Polymer-Stabilized Blue Phase Liquid Crystal Droplets

Cholesteric liquid crystals with a self-organized helical structure exhibit a photonic band gap along the helical axis. At high chirality, the so-called cholesteric “blue phases” emerge. The blue phases possess highly ordered lattice structures that are stabilized by line defects. These structures exhibit selective reflection of incident light; however, they only appear in a narrow temperature window. Blue phase temperature range can be expanded by incorporating photo-polymerized mesogens into the defect networks. Past studies of polymer stabilized blue phases have mainly focused on bulk properties. In this work, we show that the confinement of the polymer-stabilized blue phase liquid crystal into the spherical droplets greatly influences their structure, color, and stability. We have found that the defect structure can be manipulated by controlling the droplet size and polymerization time, thereby offering tremendous opportunities for designing optical devices based on the highly chiral liquid crystals.