Eco-friendly Corrosion Inhibitor Research Articles

Sonophotopythochemical Functionalization of Graphene Oxide - Al - Zn Bimetal Nanocomposite for Corrosion Inhibition

The corrosion performance of steel in the marine environment has been a primary concern of engineers and garnered significant interest due to its industrial significance. To address this concern, the incorporation of green corrosion inhibitors as coating materials in mild steel has been extensively studied recently. This paper explores the synthesis of graphene doped with bimetal aluminum-zinc (GO-Al-Zn) nanocomposites via sonophoto-phytochemical functionalization using Chayote (Sechium edule) leaf extract as the doping agent to produce a corrosion inhibitor. The synthesized nanocomposites were characterized using FTIR, SEM-EDS, XRD, and TEM. The optimal nanocomposite, with a 55% Al - 45% Zn ratio, demonstrated successful bio-reduction, good dispersion, reduced particle size, and a rhombohedral crystal structure. When incorporated into an epoxy coating and applied to mild steel, the GO - 55% Al - 45% Zn coating achieved a high corrosion inhibition efficiency of 98.06% (gravimetric method) and 98.45% (electrochemical method) in 3.5 wt% NaCl solution. This study highlights the promising potential of GO - 55% Al - 45% Zn nanocomposite as an eco-friendly corrosion inhibitor. Future research should explore optimizing the functionalization process and exploring long-term environmental stability.

Biopolyurethane coatings with silica-titania microspheres (MICROSCAFS®) as functional filler for corrosion protection

In this work, we studied a biopolyurethane (BioPU) coating derived from a bio-based polyol and isocyanate for the protection of carbon steel against corrosion. The direct utilization of polyols obtained from raw biomass represents a novelty in polyurethane coatings production. The protective properties of these coatings were enhanced by incorporating unique silica-titania (ST) MICROSCAFS®, which are microspheres exhibiting interconnected macro- and mesoporosity. They were loaded with tannic acid (TA), an eco-friendly corrosion inhibitor. Confirmation of TA loading into the ST carriers (therefore called ST\\TA) was achieved through Attenuated total reflectance - Fourier-transform infrared spectroscopy (ATR-FTIR) and Thermogravimetric (TG) analyses. TG analysis revealed that ST\\TA particles contain approximately 34 wt% TA, and their average particle diameter is approximately 25 ± 5 μm, observed by SEM. The TGA shows slightly improved thermal resistance of the coatings modified with the filler MICROSCAFS®. Furthermore, it was observed that the fillers strengthened the coating hardness without negatively affecting the adhesion strength. Electrochemical Impedance Spectroscopy (EIS) results demonstrated that all modified coatings exhibited very good to excellent resistance in mild corrosive environments. The coatings maintained a high impedance modulus (|Z|) at low frequencies and phase angle values close to −90° across a wide frequency range, over an immersion period of 80 days in a 0.05 M NaCl solution. After 80 days of immersion, the best coating, BPU-ST\\TA, displayed |Z| of 3 × 1010 Ω cm2. Scanning Vibrating Electrode Technique (SVET) analysis revealed the inhibitory behaviour of TA. For the BPU-ST\\TA sample, inhibition of both anodic and cathodic activities was clearly visible, with a significant reduction of the current densities starting at 1 h and up to at least 24 h of immersion. In summary, the BioPU coatings modified with tannic acid-loaded MICROSCAFS® exhibit improved barrier properties and notable corrosion inhibition capacity in mild corrosive environments.

