Gravimetric,electrochemical, and morphological studies of an isoxazole derivative as corrosion inhibitor for mild steel in 1M HCl

In present study, an isoxazole derivative, namely, (Z)-4-(4-hydroxy-3-methoxybenzylidene)-3-methylisoxazol-5(4H)-one referred here as (IOD) has been studied as an environment-friendly corrosion inhibitor for mild steel (MS) in acidic medium (1 M HCl). The present work was investigated by gravimetric, electrochemical impedance spectroscopy (EIS), potentiodynamic polarization (PDP), fourier-transform infrared (FT-IR) spectroscopy techniques. Atomic force microscopy (AFM), scanning electron microscopy (SEM), and energy-dispersive X-ray spectroscopy (EDS) confirmed the surface morphologies of the MS surface with and without IOD in the acid medium. The inhibition efficiency (I.E.) of IOD was increased by rising its concentration attaining maximum value (96.6%) at 300 ppm at 30 °C and decreases with increasing temperature from 30 °C to 60 °C. The adsorption of studied inhibitor followed Langmuir adsorption isotherm model. The PDP study revealed that the IOD acts as a mixed-type inhibitor with predominating anodic effect. The EIS study confirmed that increasing IOD concentration enhances the charge transfer resistance (R_ct) and then reduces the double layer capacitance (C_dl) owing to the development of a protective layer on the MS surface.     

Experimental and computational chemical studies on the corrosion inhibitive properties of metamizole sodium pharmaceutical drug compound for CS in hydrochloric acid solutions

The effect of sodium metamizole as a corrosion inhibitor for carbon steel (CS) in 1 M hydrochloric acid at various concentrations was studied by using chemical (weight loss, WL) and electrochemical [electrochemical frequency modulation (EFM), electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization (PDP)] methods. The results of WL showed that the effectiveness of sodium metamizole as a CS preservative in a hydrochloric acid solution at room temperature raised by improvement of the concentration of the inhibitor and reached 82.87% at 300 ppm and 25 °C. The effect of temperature on the CS was studied and the thermodynamic parameters of activation and adsorption were computed and discussed. The results showed that the inhibition efficiency (IE) decreases with increasing temperature, suggestive of physisorption. This was collaborated by values of activation energy, which are all below 80 kJ mol^?1 and free energy which are below 20 kJ mol^?1. The adsorption mechanism was coherent with Langmuir adsorption model. Results of the PDP revealed that the inhibitor was adsorbed on CS surface by mixed type of behavior. Furthermore, EIS revealed the dip in the values of double-layer capacitance and improvement in the charge transfer resistance with increased dose of sodium metamizole. Surface examinations were performed using altered techniques. The theoretical studies were calculated to confirm the validity of the practical results and the results of both were compared with each other, demonstrating the validity of the results obtained.     

Surface interaction and corrosion inhibition of carbon steel in sulfuric acid using Petroselinum crispum extract

With the aid of the mass loss (ML) method, and a few electrochemical techniques [potentiodynamic polarization (PDP) and electrochemical impedance spectroscopy (EIS)], the inhibitory impact of Petroselinum crispum (PC) extract on C-steel corrosion in solutions of 1 M sulfuric acid was assessed. By employing Fourier-transform infrared spectroscopy (FT-IR) and X-ray photoelectron spectroscopy (XPS) techniques, the C-steel surface morphology was investigated. The data showed that the solution of plant extract can be effectively utilized to inhibit C-steel corrosion in solutions of 1 M sulfuric acid. The effectiveness of the extract was enhanced by the higher extract dose and rising temperature. The apparent activation energy and the enthalpy of the dissolution process were determined and discussed. The presence of PC decreases the double-layer capacity from 493.1 to 107.3 μF cm⁻² and raises the charge transfer resistance in a solution of 1 M sulfuric acid from 43.39 to 287.7 Ω cm². PC is a mixed-type inhibitor, as demonstrated by PDP tests. The PC extract demonstrated the highest productivity for the C-steel protection up to 90.2% at 300 ppm from the extract, according with the PDP technique. The attained data indicated that PC extract was adsorbed chemically (ΔG^o_ads > 40 kJ mol⁻¹) onto the surface of the C-steel following the Temkin isotherm. The results of numerous tests appear to agree.     

