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Sumac
(Rhus) Extract as Green Inhibitor for
Steel in Seawater |
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Sumac
extract was tested as green inhibitor for steel in seawater
(3.5wt.% NaCl) at room temperature with five concentrations
include 4, 6, 8, 12 and 16 mL/L. Corrosion tests were
investigated by Potentiostat at 5
mV.sec-1 scan rate, and the data measured by Tafel extrapolation
method such as corrosion potential, corrosion current density
and Tafel slopes. Inhibition efficiencies were calculated and
indicated that 8 mL/L was the best
concentration for inhibition. Sumac extract was anodic inhibitor
type and obeys Langmuir adsorption isotherm with R2 equal to
0.992. The equilibrium constant of the adsorption-desorption
process and the apparent free energy
of adsorption also calculated which 0.66313 and - 8.7370
kJ.mol-1 respectively were. FTIR spectroscopy was used to test
film formed on steel surface compared with FTIR spectrum of
Sumac powder. This test showed the
decreasing in intensities of main peaks due to formation Fe2+
organic molecules complexes at functionally groups.
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