Particle Size Controlled Chiral Structural Color of Monodisperse Cholesteric Liquid Crystals Particles

摘要

Cholesteric liquid crystals (CLCs) are becoming increasingly popular due totheir unique chiral structural color. Unlike ordinary CLCs materials, CLCsparticles exhibit angle-independence, making them particularly noteworthy.However, currently, there are limited effective methods for controlling thestructural color of CLCs particles, other than adjusting the concentration ofchiral dopants or introducing stimuli-responsive groups. Here, a scalable andcost-effective process for preparing monodisperse CLCs particles viadispersion polymerization is reported. By making CLCs into micrometer-sizedmonodisperse spheres, the helical pitch of CLCs can be varied according to itsparticle size, and the resulting structural color hue due to Bragg reflection canalso be changed. Covering the CLCs particles with polydimethylsiloxaneresults in the formation of a polymer dispersed liquid crystals–like structure,which enhances the structural color appearance and thermal stability of theCLCs particles. Additionally, a simple strategy to produce chiralanti-counterfeiting QR codes is developed. By combining CLCs particles withcommercially available pigments, an anti-counterfeiting QR code that can onlybe displayed under a specific circular polarizer is created. This approach andresulting CLCs particles expand the modulation of CLCs structural color andenrich the application of structural color in the field of chiral opticalanti-counterfeiting.