Synthesis and characterization of photoreactive silica nanoparticles for super-hydrophobic cotton fabrics application

In this research, a novel method was developed to improve the super-hydrophobic stability of cotton fabrics without affecting the washing ability. The cotton fabrics were treated with hybrid photoreactive silica nanoparticles (denoted as silica-N ₃ ) and hexadecyltrimethoxysilane under ultraviolet light. Silica nanoparticles were synthesized by grafting an azido group onto silica and confirmed by proton nuclear magnetic resonance, carbon-13 nuclear magnetic resonance and Fourier transform infrared spectroscopy. Untreated and treated cotton fabrics were characterized by scanning electron microscopy, X-ray photoelectron spectroscopy and thermogravimetric analysis. Wettability was investigated by water contact angle (WCA) and water shedding angle (WSA). Moreover, the super-hydrophobic durability of coated cotton fabrics was evaluated by washing tests. The results showed that the treated cotton fabrics exhibited excellent chemical stability and outstanding non-wettability with a WCA of 154.9° for a 5 µL water droplet and a WSA of 8.7° for a 15 µL water droplet. In addition, the super-hydrophobic cotton fabric showed excellent washing durability. After 30 cycles, the contact angle was still larger than 135°.