Synergism and antagonism in iron base metallic glass corrosion inhibition by thiosemicarbazone compounds and bromide ions

Abstract EN

The synergistic and antagonism action caused by Br- ions on the corrosion inhibition of Fe78B13Si9 glassy alloy in 0.2 M Na2SO4 in absence and presence 10-4 M of some thiosemicarbazone derivatives have been investigated using potentiodynamic polarization, a.

c.

impedance techniques and morphological study.

Results show that the addition of Br-ions to sulphate solution inhibit the corrosion process by acting as an electron transfer barrier due to direct adsorption of these ions on alloy surface.

A synergistic effect exists when fixed concentration of studied thiosemicarbazone derivatives and low concentrations of Br- ions are used together to prevent glassy alloy corrosion in Na2SO4.

The increase in surface coverage values in the presence at low concentrations of Br- ions indicates that an insoluble complex formed by undergoing a joint adsorption.

The synergism parameter (S) is defined and calculated by surface coverage values.

The parameter in the case of small amount of Br- found to be more than unity, indicating that the enhanced inhibition efficiency caused by the addition of Br- ions is only due to synergism and there is a definite contribution from the inhibitor molecule.