Abstract

ABENG, F.E.; ANADEBE, V.C.; IDIM, V.D.  and  EDIM, M.M.. Anti-corrosion Behaviour of Expired Tobramycin Drug on Carbon Steel in Acidic Medium. S.Afr.j.chem. (Online) [online]. 2020, vol.73, pp.125-130. ISSN 1996-840X.  http://dx.doi.org/10.17159/0379-4350/2020/v73a18.

The anti-corrosion behaviour of the expired Tobramycin (ETo) drug for carbon steel in 2 M HCl solution was investigated by thermometric methods (Thermo), potentiodynamic polarization (PDP), electrochemical impedance spectroscopy (EIS) and scanning electron microscopy (SEM). The results obtained from Thermo, PDP and EIS show that the level of anti-corrosion behaviour is in direct association to the ETo application. The model of adsorption isotherm fitted Langmuir, confirming a chemical adsorption system. The SEM image of carbon steel immersed in optimum concentration of ETo has confirmed the film formation on the carbon steel surface. The PDP technique, indicated by the Tafel plots, demonstrated that the ETo inhibitor acted as a mixed-type inhibitor. The results obtained from activation energy, E_a, the quantity of heat adsorbed, Q_ads, and standard free energy of adsorption, AG°_ads, show a chemical adsorption mechanism of the ETo inhibitor.

Keywords : Tobramycin; thermometric; potentiodynamic polarization; electrochemical impedance spectroscopy; carbon steel; corrosion.

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