- 學位論文
奈米級微粒子摻合液晶之PDLC製法及特性研究
The Thesis in PDLC of Nanometer Particles Dispersed in Liquid Crystal
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摘要
高分子分散液晶薄膜(Polymer dispersed liquid crystal film, PDLC) 或稱為高分子/ 液晶複合膜，是由微米級之小滴狀nematic液晶，分散在高分子基材中，所組成之一種相分離構造，其操作原理是利用改變外部施加電場的大小，來改變其光散射之程度。在未施加電場之前，液晶之折射率與高分子基材之折射率相差很大，因而導致光散射之現象發生，複合膜會呈現不透明狀。當外加電場時，液晶分子會朝著電場方向排列(正誘電異方性液晶)，此時液晶分子之有效折射率與高分子基材之折射率會相接近，使得複合膜會呈現透明狀態。當外加電場關閉後，藉由高分子壁面的推擠，液晶會自動回到光散亂狀態。其優點是可以省略偏光板。 在此，吾人將以微粒子摻合液晶之方式，來製作高分子分散液晶薄膜，並針對在不同之頻率與電壓下，所發現之光透過率變化現象，進行對其之光電行為作特性研究。
並列摘要
Polymer dispersed liquid crystal film is a phase separation structure of micron size drops of nematic liquid crystal dispersed in polymer base materials. The working principle is to change the light performance by changing the electricity power. Before adding electricity, the difference between the refractive indexes of the liquid and the polymer is huge. Thus it leads to the outcome of light scattering and an opaque appearance. When an electric field is applied across the film thickness, the directors orient parallel to the field direction (LC with a positive dielectric anisotropy). In this state the film becomes transparent due to the matching between the ordinary refractive indexes of the LC and the polymer. After shutting down the electricity, the film will return to the original status. The unique LC light electrical reaction can be fully exercised in the polymer. Also, the polymer material is easy of fabrication. These two reasons make PDLC capable in many fields. The advantage is to skip the usage of polarizers. Thus, we would produce the PDLC film and discuss its unique effect through the report of transmittance by changing the electricity power.
參考文獻
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