Preparation and properties of super hydrophobic cotton fabric constructed by modified nano-SiO2 hybrid fluoro-epoxy copolymer

Most of the super hydrophobic cotton fabric surfaces changed the original properties of cotton fabric and cannot be continuously used for oil-water separation. In this paper, the fluorine-containing epoxy polymer P(GMA-r-DFMA) was reacted with KH550 modified nano-SiO2 to obtain an organic-inorganic hybrid super hydrophobic solution. By dipping process, the super hydrophobic cotton fabric surface was obtained. P(GMA-r-DFMA) can reduce the surface energy of cotton fabric, and modified silica can improve the surface roughness of cotton fabric to achieve super hydrophobic effect. The optimum parameters (polymer concentration, soaking time, drying time and drying temperature) for constructing super hydrophobic cotton fabric surface were explored. The optimal parameters are polymer concentration 5 mg/mL, soaking time 5 h, drying time 4 h, and drying temperature 120 °C. Under the optimal conditions, the water contact angle of the modified cotton fabric surface is 162 ± 3° and the water rolling angle is 10 ± 1°. The study on surface self-cleaning property of modified cotton fabric shows that modified cotton fabric can be restored to clean state after being soiled by toner and washed by deionized water. When the oils were n-hexane, n-octane and trichloromethane, the oil-water separation efficiency of the modified cotton fabric could reach 98 %, 98 % and 96 %, and the effect was stable. The surface of modified cotton fabric has obvious silver mirror phenomenon. The results of Scanning Electron Microscopy showed that the surface of cotton fabric was smooth before modification, but many small bumps and folds were added on the fabric surface after super hydrophobic modification, and the roughness became larger. The super hydrophobic coating is very thin and does not change the color, softness and other properties of the cotton fabric.