Ficus carica extract as environmentally friendly inhibitor for the corrosion of L-80 carbon steel in 0.5 ​M ​H2SO4 media

We reported here, the corrosion inhibition of carbon steel (CS) in H₂SO₄ media by Ficus carica leaves extract as green sustainable inhibitor. This study was investigated using mass loss method (ML), potentiodynamic polarization (PDP), electrochemical frequency modulation (EFM) and electrochemical impedance spectroscopy (EIS). As well as the metal surface morphology was analyzed by Atomic Force Microscopy (AFM). In addition, the chemical characterization of green inhibitor is carried out by Fourier Transform Infrared (FTIR). EIS revealed that the Ficus carica extract formed a thin protective film on the metal surface and by using of 300 ​ppm of extract of Ficus carica allow reaches (92.7%) of corrosion inhibition efficiency (CIE). The PDP curves revealed that the Ficus carica extract act as a mixed-type inhibitor. It was demonstrated that %IE enhanced with rising the Ficus carica extract doses also increased with arises in temperature (95.7%). Kinetic parameters and thermodynamic adsorption of the system have also been measured and studied. The data obtained revealed that the adsorption of Ficus carica on metal surface followed the Temkin isotherm and according to the activation energy (Ea1) the Ficus carica extract acts by chemisorption process. The results from unlike measurements were in a well accord.     

Electrochemical and computational studies of an expired vilazodone Drug as environmentally safe corrosion inhibitor for aluminum in chloride medium

Through using chemical and electrochemical methods, the theoretical and experimental investigation of the expired vilazodone drug's ability to prevent corrosion on aluminium (Al) in a corrosive medium of HCl (1 M) has been examined. Weighing tests (WL), electrochemical (impedance spectroscopy (EIS), potentiodynamic polarization (PDP)), atomic force microscopy (AFM), scanning electron microscope (SEM), and Fourier transform infrared spectroscopy (FTIR) tests at 25 °C have all been used to investigate Vilazodone's capability to prevent corrosion of Al in 1 M HCl in the concentration in the range of 25–150 ppm. The corrosion inhibition effect of the investigate Vilazodone's against Al in acid environment was investigated weight loss and electrochemical methods. The highest % inhibition efficiency (%IE) was 95% resulted from weight loss technique at the highest concentration for inhibitor. According to the PDP data, this examined vilazodone function as a mixed-type inhibitor, impacting both the anodic and cathodic reactions. The inhibitors covered the active points of the metal surface, according to electrochemical impedance spectroscopy (EIS), to prevent corrosion. It was discovered that the inhibitor adsorption on the Al surface obeyed the Langmuir adsorption isothermal model. AFM, SEM, and FTIR surface examinations proved the inhibitor had a significant protective effect against Al dissolution in 1 M HCl. The outcomes from chemical and electrochemical methods are relatively consistent. Vilazodone acted as an effective corrosion inhibitor, according to all of the experimental data.     

Corrosion inhibition of mild steel by highly stable polydentate schiff base derived from 1,3- propanediamine in aqueous acidic solution

