Nanoscience in nature: cellulose nanocrystals

Abstract

Nanoscience, the study of materials so small that not even light can capture them, seeks to unravel and understand the building blocks of our planet. Nature, perhaps the most talented nanoscientist, has created very remarkable biological nanomaterials including proteins, lipids and polysaccharides. This article will explore a very unique nanomaterial, derived from cellulose, that has received great academic and industrial interest over the last few years. Cellulose nanocrystals are shards of a very common polymer and possess a number of interesting properties including a high aspect ratio and large tension modulus. Cellulose nanocrystal structure can be manipulated during the extraction procedure to control size, degree of crystallinity and surface charge. Furthermore the crystals can be functionalized with surface functional groups, including sulfate esters, and successfully incorporated into polymer matrices. This article will explore physical and chemical extraction procedures, and characterization techniques including atomic force microscopy, transmission electron microscopy and x-ray diffraction. Finally, the future promise of cellulose nanocrystals will be discussed including potential applications in electronics, materials and medical industries.