Decreasing the operating voltage of a polymer-stabilized blue phase based on intermolecular affinity

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This study demonstrates a novel material design strategy to decrease the operating voltage of the polymer-stabilized blue phase (PSBP) based on intermolecular affinity between the chiral dopant and the polymer nanonetworks in the PSBP. We focus on the weak anchoring interface, the so-called “slippery interface”, at which a disordered liquid crystal or isotropic liquid layer is formed between the liquid crystal and polymer. To introduce such a slippery interface inside the PSBP, an isosorbide-based polar chiral dopant is synthesized, and this dopant is expected to show high affinity to polymers with polar substituents. The operating voltage of the PSBP with the polar chiral dopant is considerably decreased with an increasing ratio of polar substituents on the polymer, in striking contrast with the trend observed for the PSBP containing the conventional chiral dopant. Furthermore, the PSBP displays a large electro-optical Kerr constant for the PSBP containing the polar chiral dopant and polymer with the polar substituent. The experimental results suggest that the synthesized chiral dopant with a polar component acts as a chirality inducer for the BP and as a slippery interface inducer via polar-polar interaction with the polymer inside the PSBP. The electro-optic properties of polymer-stabilized blue phases (PSBP) with polar chiral dopant and polar substituent on polymer were significantly enhanced, which is in sharp contrast with the trend observed for PSBP with conventional chiral dopant. These results indicate that polar chiral dopant showing good affinity with polar polymer induces weak anchoring condition inside PSBP.