Effect of carboxymethyl cellulose on the corrosion behavior of aluminum in H2SO4 solution and synergistic effect of potassium iodide

Abstract

The corrosion inhibition of aluminum in 2 M H2SO4 solution by carboxymethyl cellulose (CMC) alone and in combination with iodide ions has been investigated using electrochemical measurements and surface analysis techniques. The results showed that CMC moderately inhibited aluminum corrosion in the H2SO4 solution, and the inhibition efficiency of CMC was increased with the addition of inhibitor concentration, indicating the physical adsorption mechanism. The synergistic effect of 5 mM KI at all concentrations of CMC was assessed by calculating the synergism parameters, indicating that the increased inhibition efficiency of the CMC caused by addition of iodide ions is due to synergism. Additionally, the analysis of the morphology and composition of the aluminum surface suggests that with addition of iodide ions, more CMC molecules are adsorbed on the aluminum surface, thereby enhancing the inhibition efficiency of CMC.