Electrochemical and theoretical studies of adsorption and corrosion inhibition of ethyl 5-amino-1-( ( 8-hydroxyquinolin-5-yl ) methyl )-1 H-1 , 2 , 3-triazole-4-carboxylate on carbon steel in acidic solution (original) (raw)
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Journal of Dispersion Science and Technology, 2012
The use of nitrogen and sulphur donor organic inhibitors in acid solutions is a common method for the protection of metals from corrosion. The present work is the study of the corrosion inhibition efficiency of (E)-4-(2-chlorobenzylideneamino)-6methyl-3-thioxo-3,4-dihydro-1,2,4-triazin-5(2H)-one (CBMTDT) towards mild steel in 1 M HCl. The work strategy includes the conventional weight loss method, potentiodynamic polarization studies (Tafel), linear polarization studies (LPR), electrochemical impedance spectroscopy (EIS), adsorption studies and quantum chemical calculations. Results showed that the corrosion rate decreases and inhibition efficiency increases with inhibitor concentration. The results of polarization studies reveal that the additive acts as a mixed type inhibitor. The surface adsorption of the inhibitor molecules decreases the double layer capacitance and increases the polarization resistance. The adsorption process is spontaneous and follows Langmuir adsorption isotherm model. The optimized structure of the inhibitor, energies of LUMO, HOMO and other physical parameters are calculated by computational quantum chemical methods.
2017
The corrosion inhibition of mild steel in HCl acid solutions by some new triazole surfactants derivatives namely 2-(5decylthio-3-methyl-1,2,4-triazole)acetic acid (MTSC10AC), 2-(5-undecylthio-3-methyl-1,2,4-triazole) acetic acid (MTSC11AC), 2-(5-dodecylthio-3-methyl-1,2,4-triazole) acetic acid (MTSC12AC) have been studied using electrochemical polarization method and electrochemical impedance spectroscopy measurements. These inhibitors have also been studied computationally using density functional theory (DFT). Observable correlation was found between corrosion inhibition efficiency and quantum chemical parameters, using the linear quantitative structure–activity relationship (QSAR) models. Received 24 Jun 2016, Revised 22 May 2017, Accepted 24 May 2017
Journal of Molecular Liquids, 2020
The anti-corrosion potency of three synthesized 8-hydroxyquinoline derivatives, namely 5-(azidomethyl)-7-(morpholinomethyl)quinolin-8-ol (HM1), 2-(8-hydroxy-7-(morpholinomethyl)quinolin-5-yl)acetonitrile (HM2), 5-(azidomethyl)-7-(piperidin-1-ylmethyl)quinolin-8-ol (HM3) in hydrochloric acid for mild steel was investigated using weight loss and electrochemical techniques. Potentiodynamic polarization (PDP) data reveal that all three compounds were cathodic inhibitors, with HM3 presentation significant mixed-type effect at high inhibitor concentrations (10 −3 M). Electrochemical impedance spectroscopy (EIS) data reveal better adsorption of compounds species on MS surface at increased inhibitor concentrations with HM1, HM2 and HM3 reaching a maximum efficiency of 90, 89 and 88%. The three compounds HM1, HM2 and HM3 were inclined towards the Langmuir adsorption-isotherm by spontaneous chemical-physical adsorptions of inhibitors on the mild steel surface. The correlation between the electronic properties and inhibition efficacies of the tilted inhibitors was determined by using simple linear regression technique. Electronic properties were calculated for neutral and protonated forms in a polarizable continuum model using the DFT method at the B3LYP/6-311 + G (d, p) level of theory. The active adsorbed sites of HM1-HM3 on the metal surface were determined by analyzing their corresponding electrostatic surface potentials (ESP). Furthermore, molecular dynamics simulations have been performed to illustrate the most conceivable adsorption configuration between the inhibitors and metal surface.
Corrosion Engineering Science and Technology, 2010
The efficiency of 4-Amino-5-phenyl-4H-1,2,4-triazole-3-thiol (APTT) as corrosion inhibitor for mild steel metal in 1?0M HCl has been investigated. Weight loss, direct current (potentiodynamic polarisation), alternating current (electrochemical impedance spectroscopy), change of open circuit potential (OCP) with immersion time and scanning electronic microscopy were used to study the effect of APTT on the corrosion inhibition of mild steel. Results obtained from weight loss, potentiodynamic polarisation, impedance measurements and change of OCP with immersion time are in good agreement and indicated that the inhibitive efficiency of the inhibitor increases with the rise of concentration. Polarisation curves show that APTT is a mixed type inhibitor. Results showed that APTT performed excellent inhibiting effect for the corrosion of mild steel in 1?0M HCl solution and inhibition efficiency is higher than 90% at 80610 25 M APTT. The high inhibition efficiency in terms of molecular adsorption and forming a protective film on the metal surface was discussed in this work. Adsorption of the inhibitor on the mild steel surface followed Langmuir adsorption isotherm and the value of the free energy of adsorption DG ads indicated that the adsorption of APTT molecule was a spontaneous process and was typical of chemisorptions. Surface photographs showed a good surface coverage on the metal surface.
