Inhibition Of The Corrosion Of Mild Steel In Solutions Of Hydrochloric Acid By Some Quinolones :- Awa, Justice Njoku U

ABSTRACT

The inhibition potentials of ciprofloxacin and ofloxacin for the corrosion of mild steel in HCI solutions were investigated using gravimetric (weight loss), gasometric (hydrogen gas evolution) and thermometric methods of monitoring corrosion. The results obtained for gravimetric, gasometric and thermometric measurements indicate that the inhibition efficiencies of ciprofloxacin range from 91.89 to 95.74%, 88.57 to 91.43% and from 76.68 to 88.23% respectively while i that of ofloxacin range from 92.63 to 96.31% (weight loss), 88.60 to 91.45 (gasometric) and from 79.32 to 86.22 (thermometric). The activation energies and free energies of adsorption of the inhibitors were within the range expected for the mechanism of physical adsorption. The adsorption of the inhibitors is exothermic, spontaneous and supported the model of Langmuir. It was also observed that the inhibition efficiencies of the inhibitors increased with increasing concentration but decreased with increase in temperature. Kinetic modeling also revealed that the corrosion of mild steel in HCI solutions containing various concentrations of ciprofloxacin is first order and that the inhibitors extended the half life of mild steel in HCI.