A complementary experimental and in silico studies on the action of fluorophenyl‑2,2′‑bichalcophenes as ecofriendly corrosion inhibitors and biocide agents

Novel synthesized triazole derivatives as effective corrosion inhibitors for carbon steel in 1M HCl solution: experimental and computational studies

This article outlines the synthesis of two derivatives of 4-amino-5-hydrazineyl-4H-1,2,4-triazole-3-thiol for the prevention of carbon steel corrosion in 1M HCl solution. These derivatives are (Z)-3-(1-(2-(4-amino-5-mercapto-4H-1,2,4-triazol-3-yl)hydrazono)ethyl)-2H-chromen-2-one (TZ1) and 5-(2-(9H-fluoren-9-ylidene)hydrazineyl)-4-amino-4H-1,2,4-triazole-3-thiol (TZ2). Weight loss, electrochemical experiments, surface examinations, and theoretical computation are used to evaluate the effectiveness of the two compounds to be used as corrosion inhibitors. Weight loss and electrochemical studies demonstrate that these derivatives reduce the corrosion rate of carbon steel. To examine the morphology and constitution of the carbon steel surface submerged in HCl solution as well as after adding inhibitors, surface examination tests are performed. Analysis of the test solution via UV-visible spectroscopy is employed to check the possibility of complex formation between inhibitor molecules and Fe2+ ions released during the corrosion process. In order to explore their biological activity, the antibacterial activity was investigated against (E. coli and Bacillus subtilis). Finally, theoretical confirmation of the experimental findings is provided by quantum chemical (DFT) and Monte Carlo (MC) simulation studies. More adsorption sites are present in the derivatives of 4-amino-5-hydrazineyl-4H-1,2,4-triazole-3-thiol, which offer a novel perspective for developing new classes of corrosion inhibitors with substantial protective efficacy, especially at high temperatures.

Electrochemical Investigation of C-Steel Corrosion Inhibition, In Silico, and Sulfate-Reducing Bacteria Investigations Using Pyrazole Derivatives

The inhibitory impact of the two synthesized pyrazole derivatives (3 and 4) toward metallic and microbial corrosion was investigated. Using open circuit potential, potentiodynamic polarization, and electrochemical impedance spectroscopy, it was possible to determine their ability to prevent the corrosion of C-steel in 1 M HCl, which was significantly enhanced with increasing concentration (ex. 93%). They act as mixed-type inhibitors, according to polarization curves. The compounds under investigation were adsorbed on a C-steel surface in 1 M HCl following the Langmuir isotherm model. The double-layer capacitance was decreased, and the charge transfer resistance (Rct) was raised due to the examined inhibitors' adsorption. Investigating changes in the surface morphology and confirming the corrosion inhibition mechanism are done using scanning electron microscopy. Density functional theory calculations and Monte Carlo simulations were also conducted to show the adsorption affinity of the understudied compounds over the steel substrate in neutral and protonated forms. Furthermore, the antimicrobial performance of the two synthesized pyrazoles against sulfate-reducing bacteria was evaluated, and the recorded inhibition efficiency was 100%. The current research shows important developments in producing highly effective anticorrosion and antimicrobial pyrazole derivatives.

Experimental and computational approaches of methoxy naphthylbithiophene derivatives and their use as corrosion protection for carbon steel in acidic medium

The inhibition efficiency and adsorption affinity were investigated for two novel compounds, namely: 6-methoxy-2-naphthyl-[2, 2'-bithiophene]-5-carboxamidine hydrochloride salt (MA-1440) and 5'-(4-chlorophenyl)-2, 2'-bifuran-5-carboxamidine hydrochloride salt (MA-1456). The inhibition study was conducted on carbon steel surface in 1.0 M HCl with different inhibitor doses and different temperature levels, to investigate the optimum dose and preferable temperature. The performed investigation included chemical, electrochemical, instrumental, and quantum computation techniques. A chemical technique was accomplished by using weight-loss measurements. Different factors were studied using weight-loss measurements in order to reach the maximum inhibition efficiency. The adsorption study revealed that the examined inhibitors obey the Langmuir adsorption isotherm and are chemically adsorbed on the steel surface. The electrochemical measurements were accomplished through the electrochemical impedance (EIS) and potentiodynamic polarization (PDP) techniques. Based on the electrochemical measurements, the examined compounds were categorized as mixed inhibitors. The instrumental examination using different techniques namely: scanning electron microscope (SEM), energy dispersive X-ray (EDX), Fourier-transform infrared spectroscopy (FT-IR), and X-ray photoelectron spectroscopy (XPS) confirmed that the considered inhibitors are excellently adsorbed over the carbon steel surface. The extent of the adsorption affinity of these compounds on the carbon steel surface was studied theoretically using quantum computations and Monte Carlo simulation. The theoretical investigation results of quantum chemistry were validated with those obtained by chemical and electrochemical methodologies. All investigations prove that, the tested compounds were adsorbed chemically on the steel surface and achieved maximum inhibition efficiency of, 94.69% and 90.85% for M-1440 and MA-1456, respectively, at the optimum concentration 30 [Formula: see text] 10^-6 mol L^-1 and temperature 328 K.

