Exploring multiphase liquid crystal polymeric droplets created by a partial phase-separation

Hypothesis: Polymerization of the monomers lowers the miscibility of the polymer. Therefore, a partial phase separation phenomenon can be induced depending on the polymerization conditions. Based on this, usage of anisotropic material has advantages to precisely control the internal structure as well as the external shape. Experiments: Janus liquid crystal polymer (LCP) droplets and particles with unusual complex shapes were pre-pared via two steps, thermal-and photo-polymerization using the reactive mesogen(RM) mixture. The internal configuration of mesogens in the droplets and their assembly behaviors were controlled by varying surface condition. Janus LCP particles with complex shapes were formed by anisotropic deswelling and characterized via optical and electron microscopes.Findings: The partial phase separation in the RM mixture induced the density gradient throughout the droplet, forming the Janus droplets with a certain nematic configurations in each compartment. LCP Janus droplets show not only easy-control of colloidal assembly with surface condition and also complex external structures that is hardly obtained in typical ways using isotropic materials. This report demonstrates for the first time a high availability of anisotropic materials for generation of multiphase microparticles controlled with internal and external structures.