Transformation of hydrophilic cotton fabrics into superhydrophobic surfaces for oil/water separation

In the present study, silica hydrosols were firstly prepared by water-based sol-gel method with the surfactant emulsification, using tetraethoxysilane as the precursor and ammonium hydroxide as the catalyst. Then, the silica hydrosols were applied to the cotton fabrics by dipping process, followed by the modification with (heptadecafluoro-1,1,2,2-tetradecyl) trimethoxysilane and heat treatment to prepare superhydrophobic cotton fabrics. The process resulted in SiO2 nanoparticles covalently attached to the cellulose surface and fluorine-containing siloxane coupling agent which brought about an inherent microscale roughness and the superhydrophobic character. The investigation of oil/water mixture has been carried out using the as-prepared superhydrophobic cellulose fabric-based materials.