Natural Biopolymer Nanofibrils as Sustainable Filter Materials

Abstract Increasingly serious environmental problems, including air pollution and water contamination, have led to an increasing demand for filter materials (FMs). Biopolymer nanofibrils assembled by natural macromolecules such as polysaccharides or proteins exist widely as nanobuilding blocks in natural materials. Owing to the advantages of abundant source, environmental biodegradability, biocompatibility, high specific surface area and excellent mechanical properties, biopolymer nanofibrils show bright prospects for sustainable functional filters. This review summarizes the structure and preparation methods of representative biopolymer nanofibrils (cellulose nanofibrils, chitin nanofibrils, and silk nanofibrils), and then outlines their emerging applications in the field of FMs. Finally, the existing challenges and future opportunities of natural biopolymer nanofibrils in this field are summarized.