Recently, the hydrolysis of Schiff bases under experimental conditions gives suspicion for their corrosion inhibition performance. The current study employs a stable Schiff base namely, 2,2′-{propane-1,3-diylbis[azanylylidene (E) methanylylidene]}bis(6-methoxyphenol) (LPD) as corrosion inhibitor for mild steel (MS) in 1 M HCl solution. The presence of the characteristic peak of the imine group in UV-visible spectra was taken as an indicator for LPD stability in acidic media. The inhibition action was examined using electrochemical techniques including potentiodynamic polarization (PDP) and electrochemical impedance spectroscopy (EIS) besides gravimetric measurement. The inhibition efficiency reached 95.93 % for 0.75 mM LPD after 24 h of immersion at 25 °C. This high efficiency is owing to the presence of the characteristic imine group and other heteroatoms and π- electrons of the aromatic benzene rings. The mechanism of inhibition depends on adsorption phenomena on mild steel surface which obeys Langmuir isotherm model. The calculated values of adsorption equilibrium constant (K_ads), adsorption free energy ΔG_ads, adsorption enthalpy ΔH_ads and adsorption entropy ΔS_ads indicated spontaneous exothermic adsorption process of both physical and chemical nature. By rising temperature, the inhibition efficiency of LPD was decreased. The calculated activation energy was increased as the concentration of LPD increased. LPD was considered as a mixed-type inhibitor as indicated from PDP measurements. The obtained surface morphology and composition analysis using SEM/EDS, AFM and FTIR techniques ensures the high efficiency of LPD as corrosion inhibitor.     

4-phenyl-decahydro-1H-1,5-benzodiazepin-2-one as novel and effective corrosion inhibitor for carbon steel in 1 M HCl solution: A combined experimental and empirical studies

The heterocyclic system, namely 4-phenyl-decahydro-1H-1,5-benzodiazepin-2-one (POBZ) was inspected as a corrosion inhibitor of carbon steel (CS) in a 1 M HCl medium through electrochemical impedance spectroscopy (EIS), potentiodynamic polarization measurements (PDP), and scanning electron microscopy (SEM). The experimental data indicate that the inhibiting action augments with augmenting POBZ amount and reduces with augmenting temperature. The inhibiting action efficiency of 90.98% is obtained with 0.001 M at 303 K. The potentiodynamic polarization (PDP) results mentioned that the POBZ is of mixed type. The adsorption of POBZ on the CS followed Langmuir isotherm. SEM exams affirmed that the steel surface is smooth in presence of POBZ. In light of the calculations of density functional theory (DFT) and molecular dynamics simulation, the mechanism of POBZ inhibitory activity was addressed.     

Polyvinyl alcohol–sulphanilic acid water soluble composite as corrosion inhibitor for mild steel in hydrochloric acid medium

The inhibitive action of synthesised polyvinyl alcohol–sulphanilic acid (PVASA) composite on the corrosion of commercial mild steel in 1 M HCl medium has been investigated by weight loss, potentiodynamic polarization, and electrochemical impedance spectroscopic (EIS) methods. Characterization of PVASA composite has been carried out using Fourier transform infrared spectroscopy (FTIR). Experimental results reveal that PVASA composite acts as an inhibitor in the acid environment. The inhibition efficiency increases with an increase in the concentration of the inhibitor. Maximum inhibition efficiency of PVASA composite was found to be 84% at 6000 ppm. Thermodynamic and kinetic parameters have been obtained from temperature studies. Electrochemical measurement reveals that PVASA composite acts as a mixed inhibitor and the adsorption follows Langmuir adsorption isotherm.     

On the corrosion inhibition of iron in hydrochloric acid solutions,Part I: Electrochemical DC and AC studies

The inhibitive action of 4-methyl pyrazole (4MP) against the corrosion of iron (99.9999%) in solutions of hydrochloric acid has been studied using potentiodynamic polarization and electrochemical impedance spectroscopy (EIS). At inhibitor concentration range (10^?3–10^?2 M) in 1.0 M acid, the results showed that 4MP suppressed mainly the anodic processes of iron corrosion in 1.0 M HCl by adsorption on the iron surface according to Temkin adsorption isotherm. Both potentiodynamic and EIS measurements reveal that 4MP inhibits the iron corrosion in 1.0 M HCl and that the efficiency increases with increasing inhibitor concentration. Data obtained from EIS were analyzed to model the corrosion inhibition process through an equivalent circuit.     

