Excellent Corrosion Inhibition Research Articles

Mango leaves extract as sustainable corrosion inhibitor for X70 steel in HCl medium: Integrated experimental analysis and computational electronic/atomic-scale simulation

Mangoes are one of the most abundant fruit tree crops in most countries. Unfortunately, mango leaves are generally dumped as agricultural waste due to their abundance, resulting in significant waste and environmental pollution. In this study, electrochemical and weight loss techniques were utilized to investigate the inhibitory mechanism of mango leaves extract (MLE) on the corrosion of X70 steel in 1 M HCl. The results indicated that MLE was an excellent corrosion inhibitor for X70 steel to resist corrosion in an acidic environment, and the inhibition efficiency was effectively improved by increasing the inhibitor concentration and decreasing the temperature. Electrochemical tests have shown that MLE functions as a corrosion inhibitor with a mixed-type mechanism. Fitting the adsorption isotherm with electrochemical data, confirmed that MLE demonstrates corrosion resistance on metal surfaces through adsorption, and this adsorption conforms to the Langmuir isotherm. The adsorption phenomenon was deeply investigated by using atomic force microscopy (AFM) and scanning electron microscopy (SEM). MLE is further proven to interact with the steel surface to generate an adsorption layer that prevents steel corrosion in an acidic environment. In particular, the density-functional tight-binding (DFTB) calculations results also suggest that the π electron and lone-pair electrons in the main components of MLE are conducive to enhancing the adsorption of corrosion inhibitor molecules on the iron surface, to achieve a more effective inhibition effect. Furthermore, the toxicity prediction indicates that the MLE components are nearly non-toxic, which complies with environmental protection regulations. MLE has excellent corrosion resistance, with a corrosion inhibition efficiency of nearly 90 % at a concentration of 400 mg/L, while also helping to solve agricultural waste management challenges.

Synthesis, Characterization and Theoretical Calculations of a Novel Organic Corrosion Inhibitor for Mild Steel

Abstract Q235 is a carbon structural steel sheet that is widely employed in the construction and engineering sectors due to its cost-effectiveness and durability. Here, A novel organic corrosion inhibitor for Q235 sheet based on furan-thiadiazole (5-amino-2-furyl-1, 3, 4-thiadiazole, AFTZ) has been designed, successfully synthesized and characterized in this work. Results of experimental data and theoretical calculations indicated that AFTZ has an excellent corrosion inhibition property for Q235 sheet in 1.0 mol/L H2SO4. The highest efficiency of corrosion inhibitor tested by weight loss experiment can reach 91.17% and electrochemical experiment was up to 95.85% when AFTZ increased to 2 mg/mL in H2SO4 solution. The morphological characteristics of Q235 sheets with or without corrosion inhibitor showed that the target inhibitor has good corrosion inhibition performance. Quantum computation using the DFT method of guassian09 software and FT-IR date attribute the excellent corrosion inhibition to the film-forming nature of AFTZ.

Electrochemical, surface, and theoretical investigations of palm kernel shell extract as an effective inhibitor for carbon-steel corrosion in 1M HCl solution.

Herein, we employed palm kernel shell extract (PKSE) as an eco-friendly inhibitor for carbon steel in acidic-induced corrosion. The corrosion inhibition of PKSE on carbon steel in 1M HCI solution was investigated by electrochemical impedance spectroscopy, weight loss, and potentiodynamic polarization measurements. The surface was characterized by scanning electron microscopy equipped with energy-dispersive X-ray spectroscopy. Moreover, the elastic modulus and hardness tests were conducted. Weight loss measurements revealed that the optimum concentration of inhibitors is 500ppm with 95.3% inhibition efficiency in 1M HCl solution. Electrochemical results showed that the inhibitor could exhibit excellent corrosion inhibition performance and displayed mixed-type inhibition. The electrochemical impedance spectroscopy analysis shows that the inhibition performance increases by increasing the concentration of PKSE. The surface studies ensure the PKSE effectiveness in carbon steel surface damage reduction. Also, the adsorption of PKSE molecules on the carbon steel surface occurs according to the Langmuir isotherm model. The primary goal of this investigation was the utilization of palm kernel shell extract as corrosion inhibitor for 1018 low carbon steel in 1M HCl solution, which highlights its novelty. The present results will be helpful to uncover the versatile importance of palm kernel shell compounds in the corrosion inhibition process.

