Superhydrophobic metallic surfaces and their wetting properties

Two-scaled polymer patterns possessing high roughness are produced using the hot-embossing technique and coating with chromium. After covering the rough polymer surface with this metal, the resulting surface demonstrates pronounced hydrophobic properties, with water drops having apparent contact angles as high as 150°. As revealed by SEM, the surface is patterned on two scales which is known to be an important condition for superhydrophobicity of inherently wettable surfaces. The modified Cassie-Baxter approach has been used for the present relief. The calculated values of the apparent contact angles agree with the observed ones. It is important to note that the apparent contact angles almost do not depend on the local contact angles.