利用扭轉型聚合物網絡液晶製作偏振選擇性光散射之研究

簡易檢索 / 詳目顯示

回結果列表

研究生：	陳維軒 Wei-Hsuan Chen
論文名稱：	利用扭轉型聚合物網絡液晶製作偏振選擇性光散射之研究 Polarization-Selective Light Scattering by Polymer Network Twisted Nematic Liquid Crystals
指導教授：	鄭恪亭 Ko-Ting Cheng
口試委員:
學位類別：	碩士 Master
系所名稱：	理學院 - 光電科學與工程學系 Department of Optics and Photonics
論文出版年：	2016
畢業學年度：	104
語文別：	中文
論文頁數：	127
中文關鍵詞：	聚合物網絡液晶、光散射
相關次數：	點閱：12 下載：0
分享至:	分享至facebook 分享至twitter

查詢本校圖書館目錄查詢臺灣博碩士論文知識加值系統勘誤回報

本論文的研究主題主要是利用向列型液晶(E7)與聚合物液晶(RM257)依一定比例均勻混合成之液晶材料，並搭配經摩擦配向的ITO (indium tin oxide)玻璃基板成為90°扭轉向列液晶(90° twisted nematics)，再經過紫外光固化製程後成功製作出聚合物網絡液晶(polymer network liquid crystals)，該元件外加電壓後呈現光散射態，且具有偏振選擇性散射的特性，同時此特性可藉由關閉外加電壓使其回到扭轉向列型液晶結構之透射態。
經由本論文實驗結果得知，由於液晶盒本身因90°扭轉配向而產生的結構型態以及選用之向列型液晶與聚合物液晶折射率的巧妙搭配，故產生偏振選擇性散射的特性，因此在外加電壓於此液晶元件使其處於散射態時，特定方向之線偏振光入射該元件後將發生強烈散射而無法穿透液晶盒；反之，另一正交方向之線偏振入射光卻幾乎毫無阻礙地穿透液晶盒，本研究成功開發出將偏振度(degree of polarization)為0之無偏振入射光經過此液晶元件後轉變為偏振度為0.97之線偏振光的能力，且此能力會在關閉外加電壓後完全消失，亦即該類似於偏振片的液晶元件為一可電控切換之液晶元件。
此外，利用上述特性可將其應用於電控光學元件與顯示器技術等，如電控散射型液晶偏振片及半反半穿式液晶顯示器等，且從實驗結果得知，使用不同偏振態之紫外光進行固化聚合物液晶之製程亦會對此種液晶元件的數據表現有所影響，讓此種液晶元件的變化性與延伸應用更加提升。

In this study, we have successfully demonstrated a polarization selective scattering liquid crystal (LC) device based on polymer network twisted nematic LCs. Briefly, the combination of the adopted LC cell, generated by two indium-tin-oxide-coated glass substrates having orthogonally homogeneous alignment layers, and the homogeneously mixed materials of LC polymer (RM257) and nematic LC (E7), is the key point to achieve the LC devices. Such a LC device shows polarization-selective light scattering state when an external voltage is applied, and can be switched back to normally white mode twisted nematic LCs when the applied voltage is switched off.
The obtained results indicate that this LC device possesses the polarization-selective light scattering ability because of the refractive index collocation between nematic LC and LC polymer, as well as the 90o twisted alignment of LC cell. When this LC device is set as a scattering mode, the incident light with the particular direction of linearly polarization will not be able to pass through the LC cell due to strong scattering; on the contrary, the orthogonal direction of the incident linearly polarized light can easily penetrate through the LC device. Moreover, the achieved LC device can be used as an electrically controllable LC linear polarizer, which can filter an unpolarized light into a linearly polarized light when a suitable voltage is applied, and can be turned off when the applied voltage is switched off. The degree of polarization of the output linearly polarized light is 0.97.
Besides, such a reported characteristic of polarization-selective scattering can be applied to generate electrically controllable optical devices and display modes, such as electrically controllable LC polarizers and transflective LCDs. According to the obtained results, we also realize that the various polarization states of the illuminated UV light to polymerize LC polymers cause different performances for the LC devices.

