Fabrication of Roughness Enhanced Hydrophobic Coatings

Abstract

The non-wetting character derived with the lotus-leaf phenomenon of water droplet rolling off from leaf indicates the Hydrophobic/Super-hydrophobic surface which depends on the morphology and the topography of surfaces, described by the Wenzel and Cassie–Baxter theories. Hydrophobicity arises when a molecule does not partake in the hydrogen bonding of water. The water droplet is suspended on a composite interface made of solid and air trapped between the droplet and the surface. Materials with superhydrophobic or superoleophobic properties are in extreme demand due to numerous potential applications such as in anti-corrosion coatings, self-cleaning, anti-icing coatings, liquid-repellent textiles, oil/water separation, microfluidic devices, optical devices. Films of PVDF/MTMS and PVDF/MTMS/TEOS were prepared by sol-gel technique. PVDF/MTMS and PVDF/MTMS/TEOS film shows a surface roughness of 60.76 µm and 57.64 µm with contact angle 132° and 125° respectively, which ensures hydrophobicity. The film developed was found to be super-hydrophobic and could remove the dust on coated glass, metallic surfaces and hence can be assured for Self-cleaning application.