Ginger powder as sustainable and eco-friendly corrosion inhibitor for the protection of steel reinforcement bars

In the present studies, ginger powder has been used as an eco-friendly admixture for the cement mortar. Different amounts i.e. 0wt.% (M1), 0.10wt.% (M2), 0.25wt.% (M3) and 0.50wt.% (M4) ginger powder was mixed in the cement mortar (M1) and assessed the durability. The ginger powder with 0.50wt.% (M4) improves the compressive strength by 17% owing to the water reducing capability, which enhance the hydration reaction and fill the pore matrix of the cement mortar. The active ingredient of ginger powder i.e. shogaol adsorbs on the steel rebar surface through leaching mechanism by interaction of oxygen (O) and п-electrons with iron (Fe) and provide corrosion protection at longer duration of continuous immersion in 3.5wt.% NaCl solution. Following 173 d in a 3.5wt.% NaCl solution, the M4 sample exhibits 82.10% corrosion inhibition efficiency. Therefore, it is suggested that ginger powder could be a potential eco-friendly admixture to be used in construction industries to get high durability performance in the coastal areas.

Cucumber peel extract as an eco-friendly corrosion inhibitor for low-carbon steel in sulfuric acid

Cucumber peel extract as an eco-friendly corrosion inhibitor for low-carbon steel in sulfuric acid

Exploring the Effectiveness of 3-Chloro-4-morpholin-4-yl-1,2,5-thiadiazole as a Eco-Friendly Corrosion Inhibitor for Mild Steel in HCl Solution: Experimental and DFT Analysis

Corrosion is a significant issue in many industries, particularly where metals are exposed to harsh chemical environments. This study investigates the efficacy of 3-Chloro-4-morpholin-4-yl-1,2,5-thiadiazole (CMTD) as a corrosion inhibitor for mild steel in 1 M HCl solution across a temperature range of 303–333 K. Using weight loss measurements, electrochemical impedance spectroscopy (EIS), and potentiodynamic polarization techniques, the inhibition efficiency of CMTD was evaluated at different concentrations and temperatures. The results show that CMTD achieves a maximum inhibition efficiency of 96.8% at a highest inhibitor concentration, even at elevated temperatures. The adsorption of CMTD on the mild steel surface follows the Langmuir adsorption isotherm, with a calculated free energy of adsorption (ΔGads) of -39.5 kJ/mol, confirming a spontaneous chemisorption process. Quantum chemical Density Functional Theory (DFT) studies further elucidated the relationship between CMTD's molecular structure and its inhibition efficiency. Key parameters, including the energy gap (Egap = 3.551 eV), highest occupied molecular orbital (EHOMO = -6.317 eV), and lowest unoccupied molecular orbital (ELUMO = -2.766eV), were calculated to understand CMTD's reactivity. Additionally, global reactivity descriptors such as chemical hardness (η), electronegativity (χ), and the electron fraction transferred (ΔN) from CMTD to the iron surface were analyzed. These findings suggest that CMTD is highly effective in preventing corrosion and can be applied in industries where mild steel is exposed to acidic environments, such as in petrochemical and industrial cleaning processes.

Millettia aboensis leaves extract as eco-friendly corrosion inhibitor for mild steel in acidizing solution: From experimental to molecular level prediction

The development of environmentally friendly corrosion inhibitors is becoming more popular since conventional inhibitors are poisonous and non-biodegradable. The anti-corrosive effectiveness of Millettia aboensis leaves extract (MALE) has been assessed in this study using several methods, such as electrochemical measurements, X-ray Photoelectron spectroscopy and scanning electron microscopy on mild steel in acidic solution. Gas chromatography-mass spectrometry (GC-MS) analysis was combined with qualitative and quantitative phytochemical analysis to identify the phytochemicals linked to the activity of the Millettia aboensis extracts and identified key phytoconstituents such as Hexanedioic acid, Phenol derivatives, Octadecanoic acid, and Linolenic acid, which play significant roles in the extract's inhibitory performance. The results showed that the inhibition efficiency (IE%) improved to 88.6 % with the addition of inhibitor concentration from 0.1 g/L to 3.0 g/L and that the corrosion rate drastically reduced from 56.91 mpy to 16.09 mpy. Furthermore, at a greater concentration (3.0 g/L), the Rct values rose from 61.42 Ω cm2 to 176.3 Ω cm2 thus, indicating that the inhibitor molecules were forming a protective film over the metallic surface. Scanning Electron Microscopy (SEM) provided visual evidence of surface morphology, revealing a smoother surface in the presence of the inhibitor, indicative of the protective film formed by the adsorption of organic molecules onto the steel surface. Theoretical calculations using the ωB97XD functional and def2svp basis set further supported the experimental findings, showing that the protonated form of C21H36O4 exhibited the highest interaction energy, correlating with its superior inhibition efficiency on the metal surface.

