Corrosion Inhibition Of Carbon Steel Research Articles

Experimental and computational studies of novel cyclic ammonium based ionic liquids as corrosion inhibitors for carbon steel in acid medium

The challenge of corrosion posed as a result of acidic sittings is considered as a major industrial concern, wherein ionic liquids serve as crucial in addressing the corrosive impacts on metals. In this study, five selected cyclic ammonium based ionic liquids were synthesized; IL-1MPyrBr, IL-1MPipBr, IL-2PyBr, IL-3MPyBr and IL-4MPyBr and their chemical structures were characterized using a variety of spectroscopic techniques (FT-IR, IH-NMR, 13C-NMR, Elemental analysis and thermal gravimetric analysis (TGA). Their corrosion inhibition efficiency was studied on carbon steel in 1 M HCl via different concentrations at 298 K using chemical and electrochemical parameters (PDP and EIS). DFT quantum parameters were computed, and the noted results were in complete compatible with the experimental. The synthesized ILs recorded excellent inhibition on the carbon steel corrosion in acidic media with increasing efficiency by increasing the inhibitor concentrations from 20 to 100 ppm. Different cations in the synthesized ILs affect the anti-corrosion effect and IL-3MPyBr showed the highest inhibition (ηR); 96.12% using the lowest concentration. Kinetic and thermodynamic considerations were studied and illustrated.

Inhibition performance of a novel quinoxaline derivative for carbon steel corrosion in 1 M HCl

In this work, the effect of a new quinoxaline derivative, 2-phenyl-3-(prop-2-yn-1-yloxy) quinoxaline (PYQX), was evaluated as a corrosion inhibitor for carbon steel (CS) in 1 M HCl electrolyte. Weight loss measurement, atomic absorption spectroscopy, potentio­dynamic polarization, electrochemical impedance spectroscopy, scanning electron microscopy with energy dispersive spectroscopy, and UV-vis spectroscopy were employed to assess the inhibitory activity. The electronic properties of the interaction between the inhibitor molecule and the CS substrate were studied using molecular dynamics (MD) simulation, density functional theory (DFT), and Fukui functions. According to AC impedance experiments, the inhibitor under consideration showed a maximum level of 98.1 % inhibition efficiency at 1 mM and 30 °C. The Langmuir adsorption isotherm model explains the adsorption of PYQX on the CS surface. A slope of 1 denotes a strong molecule-substrate interaction, suggesting that the binding occurs at specific surface locations. To understand the functioning of the adsorption mechanism, various thermodynamic and activation parameters were evaluated. PDP tests demonstrated that PYQX functions as a mixed-type inhibitor. Computational correlations (DFT, MD, and Fukui indices) supported the experimental findings.

Synthesis and study of the inhibitory properties of a new Schiff base for C45 carbon steel in 1 M HCl

A newly Schiff base 1, 13-bis-[(4-dimethylamino) benzaldehyde 4, 7, 10-trioxatridecane-diimine] (DABT) was synthesized and characterized on the basis of the results of FT-IR, mass spectroscopy (MS), 1HNMR and 13CNMR. The desired performance of the organic compound DABT which is easy, inexpensive to prepare and eco-friendly, as a corrosion inhibitor for C45 carbon steel in 1 M HCl medium was evaluated using weight loss, potentiodynamic polarization, electrochemical impedance spectroscopy (EIS) measurements. The results suggest that the corrosion inhibition effectiveness increases with increasing inhibitor concentration and decreases with increasing temperature. The polarization experiments demonstrate that DABT exhibits the characteristics of a mixed-type inhibitor and follows the Langmuir isotherm in its adsorption behavior. Contact angle measurement revealed that the inhibitor on the surface of the carbon steel is hydrophobic. The synergistic effect of DABT has been investigated; inhibitory efficiency rises with increasing concentration of KI by competitive adsorption to form a layer of protection on the metal surface. Energy dispersive X-ray spectroscopy (EDS) combined with scanning electron microscope (SEM) was utilized to interpret the morphological study of the carbon steel surface. A good correlation was found between theoretical [Density functional theory (DFT), molecular dynamics simulation (MDS)] and experimental findings.

