Functionalizing cotton fabric via covalently grafting polyaniline for solar-driven interfacial evaporation of brine

Herein, we report a novel method for batch functionalization of cotton fabric by co-irradiation grafting polymerization of 4-aminostyrene and in situ grafting polymerization of aniline in sequence for solar-driven interfacial evaporation. The functionalized cotton fabric displayed strong absorption of solar light and good photothermal conversion property. And it not merely exhibited a high evaporation rate of 1.47 kg m -2 h −1 when treating 3.5 wt% NaCl solution with evaporation efficiency of 97% performed on a simple tilted platform (under 1 kW m −2 of power density), but also showed excellent stability for outdoor natural evaporation over 60 days. Besides that, the tilted solar evaporator unexpectedly exhibited a high evaporation rate (1.38 kg m -2 h −1 ) in the saturated NaCl solution (ca.26 wt%), which is superior to those fabric-based photothermal materials in reported literature, suggesting a great potential to the application to solar-driven evaporative crystallization of inorganic salts from brine. The promising strategy adopted here could be employed to facilitate the scale-up preparation of photothermal cotton fabrics and address current challenges in high-efficiency and sustainable solar-driven seawater desalination, even zero liquid disposal of industrial waste brine.