The inhibition of corrosion of mild steel by some fluoroquinolones in sodium chloride solution

The corrosion inhibition of mild steel in 3.4% sodium chloride solution containing various concentration of inhibitors such as, ofloxacin, amifloxacin, enofloxacin, pfloxacin, ciprofloxacin and norfloxacin has been investigated. The inhibition efficiency has been evaluated by weight loss and electrochemical polarisation techniques. Morphology of the mild steel specimens were examined using scanning electron microscopy in presence and absence of inhibitors. The inhibition efficiency increased with increasing concentration of inhibitors. At the cocentration of 40 ppm, the inhibition efficiency for mild steel is in the following order : Ofloxacin > amifioxacin > enofloxacin > pfloxacin > ciprofloxacin > norfloxacin. It shows that water soluble thin film of inhibitor is formed on the surface by a surface reaction of metal. ion of specimen with adsorbed inhibitor molecules and that film act as a protective barrier against corrosive environment.