新穎性1,3,4-Oxadiazole彎曲核心結構作為藍相液晶材料之設計與應用

Design and Applications of Novel 1,3,4-Oxadiazole Bent-Core Structures for Blue Phase Liquid Crystals

龍春吉(Chun-Ji Long)

指導教授 ： 林宏洲

國立交通大學/工學院/材料科學與工程系所/碩士(2011年)

https://doi.org/10.6842/NCTU.2011.00955

摘要

本論文主要是以本實驗室已發表過之雙光軸液晶之文獻成果，作為衍生探討新穎性藍相液晶的分子設計與合成。其中液晶分子的設計為以本實驗室發表過之1,3,4-oxadiazole作為核心的香蕉型雙光軸液晶為基礎，再配合不同長度之軟鏈段來探討其液晶相，之後再導入具旋光性的軟鏈段嘗試誘導出藍相，分別為系列一的分子：OXD4f、OXD5f、OXD7f、OXD7f*。隨後改變其中一側硬段的苯環數，但其結構依然是不對稱的型態，並加入官能基氟以及具對掌性的軟鏈段，以此兩個官能基為基礎做出對照組，互相比較其性質並且嘗試誘導出藍相，分別為系列二的分子：OXD5B7、OXD5B7F、OXD5B7*。最後我們在系列一的分子中除了成功合成出具有BPIII性質的OXD7f*，也利用混摻的模式成功混出藍相之性質，其混摻過後所誘導出的藍相可由39℃持續到室溫。在系列二部分，則成功設計出單一分子具有BPIII的性質OXD5B7*，由於溫寬較為狹窄只能在POM上觀察出其BPIII的紋理圖，大約持續0.5℃左右。以上系列一及系列二的分子，我們利用POM、DSC、UV-Visible、光電性質量測及XRD來進行驗證分析其物性。

關鍵字

彎曲型液晶 ； 藍相 ； X光繞射圖譜 ； 示差掃描熱量計 ； 偏光顯微鏡 ； 紫外可見光譜儀

並列摘要

This thesis is based on our laboratory has published the results of literature on biaxial liquid crystal, as derived from the novel of blue phase liquid crystal molecular design and synthesis.
The liquid crystal molecules designed to allow the laboratory published 1,3,4-oxadiazole as the core of the banana-shaped biaxial liquid crystal, and use the soft chain of different lengths to explore the liquid crystal phases. And then import a chirality of soft chain try to induce blue phase. Series one of molecules: OXD4f, OXD5f, OXD7f, OXD7f*.
Then one side of the hard segment to change the number of benzene rings, but its structure is still asymmetry.Adding two functional groups fluorine and a chiral soft chain, as the basis of two functional groups to make control groups to compare their properties and try to induce blue phase. Series two of molecules: OXD5B7, OXD5B7F, OXD5B7*.
Finally, we successfully synthesized a molecule which have BPIII property in the series one ,and also useed a blended method successfully induce blue phase, which blue phase temperature range from 39℃ room temperature. In the series of two, we successfully designed a single molecule which have BPIII property.Because the BPIII temperature range is too narrow,we can only be observed its texture in the POM,the range only about 0.5℃.We used the POM, DSC, UV-Visible, measurement of photoelectrical properties and XRD to verify the physical properties of these liquid crystals.

並列關鍵字

bent-core liquid crystal ； blue phase ； XRD ； DSC ； POM ； UV-Visible

參考文獻

[2]R. A.Reddy, C. Tschierske. J. Mater. Chem., 2006, 16, 907.

[4]Atsushi Yoshizawa, J. Mater. Chem., 2005, 15, 3285.

[5]Atsushi Yoshizawa, Liq. Cryst., 2007, 34, 1039.

[7]Hirotsugu Kikuchi, Nature materials, 2002, 1, 64.

[9]Atsushi Yoshizawa, Adv. Mater. 2007, 19, 4145.