Preparation and Structural Color Regulation of Ethyl Cellulose Chiral Liquid Crystal Materials

Cellulose-based chiral liquid crystal structural color materials exhibit excellent properties such as environmental friendliness, color stability, and dynamic tunability. In this study, based on a photocrosslinking strategy of ethyl cellulose (EC), EC chiral liquid crystal materials with multiple responsive structural color optical characteristics were constructed. The regulatory effects of EC concentration, ambient temperature, and the degree of photocrosslinking on the structural color and optical response of the chiral liquid crystal materials were systematically investigated. The results show that EC gels display vivid structural colors and distinct cholesteric liquid crystal birefringence characteristics. As EC concentration increases, the structural color of the liquid crystal gels undergoes a significant blueshift, with the reflection wavelength shifting from 769 nm to 393 nm. With increasing ambient temperature, the color of the EC liquid crystal gels changes from red to blue, and the reflection wavelength shifts from 731 nm to 491 nm. As the degree of photocrosslinking increases, the structural color of the EC liquid crystal materials exhibits a regular blueshift, with the reflection wavelength shifting from 611 nm to 502 nm. After photocrosslinking, the left-handed circularly polarized reflection gradually transforms into either linearly polarized reflection or disordered scattering, and the structural color stabilizes as blue with no further change. Based on the controllable optical response behavior of the EC liquid crystal materials, photomask technology can be used to precisely fabricate multiple stimulus-responsive structural color patterns, enabling dynamic visual information encryption applications. In summary, EC chiral liquid crystal materials hold great promise for applications in advanced anti-counterfeiting and optical displays.