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

The influence of SodiumGluconate (SG), cetyltrimethylammonium bromide (CTAB) and their mixture on galvanized steel corrosion in 3.0%NaCl solution was investigated by using electrochemicalmeasurement coupledwith scanning electron microscopy (SEM). The polarization measurements indicated that SG, CTAB and their mixture act as cathodic-type inhibitors. Indeed, a synergistic effectwas found between SG and CTAB. In fact, the inhibition efficiency of the mixture reached 94% at 10?3M of SGwith 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.