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

Abstract 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.