Wettability of micro and nanostructured surface of titanium based electrodes: Influence of chemical and electrochemical etching

The present work investigates the effects of different surface micro- and nanostructures on electrode morphology, wettability, and electrochemical performance. In their preparation, different etching agents have been used and compared. The nanostructures have been obtained by anodizing titanium foils in a glycerol medium. The morphology of the so-prepared electrodes was analyzed by scanning electron microscopy. The electrochemical performance was evaluated by potentiodynamic polarization and impedance spectroscopy. The wettability of the substrates was investigated by sessile-drop goniometry by the measure of the contact angle using both water and an organic solvent. The preliminary results show that the surface treatments produced a substantial variation in the wettability of the treated substrates compared to that of untreated titanium. Contrary to the alkaline etching, the acid etching resulted in increased hydrophilicity. The nanotubular structures increased the materials hydrophobicity of air aged samples.