Effect of anions on the corrosion inhibition of aluminum in HCl using ethyl trimethyl ammonium bromide as cationic inhibitor

The corrosion inhibition of aluminum in hydrochloric acid solution in the presence of ethyl trimethyl ammonium bromide (ETMAB) at temperature range of 30-50 degrees C was studied using the weight loss and polarization techniques. The effect of addition of anions (I-, SCN-, Br-) is also reported. The inhibition efficiency (%IE) increased with increase in concentration of ETMAB. The addition of the anions increased the inhibition efficiency to a considerable extent. The inhibitive action of ETMAB was discussed on the bases of its adsorption on the metal surface, which follow Freundlish adsorption isotherm. The synergistic effect of ETMAB and anions was discussed. Galvanostatic polarization curves indicated that the inhibitor behaves as mixed-type inhibitor.