Insights into the adsorption and corrosion inhibition properties of newly synthesized diazinyl derivatives for mild steel in hydrochloric acid: synthesis, electrochemical, SRB biological resistivity and quantum chemical calculations (original) (raw)
Related papers
2014
The inhibition of the corrosion of Mild Steel (MS) in 1 M HCl solution by a new synthesised organic compound, namely 1,1'-(2,2'-(2,2'-oxybis(ethane-2,1-diyl)bis (sulfanediyl))bis(ethane-2,1-diyl))diazepan-2-one, has been studied by weight loss measurements, electrochemical polarisation and electrochemical impedance spectroscopy (EIS). The experimental results have showed that this organic compound revealed a good corrosion inhibition and the inhibition efficiency is increased with the inhibitor concentration to reach 97% at 1 mM. Potentiodynamic polarisation suggested that it is a mixed type of inhibitor. EIS measurements show an increase of the polarisation resistance with the inhibitor concentration and the electrical equivalent circuit is determined. The inhibitor adsorption process on (MS) surfaces obeys the Langmuir adsorption isotherm and the adsorption isotherm parameters (K ads , ∆G ads , ∆H ads and ∆S ads) were determined. The temperature effect on the corrosion behaviour of (MS) in 1 M HCl without and with inhibitor at different concentration was studied in the temperature range from 308 to 353 K and the kinetic parameters activation such as E a , ∆H a and ∆S a were evaluated.
Int. J. Electrochem …, 2012
The inhibitor effect of 1,7− bis (2hydroxy benzamido)-4-azaheptane H 4 L 3 on the corrosion of mild steel in 1M hydrochloric acid (HCl) has been investigated at 308 K using weight loss measurements and electrochemical techniques (impedance spectroscopy and polarisation curves). Inhibition efficiency is dependent upon the 1,7− bis (2hydroxy benzamido)-4-azaheptane H 4 L 3 concentration and its inhibition efficiency increases with the increase of concentration of inhibitor to attain 96 % since 10-3 M. Polarisation curves indicate that 1,7− bis (2hydroxy benzamido)-4-azaheptane H 4 L 3 act essentially as mixed inhibitors. EIS measurements show an increase of the transfer resistance with the inhibitor concentration. The temperature effect on the corrosion behaviour of steel in 1M HCl without and with the inhibitor at 10-3 M was studied in the temperature range from 308 to 333 K, the associated activation energy have been determined. Adsorption of 1,7− bis (2hydroxy benzamido)-4-azaheptane H 4 L 3 on the mild steel surface in 1M HCl follows the Langmuir isotherm model. Significant correlations are obtained between inhibition efficiency with the calculated chemical indexes, indicating that variation of inhibition with structure of the inhibitor may be explained in terms of electronic properties.
Ionics, 2019
Isoniazid (anti-biotic) derivatives-PA1 {(E)-N′-(4′-Hydroxy-3-methoxybenzylidene) isonicotino hydrazide}, PA2 {(E)-N ′-(Pyridin-4′-ylmethylene) isonicotino hydrazide}, and PA3 {(E)-N′-(Pyridin-3′-ylmethylene) isonicotino hydrazide} were synthesized, characterized, and further examined for corrosion protection activities on mild steel (MS) in 1 M HCl via experimental, theoretical, and surface analysis. Electrochemical processes in the presence of different concentration of tested compounds were characterized as charge transfer controlled and revealed stable, spontaneous corrosion inhibition by inhibitors on mild steel in acidic media. The values evaluated for free energy change (ΔG 0 ads) assured the involvement of chemisorption process. Adsorption data was found well fitted in Langmuir isotherm. Enthalpy and entropy parameters obtained by computational analysis using ADF-band revealed parallel alignment of PA1 on the surface of mild steel as best alignment for optimal adsorption. Theoretically, computed adsorption-free energy (ΔG 0 ads) and adsorption constant (K ads) values for parallel alignment complemented the experimentally determined values.
Scientific reports, 2016
The acid corrosion inhibition process of mild steel in 1 M HCl by azelaic acid dihydrazide has been investigated using electrochemical impedance spectroscopy (EIS), potentiodynamic polarization, open circuit potential (OCP) and electrochemical frequency modulation (EFM). Azelaic acid dihydrazide was synthesized, and its chemical structure was elucidated and confirmed using spectroscopic techniques (infrared, nuclear magnetic resonance and mass spectroscopy). Potentiodynamic polarization studies indicate that azelaic acid dihydrazide is a mixed-type inhibitor. The inhibition efficiency increases with increased inhibitor concentration and reaches its maximum of 93% at 5 × 10(-3) M. The adsorption of the inhibitor on a mild steel surface obeys Langmuir's adsorption isotherm. The effect of temperature on corrosion behavior in the presence of 5 × 10(-3) M inhibitor was studied in the temperature range of 30-60 °C. The results indicated that inhibition efficiencies were enhanced with ...
2018
In this work, 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) was, for the first time, utilized as the organic corrosion inhibitor for galvanized steel in 1.0 M HCl, at 30 o C and 40 o C. The corrosion reactions of galvanized steel in 1.0 M HCl with DBU concentrations: 3.0, 6.0, 9.0 and 50.0 mM and without DBU had been investigated by gasometrical and weight loss measurements. The results from both techniques showed that DBU was found to be the highly effective corrosion inhibitor for galvanized steel in an acidic media. The highly inhibiting efficiency of DBU was up to 88% at 30 o C. The result from kinetics study showed that the corrosion rate of steel was decreased with decreasing of temperature and increasing of DBU concentration. Moreover, the activation energy ( E a ) was increased with increasing of DBU concentration. From thermodynamic analysis, the adsorption of DBU on steel surface was physical adsorption and spontaneous process, due to the free energy changes of adsorption are ...
