Abstract:
Cholesteric liquid crystal elastomer (CLCE) is a photonic crystal material with a periodic helical structure that combines unique optical anisotropy with mechanical stimulus-responsive properties, demonstrating broad application prospects in flexible photonic devices. However, the preparation of patterned CLCE still faces challenges.Based on the thiol-Michael addition reaction, this study synthesized thermochromic cholesteric liquid crystalline oligomers (CLCO) with controllable degrees of polymerization and varying chain lengths, and systematically explored the structure–property relationship between their liquid crystal phase structure and structural color. Utilizing the temperature-induced cholesteric–smectic phase transition effect, the structural color of CLCO can be tuned to cover the three primary colors, red, green, and blue, within a wavelength range of Δλ ≈ 150 nm. Patterned stretchable CLCE films were prepared through local photopolymerization at different temperatures. By further increasing the proportion of thiol monomers, the degree of polymerization of CLCO was enhanced and the crosslinking density of CLCE was reduced, resulting in an increase in its elongation at break to 200% and enabling force-induced color changes across the visible spectrum. This study not only provides new insights into the dynamic regulation and patterning of structural color in CLCE, but also establishes a material foundation for applications in information encryption and anti-counterfeiting.