Egyptian Journal of Petroleum, 2017
The efficiency of 4-(4-hydroxy-3-methoxy benzyledene amino)-4-H-1,2,4-triazole-3, 5-dimethanol, HMATD, as corrosion inhibitor for mild steel in 0.5 M HCl has been determined by weight loss measurements and electro analytical methods. The influence of various parameters such as temperature, inhibitor concentration on the efficiency has been studied. The electrochemical impedance spectroscopic measurements revealed the inhibition action of HMATD by reducing the charge transfer through metal solution interface. Polarization curves indicate the mixed type behaviour of HMATD. The inhibitor molecule functions by blocking the active sites on metal surface by adsorption and which obeys the Langmuir adsorption isotherm. Various kinetic and thermodynamic parameters have also been calculated.
Corrosion Science, 2010
A relationship between quantum chemical parameters for three triazole compounds and their inhibition ability was studied using electrochemical measurements (potentiodynamic polarization and EIS), molecular dynamic method and quantum chemical calculations. Electrochemical measurements results revealed that the inhibition efficiencies increased with the concentration of inhibitors. The molecular dynamic method results showed that the higher interaction potential between the inhibitor and metal surface, the higher the inhibition efficiency. The quantum chemical calculation results showed that the triazole ring is the active site in these inhibitors and they can absorb on Fe surface by donating electrons to Fe d-orbital.
Journal of Failure Analysis and Prevention, 2020
Corrosion inhibition using bolaamphiphile surfactants is related to the ability of these compounds to adsorb on liquid-solid interface. In this work, we have synthesized the 1,10-bis(4-amino-3-methyl-1,2,4-triazole-5-thioyl)decane (DTC10) using a new method developed in our laboratory. The synthesized compounds have been purified and characterized by NMR 1 H and NMR 13 C spectroscopy. The inhibiting action of DTC10 toward the corrosion of carbon steel in HCl1M solution was investigated using potentiodynamic and electrochemical impedance spectroscopy. We have shown that this compound acts as very good inhibitor for carbon steel in 1M HCl. The values of the transfer resistance, obtained from impedance plots of carbon steel, increase by increasing inhibitor concentration and reach 92% for 10 À3 M of DTC10. The effects of temperature and immersion time on the inhibition efficiency have also been studied. The effect of temperature was studied between 298 and 328 K; the activation energy E a and other thermodynamic parameters were calculated. Donating and anti-donating properties of the studied inhibitor 1,10-bis(4-amino-3-methyl-1,2,4-triazole-5-thioyl)decane (DTC10) were illustrated using nucleophilic PÀ and electrophilic P? Parr functions based on the density functional theory (DFT). The computational Monte Carlo (MC) method was performed to study the adsorption behavior of DTC10 onto Fe(111) surface in the solution (presence of H 3 O ? , Cl À and H 2 O particles) and in the vacuum (absence of H 3 O ? , Cl À and H 2 O particles). Accordingly, the adsorption of DTC10 on the iron surface (111) is more preferred in the solution than in the vacuum.
Journal of Molecular Liquids, 2020
The performance of two 1,2,4-triazole derivatives bearing an alkyl chain of variable length named 5octylsulfanyl-1,2,4-triazole (TR8) and 5-decylsulfanyl-1,2,4-triazole (TR10) against mild steel (MS) corrosion in 1.0 M HCl was first evaluated utilizing experimental methods such as weight loss (WL), electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization (PDP) techniques. Then, theoretical methods like Density Functional Theory (DFT) and molecular dynamics (MD) simulations were used to explore corrosion inhibition mechanisms. Effect of molecules on the MS surface was analyzed by scanning electron microscope (SEM) and atomic force microscopy (AFM). A correlation between corrosion inhibition properties and physicochemical and electronic properties as determined by DFT and MD was demonstrated. 1,2,4-triazole derivatives behave as effective inhibitors for MS corrosion in HCl at all concentrations tested with better efficacy at an optimal concentration of 10 −3 M. The maximum inhibition efficiencies (based on EIS results) were obtained 92% and 88% for TR10 and TR8, respectively. The adsorption is following the Langmuir isotherm model. Theoretical studies clearly showed that differences in carbon chain length alter inhibition performances of inhibitors and were found to be compatible with experimental results.
Research on Chemical Intermediates, 2012
In this study, 5-naphthylazo-8-hydroxyquinoline (5NA8HQ) was synthesized, characterized, and tested as a corrosion inhibitor for mild steel in 1 M HCl solution in the temperature range 20 to 50°C. Weight-loss and potentiodynamic polarization measurements were used to analyse the corrosion behaviour of the metal in the absence and presence of different concentrations of the inhibitor. Analyses of surface film and inhibited solutions by FT-IR and UV-visible spectroscopy enabled us to clarify aspects of the inhibition mechanism. Further examination using X-ray diffraction confirmed the action of 5NA8HQ as an effective inhibitor of corrosion of mild steel in acidic media. The results obtained showed that this compound was a good inhibitor of corrosion. The inhibition is of mixed anodiccathodic nature with predominance of anodic character. The Langmuir isotherm was found to accurately describe the adsorption behaviour of 5NA8HQ. Spectrophotometric analysis showed the formation of a layer at the surface of the corroded sample; this was interpreted as formation of complexes between 5NA8HQ and metal cations present in the steel structure.