Cellulose nanocrystals confined to cylinders

Liquid crystals that are confined within curved boundaries are of interest to many scientists due to their important role in optoelectronic technologies. As such, intensive research has been conducted with various types of liquid crystals constrained to droplets or cylindrical environments. Since curvature of liquid crystals costs energy, we can observe rich physical phenomena such as change in director field. Most of the fundamental studies of liquid crystalline phase of the CNCs were conducted as a film type or in the cells with flat boundaries, limited to certain concentration and time. Herein, we report the fundamental study of liquid crystalline phase of CNCs confined in cylindrical capillaries. Time, concentration, and size of the capillaries were systemically varied. We observed the formation of a chiral nematic phase of 4 wt % CNCs in 200 µm cylinders at different time periods. Specifically, small rod-like structures were observed at t = 0 h, then developed into small tactoids with periodic bands in less than an hour. After 24 h, we observed long-range fingerprint structure. We believe the study of the evolution of CNC liquid crystals in a curved geometry will provide us deeper understanding into the structure formation of the chiral nematic phase in confinement.