Corrosion Inhibition Effect of Cationic Surfactant and Synergistic Effect of the Presence of the Chloride Ions

Abstract

Corrosion inhibition effect of cationic surfactant DTAB (dodecyl threemethyl ammonium bromide) on low carbon steel in 1M HCl was studied using weight loss method. Inhibition efficiency increased with the increase of surfactant concentration. Also, synergistic effect between surfactant and chloride ions in 1M HCl was investigated with the presence of different concentration of NaCl. The inhibition efficiency increased with the increase of NaCl concentration and reached the maximum value near 0.1 M. This composite inhibitor system containing cationic surfactant and chloride ions was efficient and low-cast for steel corrosion inhibition in HCl medium, even when the concentration of DTAB was as low as 0.5x10 -4 M.

Electrochemical Effect of Cationic Gemini Surfactant and Halide Salts on Corrosion Inhibition of Low Carbon Steel in Acid Medium

“…It is obvious that at low pHs (0 -3) the solution is more corrosive than the higher pHs because of more acid concentration. Although, with presence of surfactant, more acid concentration made steel surface more polar and caused more adsorption of surfactant molecules on the steel surfactant, but the presence of this amount of acid (1-10 -3 M HCl) caused an increase in the corrosion rate of steel more than the adsorption of surfactant decreases it (29,32). It seems the cathodic reduction of hydronium ions are the predominant reaction.…”

“…So the inhibition efficiency increased sharply at these concentrations. At the concentration higher than CMC (10 -5 -10 -3 M), a bimolecular layer is formed on the steel surface and a very rigid barrier of surfactant molecules is established on the steel surface (Fig.2-III and Fig.3-c) (7,29,32,(36)(37)(38)(39)42). 4 shows similar pattern of corrosion for both cases but, it is more pronounced, when pH of the solution is low (0 -3) and no surfactant is present in the solution.…”

“…In acid solution, halides are known both to stimulate and inhibit the corrosion of metals (21)(22)(23)(24)(25)(26)(27)(28)(29). Due to the ability of halide ions to be adsorbed on the metal surface, many attempts have been made to explain the difference in the action of the halides which may depend on the atomic radii and/or the electronegativity.…”

“…It is an effective and applicable means to enhance the performance of inhibitors, by reducing the quantity of bio-recalcitrant, non-degradable, carcinogenic and more expensive cationic surfactant ingredients. Halide ions have been demonstrated to be effective additives for quaternary ammonium surfactants in corrosion inhibition system of steel in acidic media as they increase the inhibiting tendency of the positive quaternary ammonium ion by the synergistic effect (21)(22)(23)(24)(25)(26)(27)(28)(29)(30)(31)(32)(33)(34). Also it has been reported (30,31) , Ni 2+ and Fe 3+ on the general and pitting corrosion of aluminum (47).…”

“…Surfactants accumulate in special order at the interfaces and modify the interfaces and thus control, reduce, or prevent reactions between a substrate and its surroundings, when added to the medium in small quantities. Different surfactant groups have been reported to present corrosion inhibitory potential which depends on the classification of surfactants , the substrate type, inhibitor concentration (2)(3)(4)(5)(6)(7)(8)(9)(10)(11)(12)(13)(14)(15)(16)(17)(18)(19)(20), time of immersion in inhibitor solution (6), the type of acid (8), pH (8), presence of salts (9)(10)(11)(12)(13)(14)(21)(22)(23)(24)(25)(26)(27)(28)(29)(30)(31)(32)(33)(34), co-surfactant (35,36), temperature (36)(37)…”