Protection for galvanized steel in 3.0 % NaCl solution by SG/CTAB

In this book, 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 acted 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 10-3 M of SG with 2.74×10-5 M of CTAB. In addition, this inhibition efficiency improved remarkably with immersion time and slightly decreased with temperature. The SEM observations and energy dispersive X-ray (EDAX) analysis indicated that the surface homogeneity increased with mixture addition. Finally, the thermodynamic parameters (¿G*a, ¿H*a, ¿S*a) were determined and discussed.