Superhydrophobic cotton fabrics prepared by one-step water-based sol-gel coating

A simple one-step superhydrophobic coating method for cotton fabrics based on a modified silica hydrosol is presented in this study. The modified silica hydrosol was prepared by the co-hydrolysis/co-condensation of methyl trimethoxy silane and a non-fluoro compound, hexadecyltrimethoxysilane, via water-based sol-gel reaction under alkaline condition in the presence of a surfactant. The as-obtained products were characterized by particle size analyzer, scanning electron microscopy, scanning probe microscopy, X-ray photoelectron spectroscopy, and thermal gravimetric analysis. Superhydrophobic cotton fabric with a water contact angle of 151.9 degrees for a 5 mu L water droplet and a water shedding angle of 13 degrees for a 15 mu L water droplet was successfully obtained.