Highly Hydrophobic Thermally Stable Liquid Crystalline Cellulosic Nanomaterials

Highly hydrophobic cellulosic nanomaterials were prepared via iodine-catalyzed butyrate esterification of cellulose nanocrystals (CNC). The structure and properties of butyrated cellulose nanocrystals (Bu-CNC) were investigated via advanced spectroscopic, morphological, optical, thermal, contact angle, and coating analyses. Bu-CNC retained cellulose crystallinity, was hydrophobic with a static contact angle of 81.54° and displayed 18.5% enhancement in its thermal stability. Moreover, Bu-CNC possessed a solid multilamellar cellulose II structure and showed liquid crystalline behavior over a wide range of temperatures. Bu-CNC formed transparent flexible films upon drying and was easily dispersible in ethanol and acetone. As a thermally stable hydrophobic liquid crystalline biobased material, Bu-CNC presents a new class of nanomaterial, which potentially suits various industrial and medical applications.