Nanocellulose: a review on preparation routes and applications in functional materials

Nanocellulose has a wide range of applications in the field of functional materials, and it has piqued the interest of researchers for some time. This is because nanocellulose inherits the advantages of environmental friendliness and easy availability of plant cell walls in nature, as well as the unique morphology of nanostructures. This review presents four types of nanocellulose including cellulose nanocrystals (CNCs), cellulose nanofibrils (CNFs), regenerated nanocellulose (RNC) and bacterial cellulose (BC), introduces the different preparation routes and their mechanisms, analyzes the advantages and drawbacks between these approaches, and summarizes the potential applications in the field of functional materials such as reinforced composite materials, biomedical materials, soft templates, and optical materials. Finally, future development directions are proposed including further enrichment of nanocellulose raw materials, improvement of preparation methods to adapt to more diversified raw materials, and classification of products according to their morphology and properties to improve the use efficiency.