Inhibition effect of hexadecyl pyridinium bromide on the corrosion behavior of some austenitic stainless steels in H2SO4 solutions

The inhibition effect of hexadecyl pyridinium bromide (HDPB) as a cationic surfactant on the corrosion behavior of some Egyptian austenitic stainless steel SS 304L, SS 316H and SS 304H in 0.5 M H₂SO₄ solutions was investigated by using potentiodynamic polarization technique and electrochemical impedance spectroscopy (EIS). The results indicate that HDPB is a good inhibitor for the samples under investigation in 0.5 M H₂SO₄ solutions. In addition, the inhibition efficiency η% increases with the inhibitor concentration while decreases with the increasing temperature referring to physical adsorption. The adsorption of the inhibitor obeys a Temkin adsorption isotherm. Polarization curves show that HDPB is a mixed inhibitor in H₂SO₄ solutions. The results obtained from polarization and impedance measurements are in good agreement. Activation-free energies, enthalpies, and entropies for the inhibition process of HDPB were determined.     

Inhibitory action of aqueous Ruellia Tuberosa L leaves extract on the corrosion of copper in HCl solution

The inhibitive action of the aqueous extract of Ruellia tuberosa L (ART) on the corrosion of copper in 0.5 ​M HCl was investigated. The inhibition efficiency increased with the extract concentration, acid concentration, as well as increasing the temperature. The Polarization studies revealed that the ART act as a mixed-type inhibitor. Based on the analysis of electrochemical impedance spectroscopy, an equivalent circuit is suggested. The adsorption of the inhibitor ART on the copper surface obeyed the Langmuir adsorption isotherm. From the results of scanning electron microscopy, Fourier transform infrared spectroscopy, and energy-dispersive X-ray spectroscopy the adsorption of ART on the copper surface is confirmed.     

Corrosion protection of carbon steel in acidic media by expired bupropion drug; experimental and theoretical study

The effects of expired bupropion on the corrosion protection of carbon steel in hydrochloric acid (1.0 M) and sulfuric acid (0.5 M) solutions were examined by Fourier transform infrared (FTIR) spectroscopy, Tafel polarization and electrochemical impedance spectroscopy (EIS). Bupropion concentrations in both acid solutions were raised, which improved corrosion prevention. Bupropion was a mixed inhibitor because it retarded the anodic and cathodic processes, as indicated by polarization data. The inhibition efficiency decreased with the increasing temperature from 25 to 55 °C. In the presence of bupropion, the activation energies of corrosion in both acid solutions increased. The thermodynamic quantities were deduced from the influence of temperature on the corrosion process of carbon steel in both acid media. Bupropion adsorption on carbon steel followed the Langmuir adsorption isotherm. The polarization data yielded outcomes consistent with the results arising from impedance measurements. FTIR spectroscopy showed the active sites of bupropion molecule during adsorption on the alloy surface. The theoretical study and molecular dynamics simulation of bupropion was done by a density functional theory (DFT) approach to realize the effects of molecular structure on the inhibitive action of bupropion.     

Impedance spectroscopic study of corrosion inhibition of Al-Pure by organic Schiff base in hydrochloric acid

A new corrosion inhibitor namely o-Chloroaniline-N-benzylidene (o-CANB) has been synthesized and its inhibitive performance toward the corrosion of Al-Pure in 1.0 M hydrochloric acid has been investigated. Corrosion inhibition was studied by chemical method (weight loss) and electrochemical techniques including polarization method and electrochemical impedance spectroscopy (EIS). The present study has shown that this inhibitor is good in acidic media and the inhibition efficiency up to >99% in 1.0 M HCl. Polarization measurement revealed that the investigated inhibitor is a mixed type with a predominant action on cathode. Impedance measurement showed that the charge transfer resistance (R_ct) increased and double layer capacitance (C_dl) decreased with an increase in the inhibitor's concentration. Obtained results about inhibition efficiency from weight loss, polarization study and EIS are in good agreement with each other. The adsorption of the inhibitor on the metal surface in the acid solution was found to obey Langmuir's adsorption isotherm.     

