Corrosion inhibition of carbon steel in acid chloride solution using ethoxylated fatty alkyl amine surfactants

Abstract

Four novel non-ionic ethoxylated fatty alkyl amine surfactants (I-IV) were synthesised and investigated as corrosion inhibitors of carbon steel in 1 M hydrochloric acid solution using gravimetric, open circuit potential and potentiostatic polarisation techniques. The percentage inhibition efficiency (g%) for each inhibitor increased with increasing concentration until the critical micelle concentration (cmc) was reached. The maximum inhibition efficiency approached 95.1% in the presence of 400 ppm of the inhibitor (IV). It was found that the adsorption of the surfactants on carbon steel followed the Langmuir adsorption isotherm. Potentiostatic polarisation data indicated that these surfactants act as mixed type inhibitors. The values of activation energy (E a *) of carbon steel dissolution in 1 M HCl were calculated in the absence and presence of 400 ppm of each inhibitor. Finally, scanning electron microscopy (SEM) was used to examine the surface morphology of polished carbon steel surfaces and those immersed in 1 M HCl in the absence and presence of 400 ppm of inhibitor (IV).

Inhibition by tween-85 of the corrosion of cold rolled steel in 1.0 M hydrochloric acid solution

“…Recently, some nonionic surfactants have also been widely used as corrosion inhibitors for steel in acidic media [33][34][35][36][37][38]. However, data regarding the use of nonionic surfactants like the tween series are not so plentiful.…”

Surface active and thermodynamic properties of some surfactants derived from locally linear and heavy alkyl benzene in relation to corrosion inhibition efficiency

“…This reduction increases with increasing concentration. At high concentration, however, when a certain concentration was reached (CMC), the surfactant molecules form micelles, which were in equilibrium with the free surfactant molecules [27]. The CMC values were listed in Tables 4 and 5 and observed in Fig.…”

Adsorption and corrosion inhibition of amphiphilic compounds on steel pipeline grade API 5L X52 in sulphuric acid 1 M

“…Inhibition of corrosion and the reduction in current density observed was due to the inhibitor performance, Lorenz, and Mansfeld have pointed out that corrosion inhibition is linked with [22]: (1) geometric blocking of the species adsorbed in active sites on metal surface, (2) blocking the active sites for the species adsorbed on them, or (3) electrocatalytic effect of the inhibitor or its products, however, the latter seems unlikely, the addition of CI to the corrosive solution did not modify the cathodic Tafel slope or the anodic Tafel slope (b c and b a ), thus the mechanism of the processes was not affected. The decrease in current density with the inhibitor concentration is associated with a shift of corrosion potential E corr to more negative values, indicating that amphiphilic compounds act as cathodic type inhibitors [22][23][24][25][26][27][28][29][30][31]. The approximately constant values of the Tafel slopes suggest that the inhibition mechanism for amphiphilic compounds involves a single reaction site blocking.…”