The formation of supramolecular liquid-crystal gels for enhancing the electro-optical properties of twisted nematic liquid crystals

We report that the supramolecular liquid-crystal (LC) physical gel can be formed through the fibrous self-assembly of the polyfluorene-based π-conjugated polymer, poly(9,9-dioctylfluorene-alt-benzothiadiazole) (F8BT), in twisted nematic LC system for the first time. With the utility of alignment layers, the F8BT molecules can be aligned and formed the LC physical gels with the formation of self-assembled supramolecular structures in the twisted nematic LCs. In contrast to conventional LC physical gels, the presence of anisotropic π-conjugated structure makes the twisted nematic LC system exhibit excellent electro-optical properties of driving voltage reduction and contrast ratio enhancement owing to the conjugated polymer having a high π-electron delocalization degree which can efficiently drive LC molecules in much lower operating voltages. The self-assembled supramolecular network has revealed the potential for applying in various LC display devices with the ability of improving their electro-optical performance.