Superhydrophobicity of a three-tier roughened texture of microscale carbon fabrics decorated with silica spheres and carbon nanotubes

A stable superhydrophobic surface with low contact angle hysteresis using microscale carbon fabrics decorated with submicroscale silica (SiO₂) spheres and carbon nanotubes (CNTs) is created. Without any surface treatment, superhydrophobicity is achieved, and a microsized water drop can be suspended on the three-tier roughened surface, leaving an air film underneath the droplet. A modified Cassie–Baxter model analyzes that the combined effect of SiO₂ spheres and CNTs contributes a high area fraction of a water droplet in contact with air, leading to superhydrophobicity. Such a three-tier surface texture has robust superhydrophobic properties.