Fabrication of a Robust Superhydrophobic Surface on Cotton Fabric with Dual Self-Cleaning Properties via In Situ Growth and Surface Modification

This work focuses on enhancing the surface superhydrophobicity of durable superhydrophobic cotton fabric and endowing it with chemical-active decontamination through photocatalytic degradation of oily contaminants and physical-passive self-cleaning. We fabricate a photocatalytic superhydrophobic cotton fabric with a multilevel rough structure by in situ growth and surface modification. TiO₂ micro/nanoparticles are synthesized and loaded onto the cotton fabric via an ultrasound-assisted in situ growth method. A robust C-O-Ti covalent bonding interface forms between the TiO₂ micro/nanoparticles and cotton fibers, significantly enhancing the fabric's surface structural stability. Furthermore, the surface is comodified by stearic acid (STA) and poly(dimethylsiloxane) (PDMS) to finally obtain the superhydrophobic cotton fabric. Its water contact angle (WCA) reaches 162.6 ± 1.7°, and the sliding angle (SA) is reduced to as low as 8.7 ± 0.9°. The surface rapidly degrades oleic acid (OA) under 1.5 h of ultraviolet (UV) irradiation, exhibiting good chemical-active self-cleaning properties for photocatalytic degradation and restoring the physical antifouling of the fabric. Notably, the superhydrophobicity of the surface is maintained even after withstanding 30 household wash cycles, linear wear of 1800 cm, and immersion in different pH solutions for 28 h. The superhydrophobic cotton fabric with dual self-cleaning properties shows potential in protective clothing, home textiles, and specialized military equipment.