Industrial & Engineering Chemistry Research, 2014
The corrosion and corrosion inhibition of mild steel in 1.0 M H 2 SO 4 containing 10% ethyl alcohol(EtOH) by Zizyphus Spina-Christi (ZSC) extracts (aqueous extract and alcoholic extract) has been studied using chemical techniques(hydrogen evolution(HE) and mass loss(ML)) and electrochemical techniques(electrochemical impedance spectroscopy(EIS) and potentiodynamic polarization(PDP)). The effect of acid concentration on the corrosion rate of mild steel increases with acid concentration (0.25-1.5) M showing first order corrosion reaction without changing the reaction mechanism, and the results showed that when the concentration of ZSC extracts (aqueous extract and alcoholic extract) increased the rate of steel corrosion is decreased, which indicates that the inhibition of the corrosion process is produced. Electrochemical impedance spectroscopy results showed that the corrosion and corrosion inhibition of steel occurred mainly by charge transfer. The electrochemical results of polarization also showed that the extracts of ZSC plant act as mixed type inhibitors, they retarded both cathodic and anodic reaction. The experimental results from chemical and electrochemical studies were fit Langmuir isotherm. Values of equilibrium constant of adsorption K ads and the standard free energy of adsorption o. ads G Δ , for the extracts are calculated.
Transactions of the Indian Institute of Metals, 2017
Three new heterocyclic diazepines (CC-diCl, CC-Cl and CC-F) were synthesized for the first time from the natural product curcumin and evaluated as non-toxic corrosion inhibitors for carbon steel (CS) in 1 M HCl. The evaluation was carried out using electrochemical impedance spectroscopy, polarization curves (PDP) measurement, weight loss (WL) and scanning electron microscopy studies. The molecular modeling methods: density functional theory calculations and Monte Carlo simulations were performed to obtain a good insight into the inhibition process. Results obtained from electrochemical techniques and WL tests revealed that, the studied diazepines were effective corrosion inhibitors for CS in the tested medium. Among the evaluated diazepines, CC-diCl showed the highest efficiency. According to the PDP results, the diazepines behaved as mixed-type (cathodic and anodic) inhibitors. A complete thermodynamic study was also performed on the diazepine with the highest efficiency CC-diCl to gain a better understanding of the inhibition process. The adsorption of the diazepines onto CS surface obeyed a Langmuir adsorption isotherm. A good correlation was obtained between the molecular modeling studies and inhibition efficiency (IE%) of the tested diazepines.
Novel Corrosion Inhibitor for Mild Steel in HCl
Materials, 2014
Corrosion inhibitory effects of new synthesized compound namely 5,5'-((1Z,1'Z)-(1,4-phenylenebis(methanylylidene))bis(azanylylidene))bis(1,3,4-thiadiazole-2-thiol) (PBB) on mild steel in 1.0 M HCl was investigated at different temperatures using open circuit potential (OCP), potentiodynamic polarization (PDP) and electrochemical impedance spectroscopy (EIS). Results showed that PBB inhibited mild steel corrosion in acid solution and indicated that the inhibition efficiencies increased with the concentration of inhibitor, but decreased proportionally with temperature. Changes in impedance parameters suggested the adsorption of PBB on the mild steel surface, leading to the formation of protective films.
2021
One of the ways of reducing metal corrosion and its devastating effects is by using organic corrosion inhibitors. This is because of the π-conjugation in their moieties, their ability to donate electrons to the metal’s vacant d-orbitals, and their low lying LUMO orbitals for accepting electrons as well from the metal, all these improve their adsorption on the metal surface. (E)-5-((4-benzoylphenyl)diazenyl)-2-hydroxybenzoic acid (AD4) was synthesized via the coupling reaction of p-aminobenzonephenone and Salicylic acid, characterized via FTIR, UV/Vis, 1H-NMR, and 13C-NMR spectroscopy. The melting point of AD4 is 103oC–106oC indicating that it is thermally stable and pure. Gravimetric and potentiodynamic polarization techniques were employed to obtain the corrosion rates (Cr) and percentage inhibition efficiency (%IE) at different concentrations of the inhibitor and at different temperatures. The thermodynamic parameters like Enthalpy, ∆Hoads, Entropy, ∆Soads and free energy of adsor...
2017
Two novel aza-pseudopeptides such as 2-(1-(3-methyl-5,6-dihydropyridazin-1(2H)-yl)-1-oxo-propan-2-yl)isoindoline-1,3-dione (E10) and 2-(2-(5-(4-(dimethylamino) phenyl)-4,5-dihydro-1H-pyra-zol-1-yl)-2-oxoethyl) isoindoline-1,3-dione (E12) were synthesized, characterized by FTIR, 1H NMR, 13CNMR, and tested as corrosion inhibitors for mild steel in 1.0 M HCl. The inhibition effect of the preparedcompounds was studied by electrochemical impedance spectroscopy, Tafel polarization and quantum chem-ical calculations. The experimental results suggest that these compounds are efficient corrosion inhibitors andthe inhibition efficiencies increase with increasing their concentrations. The efficiencies obtained from EISmeasurements were in good agreement with those obtained from the polarization measurements. Polariza-tion curves revealed that the prepared compounds act as mixed type inhibitors. The interaction betweeninhibitor and surface of steel obey Langmuir isotherm. The density functional theory was employed for the-oretical calculations, and the obtained results were found to be consistent with the experimental findings.