Experimental and theoretical study of two Salen-type Schiff bases: green synthesis, characterization, corrosion inhibition efficiency, and biological activity

As eco-friendly corrosion inhibitors, antioxidants, and antibacterial agents, this study assesses 1,3-bis(2-hydroxybenzylidene) thiourea (B1) and 1,3-bis(2-hydroxybenzylidene) urea (B2), two new Schiff bases, on their performance in these areas. We successfully synthesized these Schiff bases in just 15 minutes using an environmentally friendly approach, and the yield was rather good, ranging from 69.8% to 87.53%. When compared to B2, B1 showed more effective corrosion inhibition and better antioxidant activity. Both chemicals were highly effective against microbes, while B1 was particularly effective against Aspergillus. B. We measured the weight loss to examine the corrosion inhibition impact of XC48 carbon steel in 1M HCl. The findings revealed that at the ideal concentration of 5.10–4 M, the estimated IE% of the Schiff bases was 63.8% for B2 and 87.28% for B1. This study employed the Langmuir isotherm model to determine a number of thermodynamic and kinetic characteristics, all of which pointed to a physical adsorbed state. Promising electrical characteristics and robust adsorption on metal surfaces for B1 were corroborated by theoretical investigations employing density functional theory (DFT) and molecular dynamics (MD) simulations. Both the theoretical and practical aspects align with one another.

Optimization, molecular dynamics and quantum parameters simulations of Zingiber officinale rhizome as a green corrosion inhibitor

This study combines experimental and theoretical approaches to investigate ginger root extract (GRE) as an eco-friendly corrosion inhibitor for mild steel in acidic environments at temperatures ranging from 303 to 333 K. Experimental techniques, including weight loss measurements, were used to assess the inhibiting performance and adsorption behavior of GRE, while GC-MS, FT-IR, and UV–visible spectrophotometric methods provided further characterization. Results indicated that the inhibition efficiency of GRE increased with higher concentrations and decreased with temperature, highlighting its potential to effectively prevent corrosion in H2SO4 medium. GC-MS analysis identified four major phenolic compounds—6-gingerol, 6-isoshogaol, zingerone, and vanillyl glycol—and two secondary metabolites, α-Farnesene and β-Bisabolene. Among these, 6-gingerol, the most active and abundant constituent, was selected for computational studies. Optimal corrosion inhibition of 81.3 % was achieved at 303 K with a GRE concentration of 10 g/L for 1 h. Thermodynamic activation parameters suggested a temperature-dependent process, and alignment with the Langmuir isotherm indicated a physical adsorption mechanism. Quantum chemical calculations for 6-gingerol revealed highest occupied molecular orbital energy (EHOMO) and lowest unoccupied molecular orbital energy (ELUMO) values of -6.286 eV and -0.366 eV, respectively, in its protonated state, and -8.338 eV and -0.247 eV, respectively, in its neutral state. Molecular simulations showed a binding affinity of -4.736 kJ/mol between 6-gingerol and the steel surface, supporting the experimental findings and underscoring the potential of GRE as an effective corrosion inhibitor.

Exploration on the corrosion inhibition performance of Salvia miltiorrhiza extract as a green corrosion inhibitor for Q235 steel in HCl environment

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.

