Synthesis of Predesigned Ferroelectric Liquid Crystals and Their Applications in Field-Sequential Color Displays

A series of low transition temperature and fast response chiral smectic C (SmC*) liquid crystals is designed and synthesized. The phase transition behaviors and electrooptical properties of the synthesized compounds are investigated and compared with reported values. The ferroelectric phase of the liquid crystals is characterized by means of differential scanning calorimetry, polarizing optical microscopy, wide-angle X-ray scattering (WAXS), and electrooptical measurements. The wide SmC* phase is achieved via the induction of achiral trisiloxane and a chiral methyl-lateral substituent onto the terminuses of the molecules. The optimized packing arrangement model is studied based on the exceptionally high apparent tilt angles (≈41°) and smectic layer spacing observed using WAXS. A fast response time of 0.3 ms in an electric field of 10 V µm−1 provides an opportunity to use the synthesized materials for field-sequential color liquid crystal displays (FSCLCDs). An FSCLCD sample cell is fabricated using the synthesized ferroelectric liquid crystals via a red (R), green (G), and blue (B) backlight. A color-frame frequency of more than 500 Hz (i.e., a frame frequency more than 166 Hz) is achieved. As a single material liquid crystal display cell, the synthesized ferroelectric liquid crystals show great performances at room temperature.