Fabrication of cardanol-based superhydrophobic cotton fabric for highly effective oil-water separation

Abstract A bio-based superhydrophobic durable cotton fabric was manufactured by using a method of ultrasonic-assisted in situ growth. The hierarchical structure of cotton fibers was generated by the deposition of the hydrophobic composite nanoparticles, which derived from the hydrolysis and co-condensation of cardanol-based benzoxazine (C-aps) and tetraethylorthosilicate (TEOS). The obtained superhydrophobic surface had a water contact angle of 158.5 ± 0.2° with special wettability. The mechanical and environmental stability of the superhydrophobic cotton fabrics were assessed through sandpaper abrasion, ultrasound treatment, high temperature tests, acid/alkaline liquids, solution immersion, and water drop experiment. Additionally, the modified cotton fabrics could separate oil-water mixtures with excellent separation efficiency (> 99.0%), high flux (as high as 6748.2 ± 237.4 L m−2 h−1), and stable reusability. The study demonstrates that the bio-based superhydrophobic cotton fabric has practical applications in the management of industrial wastewater and oil contaminants.