Influence of nitrones on corrosion inhibition and hydrogen permeation through mild steel in acidic solutions

A few nitrones such as N-benzilidene aniline-N-oxide, N-(O-hydroxy benzilidene) aniline-N-oxide (HN) and N-(alpha-naphthylidene) aniline-N-oxide (NN) have been synthesised and investigated for evaluating their efficiency as inhibitors for the corrosion of mild steel in 1M HCl at different concentrations of nitrones ranging from 0.025-1.0mM and at different temperatures ranging from 30-70 degrees C. Among these compounds NN gives the best performance even at higher temperatures. Potentiodynamic polarisation studies reveal the fact that all compounds behave as mixed type inhibitors. Hydrogen permeation studies reveal the fact that all the compounds bring down the permeation current. nle absorption of these compounds on the mild steel surface from 1 M HCl obeys Temkin's absorption isotherm.