Biomass Chitosan-Based Tubular/Sheet Superhydrophobic Aerogels Enable Efficient Oil/Water Separation

Abstract

Water pollution, which is caused by leakage of oily substances, has been recognized as one of the most serious global environmental pollutions endangering the ecosystem. High-quality porous materials with superwettability, which are typically constructed in the form of aerogels, hold huge potential in the field of adsorption and removal of oily substances form water. Herein, we developed a facile strategy to fabricate a novel biomass absorbent with a layered tubular/sheet structure for efficient oil/water separation. The aerogels were fabricated by assembling hollow poplar catkin fiber into chitosan sheets using a directional freeze-drying method. The obtained aerogels were further wrapped with -CH3-ended siloxane structures using CH3SiCl3. This superhydrophobic aerogel (CA ≈ 154 ± 0.4°) could rapidly trap and remove oils from water with a large sorption range of 33.06–73.22 g/g. The aerogel facilitated stable oil recovery (90.07–92.34%) by squeezing after 10 sorption-desorption cycles because of its mechanical robustness (91.76% strain remaining after 50 compress-release cycles). The novel design, low cost, and sustainability of the aerogel provide an efficient and environmentally friendly solution for handling oil spills.