Novel method of producing a superhydrophobic surface on Si

Superhydrophobic surfaces were produced on silicon substrates coated with gold, which facilitates the formation of SiO(2) protrusions on the Au surface in air at low temperatures. The roughness of SiO(2) increased with the oxidation period at, for example, 150 degrees C. When the SiO(2) surface is alkylated with dodecanol, the contact angle of water exhibited a transition from the Wenzel (complete penetration) wetting state to the Cassie (incomplete penetration) wetting state with increased roughness. It was discovered that Cassie wetting was optimized after a specific oxidation period at 150 degrees C to produce an advancing contact angle of approximately 170 degrees and a receding angle of approximately 160 degrees.