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Chetouani A.,University Mohammed Premier | Chetouani A.,Center Pedagogique Regional | Hammouti,University Mohammed Premier | Medjahed K.,Abou Bekr Belkaid University Tlemcen | Mansri A.,Abou Bekr Belkaid University Tlemcen
Der Pharma Chemica | Year: 2011

A brief review is given of the application of impedance measurements to electrochemical processes. Only very few applications for corrosion processes have been reported. The inhibitive action of the of poly (4-vinylpyridine isopentyl bromide) (P4VPIPBr) in three degrees of quaternisation (6%, 18% and 79 %) on the corrosion behaviour of pure iron was investigated in desaerated molar sulphuric acid solution, by means of electrochemical impedance spectroscopy measurements (EIS) at free corrosion potential. The parameters, which characterise the corrosion behaviour, can be determined from plots and diagrams of Nyquist. Their inhibition efficiency (E%) increases with the concentration of all inhibitors. Trends in the increase of charge transfer resistance and decrease of capacitance values also show the adsorption of the molecules on the metal surface. Source


Idbenali M.,Center Pedagogique Regional | Servant C.,University Paris - Sud
Journal of Thermal Analysis and Calorimetry | Year: 2013

The thermodynamic modeling of the gallium-yttrium binary system was carried out with the help of the CALPHAD (CALculation of PHAse Diagram) method. Ga 2Y, GaY, and the three polytypes Ga3Y5 have been treated as stoichiometric compounds while a solution model has been used for the description of the liquid phase and the (Ga) and (Y) solid solutions. The excess term of the Gibbs energy of the solution phases was assessed with the recent exponential temperature dependence of the interaction energies by Kaptay (Calphad 28-2:115-24, 1; Calphad 32-2:338-52, 2; Mat Sci Eng A 495:19-26, 3) and compared with the Redlich-Kister (Ind Eng Chem. 4;40:345) polynomial equation results. The calculations based on the thermodynamic modeling are in good agreement with the phase diagram data and experimental thermodynamic values available in the literature. © 2013 Akadémiai Kiadó, Budapest, Hungary. Source


Belkaid S.,Abou Bekr Belkaid University Tlemcen | Tebbji K.,University Mohammed Premier | Mansri A.,Abou Bekr Belkaid University Tlemcen | Chetouani A.,University Mohammed Premier | And 2 more authors.
Research on Chemical Intermediates | Year: 2012

The influence of the addition of poly(4-vinylpyridine-hexadecyl bromide) P4VP-Alkyl 50 % newly synthesized on the corrosion of mild steel in molar hydrochloric acid has been investigated by weight-loss measurements combined with linear potential scan voltammetry (I-E) and electrochemical impedance spectroscopy (EIS). The polymer reduces the corrosion rate and the inhibition efficiency (E %) of P4VP-Alkyl 50 % increases with its concentration and attains 95 % at 300 mg/L. E % obtained from cathodic Tafel plots, EIS, and gravimetric methods were in good agreement. The inhibitor was adsorbed on the iron surface according to the Langmuir adsorption isotherm model. Polarization measurements also show that the compound acts as a cathodic inhibitor. © Springer Science+Business Media B.V. 2012. Source


Bouzidi D.,University Mohammed Premier | Chetouani A.,University Mohammed Premier | Chetouani A.,Center Pedagogique Regional | Hammouti B.,University Mohammed Premier | And 2 more authors.
International Journal of Electrochemical Science | Year: 2012

The study of the corrosion of pure iron in physiological 9g/L NaCl medium was studied by electrochemical method under different hydrodynamic conditions. The hydrodynamic conditions were simulated by using a rotating disc electrode. The corrosion inhibition using amino acid, methionine, and some amino esters: methionine methyl ester and methionine ethyl ester, on the electrochemical behaviour of iron. The results showed that the criterion of Levich is proved. The limit current is function of the speed of rotation of the electrode of iron and process is a mixed type kinetic. On the electrochemical behaviour of iron is studied. The ethyl 2-amino-4-(methylthio) butanoate or methionine ethyl ester (MetOC2H5) is the best inhibitor of series and its effectiveness attains 80 % in 10-2M. The MetOC2H5 acts on the iron surface according to the Frumkin model. © 2012 by ESG. Source


El Ayyoubi S.,University Mohammed Premier | Chetouani A.,University Mohammed Premier | Chetouani A.,Center Pedagogique Regional | Hammouti,University Mohammed Premier | And 3 more authors.
International Journal of Electrochemical Science | Year: 2012

The inhibitive action of some poly(4-vinylpyridine-g-polyethylene-oxide) in three degree of quaternisation 5%, 15% and 45%, (P4VPPgOE) (g=136), against the corrosion of iron in 1M hydrochloric acid (HCl) has been studied at 298 K using weight loss measurements, potentiodynamic polarisation, and impedance spectroscopy (EIS) methods. Results obtained shows that (P4VPPgOE) (g=136) in degree of quaternisation 5%, is the best inhibitor and its inhibition efficiency increases with the increase of concentration of inhibitor to attain 100% since 5*10 -7 M. Polarisation measurements show also that the compound acts as a mixed-type inhibitor and were adsorbed on the iron surface according to the Langmuir adsorption isotherm model. E (%) values obtained from various methods used are reasonably good agreement. The temperature effect on the corrosion behaviour of iron in 1M HCl without and with the inhibitor at 10 -6 M was studied in the temperature range from 298 to 338 K, the associated activation energy have been determined and proved that the adsorption is a spontaneous process. Source

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