Experimental and theoretical simulations to examine the influence of nonionic surfactant on the corrosion control of mild steel in hydrochloric acid

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.

Fluorine-free superhydrophobic Ni/Mn-TiO2 composite coatings on carbon steel via one-step electrodeposition for enhanced durability and corrosion resistance

The application of superhydrophobic coatings on carbon steel (CS) surface represents an effective strategy for mitigating corrosion in these materials. This study presents the preparation of superhydrophobic Ni/Mn-TiO2 composite (SNMT) coatings on CS substrates through a facile one-step electrodeposition technique. The formation mechanism of SNMT coatings was meticulously analyzed under varying conditions of nanoparticle types and concentration levels. The inclusion of TiO2 nanoparticles, with an optimal additive concentration of 1 g, facilitated the formation of numerous low surface energy, cauliflower-like microstructures on CS interface. Surprisingly, the results indicate that SNMT coatings maintained commendable superhydrophobicity even post-exposure to superficial damages such as tape peeling, sandpaper wear, and knife-scratch, as evidenced by a static contact angle (CA) exceeding 158° and a sliding angle (SA) below 2°. Furthermore, the corrosion inhibition efficacy of SNMT coatings was quantitatively assessed via dynamic potential polarization curves in a simulated seawater environment. The results demonstrated that SNMT coatings exhibited excellent corrosion inhibition performance in simulated seawater solution, with a protection efficiency (PE) reaching 96.5%. In conclusion, superhydrophobic surfaces can effectively inhibit the penetration of corrosive liquids. The durability and robustness of such superhydrophobic surfaces advocate for their potential widespread application in enhancing the longevity and reliability of CS in corrosive environments.

The Performance of Amino‐ and Hydroxy‐Substituted Benzothiazoles in Inhibiting the Corrosion of Carbon Steel in HCl and the Molecular‐Level Mechanisms

AbstractIn the pickling process and acidizing program for oil wells, the acidic corrosion of metals is a problem that needs to be addressed. Various acid corrosion inhibitors have been studied and used to mitigate the acidic corrosion of carbon steel. In this paper, the corrosion inhibition of 2‐aminobenzothiazole (2 N‐BT), 2‐amino‐4‐hydroxybenzothiazole (2 N4O‐BT), and 2‐amino‐6‐hydroxybenzothiazole (2 N6O‐BT) on carbon steel in 0.5 mol/L HCl was investigated using electrochemical and quantum chemical methods. All three molecules exhibited corrosion inhibition effects. Compared to 2 N‐BT, 2 N4O‐BT and 2 N6O‐BT showed less sensitivity to the environmental conditions and the surface state of the metal. Among them, 0.0010 mol/L 2 N6O‐BT demonstrated the highest and most persistent corrosion inhibition, exhibiting a mixed inhibition mechanism with cathodic inhibition dominance. The adsorption of 2 N6O‐BT on the carbon steel surface was found to be non‐uniform, preferentially adsorbing at certain active sites on the surface, following Freundlich‐Langmuir thermodynamic characteristics. It showed initial strongly adsorbed points and weakly adsorbed regions. With continued adsorption of 2 N6O‐BT, the differences between strongly adsorbed points and weakly adsorbed regions decreased. The introduction of hydroxyl groups, especially in 2 N6O‐BT, extended the negative potential region and enhanced the coordination activity of the molecule, generating the orbital distribution that was advantageous to flat adsorption and the formation of feedback bonds. This provided a molecular structural basis for the excellent corrosion inhibition properties of 2 N6O‐BT.

