Colocid Dye - A Potential Corrosion Inhibitor for the Corrosion of Mild Steel in Acid Media

Abstract

Corrosion inhibition nature of Colocid dye on the corrosion of mild steel in acid media was analyzed using weightloss and electrochemical methods. The results of electrochemical and weightloss studies indicated that Colocid acid could act as a potential inhibitor for mild steel in acid media. It has been observed that the inhibition efficiency increases with inhibitor concentration and the inhibition efficiency of Colocid acid dye for the corrosion of mild steel in 1.0 M HCl solution is larger than that in 0.5 M H 2 SO 4 solution.Potentiodynamic polarization studies showed that the dye molecule is of mixed type inhibitor. The adsorption of the compound on the mild steel surface obeyed Langmuir adsorption isotherm. The potential of zero charge was measured to find corrosion inhibition mechanism in these media.

Performance of Methyl-5-Benzoyl-2-Benzimidazole Carbamate (Mebendazole) as Corrosion Inhibitor for Mild Steel in Dilute Sulphuric Acid

“…The correlation coefficient ( R 2 ) value (0.3393) for the reaction at 60°C deviated significantly from unity, which also supported the deduction that the critical concentrations of anions required for the protection of metals in corrosive media increased as the temperature was increased. There was a slight slope deviation and correlation coefficients of the Langmuir plot from unity, which may be attributed to the interactions among adsorbed species on the metal surface and changes in the adsorption heat with increasing surface coverage [ 23 , 24 , 40 ]. The adsorption isotherm, Figure 8 , was plotted for MBZ using the linear form of the Langmuir adsorption isotherm shown in equation ( 5 ): where θ , K ads , and C inh indicated the degree of surface coverage, adsorption/desorption process equilibrium constant, and inhibitor concentration, respectively.…”

“…Some of the most effective organic inhibitors include amines, sulphur compounds such as thioethers, thiourea, thioalcohols, hydrazine and thioamides, and heterocyclic nitrogen compounds [ 21 ]. Organic compounds are good inhibitors especially when they have functional electron-rich centres such as pi-electron in triple or conjugated double bonds and the presence of aromatic rings in their structures which serve as major adsorption centres [ 21 – 23 ].…”

N‐methyl‐2‐hydroxyethylammonium oleate ionic liquid performance as corrosion inhibitor for mild steel in hydrochloric acid medium

“…[ 43 ] The surface charge of steel can be calculated by the following equation: where E r is Antropov's “rational” corrosion potential. [ 41,44 ] When E r is negative, the net charge of the surface is negative, and thus the adsorption of cations is favored. However, a positive E r means that the surface charge is positive, and then preferential adsorption of anions is expected.…”

“…[41,45] Thus, two adsorption mechanisms can be proposed: first, the protonated part of [m-2HEA][Ol] can form an electrostatic bond with Cl − ions earlier adsorbed on the steel surface, and PIL molecules may attach to the metal surface through chloride bridges. [44] Meanwhile, the IL anion (carboxylic function) physically adsorbs on the positively charged steel surface. It means that chloride ions act as a bridge to subsequent adsorption of [m-2HEA][Ol] on the steel surface, and then physisorption turns into chemisorption.…”

Theoretical Evaluation of the Corrosion Inhibition Performance of an Organic Heterocyclic Compound

“…As shown in Table 2, the corrosion rate increased by increasing the temperature, while the inhibition efficiency decreased by increasing the temperature. This is because the adsorption of inhibitor decreased with the rise of matrix temperature, which also indicates that the inhibitor was chemically adsorbed on the mild steel surface due to desorption initiation at elevated temperature, resulting in the lessening of IE % values of TZ CDI at elevated temperatures [30].…”