Hydrochloric Acid Environment Research Articles

Synergism of Computational Simulation Technique and Machine Learning Algorithm for Prediction of Anticorrosion Properties of Some Antipyrine Derivatives.

This study aimed to predict the selected antipyrine compounds' inhibitory efficiencies and anticorrosion properties in a hydrochloric acid (HCl) environment. Molecular descriptors and input variables were obtained using density functional theory (DFT), and the variance inflation factor (VIF) was employed to reduce redundant variables, leading to the selection of seven quantum chemical descriptors as input variables. Using machine learning techniques such as K-nearest neighbor (KNN) and artificial neural network (ANN), a predictive model was built for 39 antipyrine compounds with known corrosion inhibition efficiencies for carbon and low alloy steel in hydrochloric acid solutions. The models' predictive capability was assessed using cross-validation, with the ANN model showing superior performance, achieving a coefficient of determination (R2) value of 0.715 compared to 0.548 for the KNN model. Performance metrics such as the mean square error (MSE), mean absolute error (MAE), and root-mean-square error (RMSE) further confirmed the superiority of the ANN model over the KNN model. The corrosion inhibition efficiencies (CIEs) of the selected antipyrine compounds ranged from 68.78 to 99.79%, with compound A1 demonstrating the highest CIE of 99.79% and compound A3 the lowest, as evaluated by the ANN model. Analysis of Fukui index parameters obtained from the Mulliken population analysis suggested that the nucleophilic and electrophilic sites play a crucial role in the interactions between the inhibitor and the metal atom through electron donor-acceptor interactions. Moreover, the energy of adsorption (Eads) in kcal·mol-1 decreased in the order of A1 (-187.8) > A2 (-132.0) > A2 (-84.4), with the high negative value of Eads indicating strong and spontaneous adsorption. Further analysis using radial distribution functions and molecular dynamics simulations revealed that inhibitor A1 exhibited predominantly chemisorption, inhibitor A2 showed a mixed type, and inhibitor A3 demonstrated predominantly physisorption, aligning well with the results of the predictive studies.

Synergistic inhibition effect of diolefinic dye and silver nanoparticles for carbon steel corrosion in hydrochloric acid solution

The current work looks at the inhibitory effects of a diolefinic dye, namely 1,4-bis((E)-2-(3-methyl-2,3-dihydrobenzo[d]thiazol-2-yl) vinyl) benzene iodide salt, in relation to CS corrosion mitigation in hydrochloric acid (HCl) environment. This study uses a variety of experimental methodologies, including weight loss (WL) analysis, electrochemical tests, and theoretical considerations. The synergistic effect of diolefinic dye and AgNPs on the corrosion inhibition of CS in 1 M HCl was investigated. The inhibition efficiency (IE) displays a notable enhancement as the concentration of the dye is elevated and as the temperature raises the IE increases. The diolefinic dye exhibited % IE of 83% even at low concentration (1 × 10–4 M) whereas 90% in the presence of (2.26 × 10–10) AgNPs. Tafel graphs demonstrate that the dye follows a mixed type inhibitor. The adsorption of the dye on CS surface follows Langmuir model. Moreover, the influence of temperature and the activation parameters disclose that diolefinic dye is chemisorbed on the CS surface. The synergistic coefficient of the diolefinic dye and AgNPs under various concentration conditions was greater than unity. The surface morphology of CS sheets was confirmed by scanning electron microscopy (SEM) and energy dispersive X-ray analysis (EDX). Density Functional Theory (DFT) calculations provide theoretical support for the inhibitory effects of the examined dye. Notably, there is a high agreement between the findings of practical studies and theoretical expectations.

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.

Imidazole derivative for corrosion protection: A comprehensive theoretical and experimental study on mild steel in acidic environments

