CORROSION STUDIES OF ZINC IN AQUEOUS BINARY MIXTURES OF ACETONITRILE THROUGH POLARISATION TECHNIQUE.

Abstract

The nature of cathodic and anodic polarisation curves is the indicative of the fact that the corrosion of zinc in the present system is cathodically controlled. With an increase in acetonitrile content in the mixture cathodic polarisation curves at first shift towards higher current density and then after a particular acetonitrile content the shift is in reverse direction. The anodic polarisation curves shift in oscillatory manner with increasing acetonitrile content in the solvent mixture. The passivity is altogether absent in the anodic curves for all the representative concentrations. Stirring of the medium leads to the enhancement in corrosion rate. Accelerated weight loss measurement at a fixed potential shows a linear increase in weight loss with polarisation time.