Preparation of magnetic hydrophobic polyvinyl alcohol (PVA)-cellulose nanofiber (CNF) aerogels as effective oil absorbents

Efficient, rapid removal of oil spills on the surface of water is technologically significant for protecting the ecological marine environment. In this work, environmentally friendly, novel, magnetic hydrophobic PVA/CNF aerogels (MHPCA) with ultralow density (13.84 kg m(-3)), high porosity (> 98%), magnetic responsivity and good mechanical properties were successfully prepared by vacuum freeze-drying PVA/CNF gel followed by a facile silanization reaction and dipping process. The hydrophobic but oleophilic nature of the as-prepared MHPCA (water contact angle over 138A degrees) came from the polysiloxane coated on the fiber surface by the silanization reaction. The MHPCA had excellent oil/water selectivity, with oil absorption capacity as high as 136 g/g being observed. Additionally, the MHPCA exhibited good magnetic response and could absorb oil on the surface of water by magnetic driving. More importantly, the MHPCA showed excellent elasticity after 30 compression-release cycles, which demonstrated the reusability and durability of the super absorbent. The results of this work provide a feasible idea for easily and efficiently removal of oil pollution from the water surface.