Green chemistry approach to corrosion prevention: Saccocalyx satureioides as an effective inhibitor for C45 steel in acidic medium (HCl)

Carbon steel's corrosion in harsh, acidic environments presents significant challenges to industrial use. While traditional inhibitors are effective, they often raise environmental and sustainability concerns. This study explores the potential of Saccocalyx satureioides extract (S. Satureioides) as an environmentally Eco-friendly corrosion inhibitor for protecting carbon steel 45 in a highly corrosive 0.5 M HCl solution. The organic components of the sample were identified using phytochemical screening, LC-MS analysis, and ATR-FTIR spectroscopy. The main compounds detected were coumaric acid (68.10%), 4-methoxybenzoic acid (15.15%), and kaempferol (11.36%). Weight loss measurements demonstrated that the S. Satureioides extract had a highly effective anti-corrosion capability, achieving an inhibitory efficiency of around 96.93% at a concentration of 3 g.L-1 at a temperature of 25°C after 360 hours of immersion. This significantly reduced the corrosion rate from 0.1721 mg.cm−2.h−1 to 0.0053 mg.cm−2.h−1. The adsorption isotherms indicated that the adsorption of S. Satureioides molecules onto the steel surface followed the Langmuir model, exhibiting a high correlation coefficient of 0.9958. The negative value of the adsorption free energy ( = -17.162 kJ mol-1) indicates that the physisorption interactions occurred spontaneously. The SEM/EDX analysis revealed that the steel surface exhibited reduced damage due to the inhibitor's protective coating formation. This research not only significantly contributes to corrosion science filed but also provides crucial support for global efforts to promote sustainable industrial practices, with potential applications in various industries worldwide.

In-depth study of a newly synthesized imidazole derivative as an eco-friendly corrosion inhibitor for mild steel in 1 M HCl: Theoretical, electrochemical, and surface analysis perspectives

The present study is concerned with the corrosion inhibition and adsorption behaviour of a series of novel imidazole derivatives. The compounds under investigation are 5,5-diphenyl-3-propyl-2-(propylthio)-3,5-dihydro-4 H-imidazol-4-one (AM3) and 3-allyl-2-(allylthio)-5,5-diphenyl-3,5-dihydro-4 H-imidazol-4-one (AM6). The objective of this study is to evaluate the efficacy of 5,5-diphenyl-3,5-dihydro-4 H-imidazol-4-one (AM6) as a corrosion inhibitor on mild steel immersed in a 1.0 M hydrochloric acid medium. This comprehensive study assesses the efficacy of these derivatives through a range of electrochemical and spectroscopic analysis techniques. Additionally, polarisation curves, electrochemical impedance spectroscopy and advanced computer simulations were employed to evaluate the efficacy and inhibition mechanism of imidazole derivatives, thereby facilitating a more profound understanding of their anticorrosive capacity. The results obtained from potentiodynamic polarisation (PDP), electrochemical frequency modulation (EFM) and electrochemical impedance spectroscopy (EIS) measurements demonstrate that the inhibition efficiency increases with increasing imidazole derivative concentration. Conversely, an inverse relationship is observed between inhibition efficiency and temperature. The thermodynamic parameters ΔG°_ads and ΔH°_ads corroborate the conclusion that the adsorption process is predominantly chemical in nature. Scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX) and X-ray photoelectron spectroscopy (XPS) were employed to characterise the surface morphology. The maximum protection afforded by imidazole derivatives was 95.2 % and 93 % for compounds AM3 and AM6, respectively. Polarisation curves indicated that imidazole derivatives exhibited mixed inhibition behaviour. Surface analysis demonstrated that imidazole derivatives were effectively adsorbed onto the carbon surface, thereby significantly reducing acid damage. This finding was corroborated by DFT calculations, as well as Monte Carlo (MC) and molecular dynamics (MD) simulations. These simulations provided a comprehensive insight into the adsorption of imidazole and its protonated form onto the carbon surface, offering valuable insight into the corrosion inhibition mechanism.

