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El Azzouzi M.,University Mohammed Premier | Aouniti A.,University Mohammed Premier | Herrag L.,University Mohammed Premier | Chetouani A.,University Mohammed Premier | And 4 more authors.
Der Pharma Chemica | Year: 2015

The inhibition effect of 3-(4-Hydroxyphenylamino) propanenitrile (Para) and 3-(2-Hydroxyphenylamino) propanenitrile (ortho) on the corrosion of steel mild 1M HCl solution was studied by weight loss, potentiodynamic polarization and electrochemical impedance spectroscopy methods. The results revealed that corrosion rate depends on the molecular structure and the concentration of inhibitors. We found that the Para Hydroxyphenylamino propanenitrile is a good inhibitor and has been tested with efficiency reaches to 85% in 10-3 M. Polarization studies through electrochemical curves and spectroscopy of electrochemical impedance clearly show that 3-(4-Hydroxyphenylamino) propanenitrile is a mixed inhibitor. The adsorption of Ortho and Para inhibitors on the mild steel surface obeys Langmuir isotherm. Both thermodynamic parameters (adsorption heat ΔH°, adsorption free energy ΔG° and adsorption entropy ΔS°) and kinetic parameters (apparent activation energy Eα) were calculated and discussed. The quantum chemical parameters calculated using DFT at the B3LYP/6-31G* level of theory show a good correlation to the inhibition efficiency. The highest occupied molecular orbital (HOMO), the lowest unoccupied molecular orbital (LUMO), the separation energy (ΔE) and the dipole moment (μ) from the inhibitor to the metal surface explain well experimental data.


Ousslim A.,University Mohammed Premier | Bekkouch K.,University Mohammed Premier | Chetouani A.,University Mohammed Premier | Chetouani A.,Center Regionale Des Metiers Of Leducation Et Of Formation Crmef | And 5 more authors.
Research on Chemical Intermediates | Year: 2014

The present study describes the inhibition effect of 4-benzyl piperidine (P1), 1,6-bis(4-benzylpiperidine-1-carboxamide)hexane (P2) and bis(4-benzylpiperidine)thiuram disulfide (P3) towards the corrosion of mild steel in 5.5 M H3PO4 solution using weight loss measurements and polarization technique. The influence of inhibitor concentration and temperature on the inhibitory behavior of P2 and P3 was investigated. Meanwhile, the inhibition efficiency (IE) was found to depend on the molecule structure and the concentration of piperidine derivatives. The IE for 10-3 M P2 and P2 in 5.5 M H3PO4 is around 90 %. Polarization studies clearly revealed that all the compounds used act as mixed-type inhibitors. Adsorption isotherms were fitted by the Langmuir isotherm. Adsorption energies (ΔG° ads and ΔH° ads) and kinetic parameters were evaluated. Significant correlations are obtained between inhibition efficiency with the calculated chemical indexes, indicating that the variation of inhibition with structure of the inhibitor may be explained in terms of electronic properties. © Springer Science+Business Media Dordrecht 2013.


Bouhrira K.,Oran University of Science and Technology - Mohamed Boudiaf | Chetouani A.,University Mohammed Premier | Chetouani A.,Center Regionale Des Metiers Of Leducation Et Of Formation Crmef | Zerouali D.,Oran University of Science and Technology - Mohamed Boudiaf | And 5 more authors.
Research on Chemical Intermediates | Year: 2014

This work reports results from potentiodynamic polarisation and impedance investigation, with a rotating disc electrode, of inhibition of corrosion of A106 steel in aerated, unstirred 3.0 % NaCl solutions using di-n-butyl bis(thiophene-2-carboxylato-O,O′)tin(IV) as inhibitor. These studies showed that it is a mixed-type inhibitor. Inhibition efficiency increased with increasing di-n-butyl bis(thiophene-2-carboxylato-O,O′)tin(IV) concentration and decreases with increasing solution temperature. Maximum efficiency of inhibition of the inhibitor of approximately 78 % is observed at a concentration at 10-2 M. The inhibition process was attributed to formation of an adsorbed film on the metal surface that protects the metal against corrosive agents. The adsorption isotherm confirms the applicability of Langmuir equation to describe the adsorption process. Thermodynamic functions for the adsorption process were determined. The efficiency of corrosion inhibitors and global chemical reactivity depend on such properties as energy of the highest occupied molecular orbital (E HOMO), energy of the lowest unoccupied molecular orbital (E LUMO), energy gap (ΔE), which were calculated. All calculation was been performed by density functional theory (DFT) using the Gaussian03W suite of software. Calculated results were usually in agreement with the experimental data. © 2013 Springer Science+Business Media Dordrecht.


