Enhanced the protection capacity of poly(o-toluidine) by synergism with zinc or lanthanum additives at C-steel/HCl interface: A combined DFT, molecular dynamic simulations and experimental methods

Publication date: 1 April 2020Source: Journal of Molecular Liquids, Volume 303Author(s): Hany M. Abd El-Lateef, Ahmed O. AlnajjarAbstractIn this paper, poly(o-toluidine) (POT) is a prepared by situ chemical oxidative polymerization method. The structural configuration of the as-prepared POT is confirmed by Fourier-transform infrared spectroscopy (FT-IR), UV–vis spectroscopy, X-Ray Diffraction (XRD), Transmission electron microscopy (TEM), Field emission scanning electron microscope (FE-SEM) analyses. The inhibition action of POT alone and in the presence of Zn2+ or La3+ additives at C-steel/1.0 M HCl solution surface is examined using linear polarization resistance (LPR) corrosion rate, potentiodynamic polarization (PDP), and electrochemical impedance spectroscopy (EIS) measurements at various temperatures (30–60 °C). The POT prevents the C-steel from corrosion up to 82.8%. The addition of Zn2+ or La3+ cations to POT is found to synergistically improve the corrosion protection capability of POT with a capacity of ~96.8 and 98.9%, respectively. Temperature–protection capacity relation indicates the physisorption of POT onto a metal surface and chemical adsorption when POT was incorporated with Zn2+ or La3+ additives. PDP findings displayed that POT alone and POT + Zn2+ or La3+ systems behaved as inhibitors of mixed-type. The adsorption of POT onto the C-steel interface followed the Langmuir isotherm model. FTIR, XRD and FE-SEM/EDX are applied to investigate the surf...
Source: Journal of Molecular Liquids - Category: Molecular Biology Source Type: research