Corrosion inhibition of AZ31 magnesium alloy in 3.5 % NaCl by green corrosion inhibitor: Maleic hydrazide derivative

A novel maleic hydrazide derivative containing multiple active groups (NOMAM) has been synthetized and characterized. Electrochemical tests revealed that it can provide effective protection for AZ31 magnesium alloys in 3.5 % NaCl. The best inhibition was achieved at 0.2 g·L−1. The observation results of the surface morphology also confirmed its excellent corrosion inhibition performance. Density functional theory (DFT) calculations and molecular dynamics simulations (MDS) revealed that maleic hydrazide derivative molecules adsorb onto magnesium alloy surfaces via a combination of physisorption and chemisorption with heteroatoms as active sites. The complexes formed by derivative molecules with Mg2+, together with the deposited Mg(OH)2, form protective barriers at the interface. The synthesized derivative has many advantages, such as low cost, simple processing and low toxicity. This study can contribute to the search for green corrosion inhibitors for magnesium alloys.

Electrochemicaland computational insightsinto the utilization of an N-heteroaromatic containing compound2-(4-Methoxy-phenyl)-5-naphthalen-2-yl-[1,3,4]oxadiazole as a promising anticorrosive agent for mild steel in corrosive medium

In this investigation, the corrosion inhibition properties of an N-heteroaromatic containing compound 2-(4-Methoxy-phenyl)-5-naphthalen-2-yl-[1,3,4]oxadiazole (MPNO), against mild steel (MS) in 1 M HCl using various analytical techniques have been examined. This study included weight-loss measurements at different temperatures (303–323 K), electrochemical analyses using Electrochemical Impedance Spectroscopy (EIS) and Potentiodynamic Polarization (PDP), and surface morphology investigations with Scanning Electron Microscopy (SEM). The experimental results demonstrated that MPNO exhibited excellent corrosion inhibition efficiency of 85.53% at a minimal 400 ppm inhibitor concentration with a mixed-type inhibition mechanism, as evidenced by the charge transfer resistance (RCT) value of 327.02 Ω.cm2 derived from the EIS analysis. Additionally, the analysis of quantum chemical descriptors revealed EHOMO (−8.6335 eV), ELUMO (−1.0277 eV), energy gap (ΔE = 7.60 eV), dipole moment (µ = 2.618 D), indicating inhibitor capability to acquire electrons and donate them to the metal's vacant d-orbitals, thus enhancing its adsorption activity and inhibitory properties. The density functional theory (DFT) computational studies complemented the experimental findings and provided a deeper understanding of the interaction modes between the inhibitors and the MS surface.

Experimental and Computational Investigation of Salicylhydroxamic Acid as a Corrosion Inhibitor for Copper in Alkaline Solutions

Inhibitors, as indispensable components in chemical mechanical polishing (CMP) slurries, have a significant impact on inhibiting copper (Cu) corrosion and enhancing post-polishing surface quality. However, one of the major challenges in CMP lies in unraveling the microscopic corrosion inhibition mechanism of Cu. This work focuses on investigating the impact of an inhibitor, salicylhydroxamic acid (SHA), on the static etching rate (SER), electrochemical parameters, and surface morphology of Cu. The experimental findings demonstrate that SHA significantly decreases the SER and corrosion current density of Cu, while notably improving the Cu surface quality. The corrosion inhibition mechanisms of SHA on Cu are revealed through adsorption isotherm models, contact angle analysis, electrochemical impedance spectroscopy, and computational chemistry method. The benzene ring, oxime group, and O1 atom of SHA exhibit significant chemical reactivity, facilitating the preferential adsorption of SHA on Cu in a parallel orientation, thereby forming a hydrophobic protective film on the Cu surface. This process hinders the interaction between corrosive solutions and Cu, therefore SHA exhibits excellent corrosion inhibition performance on Cu. These findings hold great importance in gaining a deeper comprehension of the corrosion inhibition process of Cu, and provide guidance for designing more efficient inhibitors.