摘要.............................................................................................................I
Abstract.....................................................................................................III
誌謝...........................................................................................................V
目錄..........................................................................................................VI
圖目錄.......................................................................................................X
第一章 緒論..............................................................................................1
       1-1 前言.......................................................................................1
       1-2 論文架構...............................................................................2
第二章 液晶簡介......................................................................................3
       2-1 何謂液晶...............................................................................3
       2-2 液晶的分類...........................................................................5
           2-2-1 長條狀液晶(rod-like liquid crystal)...........................7
           2-2-2 圓盤狀液晶(disk-like liquid crystal).......................14
           2-2-3 高分子液晶(liquid crystal polymer)........................15
       2-3 液晶的物理特性.................................................................18
           2-3-1 折射率異向性.........................................................18
           2-3-2 介電常數異向性.....................................................23
           2-3-3 秩序參數.................................................................26
           2-3-4 溫度對液晶折射率的影響.....................................27
           2-3-5 連續彈性體理論.....................................................27
           2-3-6 Fréedericksz Transition..............................................29
第三章 相關理論....................................................................................32
       3-1 摩擦配向技術.....................................................................32
       3-2 溝槽理論.............................................................................33
       3-3 扭轉向列型液晶.................................................................35
       3-4 聚合物網絡液晶.................................................................38
第四章 樣品製作與實驗光路................................................................42
       4-1 材料介紹.............................................................................42
           4-1-1 向列型液晶E7.........................................................42
           4-1-2 雙丙烯酸酯液晶RM257.........................................43
       4-2 液晶盒製作.........................................................................44
           4-2-1 玻璃基板清洗.........................................................45
           4-2-2空液晶盒製作...........................................................47
           4-2-3 液晶樣品調配.........................................................49
           4-2-4 完成液晶盒.............................................................50
           4-2-5 照射紫外光激發高分子液晶發生聚合反應.........50
       4-3 實驗方法與光路架設.........................................................51
           4-3-1 紫外光於TN r-PNLC內部偏振改變情形..............51
           4-3-2 電壓-穿透度曲線....................................................52
           4-3-3 TN r-PNLC對線偏振入射光偏振影響情形...........54
第五章 實驗結果與討論........................................................................55
       5-1 TN r-PNLC穿透態與散射態各項特性探討.......................56
           5-1-1 TN r-PNLC基本特性與散射態對線偏振光的特性
                觀察..........................................................................56
           5-1-2 TN r-PNLC偏振選擇性散射觀察與討論...............69
       5-2 紫外光偏振態改變對於TN r-PNLC之特性影響.............72
           5-2-1 紫外光於TN r-PNLC內偏振態改變情形..............72
           5-2-2 利用不同偏振方向之線偏振紫外光固化液晶聚合
                    物對TN r-PNLC的影響.........................................75
       5-3 TN r-PNLC之電控光電元件之應用...................................86
           5-3-1 TN r-PNLC應用於電控散射型液晶線偏振片.......88
           5-3-2 TN r-PNLC應用於電控散射型液晶光閥...............89
           5-3-3 TN r-PNLC應用於半反半穿式液晶顯示器...........90
第六章 結論與未來展望........................................................................93
       6-1結論......................................................................................93
       6-2 未來展望.............................................................................95
參考文獻..................................................................................................99

                                

[1] P. Yeh and C. Gu, “Optics of liquid crystal display,” John Wiley & Sons, New York (1999).

[2] E. B. Priestley, P. J. Wojtowicz and P. Sheng, “Introduction to liquid crystals,” Princeton, New Jersey (1975).

[3] 松本正一‧角田市良 (劉瑞祥譯)，“液晶之基礎與應用” 國立編譯館出版 (2003).

[4] 顧鴻壽，“光電液晶平面顯示器－第二版,” 新文京開發出版社 (2004).

