Biomimetic Superoleophobicity of Cotton Fabrics for Efficient Oil–Water Separation

Textile materials have gained much attention as membranes for oil–water separation. However, traditional membranes are suffered by either energy‐intensive preparation method or the fouling during the practical application. Motivated by the biomimetic surface of fish, this paper reports the modification of cotton fabrics using a single‐step hot alkali treatment, which creates roughened morphologies in micro‐ and nanoscale on fiber surface by removing noncellulosic compounds on sample and enhances the hydrophilicity of fabrics due to the introduction of numerous hydroxyl groups in the material. The developed fabrics show underwater superoleophobicity with oil contact angles more than 170°. When the textile is employed as a membrane for oil–water separation, water permeates quickly through the pores and capillary canal of fabrics, whereas oil is obstructed due to the inherent repellency with water. The cotton fabrics demonstrate high separation efficiency, excellent reusability, antifouling, and self‐cleaning properties in a single‐unit gravimetric filtration for various oil–water mixtures, thus making the material a promising and highly energy‐efficient candidate for the cleanup of oil spills.