Corrosion protection of carbon steel by methoxy naphthylbithiophene derivatives in acidic medium: Electrochemical, surface characterization and computational approaches.. [DOI: 10.21203/rs.3.rs-2233861/v1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0]

The inhibition efficiency and adsorption affinity were investigated for two novel compounds, namely: 6-methoxy-2-naphthyl-[2, 2’-bithiophene]-5-carboxamidine hydrochloride salt (MA-1440) and 5'-(4-chlorophenyl)-2, 2’-bifuran-5-carboxamidine hydrochloride salt (MA-1456). The inhibition study was conducted on carbon steel surface in 1.0 M HCl with different inhibitor doses and different temperature levels, to investigate the optimum dose and preferable temperature. The performed investigation included chemical, electrochemical, instrumental, and quantum computation techniques. A chemical technique was accomplished by using weight-loss measurements. Different factors were studied using weight-loss measurements in order to reach the maximum inhibition efficiency. The adsorption study revealed that the examined inhibitors obey the Langmuir adsorption isotherm and are chemically adsorbed on the steel surface. The electrochemical measurements were accomplished through the electrochemical impedance (EIS) and potentiodynamic polarization (PDP) techniques. Based on the electrochemical measurements, the examined compounds were categorized as mixed inhibitors. The instrumental examination using different techniques namely: scanning electron microscope (SEM), energy dispersive X-ray (EDX), Fourier-transform infrared spectroscopy (FT-IR), and X-ray photoelectron spectroscopy (XPS) confirmed that the considered inhibitors are excellently adsorbed over the carbon steel surface. The extent of the adsorption affinity of these compounds on the carbon steel surface was studied theoretically using quantum computations and Monte Carlo simulation. The theoretical investigation results of quantum chemistry were validated with those obtained by chemical and electrochemical methodologies. All investigations prove that, the tested compounds were adsorbed chemically on the steel surface and achieved maximum inhibition efficiency of, 94.69% and 90.85% for M-1440 and MA-1456, respectively, at the optimum concentration 3010-6 mol. L-1 and temperature 328 K.

Novel cationic aryl bithiophene/terthiophene derivatives as corrosion inhibitors by chemical, electrochemical and surface investigations

Two novel bithienyl fluorobenzamidine derivatives namely, 4-([2,2′:5′,2′′-terthiophen]-5-yl)-2-fluorobenzamidine hydrochloride salt (MA-1615), 5′-(4-amidino-3-fluorophenyl)-[2,2′-bithiophene]-5-carboxamidine dihydrochloride salt (MA-1740) were synthesized, characterized and their corrosion inhibition properties were evaluated by electrochemical methods for carbon steel (C-steel) in 1 M HCl. Experimental investigations revealed that the inhibition effectiveness of the investigated inhibitors (INHs) by the Tafel polarization method followed the order: MA-1740 (96.9%) > MA-1615 (95.6%), demonstrating higher efficiency than inhibitors of similar structure reported in the literature. The investigated bithiophene derivatives exhibit mixed-type corrosion inhibition characteristics by blocking the active sites on the surface of C-steel. EIS study revealed that the INHs behave as interface-type corrosion inhibitors. UV–Visible spectrometric measurements confirmed a complex formation between the Fe²⁺ cation released during the corrosion reactions and inhibitor molecules.

