Multifunctional superhydrophilic-oleophobic cellulose based aerogel with robust mechanical resilience for oil/water separation, anti-fouling and light-induced self-cleaning

Amidst the escalating discharge of oily wastewater, there is an urgent necessity for high-performance materials capable of wastewater treatment to meet fundamental demand for clean water. Cellulose nanofiber (CNF)-based aerogels are consummate choice due to the lightweight and porous structure. However, developing CNF-based aerogel with multifunctional characters and underwater compressibility is pressingly desirable yet remains a huge challenge. Herein, a straightforward one-step condensation approach was devised to prepare superhydrophilic-oleophobic composite aerogel using CNF, TiO2 and 1 H,1 H,2 H,2 H-perfluorooctyltriethoxysilane. The resultant aerogel exhibited three-dimensional structure with interconnected macropores. Notably, this composite aerogel demonstrated good superhydrophilicity and underwater oleophobic property,which allowed them to absorb trace amount of water from oil phase and separate oil/water mixtures with separation rate of 99.7 %. And the water contact angle of this aerogel reaching 0° in a very short time of 0.044 s, while the underwater oil contact angle was measured as about 105°. Also, the resultant aerogel exhibited strong mechanical tolerance against repeated compression in both dry and wet states. Furthermore, the composite aerogel displayed remarkable properties of oil rub resistance, light-induced self-cleaning and heat transport property. The resilient and versatile aerogels featuring unique surface wettability present favorable prospects for liquid purification and the treatment of oily wastewater.