Chitin Nanopapers

The evolutional success of organisms in nature depends strongly on how efficiently they utilize natural materials. Chitin is the second most ubiquitous natural polysaccharide following cellulose on earth, and it is the key component in exoskeletons of crustaceans such as crabs, shrimps, and lobsters. Nowadays, chitin nanofibers have emerged as novel nanomaterials that are extracted from exoskeletons of crustaceans, and they exhibit large surface area, high aspect ratio, and high stiffness of their crystalline structure. Inspired by nature, chitin nanofibers can be integrated into nanostructured nanopapers with high ductility and strength as well as excellent optical transparency. This chapter gives an overview of the chemical structure, sources of chitin nanofibers, methodologies for disintegrating chitin nanofibers, and fabrication technologies for assembling chitin nanofibers into nanopapers. Chitin nanopapers provide an important platform for incorporating new functionalities to form conductive nanopapers, perform as carbon-free lithium–oxygen (LiO2) cathodes and as a separator for lithium metal batteries, or construct composite films for wound-healing and packaging applications.