An electrochemical, and surface studies of synthesized Gemini ionic liquid as corrosion inhibitor for carbon steel in petroleum field

In this work, we study the efficiency of N1, N3-dibenzyl-N1, N1, N3, N3-tetramethylpropane-1,3-diaminium chloride, as anticorrosion. This compound exhibits potential as a prospective remedy to stop the deterioration of carbon steel caused by corrosion in 1.0 M HCl. The synthesis of this compound is described in a comprehensive manner, and its composition is supported by a range of precise analytical approaches such as elemental analysis, and mass spectroscopy. Based on the findings of the investigation, the synthesized Gemini ionic liquid demonstrates a robust capacity to slow down the rate at which the metal corrodes. The Prepared compound was evaluation by electrochemical and morphology study. Our results revealed that elevating the inhibitor concentration led to an augmentation in inhibition effectiveness, reaching up to 94.8% at 200 ppm of the synthesized compound at 298 K. It is crucial to emphasize that the recently prepared Gemini ionic liquid is consistent with the Langmuir adsorption model and function as a mixed inhibitor, participating in the physio-chemisorption process of adsorption.

Study the Effect of “Di-dodecyl amine” as a Corrosion Inhibitor for Carbon Steel in HCl Medium

Numerous organic compounds have been investigated for their potential to reduce corrosion under various circumstances. This study investigated the effects of di-dodecyl amine, an organic chemical, on carbon steel metal corrosion at different temperatures while HCl acid was present. The examination was carried out using accepted methods for polarization, weight loss, and corrosion process testing. The obtained findings demonstrated that the corrosion rate reduces with increasing inhibitor concentration, leading to increased inhibition efficiency. Furthermore, as shown in the weight loss technique, the corrosion rate lowers with increasing surface coverage with organic inhibitor at 313 °C. In the anodic and cathodic polarization methods, as well as in the inhibition efficiency, it is observed to see the cathodic and anodic curves through which the occurrence of the potential and corrosion current is known. The current and corrosion potential decreases with increasing inhibitor concentration. The amines and methyl motiveless in this inhibitor's composition give it their efficacy since they may coat the metal surface and stop corrosion

Synthesis, scale and corrosion inhibition evaluation and mechanism of 2-aminobenzimidazole modified polyaspartic acid

With the growing public concern for environmental preservation, this work employs environmentally friendly polyaspartic acid (PASP) as the main chain, to develop a green and efficient dual-function inhibitor with scale and corrosion inhibition. The new inhibitor PASP-2-A was synthesized by grafting 2-amino-benzimidazole (2-A) containing nitrogen heterocyclic into polysuccinimide under alkaline conditions. The corrosion inhibition of carbon steel and brass was determined by static test, polarization curve and electrochemical impedance spectroscopy (EIS). It can be found that PASP-2-A had better scale inhibition performance than PASP under different conditions. The addition of 5 mg·L−1 PASP-2-A can almost 100% prevent the formation of CaCO3 scale. Molecular dynamics simulation results showed that PASP-2-A significantly destroys the crystal structure of CaCO3 scale due to the coordination between PASP-2-A and Ca2+ groups. The modified PASP scale inhibitor can prevent the growth of calcite (110) and (104) crystal faces, regulate the transformation of CaCO3 from stable calcite to more soluble spherical vaterite, making it less deposit. The electrochemical test results showed that the corrosion inhibition of PASP-2-A is greatly improved compared with PASP, and the corrosion inhibition of Q235 carbon steel increased about 40% at the dosage of 200 ppm. The corrosion inhibition efficiency of H62 brass in 3.5 wt% NaCl was 97.97% with 300 ppm PASP-2-A. Notably, due to its degradable nature, low toxicity, and affordability, PASP-2-A serves as an excellent inhibitor, exhibiting remarkable performance in both scale inhibition and corrosion inhibition. Consequently, it presents a promising avenue for further advancements in modified PASP.

