. This work investigated the application of SME as an eco-friendly corrosion inhibitor for carbon steel in acidic medium, providing a new approach for the high value-added utilization of Salvia Milliorrhiza.

In the last decades, corrosion control of metals and their alloys has been of environmental, aesthetic, economic, and technical importance. Ecologically acceptable, environment-friendly, and readily available corrosion inhibitors are one of the best options for protecting metals against corrosion. In this regard, use of polymers for inhibiting metallic corrosion is an authentic and acceptable practice, with a low environmental threat. Polymers may be used as composites, blends, or isolation for optimal inhibitory effects. Inhibition efficiencies of corrosion inhibitors were determined using mass loss, electrochemical impedance spectroscopy, potentiodynamic polarization techniques, etc. The present study gives the idea about natural, synthetic, and conducting polymers and their utilization for corrosion inhibition applications. Effects of halide ions as additives or surfactants on their anticorrosion performances are also discussed. Polymeric materials as coatings are reviewed to align with recent research interests, such as cost-effectiveness, environment friendliness, and self-healing products, which are more convenient to synthesize and use in future applications.

Developing a sustainable and environmentally friendly inhibitor remains an essential and challenging goal for corrosion control. Here, different extracts from the same biomass (Juçara - Euterpe edulis) were applied as a new inhibitor for mild steel in different corrosive medium: 1 mol L−1 HCl (pH 0) and simulated CO2-saturated formation water (pH 5). Depending on the extraction process, the anticorrosive capacity of extracts may increase, a fact verified in gravimetric tests, reaching 94.4% maximum inhibition efficiency for the acidic medium (1000 mg L−1 of Juçara pulp in 48 h of immersion) and 86.1% inhibition efficiency for the saline medium (600 mg L−1 of Juçara pulp extract assisted by ultrasound in 24 h of immersion). Gravimetric tests, electrochemical tests, and surface and biochemical characterization analyses were carried out to better understand these extracts' performance. This work provides an interesting application of the same biomass effectively acting in different corrosive medium, depending on the extraction method.

[Display omitted] • N1 of DDAC and N13 of BDDACP are the most vulnerable to electrophilic attack. • BDDACP can form a robust protective film in a parallel direction on Fe (1 1 0) plane. • BDDACP functions as a mixed inhibitor that primarily impedes the active site of CRS surface. • The chemical bonds between BDDACP molecules and Fe atoms are detected from the inhibited CRS surface. • A novel Gemini surfactant of BDDACP is an efficient inhibitor for steel in HCl media with good application prospect. Gemini surfactants have become the research focus of novel excellent inhibitors because of their special structure (two amphiphilic moieties covalently connected at head group by a spacer) and excellent surface properties. It is proved by theoretical calculations that 1, 3-bis (dodecyl dimethyl ammonium chloride) propane (BDDACP) molecules can perform electron transfer with Fe (1 1 0). And it has a small fraction free volume, thus greatly reducing the diffusion and migration degree of corrosive particles. The potentiodynamic polarization curve showed that coefficients of cathodic and anodic reaction less than 1 and polarization resistance increased to 1602.9 Ω cm−2 after added BDDACP, confirming that BDDACP significantly inhibited the corrosion reaction by occupying the active site. The electrochemical impedance spectrum of imperfect semi-circle shows that the system resistance increases and double layer capacitance after added BDDACP. Weight loss tests also confirmed that BDDACP forms protective film by occupying the active sites on steel surface, and the maximum inhibition efficiency is 92 %. Comparison of the microscopic morphology showed that steel surface roughness was significantly reduced after added BDDACP. The results of time-of-flight secondary ion mass spectrometry show that steel surface contains some elements from BDDACP, which confirms the adsorption of BDDACP on steel surface. [ABSTRACT FROM AUTHOR]

