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.