Abstract: Owing to the chemical properties of polydopamine(PDA) and the hierarchical nanostructured of raspberry-like nanoparticles, the raspberry-like nanoparticles(PDA-SiO₂) were fixed onto the polydopamine coated cotton fibers to fabricate a super-hydrophobic cotton fibers with a micro-and nanostructure surface.Scanning electron microscope(SEM) results demonstrated that raspberry-like nanoparticles(PDA-SiO₂) were stably fixed on the cotton fibers surface. By introducing the incorporation fluorinated alkyl silane to the cotton fibers via a facile chemical reaction process, the cotton fibers surface possessed super-hydrophobicity with the water contact angle of 158.2° and super-oleophilicity with the oil contact angle of 0°. The as-prepared cotton fibers can be applied as effective materials for the separation of water and oil mixture with separation efficiency as high as 99.4%. In particular, the as-prepared cotton fibers showed excellent oil/water absorption selectivity with a high oil absorption capacity of 34 g/g. Moreover, the absorbed oils can be recovered by simple mechanical squeezing, and the porous cotton fibers maintained a high oil-absorption capacity upon multiple squeezing absorption cycles, displaying excellent recyclability. Therefore, this reported cotton fibers has the advantages of high separation efficiency, high absorption capacity, and outstanding durability, exhibiting the strong potential for industrial production.

Key words: Polydopamine, Raspberry-like nanoparticles, Cotton fiber, Oil/water separation, Oil absorption