The corrosion of metals poses a threat to the economy, the environment, and human health due to undesirable reactions and contaminated products. Corrosion inhibitors, including natural products, can play a key role in protecting metallic materials, especially under challenging conditions. In this study, the roots of the Inula viscosa plant were examined for their ability to act as corrosion inhibitors in a 1 M hydrochloric acid (HCl) solution. Different extracts of the plant were evaluated for their corrosion inhibition capacity in a 1 M HCl solution. The effectiveness of different plant extracts was assessed, including an aqueous extract, an ethanolic extract, and a combined water–ethanol extract. Compounds present in the roots of Inula viscosa were identified using high-performance liquid chromatography. The electrochemical properties of the extracts were studied using various techniques such as open circuit potential, electrochemical impedance spectroscopy, and potentiodynamic polarization. Additionally, surface analysis after immersion was performed using scanning electron microscopy. Electrochemical data revealed that Inula viscosa root (IVR) extracts acted as mixed-type corrosion inhibitors with pronounced cathodic characteristics. The inhibitory efficiency was closely related to the concentration of Inula viscosa (I. viscosa), showing a significant increase with higher concentrations. This resulted in a decrease in corrosion current and an increase in polarization resistance. Notably, inhibitory efficiency reached high levels, up to 97.7% in mixed extract which represents a mixture between water and ethanol. In our study, it was observed that the mixed extract (water + ethanol) allowed for a greater corrosion inhibition compared to the other solvents studied, 97.7%. Surface analyses confirmed the formation of an organic film layer on the steel surface, attributed to the bonding of functional groups and heteroatoms in I. viscosa components. Therefore, this study paves the way for the potential integration of I. viscosa as a promising corrosion inhibition material, offering durable protection against steel corrosion and opening avenues for various related applications.

This study investigated the potential of porous silica material extracted from volcanic ash of Mount Sinabung, Indonesia, as a corrosion inhibitor. The new material was subjected to comprehensive analysis using the X-Ray Diffraction (XRD), Fourier Transform Infrared Spectroscopy (FTIR), Search Engine Marketing (SEM), and Atomic Absorption Spectrophotometry (AAS). Corrosion test was conducted by coating the metal surface with synthesized silica. XRD data showed the presence of amorphous silica, while SEM indicated a rough and irregular pore cavity. Based on AAS characterization, the concentration of silica in the Mount Sinabung volcanic ash was 79.23 % (v/v) with a yield of 29.73 %(w/w). Furthermore, coated and uncoated iron plates, with grit variations of 800, 1200, 1500, and 2000, were tested against HCl 15 % (v/v) and NaCl 3.5 % (w/v) as model corrosive solutions. The SEM results showed that coated plates had fewer holes and cracks formation while the XRD analysis of the same samples presented a slight decrease in the intensity of iron phase. Among silica-coated iron plates, the 1500 grit variation had the lowest corrosion rate and the highest corrosion inhibitor efficiency in both HCl 15 % (v/v) and NaCl 3.5 % (w/v) corrosive solutions, recording efficiencies of 26.3 and 91.8 %, respectively.

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

Alanine hydrochloride was prepared from alanine, then its derivative was synthesized by amidation. The structure of the synthesized product was characterized by infrared and 1H nuclear magnetic resonance. The corrosion inhibition effect of alanine and alanine derivative on carbon steel at 30 ℃ in 0.5 mol/L sulfuric acid medium was studied by weight loss method, electrochemical method and scanning electron microscope. The results showed that alanine derivative had better corrosion inhibition than alanine due to the hydrophobic alkane long chain. The weight loss method and electrochemistry showed that the corrosion inhibition rate reached more than 90% at the alanine derivative dosage of 300 mg/L. The adsorption of corrosion inhibitor on carbon steel surface conformed to Langmuir adsorption model. Alanine derivative at low mass concentrations(50-100 mg/L) could inhibit the oxidation of anode metal,which was anode corrosion inhibitor. At higher mass concentrations(200-500 mg/L), the rate of hydrogen evolution reaction at the cathode and metal oxidation reaction at the anode was reduced at the same time, thus reducing the overall corrosion reaction rate, so alanine derivative was a mixed corrosion inhibitor.

Abstract Gemini-type imidazoline quaternary ammonium salt is a new type of environmentally friendly corrosion inhibitor has been widely used in engineering materials. However, most of them are hazardous/toxic compounds derived from petroleum-based products, which did harm to environment. In this work, an environmentally friendly Gemini-shaped imidazoline quaternary ammonium salt corrosion inhibitor (G211) was synthesized using cheap fatty acid recycled from dimer acid industry as feedstock. The corrosion inhibition effects of G211 on Q235 steel in 1 M HCl solution were investigated through weight loss experiments, potential polarization curves, and alternating current impedance spectroscopy experiments. The results show that the inhibition rate of G211 as a mixed-type inhibitor is up to 94.4% and the concentration drop as low as 500 ppm at 25 ℃. The adsorption of G211 on Q235 surface follows Langmuir adsorption isothermal curve. The chemical composition of the Q235 steel surface was analyzed through scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS). Furthermore, the possible corrosion inhibition mechanism of G211 on the surface of Q235 steel is proposed. This article not only presents an outstanding solution for safeguarding Q235 steel against corrosion but also introduces a feasible method for high-value utilization of monomer acid (MA).