The inhibition efficiency derivative imidazole, 2-mercapto-5,5-diphenyl-3,5-dihydro-4 H-imidazol-4-one (AM0), against corrosion in a hydrochloric acid (HCl) environment was studied. The research focused on the compound's ability to adsorb onto mild steel surfaces. Various experimental techniques, including potentiodynamic polarization (PDP), electrochemical frequency modulation (EFM), and impedance spectroscopy (EIS), were employed to analyze the inhibitory effects. Results showed that the effectiveness of AM0 increased with concentration, reaching an inhibitory efficiency of 95.1 %. Polarization studies revealed that the inhibitor displayed mixed-type behavior. The adsorption process was modeled using the Langmuir adsorption model. Surface characterization techniques such as scanning electron microscopy (SEM), energy dispersive X-ray analysis (EDS), and X-ray photoelectron spectroscopy (XPS) were utilized to examine the inhibited corrosion surfaces. Theoretical calculations based on density functional theory (DFT) and density functional tight binding (DFTB) suggested that inhibitors with electron-accepting capabilities exhibited strong interactions with the iron surface, shedding light on specific bond formations that contribute to the stability and interaction dynamics at the molecular interface. This study provides valuable information on the corrosion inhibition potential of the new imidazole compound, offering important pointers for the development of effective corrosion inhibitors in acidic environments.

Promising organoselenium corrosion inhibitors for C1018-steel in hydrochloric acid environments

BackgroundNovel organoselenium (OSe) corrosion inhibitors, namely 2-(((4-(benzylselanyl)phenyl)imino)methyl)-5-nitrophenol (BSeOH) and its Ni (II) chelate [Ni(BSeO)2(H2O)2] were synthesized in 90 % and 88 % yields, respectively. Their chemical structures were characterized using different spectroscopic tools. MethodsThe corrosion inhibition efficiency was investigated toward C1018-steel in 1.0 M HCl solutions using potentiodynamic polarization, impedance spectroscopy, X-ray photoelectron spectroscopy, density functional theory, and Monte Carlo simulations. Several quantum chemical parameters were calculated using Density Functional Theory at the B3LYP/6–31G* computational model to elucidate the inhibitory activity of the compounds. Significant findingsElectrochemical data showed that [Ni(BSeO)2(H2O)2] has more protection efficiency (96.4 %) compared to its ligand BSeOH (93.4 %) at 15.0 × 10−6 M. In addition, the corrosion current density (icor) decreases (245.96 to 8.96 µAcm−2), the charge transfer resistance (Rct) increases (95.15 to 1926.70 Ω cm2), and the admittance (Y0) decreases (173.87 to 18.07 μΩ−1 sn cm−2) with the inhibitors’ dosage indication the formation of a protective adsorbed layer on the steel surface. Furthermore, the BSeOH and [Ni(BSeO)2(H2O)2] inhibitors were spontaneously adsorbed on the steel surface, adhering to the Langmuir isotherm. Moreover, the electrochemical and theoretical results showed that these inhibitors were effectively adsorbed on the C1018-steel surface as a preventive layer. Collectively, the utilization of OSe agents as corrosion inhibitors is a novel approach that combines several advantageous characteristics, including improved efficiency, unique chemical properties, multiple inhibition mechanisms, and the potential for derivatization. Therefore, OSe inhibitors hold significant promise in the field of corrosion prevention and further studies are highly required to develop a more substantial strategy to fight corrosion by applying OSe compounds.

Corrosion behaviour of 110SS steel in hydrochloric acid and blended acid system at 200°C

The influence of organic acids (formic acid, acetic acid) on the corrosion behaviour of 110SS steel, a hydrogen sulphide corrosion resistant alloy steel, in hydrochloric (HCl) acid environments was studied. The corrosion rates of 110SS steels in HCl acid and blended acid were measured using the high-temperature and high-pressure corrosion tester. Scanning electron microscopy was utilised to observe the morphology of corrosion products on steel samples corroded by different acid systems, and the energy dispersive X-ray spectrometer was used to analyse the elemental composition of the corrosion products. The corrosion morphology was observed using a 3D laser scanner. The results indicated that the corrosion rate of 110SS steel in HCl acid at 200 °C was an exponential function of HCl concentration. Reducing the HCl concentration significantly decreased the corrosion rate of 110SS steel. Organic acids and corrosion inhibitors synergistically reduced the corrosion of 110SS steel in HCl acid. Adding 3 wt.% organic acid to the 15 wt.% HCl acid system further reduced the corrosion rate, with a more pronounced effect observed in the HCl–formic acid system compared to the HCl–acetic acid system. Organic acids chemically adsorbed onto the steel surface and decomposed to produce CO, which hindered the attack of hydrogen ions on the metal. The added corrosion inhibitor and intensifier Sb2O3 resulted in the formation of a compact adsorption film on the steel surface, further inhibiting corrosion. The optimal mass ratio of HCl acid to organic acid was found to be 15% to 3%.

