Acid Corrosion Inhibition and Adsorption Behaviour of Ethyl Hydroxyethyl Cellulose on Mild Steel Corrosion

Abstract

The corrosion inhibition of mild steel in 1.0 M H2SO4 solution by ethyl hydroxyethyl cellulose has been studied in relation to the concentration of the additive using weight loss measurement, EIS, polarization, and quantum chemical calculation techniques. The results indicate that EHEC inhibited corrosion reaction in the acid medium and inhibition efficiency increased with EHEC concentration. Further increase in inhibition efficiency is observed in the presence of iodide ions, due to synergistic effect. Impedance results reveal that EHEC is adsorbed on the corroding metal surface. Adsorption followed a modified Langmuir isotherm, with very high negative values of the free energy of adsorption (ΔGads). The polarization data indicate that the inhibitor was of mixed type, with predominant effect on the cathodic partial reaction. The frontier molecular orbitals, HOMO (the highest occupied molecular orbital) and LUMO (the lowest unoccupied molecular orbital) as well as local reactivity of the EHEC molecule, were analyzed theoretically using the density functional theory to explain the adsorption characteristics at a molecular level. The theoretical predictions showed good agreement with experimental results.

Imidazolium-Based Ionic Liquid as Efficient Corrosion Inhibitor for AA 6061 Alloy in HCl Solution

“…An inhibitor must be considered either anodic or cathodic when variation in the E corr value between the inhibited and the blank sample is more than 85 mV [ 31 ]. The present results demonstrate that the differences in the E corr values between the inhibited and the blank systems were not more than 85 mV, which suggests that the inhibitor is mixed-type, with a predominant influence on cathodic reactions [ 32 , 33 ]. Cathodic slope alters to some extent upon the addition of inhibitor, which indicates that the mechanism of hydrogen evolution is not significantly changed in the presence of the inhibitor.…”

Investigation of corrosion inhibition of C38 steel in 5.5 M H3PO4solution usingZiziphus lotusoil extract: an application model

“…If the difference is greater than 85 mV, the inhibitor can be treated as a cathodic or anodic type. In the opposite case (<85 mV), it is considered as a mixed type inhibitor (Jeroundi et al , 2016; Riggs, 1973; Arukalam et al , 2014; Verma et al , 2017). In our study, the minimum displacement is greater than 85 mV, which confirms that Z. lotus oil is an anodic type inhibitor.…”

Recent developments in sustainable corrosion inhibitors: design, performance and industrial scale applications

“…Table 2 represents the collection of cellulose derivatives used as corrosion inhibitors [183][184][185][186][187][188][189][190][191][192][193][194][195][196][197][198][199].…”