Superoleophobic Cotton Textiles

TLDR

Cotton textiles are naturally hydrophilic and oleophilic, and although superhydrophobic variants can be self‑cleaning, they typically lack super oil repellency, which compromises their self‑cleaning performance. The study reports the preparation of superoleophobic cotton textiles with a multilength‑scale structure, achieving a hexadecane contact angle of 153° and a roll‑off angle of 9°. The multilength‑scale roughness was created by combining the woven structure with two covalently bonded silica layers—microparticles and nanoparticles. Superoleophobicity was obtained by adding perfluoroalkyl groups, and the nanoparticle layer proved essential for achieving the low roll‑off angles.

Abstract

Common cotton textiles are hydrophilic and oleophilic in nature. Superhydrophobic cotton textiles have the potential to be used as self-cleaning fabrics, but they typically are not super oil-repellent. Poor oil repellency may easily compromise the self-cleaning property of these fabrics. Here, we report on the preparation of superoleophobic cotton textiles based on a multilength-scale structure, as demonstrated by a high hexadecane contact angle (153° for 5 μL droplets) and low roll-off angle (9° for 20 μL droplets). The multilength-scale roughness was based on the woven structure, with additional two layers of silica particles (microparticles and nanoparticles, respectively) covalently bonded to the fiber. Superoleophobicity was successfully obtained by incorporating perfluoroalkyl groups onto the surface of the modified cotton. It proved to be essential to add the nanoparticle layer in achieving superoleophobicity, especially in terms of low roll-off angles for hexadecane.