Excellent inhibition performance of an imidazole based ionic liquid on steel-N80 in 15 % hydrochloric acid medium

Imidazoline phenyl thiourea iodized n-butane quaternary ammonium salt (IMSQ) is synthesized from oleic acid, diethylenetriamine, iodinated n-butane, and n-phenylthiourea. The corrosion inhibition performance is studied by electrochemical test. The experimental findings underscored a pronounced positive correlation between the concentration of IMSQ and its corrosion inhibition efficacy on N80 steel. Notably, at a concentration of 0.07 mM, IMSQ attained a corrosion inhibition efficiency of 99.1 %, exhibiting exceptional protective capability for N80 steel in hydrochloric acid environments. By studying the adsorption isotherm equation, it is judged that the type of adsorption includes physical adsorption and chemical adsorption. The characterization analysis results indicate that IMSQ can adsorb on the surface of steel-N80, providing effective protection for the metal.

Insights of newly synthesized novel pyrazole compounds for mild steel corrosion inhibition in an acidic environment by experimental and computational calculations

Pyrazole derivative Ethyl (E)-2-cyano-3-(1,3-diphenyl-1H-pyrazol-4-yl)acrylate (Pz-a) and its novel nitro derivative Ethyl (E)-2-cyano-3-(3-(3-nitrophenyl)-1-phenyl-1H-pyrazol-4-yl)acrylate (Pz-b) were synthesized and characterised using Mass spectra, IR, 1H NMR, 13C NMR and utilized to safeguard mild steel from degradation in 1 M Hydrochloric acid environment. The inhibition effectiveness and mechanism were examined through both experimental and theoretical calculations. Electrochemical analysis illustrate that the protective property of pyrazoles rises proportionally with concentration. Potentiodynamic polarization reveals, both pyrazoles exhibit characteristics of mixed type inhibitors, inhibiting both oxidation and reduction processes. Pz-a and Pz-b adhesion on mild steel surface resembles the Langmuir isotherm. Gibbs free energy of adsorption (ΔGads) indicates Pz-a and Pz-b adsorbs physically and chemically over metal surface. The inhibition efficiency was found to be 89.85 % for Pz-b and 84.47 % for Pz-a at 10−2 M concentration. AFM scanning further confirms that the inhibitors are confined over mild steel. Better understanding of the corrosion inhibition mechanism has been facilitated by theoretical investigations through DFT parameters.

Experimental and theoretical investigation of 1-Hexyl-3-methylimidazolium iodide as a corrosion inhibitor for mild steel in HCl environment

This study employed 1-Hexyl-3-methylimidazolium iodide to mitigate the corrosion of Q235 steel in a hydrochloric acid environment. The evaluation of corrosion inhibition effectiveness was comprehensively characterized by combining electrochemical experiments with surface morphology observation. The experimental results demonstrated the capability of the ionic liquid in establishing a film layer on the surface of Q235 steel, which effectively hindered the charge transfer process. Notably, the corrosion inhibition efficiency attained a value of 92.3% at a concentration of 1 mM corrosion inhibitor. Moreover, the process of the corrosion inhibitor adhering to the steel surface aligns with the Langmuir isotherm, demonstrating physicochemical adsorption behavior. The density functional theory (DFT) and molecular dynamics (MD) simulation were utilized for further exploration of the corrosion inhibition mechanism, and the results indicate the ionic liquid can be adsorbed onto the (110) surface of Fe in parallel through N atoms on the imidazole ring.

Tribological and corrosive behavior under HCl corrosive environment of diamond-like carbon films with doped H, Cr and WC

Diamond-like carbon films exhibit low friction and strong wear resistance under various conditions. In order to evaluate tribological and corrosion resistant performance of different types of diamond-like carbon films in hydrochloric acid (HCl) environment, DLC, Cr/DLC, H/DLC and WC/DLC films were prepared by unbalanced magnetron sputtering technology. Their microstructure, mechanical properties, tribological properties and corrosion resistance were characterized and studied. The results show that the prepared DLC film exhibits the lowest wear rate in 1 M HCl solution. H/DLC film has an obvious corrosion resistance due to its high sp3 C bond and dense structure. Cr/DLC and WC/DLC films show a lower friction coefficient. In general, tribological failure of DLC film is mainly due to ordinary mechanical wear; while that of Cr/DLC film is mainly attributed to abrasive wear caused by, for example, hard particles and wear products; adhesive wear is found to be responsible for H/DLC film, which is caused by transformation of CH bond to oxygen group at the friction interface. The WC/DLC film is experienced with both local degradation and low resistance to elastic/plastic changes (H/E and H3/E2), and therefore both granular and chemical failures occurred. This study provides a complete and comprehensive understanding of tribological and anti-corrosive performance of diamond-like carbon films in hydrochloric acid environment, and can be used further as a reference for industrial applications.