Copyright of Corrosion & Protection in Petrochemical Industry is the property of Corrosion & Protection in Petrochemical Industry Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Carbon dots (CDs) have garnered extensive attention owing to their excellent biocompatibility, elevated specific surface area, and facile functionalization, as well as their diverse methods of preparation. In recent times, CDs have been applied for anti‐corrosion and obtained some significant results. In this work, the preparation methods of CDs are first briefly introduced, and the relative merits of different approaches are highlighted. Subsequently, the application of CDs in the realm of corrosion inhibitors is discussed, and the corrosion inhibition effects and mechanism of nitrogen‐doped CDs, nitrogen and sulfur‐co‐doped CDs, as well as CDs functionalized with other elements and nitrogen‐co‐doped are summarized. Finally, the application of CDs and functionalized CD‐modified coatings for anti‐corrosion and their protective mechanism is analyzed in detail. This review summarizes recent progress in research related to CDs and heteroatom‐doped CDs in anti‐corrosion applications and anticipates the prospects and applications of CDs in corrosion protection. With their unique properties and versatile applications, CDs are expected to assume a progressively pivotal role in the advancement of cutting‐edge corrosion protection technologies. [ABSTRACT FROM AUTHOR]

In the process of oil and gas exploitation and production, thickened acid is a commonly used working fluid in acid fracturing. The main performance supporters of thickening acid are thickening agent and corrosion inhibitor. The role of thickening agent is to increase viscosity and reduce acid rock reaction rate, and the role of corrosion inhibitor is to protect equipment. The common problem in the thickening acid is that the thickener 's own temperature resistance and acid resistance are poor, resulting in the failure to achieve the purpose of deep acidification at high temperature. In addition, the current high temperature corrosion inhibitor for acidification has poor compatibility with the acid system and insufficient anti-corrosion ability. Therefore, the acidification of carbonate reservoirs in high temperature deep wells is more difficult. A series of polyacrylamide cationic thickeners with temperature and acid resistance were designed and prepared, and their basic properties were studied. At the same time, the corrosion inhibitor suitable for high temperature acid solution was screened out, and the high temperature resistant thickening acid was formed in combination with other additives to further study the performance of thickening acid. The results show that the self-made SH4 thickener has excellent acid resistance and viscosity increasing performance. In 20% hydrochloric acid, the viscosity of 0. 6% thickener can reach 59. 88 mPa·s. The corrosion rate of N80 steel sheet is only 41. 614 g/ (m²·h) after high temperature and high pressure dynamic corrosion test at 180 ℃ . The viscosity of the thickened acid system remained at 33. 258 mPa·s at 180 ℃ and 170 s - 1, which prove that it had strong temperature and shear resistance and could be used for high temperature acidification. [ABSTRACT FROM AUTHOR]

Objective The flocculent suspended matter in fluid catalytic cracking (FCC) diesel oil from a refinery of CNOOC was separated and analyzed. Its composition, source and possible solution were deduced. Methods A scheme for separating flocculent suspended solids from an oil-water mixture was developed and characterized by Fourier transform ion cyclotron resonance mass spectrometry and Fourier transform ion cyclotron resonance spectrometry. Results The results show that flocculent suspended matter are mainly organic compounds and can be flocculated in a hydrochloric acid environment. The main body of the suspended matter is nitrogen-containing compounds about C40-C55 determined by mass spectrometry, and it shows obvious artificial synthesis characteristics. Conclusions The flocculent suspension is the compound inhibitor of amines and amides or the residue of many kinds of inhibitors. This separation and analysis method can also be used for composition analysis of similar samples, which is helpful for refineries to investigate the causes of similar faults. [ABSTRACT FROM AUTHOR]

