عنوان المقالة: Corrosion inhibition of carbon steel in 1M H2SO4 using new Azo Schiff compound: Electrochemical, gravimetric, adsorption, surface and DFT studies
Ali Ahmed Abdulridha, Mahmood A. Albo Hay Allah, Sajjad Q. Makki, Yusuf Sert, Hamida Edan Salman, Asim A. Balakit
الملخص الانجليزي
New Azo Schiff compound namely
4-((4-hydroxy-3-((pyridine-2-ylimino)methyl)phenyl)diazenyl)benzonitrile (5) which is
denoted as AS was synthesized and characterized using FT-IR, 13C-NMR and 1H-NMR
spectroscopy. The new compound was evaluated as corrosion inhibitor for carbon steel in 1
M H2SO4, using electrochemical and gravimetric techniques.Tween-80 surfactant was added
to enhance the solubility of AS in the acidic medium. The inhibition efficiency was found to
be dependent on the concentration of AS and temperature, the highest inhibition efficiency
values (91.32% and 90.30% by potentiodynamic and weight loss measurements respectively)
were recorded in the presence of relatively low concentration of AS (0.08 mM) at 303 K, and
it acts as anodic inhibitor. To understand the mechanism of the corrosion inhibition, the
adsorption of AS onto carbon steel surface was studied, the results indicated that the
adsorption process obeys Langmuir adsorption isotherm, the calculated ΔGads values were
found to be around -37 kj mol-1 which indicates that AS is adsorbed on the carbon steel
surface by chemical and physical interactions. For further investigations DFT studies were
employed to explain the nature of interaction between the AS molecules (neutral and
protonated) and metal surface. Finally, the morphology of both corroded and inhibited
surfaces were studies by scanning electron microscopy (SEM) and atomic force microscopy
علي احمد عبد الرضا | Ali Ahmed Abdulridha | 870