|
Corrosion Inhibition of Steel in
Petroleum Medium by Ficus Carica Leaves Extract |
|
This work involves study the corrosion
inhibition of steel in petroleum medium using alcoholic
extracted of Ficus carica leaves with four concentrations of
extracted (1, 3, 5 and 7mL/L) at four temperatures over the
range 50 – 80 oC. Inhibition efficiency IE% results show that 3
and 5 mL/L the best concentrations which they gave efficiencies
in the range of 71 – 80%. Thermodynamic functions of adsorption
processes were calculated from experimental polarization data
and the interpretation of the results reveals that Ficus carica
extract Ficus carica extract obey Langmuir adsorption isotherm.
Polarization curves indicate that Ficus carica extract is a
mixed type inhibitor. The small values of the equilibrium
constant of the adsorption-desorption process Kads refer to
physical adsorption process. The values of free energy of
adsorption ΔGoads, enthalpy ΔHoads and entropy ΔSoads were
negative indicating the spontaneous and exothermic adsorption
process as well as Ficus carica extract retained the metal ions
and reducing the dissolution of steel and the activated complex
in the rate determining step denotes an association rather than
a dissociation step. |
|
