The study on Formation Conditions and Electrooptical Properties of Dye Guest-Host Ferroelectric Liquid Crystal and the Composite Films of UV Curable Polymer Dispersed-Dye Guest-Host FLC

• Main Authors: Chenn Chih-Chun, 陳執群
• Other Authors: Jiunn-Yih Lee
• Format: Others
• Language: zh-TW
• Published: 1998
• Online Access: http://ndltd.ncl.edu.tw/handle/76493723267390250541

碩士 === 國立臺灣科技大學 === 纖維及高分子研究所 === 86 === This study concerns a novel process to disperse blue dichroic dyes (M483)in varying concentrations of ferroelectric liquid crystal (CS-1024) to manufature the display device of Dye Guest-Host Ferroelectric Liquid Crystals(DGHFLC)and produce the new type of Dye Guest-Host Polymer DispersedFerroelectric Liquid Crystals (DGHPDFLC) with a single polarizer. The anisotropic absorption effect of the dichroic dye and the characteristics of low threshold voltage, fast switch speed and wide viewingangle of ferroelectric liquid crystals combined with the processibility of thepolymer were used to investigate the performance and the influence of formationconditions on the cure degree of a polymer matrix and the electro-opticproperties of the Polymer/DGHFLC composite film. Formation conditions includedthe intensity of the UV light and the content of the the prepolymer(NOA65). Our main objective was to resolve the problems of traditional FLC and PDFLCliquid crystal displays, such as low brightness, narrow viewing angle and so on.We used the following equipment: polarizing microscope, polarizingmicro-spectrometer, He-Ne laser, arbitrary waveform generator and digitaloscilloscope to study the physical properties of DGHFLC and DGHPDFLC. The results show that both the addition of dye and the content of thepolymer increase the rotational viscosity of the whole mixed system and lowerresponse time. In addition, it rises the bistability and memory effect of DGHFLCand DGHPDFLC much more than those of ferroelectric liquid crystals. For bothcontrast ratio and the rate of transmitted light the DGHPDFLC is better thanDGHFLC. During the measurement of physical properties, the ferroelectric phasetransition temperature tended to go down after the addition of dye during theexperiment. The results could be attributed to the phase equilibrium of thetwo mixed compounds of dye and liquid crystal which induces little change in theliquid crystal phase transition temperature.