Experimental and computational chemical studies on the corrosion inhibitive properties of carbonitrile compounds for carbon steel in aqueous solutions

The present work aims to study 6-amino-4-aryl-2-oxo-1-phenyl-1,2-dihydropyridine-3,5-dicarbonitrile derivatives namely: 6-Amino-2-oxo-1,4-diphenyl-1,2-dihydropyridine-3,5-dicarbonitrile (PdC-H), 6-Amino-2-oxo-1-phenyl-4-(p-tolyl)-1,2-dihydropyridine-3,5-dicarbonitrile (PdC-Me) and 6-Amino-4-(4-hydroxyphenyl)-2-oxo-1-phenyl-1,2-dihydropyridine-3,5-dicarbonitrile (PdC-OH) as corrosion inhibitors to provide protection for carbon steel in a molar hydrochloric acid medium. Chemical measurements such as (weight loss) and electrochemical techniques such as (Potentiodynamic polarization, electrochemical impedance spectroscopy, and Electron frequency modulation) were applied to characterize the inhibitory properties of the synthesized derivatives. The adsorption of these derivatives on the carbon steel surface was confirmed by Attenuated Total Refraction Infrared (ATR-IR), Atomic Force Microscope (AFM), and X-ray Photoelectron Spectroscopy (XPS). Our findings revealed that the tested derivatives have corrosion inhibition power, which increased significantly from 75.7 to 91.67% on the addition of KI (PdC-OH:KI = 1:1) to inhibited test solution with PdC-OH derivative at 25 °C. The adsorption process on the metal surface follows the Langmuir adsorption model. XPS analysis showed that the inhibitor layer consists of an iron oxide/hydroxide mixture in which the inhibitor molecules are incorporated. Computational chemical theories such as DFT calculations and Mont Carlo simulation have been performed to correlate the molecular properties of the investigated inhibitors with experimental efficiency. The theoretical speculation by Dmol3 corroborates with the results from the experimental findings.

Novel pyrimidine-bichalcophene derivatives as corrosion inhibitors for copper in 1 M nitric acid solution

This study targets the investigation of three pyrimidine-bichalcophene derivatives (MA-1230, MA-1231, MA-1232) for the prevention of corrosion on copper in 1 M HNO₃ via weight loss (WL), potentiodynamic polarization (PDP), and electrochemical impedance spectroscopy (EIS) techniques. The surface morphology was also analyzed by different methods. It was found that the inhibition efficiency (% η) increased by increasing the doses of pyrimidine derivatives and the temperature of the medium. Weight loss data revealed the better adsorption of MA-1232 on the Cu surface at increased inhibitor dose, reaching a maximum efficiency of 99.14% at a dose of 21 μM at 45 °C. The best description of the adsorption of the investigated derivatives on the copper surface was given by the Langmuir isotherm. Some important thermodynamic parameters for the studied inhibitors were computed and are discussed herein. The polarization studies showed that the pyrimidine-bichalcophenes act as mixed inhibitors. Computational chemical approaches were used with informative yields, including quantum-chemical and molecular dynamics simulation techniques, which agree with the experimental results. The results obtained from all tested methods are strongly accepted.

Multifunctional Aspects of the Synthesized Pyrazoline Derivatives for AP1 5L X60 Steel Protection Against MIC and Acidization: Electrochemical, In Silico, and SRB Insights

The inhibitory impact of low-cost synthesized pyrazoline derivatives named Pz series (Pz1 and Pz2) on the corrosion of API 5L X60 carbon steel in 5 M HCl was inspected to serve as corrosion inhibitors against such a solution for its usage in the oilfield well acidization process. Also, the same compounds were unitized as biocides for sulfate-reducing bacteria (SRBs) to inhibit the microbial-induced corrosion effect. This study was conducted via several electrochemical techniques, namely, electrochemical potentiodynamic polarization (EP) and electrochemical impedance spectroscopy (EIS), in addition to computational density functional theory (DFT). The inhibition efficiency (IE) of Pz series on the corrosion of 5L X60 carbon steel in 5 M HCl was found to increase whenever the Pz series molecule concentration was increased. EP measurements revealed that Pz1 and Pz2 have both cathodic and anodic features (mixed inhibitor) and their corrosion IEs were around 90%. The physicochemical properties of the Pz1 and Pz2 compounds were studied using Langmuir adsorption isotherms, where the equilibrium adsorption data were found to follow it accurately. EIS outputs were found to comply with the values obtained from EP. Scanning electron microscopy was used to examine the topographic anisotropy between the inhibited and uninhibited 5L X60 carbon steel samples to double-check the electrochemical findings. DFT calculations and Monte Carlo simulations were utilized to predict the behavior of inhibitors and to rationalize the experimental results. The serial dilution bioassay technique was used to assess the Pz series as potential biocides to counter the effect of SRBs in compliance with the TM0194-2014-SG standard test method, and the results showed the potency of Pz series in inhibiting such bacterial growth.

