Cysteine Duality Effect on the Corrosion Inhibition and Acceleration of 3003 Aluminium Alloy in a 2% NaCl Solution

Abstract

Cysteine's action on 3003 aluminum alloy dissolution in a 2% NaCl solution, at different pH values, has been investigated. Weight-loss measurements, potentiodynamic polarization and electrochemical impedance at OCP were performed. The surface morphology was analyzed by SEM. The main results showed that the alloy underwent severe corrosion at 2 and 11 pH values, as compared to at 5 and 8 pH values. Furthermore, a duality effect of cysteine was noted, as it acted as a corrosion inhibitor or accelerator, depending on its concentration, and on the solution's pH value. This particular behavior can be related to the instability of the formed film adsorbed onto the metal surface. All these findings show the high complexity of cysteine action on 3003 aluminum alloy, under the investigated conditions.

Corrosion Inhibition of 3003 Aluminum Alloy in Molar Hydrochloric Acid Solution by Olive Oil Mill Liquid By-Product

“…In the acidic media, similar impedance spectra have been reported in the corrosion literature for aluminum and its alloys [23,25,26,[28][29][30][49][50][51][52][53][54][55][56][57][58][59][60][61][62][63][64]. The addition of the OMW does not affect the shape of the loops, indicating that no change in the corrosion mechanism of AA3003 alloy has occurred [65]. The impedance data are simulated by using the equivalent circuit illustrated in Figure 3 [66].…”

“…Accordingly, the calculated impedance parameters are given in Table 4. The inhibitory efficiency derived from the charge transfer resistance is obtained by the following relationship [49,58,65]:…”

The Application of Chitosan-Based Compounds against Metallic Corrosion

“…In the present chapter, we interesting in the organic inhibitor category, which its protection ability is related to its adsorption onto the metal surface via electrostatic attraction or/and chemical bond formation, leading to the formation of a protective layer resulting in corrosion mitigation [8]. It is well known that the adsorption process of these compounds occurs via their electron-donator sites like heteroatoms (N, O, S and P) and multiple bonds (π-bonds) and aromatic rings as well.…”

The role of pH in corrosion inhibition of tin using the proline amino acid: theoretical and experimental investigations

“…13 According to the available literature, cysteine and methionine amino acids have been studied extensively. [14][15][16][17][18][19][20] Nevertheless, studies on the application of this class of molecules for tin metal are still limited. Among the existing physiological amino acids, proline (Pro, Fig.…”

“…For instance, it was reported that the pH of the solution plays a decisive role, in which an inhibitor can be effective at certain pH values, while being nominal at other values. 16 Specically, a variation in pH leads to substantial modications in the inhibition system, especially the protonation state of the inhibitor molecule and the chemical composition of the metal surface. This means that the inhibitor/metal interactions will be affected by this variation, and subsequently, the observed inhibition behavior will also be modied.…”