向列型液晶(E7)相變化黏滯係數之研究

Studying on the viscosity coefficient of nematic liquid crystal (E7) at the phase transition

黃忠鎰(Ghung-Yi Huang)

指導教授 ： 周勝次

元智大學/電機通訊學院/光電工程研究所/碩士(2009年)

摘要

本論文主要是研究向列型液晶(E7)在變溫過程中黏滯係數的變化量測，實驗上主要是藉由偏光顯微鏡與示差熱掃描分析儀測定液晶相變點溫度，並使用圓錐-平板式黏度計量測溫變時液晶黏滯係數，同時藉由偏光顯微鏡觀察液晶(E7)隨溫度變化時相變的行為、發現相變狀態是一連續非均勻的混合態變化，並探討其黏滯係數與溫度之關係，經由本實驗結果發現，液晶(E7)的相變是經過一個與溫度有關的範圍，而不是一般物質的單一相變點，此種現象從未被證實過。

關鍵字

液晶 ； 偏光顯微鏡 ； 示差熱掃描分析儀 ； 黏滯係數

並列摘要

In this thesis, we investigated the viscosity coefficient of liquid crystal (LC) - E7, with its temperature dependence. In the experiment, we used the polarizing optical microscopy (POM) and Differential Scanning Calorimeter (DSC) to monitor the transition process of liquid crystal. To study the transient behavior of E7, we used the Cone and Plate Viscosmeter to measure the temperature-dependent viscosity coefficient. The POM experimental results show that the phase transition of E7 is a continuous and nonhomogeneous phenomenon depending on the temperature. According to the result, we could analyze the relationship of viscosity coefficient and temperature by calculating the volume ratio in the different states.
We found the there is a window for phase transition process of E7, but not a critical temperature point. This result is a new finding and different from any previous investigations. This research will give important information to the fundamental understanding of the phase transition of LC.

並列關鍵字

Liquid Crystal ； POM ； DSC ； Viscosity

參考文獻

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