Designing magnetic and superhydrophobic cellulose nanofibers based-aerogel for efficient oil water separation

In this work, we used cellulose nanofibers (CNF) as the skeleton, Fe 3 O 4 @ZnO composite particles as magnetic synergist particles, 3-(2-aminoethylamino) propyltrimethoxysilane (AS) and trimethoxy(octyl)silane (OTMS) as water-based hydrophobic modifiers to prepare magnetic and superhydrophobic cellulose nanofibers based-aerogel with low density and intricate three-dimensional structure. Fe 3 O 4 @ZnO confers magnetic properties (3.82 emu/g) and exceptional thermal stability (water contact angle of 150.1° at 200 °C) to the system, while the combination with OTMS/AS endows the system superhydrophobic (157.5°) and excellent mechanical properties (stress of 96.95 kPa at 80% strain). It is worth noting that in the process of modifying the system with OTMS/AS, no organic solvents and acidic substances are used in the solution. Benefiting from their synergies, the system demonstrates a notable oil absorption capacity (12.31–41.91 g/g) and outstanding oil selectivity (exceeding 90%), driven by gravity alone. Interestingly, this system, marked by its cost-effectiveness, simplicity, eco-friendliness, and heightened efficiency, holds promising prospects for diverse applications in different oil–water separation behavior and purifying industrial oil wastewater, as well as oil flooding incidents. Graphical