fibers or derivatives for nearly 150 years for a wide spectrum
of products and materials in daily life. What has not been
known until relatively recently is that when cellulose fibers
are subjected to acid hydrolysis, the fibers yield defect-free,
rod-like crystalline residues. Cellulose nanocrystals (CNs)
have garnered in the materials community a tremendous level
of attention that does not appear to be relenting. These
biopolymeric assemblies warrant such attention not only
because of their unsurpassed quintessential physical and
chemical properties (as will become evident in the review)
but also because of their inherent renewability and sustainability
in addition to their abundance. They have been the
subject of a wide array of research efforts as reinforcing
agents in nanocomposites due to their low cost, availability,
renewability, light weight, nanoscale dimension, and unique
morphology. Indeed, CNs are the fundamental constitutive
polymeric motifs of macroscopic cellulosic-based fibers
whose sheer volume dwarfs any known natural or synthetic
biomaterial. Biopolymers such as cellulose and lignin