Fabrication of superhydrophobic cotton fabric with multiple durability and wearing comfort via an environmentally friendly spraying method

Superhydrophobic durability of cotton fabric faces a great challenge due to the repeated washing and rubbing. The commercial pad-dry process method using polymer binders usually leads to wastewater discharge and the reduced wearing comfort. Herein, the superhydrophobic cotton fabric with strong durability was fabricated by a facile spraying method which did not produce any wastewater and can make efficient use of modifiers. The dopamine and 2-tetraethoxysilane can in-situ react to construct rough surface structure. The hexadecyltrimethoxysilane with long chain alkyl was firmly connected to cotton fiber surfaces to reduce the surface energy. The prepared sample not only obtained excellent superhydrophobicity with a water contact angle of 157 +/- 1.2 degrees and a shedding angle of 7.8 +/- 0.3 degrees, but also retained the inherent air permeability and hand feeling of cotton fabrics. Due to the strong covalent bonds between modifiers and cotton fibers, the modified cotton fabric exhibited high multiple mechanical durability and chemical stability in acid/base solution. The superhydrophobic cotton fabric showed a satisfactory self-cleaning performance toward the common stains in daily life. In addition, the modified fabric can serve as a separation filter for oil/water separation with high separation efficiency and reusability. This facile and clean preparation method showed great potential in large-scale production of durable superhydrophobic textile.