Chiral nematic liquid crystal organization of natural polymer nanocrystals

One-dimensional nanocrystals with high-aspect ratio from natural polymers such as cellulose nanocrystals are attractive due to their anisotropic dimensions, versatile surface chemistry and ability to form lyotropic liquid crystalline (LC) phase in aqueous media. Most importantly, those anisotropic natural materials preserve their LC ordering in solid films under slow drying at ambient conditions. The resulting organised films with 'frozen' chiral nematic helicoidal morphology show unique optical properties such as selective light reflection, high optical birefringence, selective circular polarisation, along with enhanced mechanical performance, e.g. high ultimate strength, toughness and stretchability. Additionally, those films are lightweight, and potentially sustainable and biodegradable. Here we briefly overview recent work from our group on the chiral nematic organisation in LC suspensions and in thin films of cellulose nanocrystals and cellulose nanofibers obtained under diverse interparticle interactions, confined drying conditions, and external magnetic field.