Biological Insights of Fluoroaryl-2,2'-Bichalcophene Compounds on Multi-Drug Resistant Staphylococcus aureus

Resistance of bacteria to multiple antibiotics is a significant health problem; hence, to continually respond to this challenge, different antibacterial agents must be constantly discovered. In this work, fluoroaryl-2,2'-bichalcophene derivatives were chemically synthesized and their biological activities were evaluated against Staphylococcus aureus (S. aureus). The impact of the investigated bichalcophene derivatives was studied on the ultrastructural level via scanning electron microscopy (SEM), molecular level via sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) method and on the biofilm inhibition via the electrochemical biosensors. Arylbichalcophenes' antibacterial activity against S. aureus was affected by the presence and location of fluorine atoms. The fluorobithiophene derivative MA-1156 displayed the best minimum inhibitory concentration (MIC) value of 16 µM among the tested fluoroarylbichalcophenes. Over a period of seven days, S. aureus did not develop any resistance against the tested fluoroarylbichalcophenes at higher concentrations. The impact of fluoroarylbichalcophenes was strong on S. aureus protein pattern showing high degrees of polymorphism. SEM micrographs of S. aureus cells treated with fluoroarylbichalcophenes displayed smaller cell-sizes, fewer numbers, arranged in a linear form and some of them were damaged when compared to the untreated cells. The bioelectrochemical measurements demonstrated the strong sensitivity of S. aureus cells to the tested fluoroarylbichalcophenes and an antibiofilm agent. Eventually, these fluoroarylbichalcophene compounds especially the MA-1156 could be recommended as effective antibacterial agents.

8-Hydroxyquinoline based chitosan derived carbohydrate polymer as biodegradable and sustainable acid corrosion inhibitor for mild steel: Experimental and computational analyses

The present study reports the synthesis, characterization and corrosion inhibition effects of chitosan (CH) and its 5-chloromethyl-8-hydroxyquinoline derivative (CH-HQ) for mild steel in acidic medium. The synthesized CH-HQ was characterized using ¹H NMR and FT-IR spectroscopic methods. Corrosion inhibition efficiencies of CH and CH-HQ were measured using electrochemical and chemical techniques. The surface protection ability of the inhibitor molecules was also ascertained by surface analysis, while computational study was used to further justify the adsorption tendencies of the molecules on mild steel surface. CH-HQwasobserved to exhibit better protection efficiency than CH, as the highest inhibition efficiencies were recorded to be 78% and 93% for CH and CH-HQ, respectively. Potentiodynamic polarization studies revealed that CH and CH-HQ are mixed-type corrosion inhibitors over the studied temperature range (298 K ± 1 to 328 K ± 1). SEM-EDS studies were performed to demonstrate the adsorption of CH and CH-HQ on the mild steel surface. Adsorption behavior of the CH and CH-HQ was also supported by UV-visible (UV-vis) spectrophotometric analyses. Monte Carlo simulations (MC) and density functional theory (DFT) calculations were carried out to corroborate the experimental results.

Impact of some pyrrolidinium ionic liquids on copper dissolution behavior in acidic environment: experimental, morphological and theoretical insights

The inhibitive and adsorption activity of some pyrrolidinium ionic liquids (ILs) for the dissolution of copper in 1 M HNO3 solution was tested using chemical methods such as weight loss and electrochemical techniques; potentiodynamic polarization, electrochemical impedance spectroscopy (EIS) and electrical frequency modulation (EFM) techniques. The results indicated that the ionic liquids under investigation exhibited promising corrosion inhibitory performance in 1 M HNO3 and their efficiencies reached up to 85% at 0.05 mM. Also, an enhancement in the inhibition efficiency (% IE) accompanied the increase in inhibitor concentration. The polarization measurements suggested that these ionic liquid inhibitors act as mixed-type inhibitors. The adsorption of the ionic liquid inhibitors on the copper surface obey the Langmuir adsorption isotherm. Thermodynamic parameters were calculated and discussed. The surface morphology of the copper surface was examined using different techniques. Correlation between the calculated % IE from experiments and some quantum chemical parameters was established.