In-situ design, characterization and use of durable superhydrophobic thin coatings applied on polymeric films

Superhydrophobic coatings on polymeric films are in high demand due to their various real-world applications in a number of different fields. However, reported coatings lack durability or have complicated processes rendering them impractical. Here, tetraethylorthosilicate is polymerized via a modified Stöber method in the presence of a corona treated PP film (in-situ) which results in a thin silica-structured layer, covalently bonded to the PP film. Fluorocarbon silanes are then further reacted with the silica layer. The high surface roughness of the silica structures and low surface energy of the fluorocarbon silanes produce superhydrophobic surfaces. PP films coated with flake-like silica structures resulted in higher surface roughness and superhydrophobicity than the particle-like coating. Additionally, the flake-like silica coating exhibited good self-cleaning properties and durability to sandpaper abrasion tests. This novel in-situ process to obtain a hydrophobized SiO₂ coating may potentially be used industrially due to its simplicity and promising results.