Rechargeable nanofibrillated cellulose aerogel with excellent biocidal properties for efficient oil/water separation

Green and renewable bio-based composites with antibacterial and oil–water separation properties are of great significance to solve oily wastewater threatened the human health and ecological environment. Herein, naturally degradable nanofibrillated cellulose (NFC) is used as substrate to prepare NFC aerogels with antibacterial and oil–water separation functions via grafting by cyanuric chloride (CC) and hexadecyltrimet -hoxysilane in aqueous phase. In particular, the grafting reaction of CC and NFC in aqueous phase overcomes the shortcomings of requiring low temperature environment and complex multi-solvent system. In addition, the aerogels have strong bactericidal activity and excellent antibacterial stability against Escherichia coli and Staphylococcus aureus. After repeated washing and long-term UV irradiation, more than 95 % of the antibacterial activity can be recovered after rechlorination. Moreover, the adsorption capacity of dichloromethane on aerogels is still higher than 50 g/g after 30 absorption-extrusion cycles under the premise of sufficient antibacterial substance. Overall, such a simple, green, low-cost method to produce renewable and reusable antibacterial materials for oil–water separation displays great potential in wastewater treatment.