Dodonea viscosa-zinc oxide (DV-ZnO) nanocomposite was synthesized and characterized using Fourier transform infrared (FTIR), thermal gravimetric method (TGA), X-ray diffraction (XRD), scanning electron microscopy (SEM), and energy dispersive X-ray spectroscopy (EDS). The most abundant compounds in the plant extract were explored using gas chromatography-mass spectrometry (GC-MS). FTIR indicated the existence of the different functional groups, XRD showed that the nanocomposite has the hexagonal wurtzite shape of ZnO nanoparticles, SEM-EDS showed a size of 50 nm, and elemental analysis depicts the existence of the different elements in the extract, which confirms, along with TGA results, the formation of DV-ZnO nanocomposite. The nanocomposite synergistic effect was examined for anticorrosion capabilities using gravimetric, electrochemical, and surface analysis methods. Both the plant extract and the nanocomposite exhibited corrosion inhibition abilities. However, the incorporation of the plant extract with ZnO increased the inhibition efficiency by 20 %. Weight loss and electrochemical methods concluded an inhibition efficiency of 80 % for DV-ZnO nanocomposite. The inhibition of the nanocomposite is due to the adsorption of the inhibitor on the carbon steel surface, which was verified using X-ray photoelectron spectroscopy and scanning electron microscopy (SEM). The adsorption was found to follow both Langmuir and Temkin isotherms. Surface examination using atomic force microscopy (AFM) found that the carbon steel surface roughness was decreased from the sample submerged in an uninhibited medium (Sa = 121.20 nm) when adding DV-ZnO nanocomposite (Sa = 22.95 nm) and DV plant extract inhibitor (Sa = 54.73 nm). [ABSTRACT FROM AUTHOR]

Context: Corrosion, the degradation of materials due to chemical reactions with their environment presents significant challenges both economically and environmentally. It affects various industries, including construction, transportation, and manufacturing, leading to equipment failures, safety hazards, and increased maintenance costs. Coumarin derivatives have shown promise due to their inherent chemical properties and potential for biodegradability. In this study, a series of the coumarin derivatives were examined in silico to reveal their potential corrosion inhibition properties toward the Fe(110) and Cu(111) surfaces. The compounds investigated include coumarin (2H-chromen-2-one, 1), furanocoumarin (7H-furo[3,2-g]chromen-7-one, 2), dihydrofurano coumarin (2,3-dihydro-7H-furo[3,2-g]chromen-7-one, 3), pyrano coumarin–linear type (8,8-dimethyl-2H,8H-pyrano[3,2-g]chromen-2-one, 4), pyrano coumarin–angular type (8,8-dimethyl-2H,8H-pyrano[2,3-f]chromen-2-one, 5), bicoumarin (3,3'-methylenebis(2H-chromen-2-one), 6), and phenyl coumarin (4-phenyl-2H-chromen-2-one, 7). The findings suggest that the bicoumarin derivative 6 exhibits the lowest adsorption energy with the Fe(110) surface, while the same energy absolute value is about two times lower for the Cu(111) surface. This is due to the formation of a planar configuration of a molecule of 6 on the metal surfaces with the participation of both coumarin fragments upon interacting with the Fe(110) surface, while one coumarin fragment interacts with the Cu(111) surface. Methods: Density functional theory (DFT) calculations were employed to study the electronic properties of the coumarin derivatives. The specific computational method used was B3LYP, a hybrid functional that combines with the 6–311 + + G(d,p) basis set. Each coumarin derivative was first subjected to a geometry optimization to find the most stable molecular structure. Electronic properties, dipole moments, and molecular electrostatic potential surfaces were calculated. The Monte Carlo simulations were used to model the adsorption behavior of the coumarin derivatives on metal surfaces, namely, Fe(110) and Cu(111). These simulations allowed to visualize interaction of the studied molecules with the metal surfaces, which is crucial for their function as corrosion inhibitors. The present study provides a comprehensive understanding of the corrosion inhibition potential of the applied coumarin derivatives. The insights gained from these methods can inform the development of effective, sustainable corrosion inhibitors that are both environmentally friendly and highly efficient. [ABSTRACT FROM AUTHOR]