Insights of 2-(Benzoxazol-2-ylthio)-N-(4-phenyl-5-phenylazo-thiazol-2-yl)-acetamide as a novel corrosion inhibitor for J55 carbon steel in hydrochloric acid: Experimental, Spectroscopic analysis, and theoretical studies

The inhibitory efficacy of 2-(Benzoxazol-2-ylthio)-N-(4-phenyl-5-phenylazo-thiazol-2-yl)-acetamide (BNP) was systematically explored through weight loss measurements, potentiodynamic polarization (PP), and electrochemical impedance spectroscopy (EIS), in relation to the corrosion mitigation of J55 carbon steel (J55CS) within hydrochloric acid (HCl) environments. This research employs a combination of experimental techniques, including gravimetric analysis, electrochemical tests, and theoretical considerations. It has been determined that BNP has an inhibitory effect on the corrosion of J55CS in strong HCl, reaching 91.8% at 18 × 10−6 M at 298 K. The inhibitory efficiency displays a notable enhancement as the concentration of the BNP is elevated within the range of 3–18 × 10−6 M. Conversely, the IE% experiences a raised when the temperature is raised. This augmentation can be attributed to the inherent ability of BNP to facilitate the formation of inhibitory films on the surface of J55CS. An analysis of Tafel plots reveals that the BNP adheres to a mixed-type inhibitor. The adsorption of BNP obeyed the Temkin adsorption isotherm. The investigated isotherm plots revealed that the adsorption process for BNP on the metal surface was endothermic, spontaneous, and chemical adsorption. Theoretical modeling [density functional theory (DFT) and Monte Carlo (MC)] revealed the correlation between the BNP molecular chemical structure and its anticorrosive property.

Drug dialysis through a semipermeable membrane as a preliminary efficacy assessment of a promising parasitocidal drug

The purpose of the research is to analyze the dynamics of fenbendazole (FBZ) and niclozamide (NZM) release from their solid dispersions (SD) of various compositions by dialysis through various semipermeable membranes in model systems that correspond to stomach and intestine environments. To evaluate the parasitocidal activity of experimental mixture compositions.Materials and methods. The study used substances of FBZ and NZM, and the polymer, polyvinylpyrrolidone (PVP). Mechanical processes were carried out in a LE-101 roller mill and an AGO-2 orbital centrifugal mill at different power density levels. The resulting SD of various compositions were studied for solubility. The dynamics of FBZ and NZM substance release from the SD were studied in a laboratory setup consisting of a temperature controlled glass with buffer solutions with pH = 9.18 (intestinal environment) and pH = 1.0 (stomach environment). The substance concentration in the dialysate was determined by HPLC and UV spectroscopy. The resulting complex SD of FBZ and NZM were studied for cestodocidal activity in a laboratory model of hymenolepiosis of white mice.Results and discussion. It was found that the substances release into a buffer solution with pH = 9.18 from the SD obtained in the roller mill is higher than that of the SD obtained in the AGO activator. The dialysis of the experimental compounds in a model system with a gastric juice medium observed only FBZ substance penetration through the membrane, which can be explained by protonation of the FBZ molecule which is a weak base. The NZM molecule, being a neutral molecule, does not penetrate through the semi-permeable partition into the hydrochloric acid environment; it remains entirely inside the dialysis bag. High anthelmintic efficacy rates (up to 100%) of SD complex FBZ : NZM : PVP obtained in the AGO activator and in the roller mill were recorded for the SD of composition 2 : 20 : 78 in the mice with hymenolepiosis. The activity of the base drug, the niclozamide substance, was 27.69%, which is 3 times lower than the activity of the resulting complex dispersions.

