Synergistic corrosion protection for galvanized steel in 3.0% NaCl solution by sodium gluconate and cationic surfactant

• Published in: Journal of molecular liquids 2016-08, Vol.220, p.549-557
• Main Authors: Azaroual, M.A., El Harrak, E.F., Touir, R., Rochdi, A., Touhami, M. Ebn
• Format: Article
• Language: English
• Subjects: Corrosion inhibition; Electrochemical techniques; Galvanized steel; Scanning electron microscopy; Sodium gluconate; Surfactant
• ISSN: 0167-7322; 1873-3166
• DOI: 10.1016/j.molliq.2016.04.117

The influence of Sodium Gluconate (SG), cetyltrimethylammonium bromide (CTAB) and their mixture on galvanized steel corrosion in 3.0% NaCl solution was investigated by using electrochemical measurement coupled with scanning electron microscopy (SEM). The polarization measurements indicated that SG, CTAB and their mixture act as cathodic-type inhibitors. Indeed, a synergistic effect was found between SG and CTAB. In fact, the inhibition efficiency of the mixture reached 94% at 10−3M of SG with 2.74×10−5M of CTAB. In addition, this inhibition efficiency improved remarkably with immersion time and temperature. The SEM observations and energy dispersive X-ray (EDX) analysis indicated that the surface homogeneity increases with mixture addition. Finally, the thermodynamic parameters were determined and discussed. SEM images for the galvanized steel surface after two days of immersion in 3% NaCl (a) blank solution, (b) with mixture. [Display omitted] •SG and CTAB were investigated for galvanized steel corrosion in 3.0% NaCl.•Their mixture is also investigated for galvanized steel corrosion.•It is shown that these compounds inhibit the corrosion.•The inhibition efficiency of the mixture increased with time and temperature.•SEM/EDX indicated that these compounds act by the formation of a protective film.