Synthesis and characterization of selenium-polyvinyl alcohol nanoparticles as eco-friendly corrosion inhibitor for carbon steel in 1.0 M H2SO4

Selenium nanoparticles capped with polyvinyl alcohol (Se-PVA NPs) have been synthesized by chemical reduction using ascorbic acid as a reducing agent. The synthesized nanoparticles were characterized using XRD, DLS, zeta potential, FT-IR, and TEM analysis and found to be stable. The solution of Se-PVA NPs was used as a carbon steel corrosion inhibitor in 1.0 M H2SO4. The effect of the presence of Se-PVA NPs in the corrosion medium was studied by potentiodynamic polarization and gravimetric analyses In the presence of Se-PVA NPs with a concentration of 600 ppm at 303 K, corrosion inhibition efficiency values of 92.86 % and 92.3 % were recorded by potentiodynamic polarization and gravimetric analysis methods, respectively. Over the Se-PVA NPs concentration range 100–600 ppm, it was found that increasing the concentration increases the inhibition efficiency, while the temperature has an adverse effect, inhibition efficiency values of 80.0 % was recorded at 323 K for the 600 ppm Se-PVA NPs solution. The potentiodynamic polarization measurements suggested that Se-PVA NPs work as a mixed-type inhibitor. The corrosion inhibition process was confirmed by testing the used specimens’ metal surface using SEM and AFM techniques, which showed that the acidic medium’s negative impact (distortion and roughness) on the carbon steel surface was reduced significantly in the presence of Se-PVA NPs. The inhibitor’s adsorption on the metal surface was studied. It obeys the Langmuir isotherm with a mixed-type adsorption process. The related kinetic and thermodynamic parameters were investigated.

Influence of metal ions on cysteine as a corrosion inhibitor for low carbon steel in sulfuric acid: Polarization, EIS, XPS, and DFT analysis

This study examines the effectiveness of cysteine as an eco-friendly in inhibiting the corrosion of low-carbon steel in a sulfuric acid solution and the impact of adding various metal ions (Cu2+, Ni2+, and Co2+) to the media. All solutions were prepared using distilled water. The results show that 5 mM cysteine inhibits corrosion (IE = 65%), increasing to 93.5% in the presence of 4×10-5 M Cu2+ ions, but decreasing with the addition of Co2+ or Ni2+ ions. The inhibitive action of cysteine-Cu is the best one and that may be attributed to the formation of a protective coating on the metal surface, which prevents chemical reactions in an aggressive environment. Moreover, the DFT calculation found that the adsorption energy increased from −17.2 to −97.7 and −104.6 kcal/mol in the case of cysteine, Cysteine-Cu SAM, and Cysteine-Cu(II) Salt and the closest atom to the surface reduced from 2.576 to 2.128 and 2.146 Å which indicates Cysteine-Cu better adhere to the surface. SEM, XRD, and XPS were used to analyze the formation of the protective layer. This has the potential to develop new and more effective corrosion inhibitors for industrial applications.

Grape Leaves and Ziziphus Spina-Christi, Extracts as a Green Inhibitors Corrosion for The Carbon Steel and Oil Pipelines in 1M H2SO4

Metals suffer from corrosion by the surrounding fluids, which causes great economic losses and bad environmental effects, especially in oil pipelines or reservoirs. The extract of grape leaves (GL) and Sidr leaves, (Ziziphus spina-christi), (Zizi) were used as green corrosion inhibitors (CI) for carbon steel (CS), and Oil Pipelines in 1M H2SO4, these extracts showed varying capabilities in resisting corrosion. Corrosion rate was decreased with increase in inhibitor dose which could be due to enhanced surface coverage, as well as the effect of increasing the temperature on the percentage of the efficiency of inhibition, are decrease, and drawing the curves for that, as well as studying some physical properties related to the process of adsorption of extracts on the surface of (CS), such as the activation energy and entropy of the process of adsorption of the extracts on the surface of (CS), and calculating those values, and the extracts showed an efficiency that exceeded 90% at concentrations up to 400 ppm and a temperature of 313-343K. The activation energy associated with this process indicated surface interaction as the main mechanism and positive values of enthalpy change confirmed the endothermic nature. The potentiometric method showed the extent of voltage change with time for each concentration of extract of grape leaves for immersion time (2–24 h), and that the voltage increases with increasing concentration, which indicates a high ability of the inhibitor to adsorb to the metal..

