Inhibitory effects of 1-butylpyridin-1-ium bromide in 0.1 M sulphamic acid for mild steel

Abstract

ABSTRACT In recent years, there has been a consistent development in the introduction of novel corrosion inhibitors due to their potential to reduce the dissolution of metal surfaces under various corrosive environments. The current study investigates the inhibitory effect of the surfactant 1-butylpyridin-1-ium bromide (BPB) on mild steel (MS) in 0.1 M sulphamic acid. The electrochemical impedance spectroscopy (EIS) and potentiodynamic polarisation (PDP) studies were used to analyse the inhibition investigations. In addition, atomic force microscopy (AFM), scanning electron microscopy (SEM) and contact angle (CA) measurements were also used to analyse the inhibition investigations. The PDP studies showed a maximum inhibition efficiency of 63.3% at 400 ppm concentration, demonstrating the inhibitor’s efficacy. The investigated compound was found to comply with the Temkin adsorption isotherm with an R 2 value of 0.99954. The results of PDP tests firmly suggest that the inhibitor is of mixed type. ΔG ads values of −9.659 kJ mol−1 suggested that the inhibitor adhered to the metal surface by physical adsorption. Based on the findings it appears that the molecules adhere to the surface of MS forming partial hydrophobic films that act as a barrier for the metal surface.