Corrosion Resistance Improvement of Mild Steel

Abstract Corrosion’s devastating consequences have become a big issue all over the world. One of the corrosion damage aspects are related to decontamination solutions which are essential for rapid degradation of toxic agents. The decontamination solutions should be non-corrosive to avoid deterioration of steel container. Decontamination solutions comprising have high chlorinating activity so they have a corrosive effect on mild which are used in fabrication of storage tanks. In this case, using inhibitors is one of the most effective strategies to limit the rate of corrosion. This work describes the effect of different compounds; (zinc chromate, cinnamaldehyde, sodium tripolyphosphate, zinc ortho-phosphate, ammonium molybdate and thiourea) on the rate of corrosion of mild steel within dichloroisocyanuric acid decontamination solution. Meanwhile, these inhibitors should not affect active chlorine content which is responsible for the decontamination process. By using kelthoff and AquaChec® methods for measuring active chlorine, it was found that only zinc chromate passed the tests. For measuring electrochemical behaviour of mild steel in decontamination solutions, different techniques were used. Zinc chromate inhibition on mild steel in a 0.5% dichloroisocyanuric acid solution at different temperatures (298–313 K) were studied utilising electrochemical impedance spectroscopy, weight loss, and potentiodynamic polarisation. The results reveal that zinc chromate is an excellent mild steel corrosion inhibitor in dichloroisocyanuric acid, with an inhibition efficacy of 96% at a concentration of 0.005 M. Finally, surface morphology of mild was also investigated using SEM.

The performance of hydrophilic moieties in synthesized fluorinated cationic surfactants on corrosion inhibition of carbon steel pipelines

Compared with traditional hydrocarbon surfactants, fluorinated surfactants exhibit unique characteristics such as reduced surface tension, enhanced efficacy in reducing interfacial tension, dual hydrophobic and oleophobic nature, increased thermal stability, and superior chemical resistance. These characteristics make them a favorite material for many kinds of applications. This study aims to highlight the synthetic route for three novel cationic fluorinated surfactants (CFS) and applied them in the oilfield as corrosion inhibitors. Characterization of the prepared surfactants took place using different spectroscopic techniques. The influence of hydrophilic moieties on the micellar characteristics of ionic surfactants that have the same hydrophobic fluorinated chains are investigated in this research. Also, an evaluation of the influence of these groups on thermodynamic parameters was carried out.The metal corrosion inhibition efficiency of the CFS was studied in acidic medium by three different techniques, including potentiodynamic polarization, electrochemical impedance spectroscopy (EIS), and weight loss procedures, at three different temperature ranges (25, 40, and 60 °C).The achieved results displayed the inhibition efficiency of the metal corrosion that was elevated by increasing both the CFS's concentration and the applied temperature values. The highest level of inhibition, reaching 97.48 %, was achieved at a concentration of 700 parts per million (ppm) and a temperature of 60 °C. Furthermore, it was noticed that the charge transfer resistance value was raised; however, the constant phase element was decreased with increasing the CFS concentrations. The CFS regards an excellent and mixed-type corrosion inhibitor. The adsorption of CFS has agreed the Langmuir's adsorption isotherm and was related to chemisorption. SEM photos show a good CS surface in the presence of CFS versus the absence of them.

Excellent corrosion inhibition efficiency of Catharanthus roseus (Nayantara or Sadabahar) leaf aqueous extract on mild steel in chloride-contaminated solutions at different pH

The efficacy of Catharanthus roseus (Nayantara or Sadabahar) leaf extract as a green corrosion inhibitor for mild steel in chloride-contaminated environments has been investigated in the present work. This study has employed a straightforward, practical, and less expensive Maceration process to prepare leaf extract. The adaptability of the extract as a corrosion inhibitor has been evaluated through electrochemical polarization and impedance studies in chloride-contaminated environments with varying pH levels. In addition, long-term corrosion monitoring has been conducted to evaluate the sustainability of the inhibitor against chloride-induced corrosion at a neutral pH level. This novel study has revealed that the extract defends mild steel against chloride assaults better at pH 2 than it does in neutral or alkaline conditions. Moreover, electrochemical studies and subsequent characterizations have confirmed the film-forming nature of the inhibitor.