Eco-friendly corrosion inhibitor of Q235 carbon steel in 1.0 M HCl by Isatin/Chitosan Schiff base

This study presents the synthesis of an eco-friendly and green Schiff base, namely Isatin-Cs Schiff base corrosion inhibitor for Q235 carbon steel in 1.0 M HCl corrosion solution. Fourier-transformed infrared FT-IR and 1H NMR was utilized to characterize the prepared Isatin-Cs Schiff base corrosion inhibitor. The inhibition performance in 1.0 M HCl solution was investigated via classic weight loss at various temperatures, potentiodynamic polarization (PPD), and electrochemical impedance spectroscopy (EIS). Scanning electron microscopy SEM, X-ray photoelectron spectroscopy XPS, and water contact angle methods are used to analyze the surface morphology of Q235 carbon steel. The polarization measurements indicate that the corrosion inhibitors act as mixed type. Moreover, the weight loss studies show that the efficiency of inhibitor increases with the concentration of inhibitor to reach a maximum efficiency of 88.4 % with 250 ppm at 25 °C. Nevertheless, increasing temperature has negative effect on the efficiency of the Isatin-Cs inhibitor. The Langmuir isotherm Unveil that Isatin-Cs adsorption on Q235 carbon steel is mediated via physi/chemi-sorption. Based on SEM and XPS analyses Isatin-Cs forms stable protective film on Q235 carbon steel. The DFT results complemented the experiments results, both observed the effectiveness of inhibitor adsorption.

Eco-friendly corrosion inhibition of steel using phenolic compounds from Cynara syriaca

This study evaluates the corrosion inhibition performance of the n-butanol (n-BuOH) fraction derived from Cynara syriaca on mild steel in acidic environments. The n-BuOH fraction achieved up to 94 % inhibition at 500 ppm, as assessed through gravimetric analysis, potentiodynamic polarization (PDP), and electrochemical impedance spectroscopy (EIS). Key phenolic compounds, including kaempferol, naringenin, myricetin, chlorogenic acid, and quercetin, were identified by UPLC-MS/MS. These compounds form stable flavonoid-metal complexes, as confirmed by UV–Vis spectroscopy. FT-IR and SEM-EDS analyses revealed the formation of protective coatings and interactions with the steel surface. Polarization curves indicate that the n-BuOH fraction acts as a mixed-type inhibitor, predominantly affecting the anodic reaction. The inhibition efficiency decreased from 93.89 % to 73.43 % with increasing temperatures. Thermodynamic analysis showed an increase in activation energy (Ea = 58.20 kJ/ mol) and a positive ΔH value of 56.17 kJ/mol, which can be attributed to the increased thickness of the double layer, enhancing the activation energy of the corrosion process. A Gibbs free energy (ΔG0ads) value of −25.48 kJ/mol confirms that the adsorption process is spontaneous and involves both physisorption and chemisorption. pKa analysis identified specific adsorption sites. This research underscores the potential of the n-BuOH fraction as a novel, eco-friendly corrosion inhibitor, offering valuable insights for sustainable corrosion control strategies.

Synthesis, characterization, theoretical, and experimental evaluation of novel imidazolone − based compounds as eco-friendly corrosion inhibitors for mild steel

This study investigates the corrosion inhibition properties of two newly synthesized namely (E)-2-(2-benzylidenehydrazineyl)-5,5-diphenyl-3,5-dihydro-4H-imidazol-4-one denoted Ph-DDI and (E)-2-(2-(4-methylbenzylidene)hydrazineyl)-5,5-diphenyl-3,5-dihydro-4H-imidazol-4-one denoted CH3Ph-DDI, on mild steel (MS) in a 1 M HCl solution. These compounds demonstrated high inhibition efficiencies of 98.3 % and 98.7 %, respectively. Structural characterization was performed using FT-IR, 1H NMR, 13C NMR, and HRMS-ESI. Theoretical evaluations indicated high reactivity and potent inhibition capacity. Electrochemical tests confirmed a concentration-dependent inhibition effectiveness up to 328 K. Adsorption studies suggested that the compounds displace water molecules to form an adsorbed protective layer. Microscopy analysis provided insights into the corrosion inhibition mechanisms, confirming the formation of protective layers and iron/inhibitor complexes. Further molecular structure analysis using Monte Carlo (MC) simulations and density functional theory (DFT) calculations elucidated the structural features contributing to the compounds’ effective corrosion inhibition properties.

