Electrochemical and DFT studies of a new synthesized Schiff base as corrosion inhibitor in 1 M HCl

A new Schiff base namely 1,13-bis-[(2-hydroxynaphtaldehyde) 4,7,10-trioxatridecane diimine] (HNTTD) was synthesized and its corrosion behavior in 1 M hydrochloric acid solution on mild steel (MS) X48 was studied by using weight loss, polarization curves, electrochemical impedance spectroscopy (EIS) and quantum chemical calculations. All measurements showed that, inhibition efficiency increases with increasing inhibitor concentration. Polarization curves indicate that the studied compound was acting as mixed type inhibitor. The adsorption of HNTTD on steel surface followed Langmuir's adsorption isotherm. The molecular structure effect on the corrosion inhibition efficiency was investigated by using DFT calculations. The structural and electronic parameters were calculated and discussed. The results of AFM studies further confirmed the inhibition action of HNTTD. (C) 2016 Elsevier Ltd. All rights reserved.