Macro and micro wettability of hydrophobic siloxane films with hierarchical surface roughness

作者：Terpilowski Konrad; Goncharuk Olena; Gun'ko Vladimir M

来源：Smart Materials and Structures, 2018, 27(7): 075002.

DOI：10.1088/1361-665X/aac243

• macro and micro wettability
• hydrophobic surfaces
• roughness adjustment
• equilibrium contact angle

A method has been proposed to control the macro-and microwetting properties of hydrophobic surfaces through changes in the roughness due to modifying siloxane films with silica microparticles (MP). An experimental and theoretical analysis of macro-and micro-wettability dependence on the roughness of a film surface was carried out by combination of SEM and XPS methods with evaluation of equilibrium contact angles from Tadmor's equation. SEM images (environmental mode) allowed characterizing the mosaic hydrophobicity/hydrophilicity of the siloxane film surface. Hydrophobic siloxane films filled with silica MP were synthesized on the plasma activated and non-activated glass substrates by the sol-gel dip-coating method using tetraethylorthosilicate based precursor compositions with subsequent reaction with hexamethyldisilazane. The values of water contact angles higher than 150 degrees indicating a superhydrophobic effect were observed for films with combining nano-and micro-hierarchical roughness. Moreover, considering wettability on the micro scale the hybrid effect was discovered and confirmed by the SEM and XPS studies showing the presence of not only hydrophobic but also hydrophilic surface domains.

• 出版日期2018-7