Research On Chiral Polymer Network Stabilized Blue Phase Liquid Crystal

The topic of the paper is the study of the properties of chiral polymer network stabilized blue phase liquid crystals,including optical characteristics such as transmittance and reflection wavelength,electrical characteristics such as driving voltage,Kerr constant,and response time,as well as temperature characteristics and material characteristics.Comprehensive research on chiral polymer-stabilized blue-phase liquid crystals.First we introduce the blue phase liquid crystal.From the perspective of molecular arrangement and lattice structure,blue phase liquid crystal can be regarded as a three-dimensional photonic crystal with a self-assembled structure and a double twisted cylinder structure.It is divided from the temperature range of each phase state.The blue phase liquid crystal is located between the isotropic phase and the chiral nematic phase.Because of its weak thermal stability,the temperature range is usually only a few degrees.The characteristics of blue-phase liquid crystal are significantly different from ordinary liquid crystal materials which widely used in the fields of display,filtering,sensing,etc.,and it also have unique applications.For example,the crystal lattice of a blue phase liquid crystal is composed of multiple double twisted cylinder structures.The double twisted cylinder structure is shaped like a cylinder.The diameter of a cylinder is several hundred nanometers.When a voltage is applied to drive the blue phase liquid crystal,the liquid crystal molecules undergo mechanical movement and the propagation distance is short,a sub-millisecond response time is obtained.At the same time,blurring and stuttering of display motion status at low frame rates can be effectively alleviated by increasing the frame rate,and increasing the frame rate also requires shorter response times.In the case of high frame rates,color pictures in non-moving state can be displayed.Time-series color display(color field sequence display)can also be used to improve light efficiency;due to the unique structure of blue-phase liquid crystal,liquid crystal molecules have been crystallized in three dimensions The lattice structure arrangement can eliminate the alignment layer structure of traditional liquid crystal display devices,which can improve light efficiency,improve yield,and reduce costs;Because of the periodic lattice structure of blue-phase liquid crystal,it has macro optics without changing the lattice structure.Isotropic,applied to display devices that exhibit characteristics such as non-light leakage and wide viewing angle.Based on the above-mentioned excellent characteristics,the blue phase liquid crystal has high scientific research value and commercial value.In 2002,Kikuchi's group at Kyusu University in Japan occupied the defects in the crystal lattice by introducing polymers into the blue phase liquid crystal system,reducing the free energy within the lattice defects,thereby improving the stability of the blue phase liquid crystal,but it also caused some problems such as high driving voltage,hysteresis effect,residual birefringence and so on.In recent years,chiral polymer monomers have been synthesized,which have the functions of both chiral agents and polymer monomers.Compared to conventional polymer networks,chiral polymer networks formed using chiral monomers have chirality.The polymer network can induce and stabilize the blue phase with less chiral dopant and monomer ratio.Due to the additional chiral force of the chiral monomer and good compatibility with the liquid crystal,the polymer stability is greatly reduced.The driving voltage of the blue phase liquid crystal has a positive effect on the application research of the blue phase liquid crystal.In this paper,two new types of chiral monomers are designed.By changing the polymer system and the material composition and ratio,a new type of chiral polymer stabilized liquid crystal is proposed.The specific gravity of the chiral monomers against blue is specifically studied through experiments.The influence of phase liquid crystals and the optical and electrical properties of the chiral polymer-stabilized blue phase liquid crystals,such as transmittance,driving voltage,reflection wavelength,and response time,are studied.Compared with conventional PS-BPLC,the driving ability of chiral PS-BPLC It can be greatly improved by 65%,and the problems of hysteresis and residual birefringence can also be improved by introducing chiral monomers with high stiffness and small molecular weight.Since the chiral polymer network has strong stability and provides chiral force,similar to the function of the polymer template,it can improve the driving performance of the blue phase liquid crystal.It is envisaged to combine the template process and the chiral polymer network to further Reduce driving voltage and improve reusability.The experiments show that the chiral template greatly widens the temperature width of the blue phase liquid crystal,and explores the lower limit of the polymer content at10% by weight,laying a foundation for the next research.