Cellulose nanomaterials are one of the most relevant scientific-technological discoveries in recent years. Cellulose nanocrystals (CNCs) stand out among them because their extraordinary chemical, mechanical, thermal, and optical properties make them an interesting alternative to manufacture advanced materials from the most abundant biopolymer on Earth. This work presents a critical analysis of the literature published in the last years, emphasizing the various obtaining processes that have emerged in the search for greener methods. A comparative table of the processes used in the extraction of CNCs from various sources (non-edible biomass and agro-industrial wastes) is included, indicating the process’s effectiveness and the characteristics and applications of this sustainable advanced bionanomaterial.
Keywords: cellulose; nanocellulose crystals; biopolymer; bionanocoposites; nanomaterials.