Punica grantum peel extract decorated Al-MOF scaffold as Solid-State Sensor/Concentrator for the Sensing/Reduction of Cr(VI) and its extended utility as a corrosion inhibitor in Al-Air batteries

The growing presence of hexavalent chromium in environmental and industrial settings highlights the importance of developing an eco-benign platform for real-time in-situ sensing/screening and decontamination. This research presents a facile and portable solid-state optical sensor using waste Punica Granatum, i.e., pomegranate peel extract (PPE) adorn onto Aluminium-based Metal-Organic Frameworks (Al-MOFs) for the sensing of carcinogenic Cr(VI) and its decontamination to benign Cr(III). The sensor fabrication entails a hydrothermal synthesis to form Al-MOF scaffolds decorated with PPE through direct immobilization. Al-MOF exhibits a large surface area with well-defined pore channels that facilitate PPE’s voluminous/uniform anchoring in restricted orientations to serve as an ion-selective probe for specifically targeting ultra-trace Cr(VI). The surface/structural morphology and porosity of the Al-MOF-PPE material are characterized using scanning/transmission electron microscopy and BET/BJH analysis. The reduction of Cr(VI) by the Al-MOF-PPE is validated by electron spectroscopy for chemical analysis, corroborated by a conspicuous color transition from light yellow to dark brown. The efficient reduction of Cr(VI) by Al-MOF-PPE is achieved at pH 2–3, in the linear response range of 0.3–300 ppb and a detection limit of 0.23 ppb for Cr(VI). The sensory system prefers minimal PPE probe content (4 mg) and sensor dosage (5 mg) for ion-sensing and decontamination studies, highlighting its remarkable operational efficacy. Post Cr(VI) reduction, electrochemical studies confirm the utility of Al-MOF-PPE-Cr(III) as a corrosion inhibitor for metal surfaces. Tafel plots demonstrate that Al-MOF-PPE-Cr(III) exhibits cathodic and anodic inhibition characteristics, ensuring excellent surface protection for aluminum electrodes upto 220 min in Al-air batteries. The proposed Al-MOF-PPE offers dual functionality as a naked-eye platform for Cr(VI) decontamination, and the Al-MOF-PPE-Cr(III) material is an excellent corrosion inhibitor for energy storage devices.

BF2 complexes of pyridyl‐isoindoline‐1‐ones as an efficient corrosion inhibitor for mild steel in 1 M HCl and the application for surgical instruments anticorrosion

AbstractIn 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.

Preparation of efficient hydrochloric acid corrosion inhibitor from natural grease

Abstract 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.

Selective etching-induced surface modifications of FeCrAl alloy bipolar plates: Mechanisms for enhanced corrosion resistance and hydrophobicity

The FeCrAl alloy has been considered a potential candidate material for bipolar plates (BPs) in fuel cells, emphasizing the improvement of corrosion resistance through surface modification. This study involves a selective etching process that facilitates the preferential dissolution of iron ions to establish a high-chromium surface, enhancing both corrosion resistance and hydrophobic properties. This crucial etching process alters the surface roughness and enhances the surface energy. The transformed rough surface due to surface polishing and etching changes from hydrophilic to hydrophobic, which facilitates corrosion management and moisture control based on the Cassie-Baxter model. The modified micro/nanostructure of the FeCrAl alloy surface and the reconstituted protective film exhibit excellent corrosion inhibition and long-term stability. The study elucidates how the correlation between surface free energy (SFE) and the formation of hydrophobic and rough surfaces acts as a mechanism for enhancing the corrosion resistance of FeCrAl surfaces. Utilizing the Van Oss-Chaudhury-Good (Van Oss) method based on the Lewis acid/base theory further clarifies this corrosion inhibition process, proposing a novel approach that offers significant advantages over traditional methods. Furthermore, this method offers economic and efficient benefits compared with traditional coating methods, providing a promising avenue for reliable corrosion protection in fuel cell applications.

Isoindigo derivatives as some potential corrosion inhibitors for mild steel in hydrochloric acid solution: Synthesis, experimental and theoretical studies

This investigation synthesized two isoindigo derivatives (IIDBr-NBr and IIDBr-MBr). These derivatives were then applied as green corrosion inhibitors for mild steel in a 1 mol L−1 HCl aqueous solution. The study investigated the corrosion inhibition performance of IIDBr-NBr and IIDBr-MBr through electrochemical and weight loss (WL) measurements, as well as surface analysis (SEM, AFM and XPS). The results showed that both IIDBr-NBr and IIDBr-MBr exhibited excellent corrosion inhibition performance (inhibition efficiency of 96.27 % for IIDBr-NBr and 96.46 % for IIDBr-MBr). Quantum chemical calculations based on density functional theory (DFT) and molecular dynamics (MD) were used to reveal the adsorption mechanisms of IIDBr-NBr and IIDBr-MBr at the steel/solution interface.

