The inhibition effect of animal glue toward the corrosion of aluminum and two aluminum-silicon alloys in 0.1 M
NaOH solution was investigated using potentiostatic polarization, electrochemical impedance spectroscopy
(EIS), cyclic voltammetry and potentiodynamic anodic polarization techniques. The percentage inhibition effi-
ciency increases with increasing concentration of animal glue and decreases with increasing temperature as
well as Si content. The inhibiting effect of animal glue is due to the adsorption on the Al and two Al\Si alloys surface.
The adsorption process follows Langmuir isotherm. Polarization curves revealed that the studied inhibitor
acts as a mixed type inhibitor mainly cathodic. The effect of rising temperature on the inhibition efficiency was
studied and the values of activation thermodynamic parameters were computed and explained. It was found
that the animal glue provides a good protection to Al and Al\Si alloys against pitting corrosion by shifting the
pitting potential to more noble direction. Results obtained from all electrochemical techniques were consistent
with each other