Structure, Pretreatment, and Extraction of Nanocellulose

Cellulose is a linear chain biopolymer, and all plants inherently contain cellulose, being present in the plant cell walls. Being the most prevalent natural polymeric substance worldwide, it also offers numerous benefits, such as relatively low density with significant mechanical strength, excellent biocompatibility and affordable cost. Lignocellulosic sources are typically processed to produce cellulose nanofibers or cellulose nanocrystals, collectively referred to as nanocellulose, through mechanical, chemical, or a combination of both approaches. Recently, nanocellulose has emerged as one of the most significant green materials for various applications. The inherent qualities of nanocellulose, such as its high mechanical strength, expanded surface area, abundance and renewability, low toxicity, biocompatibility, and decomposability, have made it a highly recognized nanomaterial. This review offers a comprehensive introduction to nanocellulose, its different types, and the various extraction methods.