Efficiency of alcohol and ester-imidazole in preventing mild steel corrosion: An integrated approach combining experimental and computational studies

In the present work, the two imidazopyridine derivatives namely ethyl 6,8-dibromoimidazo [1,2-a] pyridine-2-carboxylate (ES-IMD) and (5-methylimidazo [1,2-a] pyridine-2-yl) methanol (OL-IMD) were presented as powerful anti-polarizing agent for steel surface in aggressive system related to the obtained results in experimental and computational methods. 1H NMR and mass spectrometry (MS) were used to confirm the structures of resynthesized molecule. We assessed the effectiveness of OL-IMD and ES-IMD inhibitors in safeguarding mild steel from corrosion in a 1 M hydrochloric acid environment. We adopted an integrated experimental and computational approach to evaluate the inhibition efficiency and mechanism of OL-IMD and ES-IMD, utilizing gravimetric method, polarization curves and electrochemical impedance spectroscopy. Quantum chemical calculations and molecular dynamics simulations provided atomic-level insights into adsorption behaviour. Scanning electron microscopy characterized surface morphology. Findings revealed that OL-IMD and ES-IMD compounds performed as mixed-type inhibitors. At the greatest inhibitor concentration (10−3 M), the polarization curves gave inhibition efficiency values of 98.91% (ES-IMD) and 95.42% (OL-IMD). Thermodynamic activation parameters indicated a spontaneous adsorption process of OL-IMD and ES-IMD on the steel surface, which effectively increased the energy barrier for the corrosion process. The EIS parameters demonstrated that when inhibitor concentration raised, the double-layer capacitance (Cdl) dropped which suggested that the dielectric constant was decreasing. The results reveal a substantial correlation produced by the three analysed approaches EIS, PDP, and WL. Thermodynamic activation parameters indicated a spontaneous adsorption process of OL-IMD and ES-IMD on the steel surface, which effectively increased the energy barrier for the corrosion process. Furthermore, the calculated ΔGads values for the considered compounds were -47.39 (kJ/mol) and 49.26 (kJ/mol) for OL-IMD and ES-IMD respectively, proving the chemical nature of the adsorption. Furthermore, SEM surface studies displayed a homogeneous surface while the tested inhibitors were present, but a damaged surface in the blank solution. The theoretical models closely aligned with the experimental data, presented an excellent overview of the investigated inhibitors' reactivity against mild steel confirming the validity of the findings.

Exploration of rigid double schiff base with a symmetrical plane as highly effective corrosion inhibitor for mild steel in hydrochloric acid environment: Experimental and theoretical approaches

A rigid double Schiff base with a symmetrical plane, (1E,1′E)-N,N’-(1,4-phenylene)bis(pyrazin-2-yl)ethanimine) (PBPE), has been synthesized and characterized by 1H NMR and FTIR spectroscopies. The corrosion inhibition performance of PBPE for mild steel in 1.0 mol L−1 HCl solution was systematically measured by weight loss method, electrochemical impedance spectroscopy (EIS), potentiodynamic polarization technique, field emission scanning electron microscopy (FE-SEM), energy dispersive spectrometer (EDS), atomic force microscope (AFM), and water contact angle measurement. The inhibition efficiency depends upon the PBPE concentration and the maximum inhibition efficiency by weight loss analysis is 93.10 % at 800 mg L−1 PBPE. The potentiodynamic polarization measurement revealed that PBPE behaves as a mixed-type inhibitor with a predominant anodic reaction. The thermodynamics adsorption analysis showed the adsorption of the PBPE molecules on the surface of mild steel obeys Langmuir adsorption isotherm, with both physisorption and chemisorption. In the corrosion reaction, the activation energy, activation enthalpy, and activation entropy all increased with increasing PBPE concentration. The surface morphology analysis such as SEM-EDS, AFM, and water contact angle further confirmed adsorption on the mild steel surface and resulted in the formation of protective film on the mild steel surface in PBPE solution. The quantum chemical parameters obtained such as global softness, electron transfer fraction, and energy gap together with Fukui indices can explain the good inhibition efficiency. Molecular dynamics simulations discovered that the PBPE molecules in a flat manner are adsorbed on the surface of mild steel, thus giving rise to a more effective adsorption and corrosion inhibition.

