TY  - JOUR
T1  - Tannin as Corrosion Inhibitor for Aluminium in Acidic Medium
AU - Hussien Ali, Enas AU - A. Himdan, Takialdin 
JO  - Journal of Engineering and Applied Sciences
VL  - 15
IS  - 17
SP  - 3250
EP  - 3257
PY  - 2020
DA  - 2001/08/19
SN  - 1816-949x
DO  - jeasci.2020.3250.3257
UR  - https://makhillpublications.co/view-article.php?doi=jeasci.2020.3250.3257
KW  - Corrosion inhibition
KW  -aluminium
KW  -tannin
KW  -adsorption mechanism
KW  -thermodynamic parameters
AB  - Corrosion of aluminium in 0.6 mol. dm<sup>&#150;3</sup> NaCl
solution in acidic medium (pH = 1) was investigated in
the absence and presence of different concentrations of
tannin as environmentally friendly corrosion inhibitor
over temperature range (298-313) K. The investigation
involved electrochemical polarization method using
potentiostatic technique and optical microscopy, the
inhibition efficiency increased by increasing inhibitor
concentration but decreased with temperature raising.
Results showed that the inhibition occurs through
adsorption of the inhibitor molecules on the metal surface
and it was found to obey Langmuir adsorption isotherm.
Some thermodynamic parameters (&#916;G<sub>ads</sub>) and activation
Energy (E<sub>a</sub>) were calculated to elaborate the mechanism
of inhibition. The polarization measurements indicated
that tannin is of mixed type. The surface characteristic of
the inhibited and uninhibited metal samples were
investigated by optical microscopy.
ER  -