Theoretical evaluation of corrosion inhibition performance of decylamides of α amino acids derivatives

Key words:  corrosion inhibitor  theoretical evaluation  quantum chemistry calculation  molecular dynamics simulation

Abstract:

The corrosion inhibition performances of four corrosion inhibitors in HCl on mild steel, including 2 amino N decyl 3 (4 hydroxyphenyl) propionamid (A), 2 amino N decylacetamide (B), 2 amino N decylpropionamide(C) and 2 amino N decyl 3 methylbutyramide (D), were theoretically evaluated using quantum chemistry calculations and molecular dynamics simulations. Frontier orbital theory and global activity, Fukui indices and the contributions of heavy atoms to frontier orbital were studied. Adsorption energy of corrosion inhibitors on Fe(001) surface was calculated. The results indicate that inhibitor A shows the highest reaction activity among the four molecules. The inhibitor B displays higher local reaction activity, followed by C and D minimum. The order of bonding energy between corrosion inhibitors and metal surface is defined as A>B>C>D. Quantum chemistry calculation and molecular dynamics simulations show that the order of corrosion inhibition property for four inhibitors is as follows A>B>C>D, which agrees well with the experimental data.