Cellulose Nanocrystals – Sources, Preparation, and Applications: Research Advances

Cellulose is the most abundant biopolymer in nature which is constituted by thousands of β-D glucose units, covalently linked together by 1 → 4 glycosidic bonds. Owing to the hierarchical architecture of native cellulose, its nanoparticles are extracted by destructuring the native hierarchical structure. Cellulose nanocrystals (CNCs) are highly crystalline elongated rod-like (or needle-like) nanoparticles produced due to preferential dissolution of amorphous domains when cellulose substrates are subjected to a strong acid hydrolysis treatment. Because of the unique characteristics such as special morphology and geometrical dimensions, crystallinity, high mechanical strength, high specific surface area, liquid crystalline behavior, rheological properties and surface chemical reactivity etc., CNCs have several potential applications as polymeric matrix materials, reinforcement fillers, rheology modifiers, and liquid crystalline materials for liquid crystalline displays. Therefore, CNCs have garnered a great deal of research interests focused on the optimization of preparation processes, tailoring properties for a specific application, and exploring new avenues of applications. In the first section of this chapter, we present recent progress and preparation of CNCs. In the second section, different applications of CNCs as polymeric scaffold material, reinforcement fillers, rheology modifiers, and in electronics are reviewed and discussed.