NIST logo

Publication Citation: Hierarchical Roughness Makes Superhydrophobic States Stable

NIST Authors in Bold

Author(s): Michael Nosonovsky; Bharat Bhushan;
Title: Hierarchical Roughness Makes Superhydrophobic States Stable
Published: Date Unknown
Abstract: Roughness enhances hydrophobicity of a solid surface leading to high contact angles with water. To achieve low contact angle hysteresis along with a high contact angle, superhydrophobic surfaces should form composite interface (CI) with air pockets in the valleys between asperities. The CI is often unstable and can be irreversibly transformed into the homogeneous interface. We formulate stability criterion, identify mechanisms, which lead to destabilization of the CI, and show that these mechanisms are scale-dependent. To effectively resist these scale-dependent mechanisms, a multiscale (hierarchical) roughness is required. Such multiscale roughness is found in natural and artificial superhydrophobic surfaces.
Citation: Microelectronic Engineering
Keywords: superhydrophobicity;wetting
Research Areas: Characterization, Ceramics