Recent trends in environmentally sustainable Sweet corrosion inhibitors

Green synthesis of cadmium oxide nanoparticles (CdO-NPS) using syzygium cumini: exploring industrial applications of CdO NPs as a corrosion inhibitor of mild steel in the acidic environment

Potentiodynamic polarization (PDP), electrochemical impedance spectroscopy (EIS) and weight loss measurements were used to assess the effectiveness of CdO-NPs as a corrosion inhibitor for carbon steel in 0.5 M H2SO4. It was amply shown that as the concentration of CdO-NPs increased, the cathodic currents decreased and the active corroding sites were blocked completely. Moreover, a decrease in the mass of mild steel in an aggressive environment was reduced gradually with an increase in the concentration (ppm) of CdO-NPs inhibitor, resulting in an increase in the inhibition efficiency. The novel synthesized CdO-NPs were characterized by FT-IR, XRD and SEM-EDX spectroscopy.

Zwitterions and betaines as highly soluble materials for sustainable corrosion protection: Interfacial chemistry and bonding with metal surfaces

The primary requirements for interfacial adsorption and corrosion inhibition are solubility and the existence of polar functional groups, particularly charges. Traditional organic inhibitors have a solubility issue due to the hydrophobic moieties they incorporate. Most documented organic inhibitors have aromatic rings, hydrocarbon chains, and a few functional groups. The excellent solubility and high efficacy of zwitterions and betaines make them the perfect replacements for insoluble corrosion inhibitors. Zwitterions and betaines are more easily soluble because of interactions between their positive and negative charges (-COO-, -PO3-, -NH3, -NHR2, -NH2R, -SO3- etc.) and the polar solvents. The positive and negative charges also aid these molecules' physical and chemical adsorption at the metal-electrolyte interfaces. They develop a corrosion-inhibiting layer through their adsorption. After becoming adsorbed at the metal-electrolyte interface, they act as mixed-type inhibitors, slowing both cathodic and anodic processes. They usually adsorb according to the Langmuir adsorption isotherm. In this article, the corrosion inhibition potential of zwitterions and betaines in the aqueous phase, as well as their mode of action, are reviewed. This article details the advantages and disadvantages of utilizing zwitterions and betaines for sustainable corrosion protection.

Surfactants as biodegradable sustainable inhibitors for corrosion control in diverse media and conditions: A comprehensive review

BACKGROUND

Corrosion is a challenging and potentially harmful process that involves the continuing, impulsive deterioration of metallic structures via reactions involving environmental components and electro- or chemical processes. To inhibit corrosion, various additives are added. Traditional additives, on the other hand, contain environmentally hazardous substances. Surfactants are less expensive, easier to manufacture, and have high inhibitory efficacy and low toxicity compared to standard corrosion inhibitors. They are often employed as corrosion inhibitors to protect metallic materials against corrosion.

METHODS

Surfactant molecules' amphiphilic nature promotes adsorption at surfaces such as the metal/metal oxide-water interface. Surfactant adsorption on metals and metal oxides forms a barrier that can prevent corrosion.

SIGNIFICANT FINDINGS

This review of surfactants as corrosion inhibitors aims to offer a systemic evaluation of various surfactant physical and chemical properties, surfactant influence in corrosion inhibition, and surfactant used in corrosion inhibition that can be used to enhance the efficacy of surfactant use as corrosion inhibitors in a variety of environments. The effect of several parameters on the potential to suppress corrosion of surfactant molecule series is also discussed here.

Inhibition of corrosion of an aluminum alloy by rosemary and eucalyptus extracted oils in 1 M hydrochloric acid medium: an experimental and theoretical study

In this study, we explored aluminum corrosion inhibition field of study in a 1 M HCl solution, harnessing the power of essential oils extracted from rosemary and eucalyptus plants. Our exploration gives a comprehensive analysis of the pivotal factors that shape the corrosion inhibition process. Our scientific journey was marked by a deliberate and systematic approach, encompassing the utilization of gravimetric analysis (weight loss), electrochemical potentiodynamic polarization, and the sophisticated electrochemical impedance spectrometry (EIS) techniques. Our findings unveiled promising and nuanced outcomes, particularly in the area of the electrochemical technique. This method demonstrated remarkable inhibition efficiencies, ranging from 42% to an impressive 92% for rosemary essential oil and from 37 to 84% for eucalyptus essential oil. These results unveiled a dynamic relationship between essential oil concentration and inhibition efficiency, a revelation that further deepens our understanding of the corrosion inhibition process. The inhibition efficiency increased with higher concentrations of essential oil but decreased with elevated temperatures. Furthermore, our analysis traversed into the realms of potentiodynamic and thermodynamic insights. These analytical techniques unearthed the complex mechanisms at play, explaining the pathway followed by the studied inhibitors. They exhibited their prowess by forming protective films on the metal surface, acting as vigilant protectors against the relentless forces of corrosion. Complementing our experimental findings, our study of computational chemistry through density functional theory (DFT) unveiled remarkable insights. It elucidated the spontaneous adsorption process of inhibitor molecules onto the aluminum surface in the presence of H2O solvent. This computational harmony with our experimental results strengthened our confidence in the robustness of our findings. One of the key findings of this study was the superior inhibitory power of camphor in rosemary EO and β-myrcene in eucalyptus essential oil EO, respectively, attributed to the distinctive characteristics of the active sites found in each compound. The inhibitory effectiveness followed the order β-myrcene > camphor > borneol > α-pinene > bornyl acetate > p-cymene > 1,8-cineole. These compounds, notable for their distinct active sites, emerged as exceptional agents in the pursuit of effective corrosion inhibition.

