Tunable optical materials based on self-assembly of polysaccharide nanocrystals

Abstract

Rod-like polysaccharide nanocrystals, cellulose nanocrystal (CNC) and chitin nanocrystal (ChNC), can form the chiral nematic liquid crystal phase in suspensions, which can be preserved in the self-assembly solid materials (films) exhibiting colorful optical behaviors origin from the reflective wavelengths of the light. This chapter covers the studies on the topic of CNC and ChNC-based optical-tunable materials during last ten years including the self-assembly mechanism and liquid crystal behaviors of CNC nanoparticles in suspensions, preparation of optical films based on the pristine CNC and surface-modified CNC, summarization of diverse treatments and approaches to regulate the pitch and optical properties of self-assembly films (external energy fields and additives), and fabrication of mesoporous materials based on the strategy of CNC template. Finally, the self-assembly properties and optical applications of ChNC are discussed in the last section as the comparison with those studies introduced in CNC. The development of optical materials based on polysaccharide nanocrystals is an attracting functional application in the structural color field, and this chapter provides the summarization on the controlling strategy, structural design, regulating approach and mechanism explanation aiming to create the novel inspiration.