Controlled Self-Assembly of Cellulose Nanocrystal as Custom-Tailored Photonics and Complex Soft Matter

Cellulose is widely distributed in nature and imparts structural integrity and mechanical support to the cell walls of plants, algae, and some bacteria. It has gained significant attention due to the growing demand for the fabrication of sustainable and high-performance materials. Various types of cellulosic materials are involved, among which cellulose nanocrystals (CNCs) emerge as a compelling next-gen material extracted from bulk cellulose, attracting considerable attention from both industry and academia. These rodlike colloidal materials exhibit remarkable mechanical, optical, and thermal properties due to their high aspect ratio, biodegradability, and renewable nature, providing promising opportunities for sustainable solutions to modern complex technological and societal challenges. Particularly noteworthy is the inherent chirality of CNC that triggers spontaneous self-assembly into left-handed helicoidal arrangements, termed cholesteric organization and sustained in both suspension and solid films. This unique property begets long-range ordered liquid crystallinity and polarization-sensitive structural color, highlighting the potential of CNC as a versatile platform for the design and fabrication of artificial functional materials with naturally derived alternatives. Benefiting from the robust self-assembly power of CNC, there is a burgeoning development in the creation of innovative nanocellulose-based materials.