Controlled Delivery of 2-Mercapto 1-Methyl Imidazole by Metal-Organic Framework for Efficient Inhibition of Copper Corrosion in NaCl Solution

In this paper, zeolitic imidazolate framework-8 was modified by N-(3-aminopropyl)-imidazole to obtain a novel MOF called AMOF. Subsequently, AMOF served as a carrier for the delivery of 2-mercapto-1-methyl imidazole (MMI) to inhibit the corrosion of Cu. Scanning electron microscopy, Fourier transform infrared spectroscopy, and X-ray diffraction were applied to characterize the morphologies and structures of AMOF and AMOF@MMI. Ultraviolet-visible spectroscopy and thermogravimetric analysis were adopted to value the capacity of the load and release of the AMOF, respectively. The mass ratio of loaded MMI molecules was 18.15%. In addition, the inhibition behavior of AMOF@MMI for Cu was evaluated by polarization curves and electrochemical impedance spectroscopy. The results indicated that the AMOF loaded MMI successfully, and the released MMI could adsorb on the Cu surface and inhibit the Cu corrosion. The inhibition efficiency could reach 88.2%. The binding and interaction energies between the AMOF surface and the MMI were -16.41 kJ/mol and -20.27 kJ/mol.

Synthesis and characterization of novel acrylamide derivatives and their use as corrosion inhibitors for carbon steel in hydrochloric acid solution

Two new acrylamide derivatives were prepared namely: "N-(bis(2-hydroxyethyl) carbamothioyl) acrylamide (BHCA) and N-((2-hydroxyethyl) carbamothioyl) acrylamide( HCA) and their chemical structures were analyzed and confirmed using IR and 1H NMR". These chemicals were investigated as corrosion inhibitors for carbon steel (CS) in 1 M HCl medium using chemical method (mass  loss, ML), and electrochemical techniques including potentiodynamic polarization (PDP), and electrochemical impedance spectroscopy (EIS). The results showed that the acrylamide derivatives work well as corrosion inhibitors, with inhibition efficacy (%IE) reaching 94.91-95.28% at 60 ppm for BHCA and HCA, respectively. Their inhibition depends mainly on their concentration and temperature of the solution. According to the PDP files, these derivatives function as mixed-type inhibitors that physically adsorb on the CS surface in accordance with the Langmuir adsorption isotherm, creating a thin coating that shields the CS surface from corrosive fluids. The charge transfer resistance (R_ct) increased and the double layer capacitance (C_dl) decreased as a result of the adsorption of the used derivatives. Calculated and described were the thermodynamic parameters for activation and adsorption. Quantum chemistry computations and Monte Carlo simulations were examined and discussed for these derivatives under investigation. Surface analysis was checked using atomic force microscope (AFM). Validity of the obtained data was demonstrated by the confirmation of these several independent procedures.

Inhibitory Capabilities of Sweet Yellow Capsicum Extract toward the Rusting of Steel Rebars in Cement Pore Solution

The inhibitory capabilities of the sweet yellow capsicum extract (SYCE) toward the rusting of steel rebars in cement pore solution (CPS) were tested employing the electrochemical and mass loss methods. Gallic acid, caffeic acid, p-coumaric acid, ferulic acid, luteolin, and cinnamic acid are the most important constituents in the SYCE extract. By adsorbing them on steel bars, the organic compounds in the CSA extract enable them with an effective mixed-type inhibition, suppressing both anodic and cathodic procedures. At 300 ppm, the highest performances were 95.3 and 97.5% utilizing mass loss and electrochemical approaches, respectively. The activation energy for the corrosion process is greatly increased by the addition of the SYCE extract, going from 13.2 kJ mol^-1 (blank solution) to 30.0 kJ mol^-1 (300 ppm SYCE extract). The physical adsorption actions of the SYCE extract are described by the Freundlich equilibrium constant's smallest value, which is 0.074 ppm^-1. Many future investigators will be attracted by these discoveries to work relentlessly to uncover the anti-corrosion characteristics of novel plant extracts in the area of concrete additives.

