A novel fluorine/nanoparticle-free self-roughened organosilicon finishing agent with robust durability: toward superhydrophobic restoration and anti-icing of firefighting suit

Abstract

The hydrophobicity of firefighting suit is crucial as it effectively blocks liquid-phase hazards (water/chemicals), maintains wear comfort, and enhances durability and safety by preventing water penetration, essential for firefighters' operational reliability in harsh environments like cold conditions. However, the preparation of abrasion resistant and transparent superhydrophobic coating without fluorine/nanoparticle by environmentally friendly methods is still a major challenge. In this study, a highly abrasion resistant silicone polymer was synthesized by vinyl-terminated polydimethylsiloxane, hydride-terminated polydimethylsiloxane, and methyl vinyl MQ silicone resin. Through solvent-induced phase separation, the silicone polymer could be stably dispersed in the phase-separated system at micro/nano scales. Systematic optimization of the solvent (tetrahydrofuran) to non-solvent (deionized water) ratio yielded a water-rich organosilicon finishing agent capable of spontaneously forming micro/nanoscale rough surfaces following a mild curing temperature. The cured organosilicon finishing agent showed highly transparency with a transmittance reaching 88 %. The aramid fabric after being coated by organosilicon finishing agent showed excellent superhydrophobicity with contact angle of 159° and sliding angle of 5.5°. After 10 standard washing cycles, 400 cycles of sandpaper abrasion, and 24 h acid, alkali, and salt immersion, it still retains its superhydrophobicity with a contact angle greater than 150°. Notably, the finished aramid fabric maintains nearly unchanged breathability and flexibility while exhibiting exceptional anti-icing properties. These characteristics significantly enhance the operational efficiency and safety for firefighters in northern cold regions. The preparation of environmentally friendly superhydrophobic organosilicon finishing agent demonstrates large-scale production potential and shows promising application prospects in high-end textiles and specialized protective equipments.