Abstract

Corrosion Inhibition of Mild Steel by using Mixed Ligand Metal Complexes

Author(s): Sagar V. Sanap, Raju M. Patil and Ram S. Dubey

Chiral mixed ligand (CML) metal complexes of the type [M(PMINAP) (aa)·2H2O], where M is Ni (II), PMINAP is sodium salt of p-methoxyisonitrosoacetophenone and aa is chiral amino acid have been tested for inhibitive action on corrosion of mild steel in 1 M HCl. The inhibition was investigated by using weight loss, corrosion potential, potentiodynamic polarization and surface analytical techniques. The change in electrochemical parameters observed by variation on inhibitors concentration 100 ppm, 200 ppm and 500 ppm, favours its adsorption. The compounds influence the anodic dissolution of mild steel as well as hydrogen evolution reaction in 1 M HCl. Morphology of the mild steel specimens was examined using scanning electron microscopy in presence and absence of inhibitor. The inhibitions were due to adsorption of complexes on metal surface. Mechanism of adsorption of CML Ni (II) complexes on the surface of mild steel is proposed for its inhibition behavior. The adsorption characteristics of the inhibitor were approximated by Langmuir adsorption isotherm.