The use of toxic components and short longevity greatly restricted the commercial application of superhydrophobic surfaces in oil-water separation, antifouling, and self-cleaning. To address these concerns, a durable, robust, and fluorine-free superhydrophobic fabric is prepared on account of inspiration of nature. In this work, submicrometer-sized silica particles with different particle sizes are deposited onto cotton fabrics, followed by hydrophobic modification of poly(dimethylsiloxane) (PDMS), and consequently bonded the substrate and coating via powerful covalent bonds through a simple dip-coating technique. The rough surface with an imitated lotus-leaf-like hierarchical protrusion structure is constructed by deposited submicrometer-sized particles with different particle sizes, while the fabric with a low surface energy is achieved by the hydrophobic modification of PDMS. Ultimately, the fabricated fabric exhibits extraordinary superhydrophobicity with a high water contact angle (WCA) of 161° and a small sliding hysteresis angle (SHA) of 2.4°. Besides, considerable mechanical stability to withstand 130 sandpaper abrasion cycles and 40 washing cycles, and chemical resistance with sustained superhydrophobic property in various harsh environments (e.g., boiling water, strong acid/base solutions, and various organic solvents), are presented. Moreover, higher than 90% separation efficiency with a contact angle >150 ° is produced even after 50 cycles when the fabricated fabric serves as a filter during the oil-water separation besides its outstanding staining resistance and self-cleaning property.
Keywords: hierarchical protrusion structure; oil−water separation; poly(dimethylsiloxane); submicrometer-sized silica particles; superhydrophobic cotton fabric.