Enhanced Low-temperature Electro-optical Kerr Effect of Stable Cubic Soft Superstructure Enabled by Fluorinated Polymer Stabilization

Abstract

An enhanced electro-optical Kerr effect of the stable self-organized cubic blue phase liquid crystal superstructure at a relatively low temperature down to −50 °C was achieved through a judiciously designed fluorinated polymer stabilization. The fluorinated sample exhibited not only a rather stable cubic structure, but the promoted electro-optical performances of low driving voltage, weak hysteresis and high contrast ratio at such a low-temperature, which were much distinct from the common non-fluorinated polymer stabilized blue phase liquid crystal without conspicuous low-temperature Kerr response behaviours. Kerr constant, which reflects the obviousness of Kerr effect, of the fluorinated sample at −50 °C indicated a spectacular enhancement of two orders of magnitude in contrast to the commonly material, thereby corroborating the high efficiency of polymer fluorination in enhancing low-temperature Kerr effect. Such an enhancement of Kerr effect was probably resulted from the decreasing of interfacial anchoring between liquid crystal and fluorinated polymer network. The fluorinated polymer stabilization not only ensures the stability of self-organized cubic structure of blue phase, but overcomes the challenge and bottleneck problem of low-temperature inapplicability of common blue phase liquid crystal and paves a brilliant and broad way for relevant materials to abundant perspective applications at low temperature.

A single‐cell‐gap transflective blue‐phase liquid crystal display based on fringe in‐plane switching electrodes

“…In recent years, polymer stabilized blue-phase liquid crystal (PS-BPLC) [1][2][3][4][5] based on Kerr effect 6 has become a hot research topic for display applications. [7][8][9] BPLC is a promising material to replace the widely used nematic liquid crystal (NLC) due to its several revolutionary features, such as submillisecond gray-to-gray response time 10,11 that is approximately 10 times faster than the present NLC, no need for any alignment layers that leads to a simple fabrication process, inherently wide viewing angle owing to optically isotropic dark state in the voltage-off state, and insensitivity to cell gap if in-plane switching (IPS) electrodes are used. 12 However, the conventional BPLC display with IPS electrodes 13,14 has two major technical challenges: high operating voltage and low transmittance need to be overcome before this promising technology can be implemented.…”