Preparation, functional modification and industrial application of nanocellulose aerogels – A comprehensive review

Nanocellulose is a prospective material for preparing aerogels because of its straightforward surface modification, hydrophilicity, biocompatibility, and rich functional groups. The third-generation aerogel is an aerogel based on nanocellulose and has garnered widespread interest owing to its distinctive benefits, including a high specific surface area, three-dimensional structure, biodegradability, low density, renewability, and high porosity. This paper examines the fabrication and functional alteration of nanocellulose aerogels. The preparation of nanocellulose aerogel involves four primary steps: dissolving the nanocellulose, forming a gel, replacing the solvent in the wet gel, and drying the wet aerogel. The functional modification methods of nanocellulose aerogel mainly include mechanical functionalization, thermal functionalization, conductive functionalization, magnetic functionalization, and antibacterial functionalization. Functionalization enhances the nanocellulose composite aerogel's hydrophobicity, adsorption, mechanics, and antibacterial effects, while also endowing it with conductivity and electromagnetic shielding capabilities. This broadens its applicability and versatility in environmental protection. This paper offers an extensive overview of the progress achieved in nanocellulose aerogel research across various fields, such as adsorption, energy storage, sensing, thermal insulation, electromagnetic shielding, biomedicine, and more. In conclusion, the potential future developments and upcoming challenges facing nanocellulose aerogel are explored.