Minified dose of urispas drug as better corrosion constraint for soft steel in sulphuric acid solution

Corrosion protective performance of commercial mild steel (soft steel) by urispas drug was evaluated by gravimetric measurements, potentiostatic polarization and electrochemical impedance spectroscopy in 1 M H2SO4 solution. The results indicate that urispas acts as quite a good corrosion constraint for mild steel exhibiting 97.85% inhibition efficiency at 150 ppm of the drug at 303 K on polarizing it electrochemically which is a quite minified amount of urispas. Weight loss study also shows that inhibition efficiency gets optimized at 150 ppm of the drug molecule at lower temperature. Polarization curves depict that the drug acts as a mixed type inhibitor. The results of electrochemical impedance spectroscopy (EIS) indicate that the charge transfer phenomenon controlled the corrosion reaction. The morphological behavior of the uncorroded and corroded coupons was investigated by scanning electron microscopy and atomic force microscopy studies. The mechanism of adsorption from the variation of inhibition effectiveness with kinetic and activation parameter through Langmuir, Freundlich, Frumkin and Flory-Huggins isotherm, put forward a significant physiochemical mode of interaction of the drug on the metal surface. The outcomes obtained from all the experimental techniques and the information obtained via molecular dynamics (MD) and density functional theory (DFT) evaluation are in good correlation. (C) 2018 Elsevier B.V. All rights reserved.