Molecular heterogeneity drives reconfigurable nematic liquid crystal drops

Liquid crystals are composed of rod- or disc-like molecules called mesogens, and, as a result of the alignment of these mesogens, exhibit remarkable physical properties in between those of a solid and a liquid. The liquid crystals used in this study are made of oligomers, flexible short-chain polymers comprised of smaller rod-like molecular building blocks. Droplets containing oligomeric liquid crystal molecules are spherical at high temperature. If the chains inside the droplets are of varying lengths, they transform into “pollen,” “flowers,” “coral,” and “Medusa” when the temperature drops, as a result of balancing the surface tension and elasticity. Importantly, polydispersity of the chain length helps to drive the self-assembly, where shorter chains preferentially move to where the elastic energy is larger, near the center, while longer chains move to the surface.