Cellulose Nanocrystals (CNC) Liquid Crystalline State in Suspension: An Overview

Films made from cellulose nanocrystals (CNCs) may have iridescent structural colours (pure or in combination with other materials). Numerous fields might benefit from understanding how CNC self-assembly constructs these periodic structures. Herein, we looked at the colloidal characteristics of CNC particles as well as the development and behaviour of liquid crystals (LCs). We conducted a very brief literature analysis on the main issues related to the chiral structure creation of CNC LCs, including the origins of chirality, orientation, as well as its mechanical properties. Finally, by altering the pitch size, applications such as energy storage, humidity sensing, and photonic crystals were studied in a case-by-case manner. The manuscript, it is observed that the rational design of metamaterials built on CNCs allows for the reversible changing of colours through physical and chemical modifications by adding chemical or changing environmental factors. Examples of this alteration include the use of solvents, chemical penetration in applied fields (magnetic and electric), deflection, light, temperature change, acidity change, and molecular interaction detection. Reversible colours may be produced by altering the spacing between the particles, the filler materials, or the structural elements of the system’s refractive indices. This article briefly discusses the inner workings of CNCs, potential barriers to developing photonic structures, and several techniques and processes for achieving changeable colours.