Corrosion inhibition of carbon steel in hydrochloric acid 0.5 M by hexa methylene diamine tetramethyl-phosphonic acid

The efficiency of hexa methylene diamine tetra methyl-phosphonic acid (HMDTMP), as corrosion inhibitor for carbon steel in 0.5 M HCl, has been determined by gravimetric and electrochemical measurements. Polarization curves indicate that the compound is a mixed inhibitor, affecting both cathodic and anodic corrosion currents. Adsorption of HMDTMP derivatives on the carbon steel surface is in agreement with the Langmuir adsorption isotherm model, and the calculated Gibbs free energy value confirms the chemical nature of the adsorption. EIS results show that the charge in the impedance parameters (R_t and C_dl) with concentrations of HMDTMP is indicative. The adsorption of this molecule leads to the formation of a protective layer on carbon steel surface. The electrochemical results have also been supplemented by surface morphological studies.     

Corrosion inhibition of copper in chloride media by 2-mercapto-4-(p-methoxyphenyl)-6-oxo-1,6-dihydropyrimidine-5-carbonitrile: Electrochemical and theoretical study

Electrochemical frequency modulation (EFM), electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization have been used to investigate the inhibition effect of a new pyrimidine heterocyclic derivative, namely 2-mercapto-4-(p-methoxyphenyl)-6-oxo-1,6-dihydropyrimidine-5-carbonitrile (MPD) on copper corrosion in 3.5% NaCl solutions at 25 ± 1 °C. The electrochemical investigations showed that MPD gives sufficient inhibition against copper corrosion in 3.5% NaCl solutions. Potentiodynamic polarization measurements have shown that the MPD inhibit both the cathodic and anodic processes and thus it classified as mixed-type inhibitor. EIS measurements indicate that the values of constant phase elements (CPEs) tend to decrease and both charge-transfer resistance and inhibition efficiency tend to increase by increasing the inhibitor concentration. Electrochemical kinetic parameters obtained using EFM methods were comparable with that calculated from traditional measurements (EIS and potentiodynamic polarization). Molecular simulation technique was used to investigate the adsorption configuration of MPD on copper surface. Number of electrons transferred from MPD to the copper surface was calculated by semi-empirical quantum chemical calculations.     

Aluminum corrosion prevention in 1.0 M HCl solution by cystosiera myrica extract: An experimental and biological study

Potentiodynamic polarization (PP) and electrochemical impedance spectroscopy (EIS), tests, mass loss (ML) and Hydrogen evolutions (HE) methods were used to examine the effects of the newly plant extracted compound (Cystosiera myrica). All these quantities exhibited that the effectiveness of inhibition increase with a rise in inhibitor concentration and with a rise in temperature. Polarization curves displayed that the inhibitor studied was an inhibitor of a mixed kind. Langmuir isotherm was attained for the adsorption of the inhibitor on the Aluminum surface. Thermodynamic parameters were determine and deduced such as activation enthalpy (ΔH*), activation entropy (ΔS*), adsorption equilibrium constant (K_ads) and free adsorption energy (G^o_ads) have been measured. UV/visible spectral, Attenuated Total Reflection Infra-Red (ATR-IR) and Atomic Force Microscopy (AFM) tested have observed the effect of this inhibitor on Al surface morphology. All other data approaches were compatible and in line with each other.     

Electrochemical investigation of corrosion and corrosion inhibition of iron in hydrochloric acid solutions

The inhibition effect of 1-methyl pyrazole (MPA) on the acidic corrosion of iron in 1.0 M HCl was studied at different concentrations (10^?3–10^?2 M) by potentiodynamic polarization and electrochemical impedance spectroscopy, and EIS measurements. It is found from the polarization studies that methyl pyrazole (MPA) behaves mainly as anodic inhibitor in HCl. Values of polarization resistance (R_p) and double layer capacitance (C_dl) in the absence and presence of MPA in 1.0 M HCl are determined. The adsorption of MPA on iron surface from HCl is found to obey Temkin adsorption isotherm.     

