Spontaneous and diverse morphological transitions of nematic liquid crystal oligomer micro-droplets*

Viruses and pollen grains are known for their diverse morphologies and surface patterns, which play important roles to their functions. It begs the questions how the patterns were originated and then evolved. Here, we report the spontaneous morphological transformations from micro-droplets, consisting of polydispersed nematic liquid crystal oligomers (NLCOs) suspended in water, to a strikingly rich set of nematic structures, including roughened spheres, flowers, and filamentous structures. We investigate the interplay of elasticity and interfacial tension within the drop as a function of temperature, surfactant concentrations, and the LCO chain length distribution. We show that heterogeneity of LCO chain length is a feature leading to segregation of LCOs within the micro-droplet. The transformed morphologies are highly uniform in size and can be locked via UV curing. The study of synthetic systems offers a first attempt to understand the origin of complex morphologies in biological world.