Synthesis and characterization of bis-isoxazoline-thiosemicarbazone as a corrosion inhibitor for carbon steel: Experimental study, and molecular simulation

In this study, a novel compound, bis-isoxazoline-thiosemicarbazone (BIT), was synthesized and tested for its ability to protect carbon steel from corrosion in a 1 M HCl solution. The compound's structure was confirmed using spectroscopic techniques such as 1H NMR, 13C NMR, and HRMS. Various methods, including mass loss analysis, potentiodynamic polarization (PDP), electrochemical impedance spectroscopy (EIS), SEM, and EDX, were employed to assess BIT's effectiveness in inhibiting corrosion and its adsorption behavior on carbon steel in acidic conditions. The findings demonstrated the high effectiveness of BIT as a corrosion inhibitor, with a 95 % inhibition rate observed at a concentration of 0.77 mM and a temperature of 298°K. Analysis through PDP revealed that BIT operates as a mixed-type inhibitor, conforming to the Langmuir adsorption isotherm during its attachment to the carbon steel surface, indicating a mixed (chemical-physical) adsorption process.SEM-EDX analysis demonstrated even distribution of the inhibitor on the steel surface. Notably, BIT contains several functional groups (methoxy, carbonyl, isoxazolyl,..) and heteroatoms (N, O, and S) that play a crucial role, as supported by Density Functional Theory (DFT) studies. Experimental findings were validated by DFT and molecular dynamics (MD) simulation data.

An investigation of modified dialdehyde starch as a highly efficient green corrosion inhibitor for carbon steel in 1 M HCl medium: Synthesis, experimental and theoretical studies

Compared to small organic molecule corrosion inhibitors, polymer corrosion inhibitors offer numerous advantages in terms of adsorption coverage on the metal surface and the presence of multiple active sites for adsorption. A dialdehyde starch Schiff base was synthesized by modification of natural polymer starch and tetraethylene pentaamine, and it was characterized by X-ray diffraction, gel chromatography and thermogravimetry. The corrosion inhibition behaviors of dialdehyde starch Schiff base as an oligomer for low carbon steel in 1 M HCl were investigated. Compared to the common starch derivatives, the dialdehyde starch Schiff base has good water solubility and inhibition performance. The inhibition efficiency can reach 93.2% with 0.16 mM in 1 M HCl solution at 333 K. Double aldehyde starch Schiff base is a mixed corrosion inhibitor that mainly inhibits cathodic reactions. Its adsorption on the surface of carbon steel follows the Langmuir adsorption equation, and the nitrogen -containing groups in the molecules are adsorbed on the surface of the steel through physical and chemical reactions. Quantum chemical calculations confirmed the experimental results.

Protein-derived carbon dots as green corrosion inhibitors for carbon steel in sulfuric acid solution

At present, the development of eco-friendly corrosion inhibitors (CIs) is considered an important and attractive method for controlling the corrosion of metals in acidic media. In this study, protein-derived carbon dots (P-CDs) were prepared via hydrothermal reaction using protein as the raw material, and the corrosion inhibition performances of P-CDs for carbon steel (CS) were investigated systematically. The electrochemical test results showed that the corrosion inhibition efficiency of 500 mg/L P-CDs on CS reached 95.1 % in 0.5 M H2SO4, and the corrosion inhibition efficiency was enhanced to 98.1 % after 8 h of immersion time. The composition and characterization of P-CDs was analysed using Fourier Transform Infrared Spectroscopy (FTIR), Ultraviolet Spectroscopy (UV), X-ray Diffraction (XRD) and Transmission Electron Microscopy (TEM). Atomic force microscopy (AFM) and scanning electron microscopy (SEM) characterization showed that the surface of CS with P-CDs was smoother than that without P-CDs, and that P-CDs was able to adsorb on the surface of CS to form a protective layer, thereby inhibiting corrosion. Adsorption studies indicate that P-CDs form a protective layer on the surface of CS through both physisorption and chemisorption. Overall, these findings demonstrate that P-CDs exhibit superior protective effects against the corrosion of CS in 0.5 M H2SO4.

