Micrometrically scaled textured metallic hydrophobic interfaces validate the Cassie-Baxter wetting hypothesis

The possibility of forming a hydrophobic metallic interface is shown when it is micrometrically textured. On such surface obtained by gold coating the polymer honeycomb template, the apparent contact angle of water was observed to be close to or greater than 90°. The metal hydrophobicity is explained by trapping air inside pores of pattern according to the Cassie-Baxter wetting model. The agreement between calculated and observed values of the apparent contact angle justifies the applicability of this model in the present case. Formation of the acute local (Young) angle on the pore surface is provided by its concave form.