Corrosion Inhibitive Property of Self-Assembled Films Formed by Schiff base Molecules on Carbon Steel Surface

N,N'-bis (salicylaldehyde)-1,3-diaminopropane (Salpn) has been evaluated as corrosion inhibition for iron in 0.1 M HCl when the films of Salpn were self-assembled on the surface of iron to improve anticorrosion property of the substrate. Monolayer formation takes place when carbon steel is precoated in hot ethanolic/aqueous 1 mM Salpn solution for 10, 20 and 30 min, and rinsing the physisorbed molecules in distilled water and heating in a hot air oven. The films of Salpn inhibitor were characterized by weight loss method and electrochemical impedance spectroscopy, electrochemical polarization curves. Results revealed that Salpn performed excellently as a corrosion protection for iron in HCl solution. The formations of monolayers were confirmed by SEM study and ATR-FTIR spectra. Taken together, the outcomes of present study exhibited that precoating of Salpn on the substrate surface is able to provide protection efficiency up to 95% and escalating of the soaking time in corrosive environment up to 24 h only reduces slightly protection efficiency (around 6%) implying this layer act as effective corrosion inhibitors.