Corrosion inhibition of zinc in sodium sulphate solution using nonionic surfactants of tween series: Experimental and theoretical study

The effects of three tween compounds have been tested as corrosion inhibitors of a zinc surface in 0.1 M of sodium sulphate (Na2SO4) using potentiodynamic, potentiostatic transient in addition to the Electrochemical Impedance Spectroscopy (EIS) method. The efficiency of the inhibitory effect of these additives was found to decrease in the order: Tween-60 > Tween-80 > Tween-20. These compounds were selected based on their active surface property and high molecular weight as well as their solubility in aqueous media. Cyclic voltammetry (CV) was used to evaluate their effect on the ethanol oxidation. The experimental results were discussed and the correlation between the outcomes and inhibition properties towards Zn pitting corrosion was accomplished. Finally, quantum chemical descriptors of the tween derivatives that relate to their performance as regards corrosion inhibition efficiency have been determined and found to be in good agreement with the experimental results.