Fluorine-Free Multi-durable Superhydrophobic Cotton Fabrics Prepared by an Atomization Spraying Method for Self-Cleaning and Oil–Water Separation

Superhydrophobic textiles have special applications in many fields such as medical treatment, military protection, oil-water separation, etc. In the large-scale pad-dry-cure process, a large number of polymer binders are often added to improve the superhydrophobic durability, resulting in a significant reduction in air permeability. To address this issue, a low-liquid atomization spray method was adopted to fabricate multi-durable superhydrophobic cotton fabrics using <i>N</i>¹,<i>N</i>⁶-bis(2,3-epoxypropyl)hexane-1,6-diamine, a silica precursor, and fluorine-free hexadecyltrimethoxysilane as the main modifiers. The prepared fabric maintained excellent water repellency even after being subjected various harsh conditions tests such as 2000 cycles of friction, 40 washing cycles, ultrasonic treatment for 120 min, 200 tape peelings, and acid-alkali-salt corrosion for 24 h. The air permeability of the superhydrophobic fabric was measured to be 370.2 L m^-2 s^-1, which was merely 5% lower than that of the original fabric, indicating that the modified fabric retains satisfactory air permeability. The modified fabric exhibited an excellent self-cleaning effect with respect to various liquids. In addition, the prepared fabric showed good oil-water separation capability for both heavy and light oils. For heavy oil-water mixtures, the fabric sample exhibited a maintenance of 98.13% separation efficiency and a high flux of 18 032 L m^-2 h^-1 after 10 uses. These findings will help to promote the practical application of low-feed interface modification technology in the production of durable functional textiles.