Preparation of superhydrophobic cotton fabrics based on SiO2 nanoparticles and ZnO nanorod arrays with subsequent hydrophobic modification

Superhydrophobic cotton fabrics were prepared by fabricating rough surfaces using SiO2 nanoparticles and ZnO nanorod arrays together with subsequent n-dodecyltrimethoxysilane (DTMS) modification. The as-obtained products were characterized by particle size analyzer, field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), scanning probe microscope (SPM) and X-ray photoelectron spectroscopy (XPS) respectively. The prepared SiO2 nanoparticle and ZnO nanorod show a similar diameter while the ZnO nanorod has a much higher aspect ratio. The wettability of the cotton fabric samples was investigated by water contact angle (WCA) and roll-off angle measurements. Both treated cotton fabrics exhibit superhydrophobicity with static WCAs of more than 150° for a 5 mL water droplet. The lower roll-off angle of a ZnO treated cotton fabric, which is attributed to the discontinuous three-phase contact line, shows better water-repellent properties.