Development of superhydrophobic fabrics by surface fluorination and formation of CNT-induced roughness

Abstract

Superhydrophobic textile material having self-cleaning function was developed by employing carbon nanotubes (CNTs) and water-repellent agents. Hydrophobic fabrics were prepared on 100% polyester woven fabrics with various yarn diameters and yarn types. The wetting behavior of fabrics with different treatments was compared for: siloxane repellent, fluorocarbon repellent, and CNT added fluorocarbon repellent. Drawn textured yarn (DTY) fabrics exhibited higher contact angle (CA) than filament yarn fabrics due to the larger surface roughness contributed by the textured yarn. Fabrics treated with fluorocarbon presented larger CA and lower shedding angle than those treated with siloxane, because of the lower surface energy of fluorocarbon repellent. Specimens made of 50 denier DTY and treated with CNT-Teflon AF® showed the most superhydrophobic characteristics in the study, producing the static contact angle greater than 150° and the shedding angle smaller than 15°. CNT on fabric surface contributed to the nano-scale surface roughness to hold the air traps like papillae of lotus leaf, giving superhydrophobic characteristics.