Corrosion is a pervasive issue affecting metallic materials, with significant economic losses and safety risks in various industries. Mild steel, extensively used in construction and infrastructure, faces corrosion challenges, needing continuous research to effectively tackle them. Natural compounds, because of their eco-friendliness and corrosion inhibition potential, are attracting increasing interest for corrosion control. Lawsonia inermis (LI), or henna, a plant native to North Africa and South Asia, has bioactive compounds exhibiting corrosion inhibitive properties. This study comprehensively explores Lawsonia inermis's effectiveness as a corrosion inhibitor for mild steel, filling a gap in the existing research. Various concentrations of Lawsonia inermis extract were tested in acidic solutions to evaluate corrosion inhibition. Experimental results indicate a significant reduction in the corrosion rate with increasing inhibitor concentration. Langmuir adsorption isothermal analyses reveal the adsorption mechanism as being an interplay between physisorption and weak chemisorption. Electrochemical measurements demonstrate Lawsonia inermis's capability to alter both cathodic and anodic reactions, leading to improved corrosion resistance. Scanning electron microscopy reveals a more even surface morphology in the presence of the Lawsonia inermis, indicating corrosion inhibition. Gas chromatography–mass spectrometry (GC-MS) analyses identified organic compounds in Lawsonia inermis extract responsible for corrosion inhibition. Overall, Lawsonia inermis emerges as a promising corrosion inhibitor for mild steel, offering excellent inhibition efficiencies. This study sheds light on its adsorption behaviour and provides insights into its mechanism of action. These findings underscore Lawsonia inermis's potential as a green corrosion inhibitor, paving the way for its practical application in industrial corrosion protection strategies. [ABSTRACT FROM AUTHOR]

Copyright of Paint & Coatings Industry (0253-4312) is the property of Paint & Coatings Industry Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The durability of reinforced concrete structures is significantly influenced by the effectiveness of small molecular inhibitors in preventing the corrosion of steel reinforcements. In a concrete environment, the passive film on steel bars serves as a critical protective component. In this study, a molecular dynamics (MD) simulation is used to study the inhibition mechanism of chloride ions by common corrosion inhibitors (2-Amino-2-thiazoline) in concrete in an excess chloride solution. The results reveal that inhibitors adsorb onto the steel surface primarily through van der Waals forces, with more than 90% of the adsorption occurring vertically. Despite this strong adsorption, inhibitors alone do not form a protective film. In the presence of chloride ions, which frequently penetrate concrete, the coverage rate of inhibitors on the steel surface decreases from 74% to 64%. Nevertheless, inhibitor molecules still provide substantial protection in chloride-rich concrete environments. Further analysis indicates that inhibitor molecules inhibit chloride ions in two ways. Corrosion inhibitor molecules actively desorb from the steel surface to capture chloride ions and prevent them from approaching. Additionally, inhibitors form a multi-electron layer on the steel surface to enhance passive film protection and hinder chloride ion diffusion through Coulombic interactions. [ABSTRACT FROM AUTHOR]

The study concentrated on the fabrication of an environmentally friendly inhibitor, namely ethyl 4-(4-methoxyphenyl)-2,7,7-trimethyl-5-oxo-1,4,5,6,7,8-hexahydroquinoline-3-carboxylate derivative of quinoline (MQC), in a single step, and assessed its inhibiting property in highly acidic fluid (15 % HCl) for protecting Q235 steel at 1500 rpm rotation speed. Weight reduction, Potentiodynamic polarization, and electrochemical impedance spectroscopy were utilized in the study to investigate the inhibiting impact of MQC. The estimated findings corroborated the inhibiting data of 93.54 and 98.38 % at 308 K with 100 mg/L/only MQC and MQC + KI/75 mg/L + 0.5 mM, respectively, and the impact of temperature upon the inhibitory capability possessed little impact at larger dose quantities. According to the electrochemical outcomes, the MQC is a mixed-type corrosion inhibitor. The findings of the SEM, EDX, and AFM examinations demonstrated that the MQC established a barrier over the surface of Q235 steel by adsorption, changing the hydrophilic and hydrophobic attributes of the Q235 steel surface. An additional XPS assessment demonstrated MQC molecule adsorption on the Q235 steel surface. Density functional theory (DFT) and molecular dynamic simulations (MD) calculations were further performed to justify the experimental results. [ABSTRACT FROM AUTHOR]

