Study on the Application of Nanoparticles on the Black-White Cholesteric Liquid Crystal Display

• Main Authors: Yu-hsiang Hung, 洪鈺翔
• Other Authors: Shug-june Hwang
• Format: Others
• Language: zh-TW
• Published: 2009
• Online Access: http://ndltd.ncl.edu.tw/handle/51971682634149383563

碩士 === 國立聯合大學 === 光電工程學系碩士班 === 97 === In this work, effects of temperature on the molecule distribution of cholesteric liquid crystal (CLC) cells containing nanoparticles of polyhedral oligomeric silsesquioxane (POSS) are investigated. The dispersed POSS aggregates, which can be controlled under various temperature process, produce defects and create a multi-domain planar structure. Furthermore, due to spontaneous vertical alignment of LC was induced by adding POSS nanoparticles in LC layer; the black-white reflective CLC display is demonstrated. The mixture is injected into an empty cell without surface treatment in isotropic phase. When the specimen cooled rapidly from the temperature higher than its clearing temperature, the orientation of the helical axes of the multi-domain CLCs has a wide distribution by phase segregation CLC structures and the dispersed POSS aggregates self-assembly. The spectrum of the light observed is a summation over multiple domains and therefore is broad. The absorption layer is placed on the bottom substrates, the sample has a good white appearance and has a black appearance in the focal conic texture. Optimization of self-assembly nanoparticles black-white CLC display are observed with the POM, reflection spectrum, reflectance, contrast ratio, and viewing angle. From the measured results, the CLC display containing POSS with rapid cooling process can obtain wide band reflection property to realize black-white displays.