UMIM, Faculté Polydisciplinaire de Taza, Université Sidi Mohamed Ben Abdellah, Taza, Morocco
Preferred Abstract (Original):
2Z)-1-(4-chlorophenyl)-2-[(3E)-3-[2-(4-chloropheny l)-2-oxoethylidene]-3,4dihydro quinoxalin- 2 (1H)-ylidene]ethanone (Q4) was tested as inhibito r for the corrosion of copper in 2M HNO 3 using gravimetric method at 303 – 343 K. The inhibi tor (Q4) showed about 90% inhibition efficiency (E (%)) at an optimum concentration of 1 0 -3 M. The inhibition efficiency increases with increase in inhibitor concentration but decrease wi th rise in temperature. Various parameters (Ea , ∆G ° ads , K ads ) for adsorption reveal a strong interaction betwee n inhibitor and copper surface. The negative values of ∆G° ads indicate the spontaneous adsorption of the inhibit or on copper surface. Kinetic parameters activation such as a E , aH °∆ , aS °∆ and pre-exponential factor have been calculated and discussed. Further, theore tical calculations were carried out and relations between computed parameters and experimen tal inhibition efficiency were discussed.
Laboratoire d’Application des Electrolytes et des Polyélectrolytes Organiques (LAEPO), Département de Chimie, Université de Tlemcen, B.P. 119, 13000, Tlemcen, Algeria
Laboratoire d’Application des Electrolytes et des Polyélectrolytes Organiques (LAEPO), Département de Chimie, Université de Tlemcen, B.P. 119, 13000, Tlemcen, Algeria
B. Hammouti
LCAE-URAC18, Faculté des Sciences, Université Mohammed Premier, Oujda, Morocco
I. Warad
Department of Chemistry, King Saud University, P.O. Box 2455, Riyadh, 11451, Saudi Arabia
A. Chetouani
Laboratoire de chimie physique, Centre Pédagogique Régional des Professions de l’Education et de Formation “CRPEF”, Académie Régionale de l’Orientale, Oujda, Morocco
he effect of iodide ions on the corrosion inhibition of mild steel in 1 M sulfuric acid in the presence of poly(acrylamide-co-4-vinylpyridine) copolymer abbreviated by (AM-4VP-9) was studied by weight loss measurements and electrochemical techniques (impedance spectroscopy and polarisation curves) at 18 °C. The results obtained showed that the inhibition efficiency increased with increasing copolymer concentration. It was also found that the inhibition efficiency increased with the addition of potassium iodide (KI) to the copolymer. A synergistic effect was observed between the AM-4VP-9 copolymer and KI. On the other hand, it was found that the inhibiting effect of the system (AM-4VP-9 + KI) increased with increasing immersion time. Polarisation curves indicate that (AM-4VP-9) copolymer act as mixed inhibitors. EIS measurements show an increase of the transfer resistance with the inhibitor concentration.