The amino acid L-histidine, which has an imidazole ring, was investigated as a corrosion inhibitor for AISI 1018 carbon steel in chloride solution based on the effectiveness of inhibitors containing imidazole in their composition. A neutral environment was chosen for this study due to the scarcity of research on this amino acid in this environment type. Concentrations of 250, 500, and 1000 ppm were evaluated. Various methods were used to determine inhibition effectiveness, including mass loss, open circuit potential, linear potentiodynamic polarization, and electrochemical impedance spectroscopy. For mass loss, the inhibition efficiency varied from 83 to 88% according to the increase in concentration. For the electrochemical tests, the efficiency variation ranged from 62 to 90% with increasing amino acid concentration. Furthermore, a simulation analysis using quantum chemical calculations within the scope of Density Functional Theory (DFT) revealed that histidine's nucleophilic character is crucial for its corrosion inhibitory capacity in an aqueous medium at pH 7. The inhibition efficiency increased with increasing concentration in a neutral medium, following the Langmuir isotherm for the adsorption of L-histidine. Additional studies were carried out using Fourier transform infrared spectroscopy (FTIR) and thermogravimetry (TGA). Analysis of the substrate surface by scanning electron microscopy (SEM) showed greater preservation with the addition of L-histidine, confirming its adsorption on the steel. Atomic Force Microscopy (AFM) also demonstrated an improvement in surface roughness in the presence of amino acids compared to the medium without an inhibitor. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

In this paper, nickel chloride was selected as metal ions and 2,2′-bipyridine (bipy) and benzoic acid (ba) as ligands to synthesize Ni-bipy-ba ternary complex. Its corrosion inhibition effects on the corrosion of P110 carbon steel in 0.5 M HCl were evaluated by weight loss test, electrochemical measurements, surface analyses, and theoretical calculations. The results show that the Ni-bipy-ba ternary complex exhibits excellent corrosion inhibition properties compared with the two ligands, especially at high temperatures, which is supported by the calculation of thermodynamic parameters. Surface analyses indicate that Ni-bipy-ba ternary complex can inhibit corrosion by forming adsorption film on the metal surface. Theoretical calculations show a good correlation with the experimental results. The best corrosion inhibition efficiency of Ni-bipy-ba ternary complex could be ascribed to the synergistic effect of metal ligands and the complex structure with larger dimension and molecular mass. [ABSTRACT FROM AUTHOR]

A corrosion inhibitor composite was developed for carbon dioxide corrosion and it was adapted to the requirements of dosage, protective capacity, temperature characteristics, and compatibility with other reagents. The development process and the main requirements, observance of which was monitored, are described stage-by-stage. The outcome of the conducted research was two grades of a carbon dioxide corrosion inhibitor based on an imidazoline derivative. The difference between the developed composites lies in the solvent type and, correspondingly, in the temperature characteristics (flash and dew points). The influence of the amount of the active base on the effectiveness of the composite was evaluated and the optimum content of the components in the corrosion inhibitor was found. The importance of flash and dew points for corrosion inhibitors is underscored and a way of controlling these composite indicators is proposed. [ABSTRACT FROM AUTHOR]

The inhibition performance and adsorption behavior of an unsymmetrical tridentate Schiff base, 2-(((2-((2-nitrophenyl) thio) phenyl) imino) methyl)phenol (NOS) on mild steel in 2M hydrochloric acid solution has been studied using electrochemical and quantum chemical techniques. The electrochemical outcomes suggest that NOS works as an anodic-type inhibitor. The adsorption process of the NOS Schiff base obeys the Langmuir model. The theoretical evaluation has been performed using DFT calculations to investigate the correlation of effective corrosion inhibition with some NOS Schiff base structural parameters. The obtained results revealed that there was a good agreement between the theoretical and experimental results. [ABSTRACT FROM AUTHOR]

Study of sodium silicate from rice husks as coating material is reported. The extraction was conducted via precipitation method with sodium hydroxide, nitric acid and ethanol at pH 8. The resulting silica was tested as hydrophobic coating by coating it on a glass surface. Based on the value of the contact angle, silica has good hydrophobic properties. The highest hydrophobic properties were obtained from sample, which labeled as Si10A:Si5B with an average contact angle of 105.3 °. Investigation of the potential application of sodium silicate as an inhibitor of corrosion has been conducted by coating it on steel surfaces. The effect of the concentration of sodium silicate was conducted at 0, 10, 20 and 30 ppm and found that the morphology of steel coated with 20 ppm has the lowest corrosion rate with 81 % inhibition efficiency. [ABSTRACT FROM AUTHOR]