Mokhtari O.,University Sidi Mohammed Ben Abdellah | Hamdani I.,University Mohammed Premier | Chetouani A.,University Mohammed Premier | Chetouani A.,Center Regionale Des Metiers Of Leducation Et Of Formation Crmef | And 4 more authors.
Journal of Materials and Environmental Science | Year: 2014

The effects of natural Jatropha curcas oil on the corrosion of steel in molar hydrochloric acid were studied via the measurements of weight loss, electrochemical and EIS polarisation. The results obtained revealed that Jatropha curcas oil reduced the rate of corrosion. The corrosion inhibition efficiency increased with the increase of inhibitor concentration. Potentiodynamic polarisation studies clearly revealed that the presence of the natural Jatropha curcas oil did not alter the mechanism of the hydrogen evolution reaction and acted a mixed inhibitor. The adsorption of Jatropha curcas oil on the steel surface in molar in hydrochloric acid obeys to the Frumkin adsorption isotherm model.


Elmsellem H.,University Mohammed Premier | Youssouf M.H.,University Mohammed Premier | Aouniti A.,University Mohammed Premier | Ben Hadda T.,University Mohammed Premier | And 3 more authors.
Russian Journal of Applied Chemistry | Year: 2014

The inhibition effect of curcumin on the corrosion of mild steel in 1.0 M HCl solution was studied by weight loss, potentiodynamic polarization curves and electrochemical impedance spectroscopy (EIS) methods. The experimental results suggest that this compound is an efficient corrosion inhibitor and the inhibition efficiency increases with the increase in inhibitor concentration. Adsorption of this compound on mild steel surface obeys Langmuir isotherm. Also the objective of this work is to attempt to find relationships between electronic structure and inhibition efficiency. The structural parameters, such as the frontier molecular orbital energies (E HOMO and E LUMO), gap of energy ΔE, from the molecule to iron as well as electronic parameters such as Mulliken atomic populations were calculated and discussed using the Density Functional Theory method (DFT). © 2014 Pleiades Publishing, Ltd.


Tennouga L.,Abou Bekr Belkaid University Tlemcen | Mansri A.,Abou Bekr Belkaid University Tlemcen | Medjahed K.,Abou Bekr Belkaid University Tlemcen | Chetouani A.,University Mohammed Premier | And 2 more authors.
Journal of Materials and Environmental Science | Year: 2015

In this paper, the micellization of anionic surfactant sodium dodecyl sulphate (SDS) and cationic surfactant Ndodecylpyridinium chloride (DPC) in aqueous solution at various temperatures has been reported using conductivity measurements. The thermodynamic parameters of micellization; the free energy, ΔGmic 0, the enthalpy, ΔHmic 0, and the entropy, ΔSmic 0 were calculated from the critical micelle concentration (CMC) at different temperatures. The results show that the CMC of surfactants decreases to reach a minimum and then increases with temperature. Also, the thermodynamic parameters of micellization are discussed.


Elmsellem H.,University Mohammed Premier | Nacer H.,University of Oum El Bouaghi | Halaimia F.,University Mohammed Premier | Aouniti A.,University Mohammed Premier | And 8 more authors.
International Journal of Electrochemical Science | Year: 2014

The effect of (E)-4-methoxy-N-(methoxybenzylidene)aniline (P1) and (E)-N-(4-methoxybenzylidene) -4-nitroaniline (P2) on the corrosion of steel in molar hydrochloric acid studied by weight loss and electrochemical polarisation. The results obtained reveal that the compounds reduce the corrosion rate. The inhibition efficiency increases with the increase of inhibitor concentration. Potentiodynamic polarisation studies clearly reveal that the presence of the inhibitors does not change the mechanism of the hydrogen evolution reaction and acts essentially as mixed inhibitors. We note good agreement between gravimetric and electrochemical methods. The influence of temperature and inhibitor concentration on the corrosion of mild steel has also been investigated in the temperature range 308-353K, indicates that inhibition efficiency remains almost constant with temperature. The adsorption of the inhibitors on the mild steel surface in both acids obeys the Langmuir' adsorption isotherm. The thermodynamic parameters of adsorption deduced reveal a strong interaction and spontaneous adsorption of P1 and P2 on the mild steel surface. Also the objective of this work is to attempt to find relationships between their molecular and electronic structures and inhibition efficiency. The structural parameters, such as the frontier molecular orbital energies (EHOMO and ELUMO), gap of energy ΔE, the charge distribution, the absolute hardness η and the softness σ, the fraction of electrons ΔN transferred from the molecules to iron as well as electronic parameters such as Mulliken atomic populations and Fukui indices were calculated and discussed. © 2014 The Authors.


