Fabrication of superhydrophobic coatings with self-cleaning properties on cotton fabric based on Octa vinyl polyhedral oligomeric silsesquioxane/polydimethylsiloxane (OV-POSS/PDMS) nanocomposite

Wetting behavior of solid surfaces plays an important role in various industrials and even daily life applications. Controlling the surface wettability through fabricating strongly hydrophilic or hydrophobic properties is achieved by tailoring surface topography and chemical composition. Polyhedral oligomeric silsesquioxanes (POSSs) are a class of hybrid materials with the possibility of hydrophobicity enhancement through simultaneous increase in surface roughness and reduction of surface energy.In this study, octavinyl-POSS (OV-POSS) structures were utilized in fabrication of superhydrophobic cotton fabric. Coating was successfully performed through creating a two-layer topography via spraying method. In brief, surface roughness was enhanced by spraying a base layer of TiO2 sol over the surface followed by applying a nanocomposite layer composed of 0.02 wt% of POSS in polydimethylsiloxane (PDMS).It was observed that, water contact angle (WCA) of pristine and TiO2 coated fabric was enhanced from 0° up to ∼168° using 0.02 wt% OV-POSS/PDMS nanocomposite with a water sliding angle (WSA) of <10°. According to the results, environmentally friendly nature of precursors, high thermal, mechanical and chemical stability, self-cleaning and anti-adhesion propertiesof the as-prepared coating and simple preparation method with no special post-treatment requirement, confirm that the as-prepared coating is perfect candidate for large-scaled applications.