H3O+…Cl− ion pairs on the surface of concentrated hydrochloric acid: Reverse mass transfer of dissociated hydronium and chloride ions and the effect on separation at interface

The separation process in hydrochloric acid environments is determined by the interfacial chemistry of the acid. However, the surface species of concentrated acids are complex. The effect of dominant species on the surface of concentrated acids and their dissociation behavior on interfacial separation has been the focus of academic debate. The extraction and separation of two typical anions, PdCl42− and PtCl62−, with different hydration characters on the surface of concentrated hydrochloric acid were investigated by thin layer extraction (TLX). A new phenomenon was discovered that the effect of hydrochloric acid concentration, extractant concentration, organic film thickness, and shear flow rate on the extraction of easily hydrated PdCl42− anions is greater than that of hardly hydrated PtCl62−. However, during the conventional SX process, the phenomenon cannot be observed due to the continuous dispersion and aggregation of oil droplets. It found that HCl molecules only dissociate into solvated H3O+…Cl− ion pairs on the surface of concentrated hydrochloric acid, but not H3O+ and Cl− ions respectively. The concentration of dissociated H3O+ ions at the interface is lower than that in the bulk phase. The protonation of the A336 molecule promotes the migration of dissociated H3O+ ions in the bulk phase towards the interface. Because the PdCl42− anions are more likely to be hydrated than PtCl62− anions and combine with H3O+ ions, the orderly migration of H3O+ ions in the laminar boundary layer towards the interface drives the mass transfer of easily hydrated PdCl42− anions. The anion exchange between PdCl42− and Cl− ions associated with the A336 molecules results in a higher concentration of Cl− ions enriched at the interface than that in the bulk phase. The migration of easily hydrated Cl− ions towards the bulk phase would drag the water molecules around PtCl62− anions and therefore inhibit the mass transfer of PtCl62− anions. The orderly reverse migration of H3O+ and Cl− ions enhances the separation between easily hydrated PtCl62− and hardly hydrated PdCl42− anions. This study offers a new perspective on the dissociation of species on the surface of concentrated hydrochloric acid and its impact on separation processes.

Corrosion inhibition and Adsorption characteristics of 3,4,5-trihydroxy-n-(3,4-dimethoxy benzylidene) benzo hydrazide schiff base on aluminium in different concentration of Hydrochloric acid environment

In the present paper we are presenting our studies on the synthesis of Schiff bases typically formed by condensation of 3,4,5-trihydroxy benzohydrazide and 3,4-dimethoxy benzaldehyde by microwave induced irradiation, reaction showed enhanced yield and less time, easier workup. The characterization of synthesized compound has been done on the basis of elemental analysis, spectral studies (FTIR,1HNMR, Mass) and surface morphology by Scanning Electron Microscopic (SEM). The structural composition of synthesized compound has been determined by X-Ray diffraction (XRD). The inhibition property of Schiff base 3,4,5-trihydroxy –N-(3,4dimethoxy benzylidene) benzo hydrazide on the corrosion of aluminum in 0.5N HCl,1NHCl, 2N HCl were studied using weight loss technique and electrochemical studies revealed mechanistic aspects of corrosion inhibition like potentiodynamic polarization measurements indicated the nature of inhibitor is a mixed type and impedance studies supported the formation of a protective layer of inhibitor on a metal surface. Adsorption of the inhibition molecule on aluminium surface was consistent with the Langmuir isotherm.

Non thermal plasma synthesis of ZnO nanoparticles and their corrosion inhibition activity on XC70 mild steel pipeline in 1 M HCl acidic medium

This paper investigates the inhibitory efficiency of zinc oxide nanoparticles (ZnO Nps) as an eco-friendly inhibitor against the corrosion of XC70 mild steel pipelines in a 1 M HCl acidic medium. The ZnO Nps were synthesized using non thermal plasma, in particular the gliding arc discharge-assisted (GAD) method, a chemical solvent free and safe approach that utilizes humid air as the vector gas and distilled water as the solvent. Characterization techniques such as DLS, EDX, SEM, and XRD confirmed the positive zeta potential, hexagonal wurtzite structure, spheroidal shape, and median particle size of 65.6 nm for the synthesized ZnO Nps, respectively. To evaluate the corrosion inhibition efficiency, investigations were conducted utilizing electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization (PDP) techniques at varying temperature range (298–333K). Results showed that increasing the concentration of ZnO Nps improved their ability to inhibit corrosion, with an optimum concentration of 70 mg/L achieving a high effectiveness of 90.71 % at ambient temperature. SEM analysis confirmed the formation of a protective barrier film on the inhibited substrate, effectively hindering the diffusion of corrosive ions. Furthermore, the DFT method was employed to examine the corrosion mitigation mechanism. These results demonstrate the significant inhibiting properties of ZnO Nps in preventing corrosion of XC70 mild steel in a 1 M hydrochloric acid environment.

