Electrochemical Characterization of Catechol-Dimethylamine Adduct at Different pH Values

Abstract

The efficiency of Commelina benghalensis leaves extract as a mild steel corrosion inhibitor in hydrochloric acid (HCl) and sulphuric acid (H2SO4) has been evaluated. The corrosion rates were determined using the gravimetric (weight loss) and electrochemical techniques. The results obtained in the absence and presence of Commelina benghalensis extracts were used to calculate the inhibition efficiency (%), and to propose the inhibition mechanism and adsorption type. The obtained results showed that the inhibition efficiency increased with the increase in concentration of Commelina benghalensis extract. The phenomenon of chemical adsorption was proposed, and the inhibitor adsorption was found to obey Langmuir, Temkin and kinetic thermodynamic models. The polarization study reveals that, in the inhibitor presence, the corrosion current value decreases, indicating the formation of a protective film on the metal surface, which prevents the electron release from it.

Experimental and Theoretical Studies of Tailor-made Schiff Bases as Corrosion Inhibitors for Carbon Steel in HCl

“…The relationship between the surface coverage (θ) and the inhibitor concentration (C) is used in the isothermal adsorption model 54 . The tested models were Langmuir (Equation 7), Temkin (Equation 8), El-Awady (Equation 9), and Freundlich (Equation 10) 55,56 :…”

INHIBITION PROFICIENCY OF Al 3+ ON MILD STEEL CORROSION IN DIFFERENT pH AQUEOUS MEDIUM

“…However, these steels have poor corrosion resistance in aqueous solutions. Several research have been done regarding the mild steel corrosion in dilute sulfuric acid solution, in coal and iron ore environment, in aqueous extract of commelina benghalensis leaves, in hydrochloric acid solution, in acetic acid solution , in acid sulfate solution, and in chloride aqueous solutions (Zhou et al, 2019;Khara et al, 2016;Medrano-Vaca ert al., 2008;Gardiner and Melchers, 2002;Ahamed et al, 2019;Hassan et al, 2007;Veloz and Gonzalez, 2002;Krstajic et al, 1997). It is known that chloride ions are very much aggressive and have a tendency to reduce protective ability of the passive film by film thinning, penetration, and film rupture mechanisms (Zhou et al, 2019;Foley, 1970;Macdonald, 1992;McCafferty, 2010;Deyab, 2016;Song, 2017).…”