Production of Cellulose Nanocrystals from Agricultural Waste, Their Characteristics and Application Areas

Cellulose nanocrystals (CNs) are rod-shaped particles with a high degree of crystallinity that can be measured from 100 nm up to several micrometers, and can have a diameter of between 5 to 70 nm. CNs can be obtained from lignocellulosic raw materials. In recent years, agricultural wastes such as roots, stems, straw, leaf and skin of agricultural products have been used as a lignocellulosic raw material source for the production of CNs. New sources have been significantly increased due to the economic and environmental reasons. The production of CNs from agricultural waste such as corn cob, bagasse, rice and wheat straw, etc. is carried out mostly in three main steps: (i) pretreatment – washing, milling, (ii) purification – the removal of hemicellulose and lignin, and the isolation of pure cellulose fibers, and (iii) chemical treatment (acid hydrolysis). The properties of CNs vary depending on their source and extraction conditions. CNs are edible and self-degradable, and can be used as an alternative to synthetic reinforcing agents in the production of composite materials, while also contributing to the improvement of the mechanical and barrier properties of materials. Therefore, they can be served as a sustainable and environmentally friendly material for various applications in a large number of industrial areas such as food packaging, automobile and pharmaceuticals. In this article, the production of CNs from agricultural products, the effect of raw material sources on the properties of CNs and their applications in different areas are investigated