Hydrothermal route upcycling surgical masks into dual-emitting carbon dots as ratiometric fluorescent probe for Cr (VI) and corrosion inhibitor in saline solution

Exploration effective route to convert plastic waste into valuable carbon dots with bifunction of metal fluorescence monitoring and corrosion protection in seawater is promising. Herein, using “white-pollution” polypropylene surgical masks as a single precursor, dual-emitting carbon dots (CDs) with excellent ratiometric fluorescent sensitivity and corrosion inhibitor efficiency were fabricated with high yield (∼100 %) by a one-pot in situ acid oxidation hydrothermal strategy without post-treatment and organic solvents. Chemical, structural, morphological, optical properties and the Cr (VI) detection and Cu inhibition mechanism of the synthesized CDs had been systematically studied. Furthermore, a dual-response-OFF proportional fluorescent probe had been developed for the detection of the analyte Cr (VI) with a low detection limit of 24 nM. Additionally, the corrosion inhibition efficiency of the prepared CDs reached approximately 94.01 % for Cu substrate in 3.5 wt% NaCl electrolyte under a CDs concentration of 200 mg/L, which is higher than that of most previous reports.

Theoretical Study and Virtual Screening of Nitrogen‐Containing Corrosion Inhibitors Based on Quantitative Structure–Activity Relationship

AbstractNitrogen‐containing corrosion inhibitors have a wide range of promising applications, and current conventional corrosion design and evaluation methods are largely based on empirical speculation and extensive exploratory experiments. Unfortunately, these efforts are often associated with high costs, long lead times, and a lot of “blind work.” In this work, we have computationally screened the quantum chemical parameters of five nitrogen‐containing corrosion inhibitor molecules and their corrosion inhibition properties by a molecular simulation method based on density functional theory calculations. The ultimate relationship between the corrosion inhibition efficiency (IE) of an adsorbent and its quantum chemical parameters was analyzed using linear regression by comparing the various quantum mechanical parameters of each inhibitor molecule, as well as the fraction of electrons (ΔN) that are transferred to the metal surface from the chemisorbed inhibitor molecule. Five different nitrogen‐containing corrosion inhibitor molecules were screened based on structural similarity. Meanwhile, their corrosion inhibition performance was evaluated using the most relevant structure–activity equations. The results showed that the synergistic effect between the corrosion inhibition performance and the orbital energies of highest occupied molecular orbital and lowest unoccupied molecular orbital was optimal under the HF/6‐31G(d) method, and the corresponding structure–activity relationship was established. Based on these results, a specific inhibitor molecule was found to have excellent corrosion inhibition performance with a predicted corrosion IE of up to 94.12 %.

An improved protection of alanine for atmospheric corrosion of mild steel using carbon dots-montmorillonite hybrid materials

PurposeThe aim of this paper is to solve the toxic and harmful problems caused by traditional volatile corrosion inhibitor (VCI) and to analyze the effect of the layered structure on the enhancement of the volatile corrosion inhibition prevention performance of amino acids.Design/methodology/approachThe carbon dots-montmorillonite (DMT) hybrid material is prepared via hydrothermal process. The effect of the DMT-modified alanine as VCI for mild steel is investigated by volatile inhibition sieve test, volatile corrosion inhibition ability test, electrochemical measurement and surface analysis technology. It demonstrates that the DMT hybrid materials can improve the ability of alanine to protect mild steel against atmospheric corrosion effectively. The presence of carbon dots enlarges the interlamellar spacing of montmorillonite and allows better dispersion of alanine. The DMT-modified alanine has higher volatilization ability and an excellent corrosion inhibition of 85.3% for mild steel.FindingsThe DMT hybrid material provides a good template for the distribution of VCI, which can effectively improve the vapor-phase antirust property of VCI.Research limitations/implicationsThe increased volatilization rate also means increased VCI consumption and higher costs.Practical implicationsProvides a new way of thinking to replace the traditional toxic and harmful VCI.Originality/valueFor the first time, amino acids are combined with nano laminar structures, which are used to solve the problem of difficult volatilization of amino acids.