Recent Advances in Cellulose Nanocrystal Production from Green Methods

The outstanding properties of nanocellulose have led to a wide range of applications in packaging, construction, medicine, electronics, cosmetics, environmental solutions, and the food industry. Specifically, cellulose nanocrystals (CNC) have demonstrated excellent biocompatibility, adaptable surface chemistry, low density, optical capabilities, biodegradability, renewability, and good mechanical properties. However, these unique characteristics depend on the raw material, processing, and post-treatment. New opportunities in CNC production are being explored based on unconventional resources and new, environmentally friendly production processes to replace highly polluting and inefficient conventional methods. This review evaluated the current methods for obtaining CNC from green processes, focusing on organic acids, enzymes, mechanical, oxidative, and radiation-based methods.