Fabrication of multi-network aerogels based on sesbania gum/nanocellulose and its application in oil recovery (from oily wastewater)

Bio-based aerogels possess high porosity, low density, biodegradability, and environmental friendliness, offering significant potential in the field of oil-water separation. In this study, we developed a hydrophobic porous aerogel with a triple cross-linked network consisting of polysaccharide sesbania gum (SG) and nanocellulose (CNF). The aerogel was cross-linked with polyamide epoxy chloropropane resin (PAE) and methyltrimethoxysilane (MTMS), followed by MTMS hydrolysis for silane hydrophobic modification. The hydrophobic SG/CNF aerogel (SCA) was prepared through freeze-drying and annealing processes. SCA exhibits excellent properties, including low density (11.83–26.18 mg/cm 3 ), high porosity (98.95–97.8 %), high adsorption capacity (39.4–72.9 g/g), and rapid adsorption. Additionally, the oil adsorbed by SCA can be easily desorbed using centrifugal method. Even after 10 adsorption-desorption cycles, the adsorption capacity remains at 81.8 % of the initial value. Therefore, SCA provides a simple, low-cost, efficient, and recyclable solution for the removal of organic pollutants, offering a sustainable approach for industrial wastewater treatment.