Inhibition of Carbon Steel Corrosion Using Dextran Derivatives in Circulating Cooling Water

Developing environmentally friendly and biodegradable corrosion inhibitors is an important research direction due to the toxicity and non-degradability of conventional carbon steel corrosion inhibitors added to circulating cooling water environments. Polysaccharides in EPSs (Exopolysaccharides) can be used as green corrosion inhibitors, but a low inhibition rate limits their practical application. Chemical modification is widely used to modify the functionality of polysaccharides by altering their physicochemical properties and structures, thereby enhancing or supplementing their functional characteristics. In this study, we employed chloroacetic acid as an esterifying agent to chemically modify Dextran and successfully synthesized a modified polysaccharide derivative with a substitution degree of 0.326. This derivative efficiently inhibited the corrosion of carbon steel in circulating cooling water environments. The carboxymethylated dextran (CM-Dextran) formed after synthesis could adsorb onto metal surfaces to form a protective film, thereby inhibiting metal surface dissolution reactions and exhibiting anodic corrosion inhibition properties. The experimental results showed that the corrosion inhibition efficiency of CM-Dextran after modification increased by up to 57.4%, with a maximum inhibition efficiency of 82.52% at a concentration of 4 mg/mL. This study provides new insights and opportunities for the development of environmentally friendly corrosion inhibitors derived from polysaccharides.

Furosemide drug as a corrosion inhibitor for carbon steel in 1.0 M hydrochloric acid

Furosemide (4-chloro-2-furan-2-ylmethylamino-5-sulfamoylbenzoic acid) was examined as an inhibitor for the corrosion of carbon steel (CS) in 1.0 M HCl. The investigation included mass loss (ML) and electrochemical techniques: potentiodynamic polarization (PP), electrochemical impedance spectroscopy (EIS), and electrochemical frequency modulation (EFM). The efficiency of inhibition rises with increasing Furosemide concentration and temperature. This compound follows the Temkin isotherm with good fit. The presence of varying quantities influences both anodic metal dissolution and cathodic hydrogen evolution. Scanning electron microscopy (SEM), atomic force microscopy (AFM), X-ray photoelectron spectroscopy (XPS), and Fourier transform infrared spectroscopy (FT-IR) were used to detect the effect of the compound on the CS surface. The molecular inhibitory effect of Furosemide was demonstrated using quantum chemical calculations, and the molecular simulation results demonstrated the adsorption on the carbon steel surface.

Green Synthesizing and Corrosion Inhibition Characteristics of Azo Compounds on Carbon Steel under Sweet Conditions: Experimental and Theoretical Approaches.

The deterioration of carbon steel in saline solutions enriched with carbon dioxide represents a significant challenge within the oil and gas industry. So, this study focuses on the design and structural analysis of four azo derivatives: 4-(2-quinolinylazo)-catechol (AZN-1), 4-(4-phenoxyphenylazo)-1-naphthol (AZN-2), 4-(4-pyridylazo)-1-naphthol (AZN-3), and 4-(2-pyridylazo)-1-naphthol (AZN-4), and their first application as effective corrosion inhibitors for carbon steel in a carbon dioxide saturated 3.5% sodium chloride solution. Spectroscopic methods were used to characterize the structural configurations of these compounds. The corrosion protection properties of these compounds on carbon steel in a carbon dioxide saturated 3.5% sodium chloride solution (under sweet conditions) were investigated using Tafel polarization (PDP), electrochemical impedance spectroscopy (EIS), and field emission-scanning electron microscopy (FE-SEM) studies. The results indicate that the inhibition efficiency increases as the concentration of the inhibitors increases. There is a notable agreement between the results obtained from the PDP and EIS measurements, supporting the findings. Moreover, the results displayed that these compounds had significant corrosion protection capabilities at low concentrations, ranging from 91.0 to 98.3% at an additive concentration of 5 × 10-4 M. The PDP profiles showed that these compounds acted as mixed inhibitors, and their adsorption behavior followed the Langmuir isotherm model. Besides, EIS results corroborate the adsorption of AZN compounds through a reduction in double-layer capacitance (Cdl) alongside an augmentation in polarization resistance (Rp) after the addition of AZN compounds into the corrosive solution. Field emission scanning electron microscopy (FE-SEM) and Fourier-transform infrared spectroscopy (FTIR) analysis confirmed the formation of a protective layer on the surface of carbon steel when these inhibitors were applied. In addition, computational calculations and Monte Carlo simulations were performed to support the experimental observations, gain insights into the adsorption properties, and elucidate the corrosion inhibition mechanisms of these compounds.

