Rate-dependent thermotropic phase transitions in liquid crystalline oligomers

Thermotropic liquid crystals (LCs) undergo temperature-dependent phase transitions between the isotropic, liquid crystalline, and crystalline states. However, metastable states are often only accessible at fast cooling rates that kinetically limit the transition from the isotropic to the equilibrium state. In this study, we synthesized monodisperse liquid crystalline oligomers by combining two different mesogens in varying sequences via iterative exponential growth synthesis using alkyne-azide click chemistry. These oligomers exhibit highly rate-dependent LC phase transitions, which we characterized through thermal, optical and X-ray scattering methods under targeted temperature ramp rates and annealing protocols. Precisely defining the conditions at which LC phases are accessible and stable (or metastable) allows us to tailor processing and chemical structure for targeted applications.