Synergistic inhibition between dodecylamine and potassium iodide on the corrosion of cold rolled steel in 0.1 M phosphoric acid

Abstract

The corrosion inhibition of cold rolled steel in 0.1 M aerated phosphoric acid (H 3 PO 4 ) in the presence of dodecylamine (DDA) and potassium iodide (KI) has been investigated by Tafel polarization curve and electrochemical impedence spectroscopy (EIS) at 20 8C. The results obtained from polarization curve show that the inhibition efficiency of DDA with and without KI increases with increase in concentration of DDA but the inhibition efficiency of DDA without KI is not too high. A synergistic effect exists when DDA and KI are combined together to prevent cold rolled steel corrosion in 0.1 M H 3 PO 4 . All impedance spectra in EIS tests exhibit one capacitive loop which indicates that the corrosion reaction is controlled by charge transfer process. Inhibition efficiencies obtained from Tafel polarization, transfer resistance (R t ) are consistent.

Inhibition effect of deanol on mild steel corrosion in dilute sulphuric acid

“…This is chiefly responsible for the chemisorption mechanism with the steel through charge transfer between the polar species. [19][20][21] The inhibition efficiency at lower concentrations in H 2 SO 4 suggests the mechanism of formation of the inhibitor film is due to an initial increase of the anodic activity in some sites on the surface, probably the displacement of the first hydrated monolayers of the iron oxide formation. It is proposed that these anodic points can act as favourable anchorage points for the development of the inhibitor monolayer film.…”

Synergistic Influence of Halide Ions on Corrosion Inhibition Performance of Gum Exudates of Azadirachta indica on Carbon Steel in Sulphuric Acid Medium

“…Competitive adsorption is one where cations of the inhibitor is adsorbed at various metal sites while in co-operative adsorption anions are chemisorbed on metal substrate and the cations on anion layers. There are some cases where both mechanisms operate occur simultaneously [19]. Generally, S < 1 denotes antagonistic effect while S > 1 denotes synergistic behaviour [44].…”

3-Formylindole-4-aminobenzoic Acid: A Potential Corrosion Inhibitor for Mild Steel and Copper in Hydrochloric Acid Media

“…It is well known that the surface of the metal is positively charged in acidic media [33]. It is believed that the Cl − ions could be specifically adsorbed on the metal surface and creates an excess of negative charge on the surface.…”