Bio-inspired castor oil modified cellulose aerogels for oil recovery and emulsion separation

Cellulose/tannic acid/castor oil (CNF/TA/ICO) aerogels were prepared through the co-precipitation of tannic acid (TA) and castor oil-based siloxane (ICO) on cellulose nanofiber (CNF) surface and subsequent freeze-drying. The CNF/TA/ICO aerogels had the properties of lightweight, low density, high porosity, excellent hydrophobicity/superoleophilicity, and great recyclability. Adsorption study demonstrated that the adsorption capacity of the CNF/TA/ICO aerogel to various oil and organic solvents could reach 53.2–113.8 g g −1 , and the aerogel displayed favorable recyclability after 10 cycles. Moreover, the CNF/TA/ICO aerogel could be used as a filter to achieve the efficient separation of water-in-oil emulsions with separation efficiency higher than 94.4%. The successful fabrication of the multifunctional CNF/TA/ICO aerogel facilitates the comprehensive utilization of biomass resources . The facile and mild preparation method, green and eco-friendly raw materials, excellent adsorption capacity, and high separation efficiency make the CNF/TA/ICO aerogel a promising material for efficient oil recovery and emulsion separation with great applicability.