Sustainable, Reusable, and Superhydrophobic Aerogels from Microfibrillated Cellulose for Highly Effective Oil/Water Separation

The development of sustainable and efficient absorbents for oil and organic pollutants cleaning is an attractive and challenging work. Here, novel superhydrophobic microfibrillated cellulose aerogels (HMFCAs) with high lipophilicity, ultralow density (≤5.08 mg/cm³), superior porosity (≥99.68%) as well as extremely high mechanical stability were successfully prepared from microfibrillated cellulose aerogels (MFCAs) via a facile and environmentally friendly silanization reaction in liquid phase. The superhydrophobicity of the as-prepared HMFCAs (water contact angle as high as 151.8°) was attributed to the formation of polysiloxane on the surface of HMFCAs by the silanization reaction. The HMFCAs exhibited excellent oil/water selective absorption capacity with oil absorption up to 159 g/g. The reusability experiment showed that the adsorption capacity still exceeded 92 g/g for pump oil after 30 absorption cycles, demonstrating its superior reusability. Our work paves the way for the development of sustainable and efficient absorbents toward oils and organic pollutant removal applications.