Fabrication of a novel superhydrophobic cotton by HDTMS with TiO2 supported activated carbon nanocomposites for photocatalysis and oil/water separation

The strong superhydrophobic and photocatalytic cotton was fabricated by a simple one-step dip rolling technique using activated carbon supported titanium dioxide (TiO2) composite with fluoride-free hexadecyltrimethoxysilane (HDTMS) coupling agent. The experimental result shows that the contact angle of cotton fabric treated with TiO2-AC/HDTMS reaches 158°. More importantly, 0.7 g TiO2-AC provided the same superhydrophobic effect as 5 g TiO2. Moreover, the surface physical morphology and chemical composition of modified cotton fabric were observed via scanning electron microscopy (SEM), atomic force microscope(AFM), X-ray diffractometer(XRD), X-ray photoelectron spectroscopy (XPS) and Fourier transform infrared spectroscopy (FT-IR) correspondingly. The experimental results show that the micro-/nano-scale rough structure, together with the long side chain alkyl in HDTMS and the siloxane (Si-O-Si) structure generated after hydrolysis and crosslinking, endows the modified cotton fabric with superhydrophobic properties. In addition, the thermogravimetric analysis shows that the modified sample exhibited excellent thermal stability. Besides, the degradation rates of methylene blue (MB) solution was 90 % when photocatalytic performance was tested on the modified fabric under simulated sunlight, and the contact angle still reached 150°. In addition, the modified fabric showed superior oil-water separation ability, with the separation efficiency higher than 98%, separation flux is greater than 1600 Lm−2 s−1, oil absorption is more than twice its own weight and it has excellent recyclability and reusability, because of its superhydrophobic surface, TiO2-AC/HDTMS fabric also showed superior stain resistance and self-cleaning ability. At the same time, the TiO2-AC/HDTMS treated fabric remained hydrophobic in acid and alkali immersion, 25 home washes, and high strength mechanical properties tests. In short, this simple porous nano-composite material combined with non-fluorosilane coupling agent finishing technology has a broad development prospect in the industrial production of multifunctional advanced textiles.