Corrosion of mild steel in aggressive environments such as HCl solution poses significant challenges across industries. This research explores the potential of 4-(2-Mercapto-1,3,4-oxadiazole-5-yl)pyridine (MOP) as a corrosion inhibitor for mild steel in HCl solution. Notably, MOP exhibits an impressive inhibition efficiency of 93.6 % at an optimal concentration of 0.5 mM in 1 M HCl. The study comprises a comprehensive analysis, encompassing varying inhibitor concentrations (0.1 to 1 mM), immersion durations (1 to 48 hours), and temperatures (303 to 333 K). Corrosion rate quantification employs weight loss measurements. Additionally, adsorption isotherms unveil MOP's interaction with the mild steel surface. Importantly, Density Functional Theory (DFT) unravels intricate electronic and molecular interactions at the atomic scale. These findings underscore MOP's exceptional corrosion inhibition capacity, making it a promising candidate for mild steel corrosion control in HCl environments. The combined insights from weight loss measurements, adsorption isotherms, and DFT analysis provide a holistic understanding of the inhibition mechanism, opening doors for practical applications in corrosion management. [ABSTRACT FROM AUTHOR]

Corrosion has been identified as the primary mechanism causing pipeline failures, leading to significant economic losses and environmental problems. One of the effective and economical methods to prevent metal corrosion is to add corrosion inhibitors. Although environmentally friendly corrosion inhibitors are beneficial to the ecological environment, their lower corrosion inhibition efficiency compared to traditional corrosion inhibitors has limited their application. Therefore, this paper aims to develop an environmentally friendly compound corrosion inhibitor that can meet the practical industrial requirements. The corrosion inhibition effect of two complexes of cystine, namely cystine + sodium molybdate (Cys-Cys + MS) and cystine + zinc gluconate (Cys-Cys + ZG), on pipeline steel in 1 M HCl was investigated. And the synergistic corrosion inhibition mechanism of these two composite corrosion inhibitors was discussed. The results indicated that the corrosion inhibition performance of Cys-Cys + MS and Cys-Cys + ZG complexes was significantly better than that single inhibitors at higher concentration. Furthermore, it was observed that the corrosion inhibition performance of Cys-Cys + ZG was superior to that of Cys-Cys + MS. The maximum corrosion inhibition efficiency of the two compound corrosion inhibitors was achieved at the concentration of (2 + 4) mM. [ABSTRACT FROM AUTHOR]

This study investigated the potential of porous silica material extracted from volcanic ash of Mount Sinabung, Indonesia, as a corrosion inhibitor. The new material was subjected to comprehensive analysis using the X-Ray Diffraction (XRD), Fourier Transform Infrared Spectroscopy (FTIR), Search Engine Marketing (SEM), and Atomic Absorption Spectrophotometry (AAS). Corrosion test was conducted by coating the metal surface with synthesized silica. XRD data showed the presence of amorphous silica, while SEM indicated a rough and irregular pore cavity. Based on AAS characterization, the concentration of silica in the Mount Sinabung volcanic ash was 79.23 % (v/v) with a yield of 29.73 %(w/w). Furthermore, coated and uncoated iron plates, with grit variations of 800, 1200, 1500, and 2000, were tested against HCl 15 % (v/v) and NaCl 3.5 % (w/v) as model corrosive solutions. The SEM results showed that coated plates had fewer holes and cracks formation while the XRD analysis of the same samples presented a slight decrease in the intensity of iron phase. Among silica-coated iron plates, the 1500 grit variation had the lowest corrosion rate and the highest corrosion inhibitor efficiency in both HCl 15 % (v/v) and NaCl 3.5 % (w/v) corrosive solutions, recording efficiencies of 26.3 and 91.8 %, respectively. [ABSTRACT FROM AUTHOR]

Copyright of Oilfield Chemistry is the property of Sichuan University, Oilfield Chemistry Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In this study, trimercapto‐S‐triazine trisodium salt (TMT) with threefold rotational symmetry as a corrosion inhibitor was introduced into 2 mol ⋅ L−1 ZnSO4 medium. By electrochemical measurements, the corrosion inhibition efficiency of the zinc electrodes was 92.52 % when the concentration of TMT corrosion inhibitor was 2 mmol ⋅ L−1. Based on the microstructural characterization and theoretical analysis of Zn electrodes, it was confirmed that S and N atoms of TMT corrosion inhibitor serve as alternately zinc‐philic adsorption sites with sixfold rotational symmetry for the formation of intermolecular complexes. Adsorption energies of TMT on Zn surfaces were calculated and indicated that the bonds of Zn−N and Zn−S promoted anchoring adsorption on sixfold symmetric (002) plane of zinc. Meanwhile, TMT corrosion inhibitor can adsorb Zn2+ from the electrolyte and directionally deposit them on the surface of Zn (002), effectively avoiding the occurrence of dendrites. This study changes the common knowledge that organic corrosion inhibitors must form hydrophobic films to have corrosion inhibition performance, and provides a new approach for using small organic molecules with anchoring adsorption as metal corrosion inhibitors. [ABSTRACT FROM AUTHOR]

