One-pot preparation of robust, ultraviolet-proof superhydrophobic cotton fabrics for self-cleaning and oil/water separation

Robust superhydrophobic cotton fabrics with ultraviolet (UV)-proof performance were prepared via a simple one-pot method with composite coating of hierarchical CuS microflower nanoparticles and silicone elastomer polydimethylsiloxane (PDMS). The facile preparation of CuS microflower nanoparticles was conducted via relatively low-temperature reaction. The surface morphology, chemical composition, thermal degradation behavior, and crystal structure of the products were evaluated. The simultaneous roughening due to hierarchical rough morphology of CuS microflower nanoparticles and PDMS hydrophobization resulted in the coated fabric with microscale fibers exhibiting superhydrophobic property and its water contact angle was 159.3° ± 0.6°. The superhydrophobic textile also displayed outstanding UV-proof performance with a large ultraviolet protection factor of 535.36 due to ultraviolet-absorption, light scattering and frequent light reflection of hierarchical CuS nanoparticles. The superhydrophobic textile showed excellent stain resistance and self-cleaning property and also was able to separate oil and water with high efficiency and good separation reusability caused by the contrasting wettability of the coated textile for water droplets and oil droplets. The as-prepared superhydrophobic fabric displayed excellent robustness against 2000 cycles rubbing, water jetting and long-time UV illumination and satisfactory chemical stability. This superhydrophobic coating showed no negative impact on the mechanical strength of cotton fabric. The facile approach in favor of large-scale preparation showed promising potential for wide application of flexible superhydrophobic cotton textiles with ultraviolet-blocking performance.