Exploring the potential of isonicotinohydrazide derivatives in N80 steel corrosion control: An integrated approach through synthesis, modeling, and experimentation in acidic environments

N80 carbon steel (N80CS) is recognized for its superior mechanical properties and cost-effectiveness. However, its susceptibility to corrosion, particularly in hydrochloric acid (HCl) environments, necessitates the exploration of corrosion inhibitors. This research centers on the evaluation of N′-[(Z)-(4-bromophenyl)methylidene]pyridine-4-carbohydrazide (BBI) and N′-[(1Z)− 1-(4-chlorophenyl)ethylidene]pyridine-4-carbohydrazide (CEI), green organic compounds from the isonicotinohydrazide family, as potential eco-friendly and non-toxic inhibitors for N80CS in a 15 wt% HCl solution. An array of investigative methods, including weight loss measurements, electrochemical impedance spectroscopy (EIS), and potentiodynamic polarization (PDP), were employed to examine the corrosion inhibition performance of these compounds for the N80CS surface in a strong HCl medium. Our experimental findings demonstrated that the inhibitors' efficiency was concentration-dependent, enhancing as concentrations ranged from 10−4 mol/L to 5 × 10−3 mol/L. Notably, BBI's inhibitory efficiency varied between 97.6% and 99.28%, while CEI's ranged from 94.31% to 98.44%. PDP curves elucidated the capability of BBI and CEI to control both anodic and cathodic reactions, thereby classifying them as mixed-type corrosion inhibitors. The improved inhibition efficiency was evidenced by the decrease in double-layer capacitance, supporting the formation of a protective layer that delays the corrosion process. Consistent with the Langmuir adsorption isotherm model, our results suggested these inhibitors involved in both physical and chemical interactions with the iron atoms on the steel surface. This protective formation was further corroborated by scanning electron microscopy (SEM) and atomic force microscopy (AFM) analyses, which highlighted a significant reduction in the surface roughness of N80CS. Supplementing our experimental data, theoretical investigations using Density Functional Theory (DFT) and semi-empirical Density functional tight binding (DFTB) simulations were conducted. They confirmed the advantageous reactivity of BBI and CEI, attributable to their molecular structures, which promote facile adsorption onto the Fe(110) surface through covalent bonding. This research provides valuable insights into developing non-toxic and environmentally benign corrosion inhibitors for N80CS in acidic conditions.

Evaluation of the effectiveness of gabapentin as a corrosion inhibitor for mild steel in a 1 M hydrochloric acid environment using theoretical and experimental methods

Evaluation of the effectiveness of gabapentin as a corrosion inhibitor for mild steel in a 1 M hydrochloric acid environment using theoretical and experimental methods

Synergistic assisted hydrogen production of tailings slurry and coal slurry: Process and mechanism investigation

This study investigated the process and mechanism of synergistically assisted hydrogen production from tailings and coal slurry. We have identified the optimal tailings as lead-zinc tailings through experimentation with different tailings mixed with pulverized coal. Furthermore, we have analyzed the electrochemical properties of Fe2+ and Fe3+ at different concentration gradients in a hydrochloric acid environment and our results have confirmed that the presence of Fe3+ in the simplified environment does not affect the electrochemical processes. to determine the respective roles and effects of the extract and residue of the lead-zinc tailings slurry with equal amounts of coal dust added to them, which has confirmed that it is the lead-zinc tailings extract that has the primary influence. In addition, the electrocatalysis of Fe3+ in the presence of both lead-zinc tailings and coal results in a small increase in current density, and the improvement in current density due to direct and indirect oxidation of coal particles is also extremely limited. Based on our analysis, we have concluded that the increase in current density brought about by the synergistic hydrogen production from lead-zinc tailings-supported coal is mainly due to the different oxidation processes of Fe2+.