| abstract |
A new class of phototropic liquid crystal mixture comprises a liquid crystal host and one or more photodichroic dyes, wherein exposure of the mixture to an activating light causes a light-induced increase in order parameter of the mixture. In some examples, in the absence of the activating light, the phototropic mixture has a lower order parameter than the liquid crystal host, while in the presence of activating light, the phototropic mixture has a higher order parameter than the liquid crystal host. In some examples, upon exposure to the activating light, the phototropic mixture undergoes a phase transition from a material with a lower order to a material with higher liquid crystalline order. In some examples, activating light causes the mixture to transition from an isotropic phase to a nematic phase, from an isotropic phase to a cholesteric phase or form a nematic phase to a smectic phase. |