Unraveling the Governing Mechanisms Behind the Chiral Nematic Self-Assembly of Cellulose-Based Polymers

Thanks to their abundance and ability to self-assemble into photonic crystals that selectively reflect light, chiral nematic liquid crystalline cellulose polymers have been investigated as the basis for colorimetric sensors responsive to humidity, pressure, temperature, and other stimuli. In this perspective, we start by revisiting the early research on these materials to explain how different geometric and thermodynamic factors influence the self-assembly and optical properties of cholesteric phases constructed from cellulose derivatives. We explore how solubility, viscosity, and hydrogen bonding impact the onset of mesophase formation and the helicoidal arrangement. Having elucidated the controlling factors influencing the pitch-concentration relationship in these materials, we discuss efforts to preserve liquid crystalline order in solids and underscore the critical knowledge gaps in understanding how the kinetics of self-assembly affects both cholesteric order formation and retention.