El Ouali I.,University Mohammed Premier | Chetouani A.,University Mohammed Premier | Chetouani A.,Center Regionale Des Metiers Of Leducation Et Of Formation Crmef | Hammouti B.,University Mohammed Premier | And 4 more authors.
Portugaliae Electrochimica Acta | Year: 2013

The effect of synthesized 1,1'-propane-1,3-diylbis[3-(chloromethyl)-5-methyl-1Hpyrazole], dimethyl 1,1'-butane-1,4-diylbis(5-methyl-1H-pyrazole-3-carboxylate) and 1,1'-butane-1,4-diylbis[3-(chloromethyl)-5-methyl-1H-pyrazole] on corrosion of C38 steel in hydrochloric acid solution has been investigated in the temperature range from 298 K to 328 K by weight loss, potentiodynamic polarization method and modelled with an equivalent electric circuit. All the compounds exhibited more than 90% anticorrosion activity, the highest is 96 % by 1,1'-butane-1,4-diylbis[3-(chloromethyl)- 5-methyl-1H-pyrazole], and it has been shown that the inhibition efficiencies increased with the concentration of the inhibitors, remaining almost constant in a wide temperature range. Potentiodynamic polarization studies suggested that it is a predominance cathodic type. Nyquist plots showed depressed semicircles with their centre below the real axis. The adsorption on the C38 steel surface followed the Langmuir adsorption isotherm. The thermodynamic parameters for dissolution were investigated at different concentrations and temperature. The theoretical study by modelling the molecules of these inhibitors has been performed by considering the Density Functional Theory (DFT) using the Gaussian 03W suite of programs that can calculate the different quantum parameters such as EHOMO, ELUMO, Δ EHOMO, ELUMO, and μ dipolar moment, allowing us to confirm the results found by the gravimetric and electrochemical methods.


Ramdani M.,University Mohammed Premier | Elmsellem H.,University Mohammed Premier | Elkhiati N.,Faculte des science Ain Chock | Haloui B.,University Mohammed Premier | And 5 more authors.
Der Pharma Chemica | Year: 2015

The marine macroalgae extract of caulerpa prolifera in aqueous 1 M HCl was systematically investigated to ascertain its inhibitor effect on corrosion of mild steel and its mechanism of the inhibition by electrochemical and weight loss methods. The results revealed a high inhibitive effect of C. prolifera. The inhibition efficiency was found to increase with increasing concentration of the algal extract but decreased with increase in temperature which is attributed to the physisorption. Potentiodynamic polarization measurement showed that C. prolifera extract acted as mixte type inhibitor. The increase in activation in energies of corrosion process in presence of the extract indicates that C. prolifera retarded the rate of corrosion of mild steel in 1 M HCl solution. The nature of adsorption of the C. prolifera on mild steel surface was in conformity with Langmuir isotherm. The results obtained with different method are in good agreement.


Missoum N.,British Petroleum | Guendouz A.,CNRS Laboratory of Engineering and Materials Science | Boussalah N.,British Petroleum | Hammouti B.,Premier University | And 5 more authors.
Research on Chemical Intermediates | Year: 2013

Methyl 2-(bis((3,5-dimethyl-1H-pyrazol-1-yl)methyl)amino) acetate, BT36, and methyl 2-(bis((3,5-dimethyl-1H-pyrazol-1-yl)methyl)amino)-3-(1H-indol-3-yl) propanoate, BT 43, have been synthesized. Investigation by weight-loss measurement and use of electrochemical techniques revealed the compounds are very effective inhibitors of corrosion of C38 steel in 1 M HCl solutions - percentage protection exceeded 95 % for BT43 at concentrations as low as 10 -2 M. An impedance study in the absence and presence of these compounds revealed the mechanism of protection was cathodic inhibition by polarization and charge-transfer. The Langmuir adsorption isotherm was obeyed. Quantum chemical data calculated by use of DFT at the B3LYP/6-31Glevel of theory revealed a good correlation between inhibition efficiency and the molecular structure of BT36 and BT43. The highest occupied molecular orbital, the lowest unoccupied molecular orbital, the separation energy (ΔE), and the dipole moment (μ) from the inhibitor to the metal surface explain the experimental data well. © 2012 Springer Science+Business Media Dordrecht.

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