Naslov
A Nonlinear Kinetic Model Introduced for the Corrosion Inhibitive Properties of Some Organic Inhibitors

Autori
Martinez, Sanja ; Metikoš-Huković, Mirjana

Izvornik
Journal of Applied Electrochemistry (0021-891X) 33 (2003);

Vrsta, podvrsta i kategorija rada
Radovi u časopisima, članak, znanstveni

Ključne riječi
acid corrosion; adsorption; corrosion inhibitor; low-carbon steel; tannin

Sažetak
Corrosion kinetics of low-carbon steel in hydrochloric acid was studied at various concentrations of mimosa tannin inhibitor. This system was subjected to impedance spectroscopy and quasy-steady state polarization. The inhibition efficiency was derived from the corrosion currentand charge transfer resistance. The fractional surface coverage as a function of the inhibitor concentration was calculated from the rate of hydrogen evolution reaction (h.e.r.) at constant cathodic potential. Based on the theoretical model and the observed experimental relationship between the ratio of the corrosion current densities in the uninhibited and inhibited systems and the surface coverage, the relative influences of the geometric blocking action and the energy effect of the inhibitor on the corrosion process were estimated. Fittinh the nonlinear model to the experimental data was carried out by the Levenberg-Marquardt nonlinear fir implemented into the programming system Mathematica. Restructuring of the adsorbed layer and the change in the orientation of adsorbed inhibitor molecules upon the increase of surface coverage was assumed on the basis of experimentally observed functional relationship of the double layer capacitance and the surface coverage. The results were explained with respect to the molecular properties of the inhibitor - geometry and size of the molecule, electronic orbital structure and dipole moment.

Izvorni jezik
Engleski

Znanstvena područja
Kemija, Kemijsko inženjerstvo

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