A Study of the Synthesis and Characterization of New Acrylamide Derivatives for Use as Corrosion Inhibitors in Nitric Acid Solutions of Copper

The objective of this research was to explore the impact of corrosion inhibition of some synthetic acrylamide derivatives 2-cyano-N-(4-hydroxyphenyl)-3-(4-methoxyphenyl)acrylamide (ACR-2) and 2-cyano-N-(4-hydroxyphenyl)-3-phenylacrylamide (ACR-3) on copper in 1.0 M nitric acid solution using chemical and electrochemical methods, including mass loss as a chemical method and electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization (PP) as electrochemical methods. By Fourier-transform infrared spectroscopy (FTIR), proton nuclear magnetic resonance (1HNMR), and mass spectroscopy (MS) methods, the two compounds were verified and characterized. There is evidence that both compounds were effective corrosion inhibitors for copper in 1.0 M nitric acid (HNO₃) solutions, as indicated by the PP curves, which show that these compounds may be considered mixed-type inhibitors. With the two compounds added, the value of the double-layer capacitance was reduced. In the case of 20 × 10^-5 M, they reached maximum efficiencies of 84.5% and 86.1%, respectively. Having studied its behavior during adsorption on copper, it was concluded that it follows chemical adsorption and Langmuir isotherm. The theoretical computations and the experimental findings were compared using density functional theory (DFT) and Monte Carlo simulations (MC).

Electrochemical and computational estimations of cephalosporin drugs as eco-friendly and efficient corrosion inhibitors for aluminum in alkaline solution

In this study, the anionic state of Ceftriaxone sodium (Cefx) and Ceftazidime (Cefz) medication corrosion inhibition capabilities for Al in 0.1 M NaOH solution are explored using various electrochemical analyses. Furthermore, the morphological structure and surface chemical composition of the impact of these drugs on the Al substrate in NaOH are investigated. For the prediction and analysis of interactions between molecule structure and inhibition efficiency, quantum chemical calculations (QC), Monte Carlo simulations (MC), and molecular dynamics (MD) simulations (MD) are performed. The electrochemical findings reveal that the inhibitory effectiveness increases with increasing drug concentrations and declines with rising temperature, reaching a maximum value of 78.4% for 300 ppm Cefx while 59.5% for 300 ppm Cefz at 293 K, implying that Cefx outperforms for Cefz. In addition, the studied drugs act as cathodic inhibitors, and their adsorption is spontaneous and mixed type adsorption in its nature that obeys Freundlich isotherm for Cefz while Temkin isotherm is the best-fitted one for Cefx. Surface analysis and wettability measurements imply that Cefx and Cefz shield the Al against corrosion by surface adsorption and generating a protective hydrophobic film. Thermodynamic activation parameters in the absence and presence of 300 ppm of the studied drugs are calculated and discussed. The energies of the border molecular orbitals and computed molecular parameters for the investigated drugs revealed that anionic Cefx is more readily adsorbed on the Al surface than Cefz. This finding is validated further using MC and MD simulations. Overall, the proposed cephalosporin drugs delivered a cost-effective and facile approach for boosting the efficiency of corrosion inhibitors for Al under aggressive conditions.

Theoretical, chemical, and electrochemical studies of Equisetum arvense extract as an impactful inhibitor of steel corrosion in 2 M HCl electrolyte

A new type of Equisetum arvense aerial part (EAAP) extract was ready to be tested as a corrosion inhibitor for steel-based parts in Multi-stage flash (MSF) segments while the segments were being acid cleaned. The EAAP extract was identified using Fourier-transform infrared (FTIR) and High-performance liquid chromatography (HPLC). When compared to the specimen exposed to blank solution, EAAP extract molecules covered about 97% of the carbon steel surface in 2 M HCl solution, and the corrosion rate was reduced to 0.58 ± 0.02 μg cm^-2 h^-1 at 300 mg l^-1. EAAP extract tends to have a blended impact on both anodic and cathodic sites on the surface of carbon steel. The thermodynamic activation factors are substantially higher in the presence of extract solution than in the absent of extract, demonstrating that the carbon steel surface would corrode slowly in the presence of EAAP extract. Theoretical models were used to validate the adsorption of EAAP extract on steel surfaces.

Substrate Protection with Corrosion Scales: Can We Depend on Iron Carbonate?

Controlling corrosion with naturally occurring corrosion scales is potentially a more environmentally sustainable alternative to current approaches, including dosing of organic corrosion inhibitors. We report operando grazing incidence X-ray diffractograms correlated with electrochemical measurements to elucidate the growth and corrosion protection properties of a corrosion scale composed of FeCO₃ crystallites, which is encountered in various key energy industry applications. Data, acquired as a function of time from high-purity iron immersed in CO₂-saturated deionized H₂O at pH 6.8 and T = 80 °C, show that the FeCO₃ scale not only prevents corrosion of the covered substrate but also acts as a significant interfacial diffusion barrier for corrosion reagents and/or products once sufficient coverage is achieved. Most notably, from a corrosion engineering perspective, however, it is determined that corrosion occurring in gaps between scale crystallites remains appreciable; this important insight is gained through the analysis of electrochemical impedance spectra to estimate the variation in electrochemically active surface area as scale coverage increases. These results indicate that naturally occurring FeCO₃ scales are not a tenable solution for corrosion protection, as even in their intact state they are highly likely to be, at best, semiprotective.

Potential of dibenzo-18-crown-6-ether derivatives as a corrosion inhibitor on mild steel in HCl medium: electrochemical and computational approaches

The corrosion inhibition behaviour of the macrocyclic dibenzo-18-crown-6 derivatives BOH and OHB was investigated experimentally and theoretically on mild steel in a 15% hydrochloric acid medium.