Electrodeposition of Corrosion Protective Zinc Films from Reverse Micellar Solutions

Electrodeposition of metallic zinc (Zn) from reverse micellar solutions of cetyltrimethylammonium bromide (CTAB) of different compositions was successfully performed using constant potential electrolysis on copper (Cu) substrate. Electrochemical behavior of ZnSO 4 was investigated in reverse micellar solutions of CTAB on a glassy carbon (GC) electrode by cyclic voltammetric technique and the electroreduction of Zn(II) to Zn(0) was suggested to be an electrochemically irreversible diffusion controlled process. Morphology and microstructure of the electrodeposited Zn films onto a Cu substrate were examined by scanning electron microscopy, while elemental characterizations were carried out by energy dispersive X-ray spectroscopic method and X-ray diffraction technique. Electrodeposition of Zn from reverse micellar solutions occurred with definite homogeneous shapes whereas, inhomogeneous/random gross Zn deposition was obtained from aqueous system. Moreover, morphology of the electrodeposited Zn films obtained from reverse micellar solutions was found to be varied with the variation of composition of reverse micellar solutions of CTAB. The corrosion protective behavior of the electrodeposited Zn films evaluated through electrochemical impedance spectroscopy and potentiodynamic polarization techniques with 3.5 wt% NaCl solution as corrosion media showed that Zn deposits obtained from reverse micellar solutions exhibited better corrosion protection behavior compared to that obtained from aqueous solution.