In the current context of fossil energy depletion and the requirement for low carbon emissions, the efficient use of energy and a diversified energy mix have become increasingly important. The use of cleaner and low-carbon alternative fuels is rapidly growing. However, corrosion remains a key issue limiting the large-scale application of alternative fuels. This paper describes the corrosion characteristics of different alternative fuels. Also, the mechanisms of fuel corrosion, corrosion measurement methods, and the future of corrosion inhibitor applications are discussed. Corrosion causes changes in material weight and surface morphology and generates electrical signals as it progresses. Although there are well-established methods to characterize corrosion by recognizing these changes, there is still a need to identify a universal standard signal for their detailed description. For the foreseeable future, corrosion in fuels will continue to be mitigated by the addition of corrosion inhibitors. The research on corrosion inhibitors focuses on green corrosion inhibitors and multifunctional corrosion inhibitors. However, further analysis is needed to understand the active ingredients in green corrosion inhibitors, and the mechanism of corrosion inhibition for different types of corrosion inhibitors needs further research. [ABSTRACT FROM AUTHOR]

Gemini-type imidazoline quaternary ammonium salt is a new type of environmentally friendly corrosion inhibitor has been widely used in engineering materials. However, most of them are hazardous/toxic compounds derived from petroleum-based products, which did harm to environment. In this work, an environmentally friendly Gemini-shaped imidazoline quaternary ammonium salt corrosion inhibitor (G211) was synthesized using cheap fatty acid recycled from dimer acid industry as feedstock. The corrosion inhibition effects of G211 on Q235 steel in 1 M HCl solution were investigated through weight loss experiments, potential polarization curves, and alternating current impedance spectroscopy experiments. The results show that the inhibition rate of G211 as a mixed-type inhibitor is up to 94.4% and the concentration drop as low as 500 ppm at 25 ℃. The adsorption of G211 on Q235 surface follows Langmuir adsorption isothermal curve. The chemical composition of the Q235 steel surface was analyzed through scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS). Furthermore, the possible corrosion inhibition mechanism of G211 on the surface of Q235 steel is proposed. This article not only presents an outstanding solution for safeguarding Q235 steel against corrosion but also introduces a feasible method for high-value utilization of monomer acid (MA). [ABSTRACT FROM AUTHOR]

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

Polyaniline (PANI) is considered as one of the most promising corrosion inhibitors because of its unique redox and environmental stability. Pyridine and its derivatives can chelate metal ions during corrosion, forming an inert protective layer on the metal surface to achieve the anticorrosion effect. Therefore, polyaniline is combined with pyridine together to achieve deep anticorrosion in this work. 4‐((2,2′:6′,2″‐terpyridin)‐4′‐yl)aniline (TPY) and 1,3,5‐benzenetricarbonyl chloride (TMC) were applied to synthesize a novel corrosion inhibitor N1, N3, N5‐tri (4‐((2,2′: 6′, 2′‐tri‐pyridine)‐4′‐yl) phenyl) benzene‐1,3,5‐tri‐formamide (TBT). Then, TBT was in situ loaded onto the PANI surface to obtain the composite TPANI. The TPANI was successfully dispersed in epoxy resin (EP) at various dosages to prepare composite coatings. Electrochemical impedance spectroscopy and salt fog tests were employed to evaluate the performance of the coatings. After experimentation, we discovered that when the TPANI content was 0.25 wt%, the impedance value remained stable at 5.83 × 109 Ω cm2 after immersing the coatings in a 3.5 wt% NaCl solution for 28 days. In contrast, the EP coating exhibited a resistance decrease ranging from 9.56 × 109 to 7.8 × 108 Ω cm2 within the same soaking time, decreasing by an order of magnitude, while the TPANI‐0.25% coating still maintaining a high order of magnitude. These results indicated that the TPANI filler effectively preserved long‐term stability and provided persistent protection against corrosion. The protective mechanism of TPANI composite coatings was further elucidated through detailed analysis. Overall, the incorporation of TPANI into the epoxy resin yielded promising results, demonstrating its potential as an effective corrosion inhibitor for protective coatings. [ABSTRACT FROM AUTHOR]