Research On Multicolor Bistable Fiber Devices Based On Chiral Liquid Crystal

With the rapid development of smart materials,discoloration fabrics become more and more popular in many applications.As an important part of the current color-tunable fabric,color-tunable materials generally use tungsten trioxide,titanium dioxide,violet and other materials to control the change of energy levels to achieve color-tunable.So that the entire system has a certain problems in integration,which has many disadvantages such as poor controllability,poor cycle stability,short life,high cost,and narrow optical modulation range.In its essence,it is precisely because of the change in its chemical properties of the material energy levels that the above-mentioned disadvantages cannot be avoided.Therefore,the application requirement of non-material-level and color-tunable technology is increasing day by day in color-tunable clothing,infrared stealth clothing,military camouflage and other smart fabrics.Liquid crystal materials have unique advantages,such as wide optical modulation range,strong controllability,long life and so on.So that the bragg effect of cholesteric liquid crystals is usually used to modulate the wavelength of incident light to achieve multi-color display of the device.Multi-color controllable modulation of discolored fabrics has become the focus and difficulty of related research,in some intelligent fabric applications,such as military camouflage,infrared stealth clothing and so on.Accroding to the preparation of color-tunable fibers based on liquid crystal materials,this paper first carried out the related theories on the analysis of the discoloration mechanism of liquid crystal fibers,and broke through the new mechanism of discoloration of liquid crystal molecules.Secondly the liquid crystal color-tunable materials was prepared,which made a breakthrough of the doping modification method based on chiral liquid crystal molecules.In addition,this paper accomplished the preparation and performance of liquid crystal fiber devices,and realized the breakthroughs in the preparation and integration of liquid crystal fiber devices and other pivotal technologies.A color-tunable liquid crystal fiber with a multilayer structure is prepared through a double-channel coaxial spinning method.The CLC fibers could be drawn with the length of tens of meters,and a diameter of about 500 microns,whose diameter of the center electrode is 300 microns,and the sum of the thickness of CLC layer and polymer layer is about 100 microns.Under the change of receiving angle from0 degrees to 60 degrees,the wavelength shift of Bragg reflection center wavelength of CLC fiber is less than 25 nm.The color-tunable of liquid crystal fiber is realized under the electric field,so that we can greatly promote the application of CLC materials in color-tunable clothing,flexible intelligent fabric,military camouflage and other fields.By changing the voltage applied to the fiber,it has different helical twisting forces(HTP)and different helical twisting phases to achieve low-consumption discoloration,so as to achieve multi-color reflection.Due to the bragg reflectivity of the cholesteric liquid crystal and the electronically controlled bistability,the fiber can achieve color display in the visible light band and low power discoloration.At the same time,it also has solvent resistance,high softness and weaving properties,due to the special structure of the fiber.