Corrosion Inhibitors for Carbon Steel in HCl Environment: Synthesis and Characterization of Trimethoprim-Metal Complexes

This study is about making and figuring out what trimethoprim (TM), a popular corrosion inhibitor, is like and then using it as an inhibiting agent to stop corrosion in carbon steel in acid media (HCl solution) through adsorption. TM has also been known as the prevalent anti-corrosive agent. It can be added to a liquid or gas to slow the pace of a chemical reaction (in the case of a material – typically a metal or alloy – that corrodes when it encounters the fluid). Many antibiotic compounds, such as TM derivatives, diiron salt dihydrate, and diiron salt tetrahydrate, have active groups that can stop metal from corroding. Spectroscopic methods like XRD (X-ray difraction), FTIR (Fourier transform infrared spectroscopy), UV-visible (ultraviolet-visible spectroscopy), and TGA (thermogravimetric analysis) were used to study the TM drug. Similarly, the OCP (open circuit voltage) technique was introduced to assess the corrosion resistance and the density of current vs. voltage. Finally, this study revealed that TM drugs could be suggested for introduction as corrosion inhibitors due to their simple production and the fact that they have many active groups that exhibit the ability to coordinate with carbon steel. Our study revealed that changes in inhibitor concentrations, the solution's acidity, and the metal's surface area all contribute to adsorption.

Corrosion Inhibition of Carbon Steel by Some Schiff Base Compounds in HCl and H2SO4 Solutions

AbstractThe inhibition power of two Schiff bases on carbon steel corrosion in 1 M HCl and 0.5 M H2SO4 solutions has been investigated using weight loss, Tafel polarization, and electrochemical impedance spectroscopy techniques. The results revealed that increasing the concentration of inhibitors in acidic solutions led to a higher inhibition efficiency. The polarization curves indicated that the Schiff bases acted as mixed inhibitors, affecting both the cathodic and anodic reactions. The adsorption of the inhibitors on the carbon steel surface followed the Langmuir adsorption isotherm, and various adsorption isotherm parameters such as Kads, ΔGads, ΔHads, and ΔSads were determined at room temperature. Furthermore, the effect of temperature on the inhibitors′ performance was examined within the range of 25–45 °C. The corrosion‐related activation energy, pre‐exponential factor (k), activation enthalpy, and entropy were calculated to assess the inhibitors′ behavior. Scanning electron microscopy (SEM) was employed to examine some carbon steel samples, revealing differences in inhibition efficiency attributed to the inhibitors′ chemical structure. The results highlighted the highest inhibition efficiency in H2SO4 medium at 93.4 %, with a corresponding free energy of 39.51 KJ/mol indicating physical‐chemical adsorption of inhibitor molecules. Furthermore, an enthalpy value of −40.6 KJ/mol suggested an exothermic inhibitor absorption process. The findings are presented and discussed in detail.

Synergistic effect of KI on corrosion inhibition of carbon steel by Styphnolobium japonicum (L.) Schott in H2SO4 solution

This work explored the synergistic effect of Styphnolobium japonicum (L.) Schott extract (SE) and potassium iodide (KI) on the corrosion inhibition of carbon steel (CS) in 0.5 mol/L H2SO4 solution. Firstly, the functional groups in the SE were identified using FTIR. The results of UPLC–Q–TOF–MS analysis confirmed the major phytoconstituents presence in SE were Glutaric acid, 2,3-Dihydroxybenzoic acid, Oxoadipic acid, Isoleucine, 2-Oxovaleric acid, l-phenylalanine, Indoline, and Trigonelline. Further a comprehensive investigation of anticorrosive properties of SE in the absence and presence of KI was conducted employing various techniques, including electrochemical impedance spectroscopy (EIS), scanning electron microscopy (SEM), ultraviolet visible spectroscopy (UV‒vis), and X-ray photoelectron spectroscopy (XPS) and theoretical studies like quantum chemical calculations (QC) and molecular dynamics simulations (MS). The results demonstrated that the SE+KI blend outperforms SE or KI individually, achieving an appreciable corrosion inhibition of 94.6 % for CS in H2SO4 solution. SEM analysis confirmed that the CS surface was smoother when SE+KI was added in the aggressive solution. Theoretical calculations were carried out to determine the dipole moments, Mulliken charges, and Fukui parameters of the eight major molecules found in SE. The results showed that SE can inhibit corrosion.