New aryl-himachalene benzylamines derivatives as eco-friendly corrosion inhibitors at low concentration for brass 62/38 in 200 ppm NaCl: Experimental, analyses and theoretical approach

This study investigates the inhibitory effect of eco-friendly synthesized aryl-himachalene benzylamines derivatives, namely (±)-N-((3,5,5,9-tetramethyl -6,7,8,9-tetrahydro-5H-benzo [7] annulen-2yl)methyl)aniline (AHB) and (±)-4-bromo-N-((3,5,5,9-tetramethyl-6,7,8,9-tetrahydro-5H-benzo[7]annulen-2-yl)methyl)aniline (AHBBR) at low concentration on the brass 62/38 (B62/38) corrosion in 200 ppm NaCl solution, employing electrochemical techniques, surface analyses and theoretical investigations. The experimental measurements indicated that these compounds exhibit as good inhibitions, where their inhibition efficiency growth with their concentrations, reaching 88.69 % and 93.35 % at 100 ppm AHB and AHBBR, respectively. I-E measurements designated that the tested products react like a mixed-inhibitor type. In addition, the EIS measurements showed the establishment of a protective layer on the B62/38 region. The effects of the temperature solution and immersion time on their performance were investigated. It is found that they decrease slowly with temperature, while they improve with the immersion time until 12 h. In the same way, it is found that these molecules react on B62/38 surface according to Langmuir isotherm adsorption. Complementary, SEM/EDX analysis established the development of an organic defending film on the B62/38 area, confirming the compound's potential as effective corrosion inhibitors. Finally, the theoretical investigations confirm the anti-corrosion character of the tested compounds according to their mode of adsorption.

The anticorrosive efficacy of newly synthesized pyrido-bis(benzo[b]azoninone) analogs on carbon steel under sweet corrosive environments: A combined empirical and theoretical approaches

This study presents a novel and eco-friendly approach to address the critical challenge of carbon steel corrosion in CO2-rich saline environments, a significant concern in the oil and gas industry. We report the efficient synthesis of a new class of corrosion inhibitors: pyrido-bis(benzo[b]azoninone) (PSA) analogs. These PSA derivatives were conveniently prepared using a one-pot, three-component reaction under microwave irradiation, with their chemical structures confirmed by 1H and 13C NMR spectroscopy. The effectiveness of the synthesized PSA derivatives was then evaluated for their ability to protect N80 steel in a CO2-saturated 3.5 % NaCl solution. The results were impressive, with the PSA demonstrating outstanding corrosion inhibition efficiencies ranging from 94.6 % to 96.2 %. Electrochemical measurements (potentiodynamic polarization and electrochemical impedance spectroscopy) revealed that the PSAs act as mixed-type inhibitors, adhering to the Langmuir adsorption isotherm on the steel surface. X-ray photoelectron spectroscopy (XPS) analysis provided further evidence, confirming the formation of a protective barrier on the steel by the adsorbed PSA. Theoretical support for these findings comes from density functional theory (DFT) calculations, which establish a connection between the theoretical predictions and experimental observations. Additionally, MC simulations further corroborated the effectiveness of PSA adsorption on the iron (110) surface. In conclusion, this research offers groundbreaking insights into developing exceptionally efficient and eco-friendly corrosion inhibitors using novel PSA analogs. This approach holds significant promise for mitigating the challenges the oil and gas industry faces in protecting steel infrastructure in harsh CO2-rich environments.

Experimental and Theoretical Studies on Long Alkyl Chain-Bearing Dibenzotriazole Ionic Liquids as Eco-friendly Corrosion Inhibitors in Aqueous Hydrochloride Acid.