Experimental,DFT studies and molecular dynamic simulation on the corrosion inhibition of carbon steel in 1 M HCl by two newly synthesized 8-hydroxyquinoline derivatives

In the present work, two new 8-hydroxyquinoline derivatives namely, 5-(((2-hydroxybenzylidene)amino)methyl) 8-hydroxyquinoline [HBMQ] and 5-(((4-chlorobenzylidene)amino)methyl) 8-hydroxyquinoline [CBMQ] were synthesized and investigated as corrosion inhibitors against the dissolution of carbon steel (C38 steel) in 1 M HCl. These compounds were obtained with high yield, and their structures were characterized by nuclear magnetic resonance spectroscopy (NMR) and elemental analysis. Gravimetric, electrochemical impedance spectroscopy (EIS), potentiodynamic polarization (PDP), and surface morphology analyses utilizing scanning electron microscopy (SEM) with energy dispersive spectroscopy (EDS) were used to quantify inhibitory performance. The adsorption process of inhibitory compounds was then demonstrated using quantum mechanics approaches such as Density Functional Theory (DFT) and Molecular Dynamic Simulation (MD). Based on EIS results, the investigated derivatives effectively inhibit the degradation of C38 steel over the entire concentration range with a maximum efficiency of 91.9% and 88.0% for [CBMQ] and [HBMQ], respectively, at 10^?3 M. In addition, the PDP studies revealed that [HBMQ] and [CBMQ] compounds acted according to a mixed-type mechanism. Moreover, the adsorption mechanism follows the Langmuir isotherm model. The quantum theoretical study by DFT and MD simulation confirmed the experimental results.     

An investigation of carbon steel corrosion inhibition in hydrochloric acid medium by an environmentally friendly green inhibitor

The inhibition effect of polyphenols extracted from olive mill wastewater (PP) on carbon steel in 1.0 M HCl solution was studied. Inhibition efficiency of PP was carried out by using chemical (weight loss method) and electrochemical techniques [potentiodynamic polarization and electrochemical impedance spectroscopy (EIS)]. The effect of temperature and immersion time on the corrosion behavior of carbon steel in 1.0 M HCl with addition of an extract was also studied. The results show that PP acts as a very good inhibitor, and the inhibition efficiency increases with the concentration of PP and decreases with rising temperature. Polarization curves show that PP behaves as a mixed-type inhibitor in hydrochloric acid. Data, obtained from EIS measurements, were analyzed to model the corrosion inhibition process through an appropriate equivalent circuit model; a constant phase element has been used. EIS shows that charge-transfer resistance increases and the capacitance of double layer decreases with the inhibitor concentration, confirming the adsorption process mechanism. The activation energy as well as other thermodynamic parameters for the inhibition process were calculated. The adsorption of PP obeys the Langmuir adsorption isotherm.     

Xanthione: A new and effective corrosion inhibitor for mild steel in sulphuric acid solution

The adsorption and inhibition effect of xanthione (XION) on mild steel in 0.5 M H₂SO₄ at 303–333 K were studied using gravimetric and UV–visible spectrophotometric methods. The results obtained show that XION acts as an effective corrosion inhibitor for mild steel in sulphuric acid and inhibition efficiency reaches 98.0% at a very low inhibitor concentration of 10 μM. Inhibition efficiency was found to increase with increase in XION concentration but decreased with temperature suggesting physical adsorption mechanism. Arrhenius law and its transition equation lead to estimate the activation parameters of the corrosion process. XION inhibits the corrosion of mild steel effectively at moderate temperature and adsorbs according to the Langmuir isotherm. Thermodynamic parameters governing the adsorption process have been calculated and discussed. The UV–visible absorption spectra of the solution containing the inhibitor after the immersion of mild steel specimen indicate the formation of a XEN–Fe complex. Attempt to correlate the molecular structure to quantum chemical indices was made using density functional theory (DFT).