Synthesis, Characterization, and Electrochemical Study of Novel Porphyrin Derivatives as Corrosion Inhibitors for Carbon Steel in HCl Solutions

This study involves the synthesis of some porphyrins derivatives, these are termed as 4,4',4'',4'''-(porphyrin-5,10,15,20-tetrayl)tetrakis(N-(6-aminoacridin-3-yl)benzamide) (3a), 4,4',4'',4'''-(porphyrin-5,10,15,20-tetrayl)tetrakis(N-(5-methoxybenzo[d]thiazol-2-yl)benzamide) (3b), 4,4'-(10,20-bis(3-hydroxyphenyl)porphyrin-5,15-diyl)bis(N-(6-aminoacridin-3yl)benzamide) (5a), and 4,4'-(10,20-bis(3-hydroxyphenyl)porphyrin-5,15-diyl)bis(N-(benzo[d]thiazol-2-yl)benzamide) (5b). These derivatives were synthesized using open circuit potential (OCP) and potentiodynamic polarization (PDP) in 0.1 M HCl solution methods. These derivatives were characterized using nuclear magnetic resonance (1H- and 13C-NMR) spectroscopy, mass spectra (ESI), and micro elemental analysis (CHN). The activity of these synthesized materials was investigated as a corrosion inhibitor using carbon steel (CS) as a model for corroded materials. The obtained results showed that the synthesized porphyrins derivatives were effective corrosion inhibitors to 0.1 M HCl solution for CS. In the case of the derivative 3a, a maximum inhibition efficiency (IE%) was recorded and it was around 74%. The derivative 3b showed an IE% of around 68.11%, while the %IE of 5a and 5b were around 18.98% and 45.16%, respectively. The best IE% value that was recorded for the derivative 3a has the potential to be effective anticorrosive coatings for industrial applications and act as mixture inhibitor because their ΔEcorr values are less than 85 mV. On the CS surface following treatment with compound 3a, the inhibitor mechanism for acidic medium (HCl) was investigated.

The Possibility of Using Barley Grains Extract as an Acidic Corrosion Inhibitor for Carbon Steel

تمت دراسة تأثير مستخلصات بذور الشعير على تآكل الفولاذ الكربوني في 1M حمض كلور الماء للتحقق من إمكانية استخدام كمثبط أخضر في عملية التنظيف وإزالة الترسبات الحمضية للمبادلات الحرارية، عند درجات حرارة مختلفة. أُجريت عمليات الاستخلاص باستخدام الايثانول والماء %50 حجماً، وبطريقتي النقع والأمواج فوق الصوتية. تمت دراسة آلية تأثير المثبط الذي أعطى أفضل كفاءة تثبيط، من خلال دراسة الامتزاز والتآكل بالطرق الكهروكيميائية (مخططات تافل، ومطيافية المقاومة الكهروكيميائية) والحسابات الترمودينامكية. أظهرت نتائج الدراسة عدم وجود تأثير لطريقة الاستخراج على سلوك التثبيط ، حيث أظهر التثبيط كدالة للتركيز زيادة معنوية في كفاءة التثبيط حتى التركيز 400 جزء في المليون ، ثم ظهرت مستقلة عنها في كلتا الطريقتين. ، ومع ذلك كانت درجة الحماية أعلى لمستخلص طريقة النقع عند التركيز 800ppm 87.01%) مقارنة بـ 80.56% لمستخلص الأمواج فوق الصوتية). أشارت دراسة آلية التثبيط لهذا المستخلص إلى إمكانية الامتزاز الكيميائي للمستخلص وإعادة لترتيب الشحنات في الطبقة المزدوجة الكهربائية . أبدت فعالية التثبيط ارتفاعاً مع درجة الحرارة.