Three long alkyl chain-bearing dibenzotriazole ionic liquids (BTA-R-BTA, R = 8, 12, and 16) were synthesized with high yield (>98%) through a simple and eco-friendly process. Their anticorrosion performance for Q235 carbon steel in 6 M hydrochloride acid was comprehensively evaluated by weight loss tests, electrochemical methods (potentiodynamic polarization and electrochemical impedance spectroscopy), and surface analysis techniques. As the length of the alkyl chain increased, the maximum corrosion inhibition efficiency enhanced from 55.02% (for BTA-8-BTA at 1.2 mM) to 97.10% (for BTA-12-BTA at 0.3 mM) and 98.84% (for BTA-16-BTA at 0.3 mM). Density functional theory calculation indicated that the alkyl chain length had little influence on the inhibitors' electronic structures, while molecular dynamics simulations revealed that the thickness, surface coverage, and compactness of adsorption films formed at the metal-electrolyte interface increased with the elongated alkyl chain. Corrosion inhibition efficiency is strongly correlated with the structures of the adsorption film.

Phytochemicals as eco-friendly corrosion inhibitors for mild steel in sulfuric acid solutions: a review

Abstract Plant extracts represent abundant sources of biomolecules distributed throughout various plant parts. These biomolecules are extracted using diverse solvents and methods. Within these plant extracts lie bioactive compounds, known for their antioxidant properties and anticorrosive capabilities. Detecting and isolating these active biomolecules from plant extracts necessitates analytical techniques such as gas chromatography-mass spectrometry and liquid chromatography-mass spectrometry. The active biomolecules within plant extracts contain heteroatoms within their structures, facilitating their adsorption on steel surfaces and conferring corrosion inhibition properties. The advantages of plant extracts as green corrosion inhibitors include ready availability, ease of application, eco-friendly characteristics, and cost-effectiveness. These extracts adhere to steel surfaces, blocking their active sites and effectively reducing the corrosion rate. This review consolidates the findings on the corrosion inhibition potential of plant extracts from various plant parts, elucidating their performance in different concentrations of sulfuric acid.

Experimental investigation and theoretical modeling of copper corrosion inhibition by Urginea maritima essential oil

Corrosion inhibition is essential for preserving metallic materials in various industrial applications. This study aims to assess the inhibition performance of Urginea maritima essential oil (HEUM) in mitigating copper corrosion within a 0.5 M sulfuric acid environment. The experimental investigation examined the inhibition properties of the essential oil using electrochemical impedance spectroscopy (EIS), potentiodynamic polarization studies (PDP) and surface analysis by scanning electron microscopy (SEM). In addition, theoretical studies have been carried out using density functional theory (DFT) to further elucidate corrosion inhibition mechanisms. The findings from both experimental and theoretical analyses suggest a notable reduction in corrosion rates with the essential oil, highlighting its promising efficacy as an inhibitor, and the inhibitory effect of HEUM essential oil can be attributed to a synergistic effect between its various components. Furthermore, thermal stability studies demonstrate sustained inhibitory action over a range of temperatures. These results demonstrate the high potential of HEUM as a natural and eco-friendly corrosion inhibitor, warranting further exploration of practical applications in corrosion control strategies.

Novel chitosan-oligosaccharide derivatives as fluorescent green corrosion inhibitors for P110 steel

In the exploitation of seawater resources, the transported pipelines are frequently corroded, resulting in economic losses and environmental pollution. The development of corrosion inhibitors is an effective measure to mitigate the corrosion of metals in seawater. In this work, novel chitosan oligosaccharide derivatives (CF) were synthesized as fluorescent eco-friendly corrosion inhibitor by modifying fluorescent monomers. The characterization of CF revealed excellent fluorescence intensity, promising the potential for on-line detection. The inhibition performance of CF on P110 in 3.5 wt% NaCl solution was investigated through experimental evaluation and theoretical analysis. The electrochemical measurements indicated that the corrosion inhibition efficiency was increased from 61.00 % to 91.19 % with the introduction of fluorane. Adsorption isotherm and XPS analysis demonstrated that CF is designed to protect metal by forming the composite film on P110 through physical and chemical adsorption. In addition, theoretical calculations revealed differences in the interaction energies, radial distribution functions and diffusion coefficients of inhibitors on the Fe (110) surface. These theoretical results aligned with the experiments and confirmed the excellent ability of CF in metal corrosion protection from the molecular perspective. This new chitosan derivative provides new possibilities for the development of the green composite inhibitor that allows on-line detection.