[5] D. Statman, E. Page, V. Werner and J. C. Lombardi, “Photoinduced reorientation of nematic liquid crystals doped with an azo dye: A dynamic and steady-state study of reorientation and loss of liquid crystal order,” Phys. Rev. E 75,021703 (2007).

[6] C. R. Lee, T. S. Mo, K. T. Cheng, T.-L. Fu, and Andy Y. G. Fuh, “Electrically switchable and thermally erasable biphotonic holographic gratings in dye-doped liquid crystal films,” Appl. Phys. Lett. 83, 4285 (2003).

[7] O. Francescangeli, S. Slussarenko and F. Simoni, “Light-induced surface sliding of the nematic director in liquid crystals,” Phys. Rev. Lett. 82, 1855 (1999).

[8] P. G. de Gennes, and J. Prost, “The physics of liquid crystals,” Oxford University Press, New York (1993).

[9] G. W. Gray, “Thermotropic liquid crystals,” the Society of Chemical Industry (1987).

[10] I. C. Khoo and S.T. Wu, “Optics and nonlinear optics of liquid crystals,” World Scientific, Singapore (1993).

[11] H. Kitzerow and C. Bahr, “Chirality in liquid crystals,” Springer Science & Business Media (2006).

[12] A. Yariv, “Optical electronics in modern communication,” Oxford University Press, New York (1997).

[13] A. Yariv, “Quantum electronics,” Wiley, New York (1988).

[14] H. S. Kitzerrow and C. Bahr, “Chirality in liquid crystals,” Springer, New York (2001).

[15] I. C. Khoo, “Liquid crystals-physical properties and nonlinear optical phenomena,” John Wiley & Sons Press, New York (1995).

[16] P. J. Collings and M. Hird, “Introduction to liquid crystals chemistry and physics,” Taylor & Francis Ltd, Hampshire (1997).

[17] 趙文元、王亦軍，“功能高分子材料學” 化學工業出版社，北京 (1996).

[18] 王新久、周其鳳，“液晶高分子” 科技出版社，北京 (1999).

[19] http://www.austin-forum.org , http://www.taopanel.com

[20] K. M. Hasegawa, M.Koden, N. I. Hasegawa and M. Sakamoto,“ Alignment technologies and applications of liquid crystal devices,” Taylor & Francis, London and New York (2005).

[21] J. M. Geary, J. W. Goody, A. R. Kmetz and J. S. Patel, “The mechanism of polymer alignment of liquid-crystal materials,” J.Appl. Phys. 62, 4100 (1987).

[22] J. J. Ge, C. Y. Li, G. Xue, I. K. Mann, D. Zhang, S. Y. Wang, F. W. Harris, S. Z. Cheng, S. C. Hong, X. Zhuang and Y. R. Shen, “Rubbing-induced molecular reorientation on an alignment surface of an aromatic polyimide containing cyanobiphenyl side chains,” J. Am. Chem. Soc., 2001, 5768 (2001).

[23] D. W. Berreman, “Solid surface shape and the alignment of an adjacent nematic liquid crystal,” Phys. Rev. Lett. 28, 1683 (1972).

[24] J. W. Doana, N. A. Vaz and B. G. Wu, “Field controlled light scattering from nematic microdroplets,” Appl. Phys. Lett. 48, 269 (1986).

[25] T. Fujisawa, H. Ogawa and K. Maruyama, “Electro-optic properties and multiplexibility for polymer network liquid Crystal display(PN-LCD),” Japan Display Lett. 89, 690 (1989).

[26] R. Yamaguchi, K. Goto, S. Sakurai, L. Xiong and T. Tomono, “Normal and reverse mode light scattering properties in nematic liquid crystal cell using polymer stabilized effect,” J. Photopolym. Sci. and Technol. 28, 319 (2015).

[27] R. Yamaguchi and T. Takasu, “Hybrid aligned nematic liquid crystal smart glass with asymmetrical daylight controls,” JSID. 23, 365 (2015).

[28] S. W. Kang, S. N. Sprunt and L. C. Chien, “Structure and morphology of polymer-stabilized cholesteric diffraction gratings,” Appl. Phys. Lett. 76, 3516 (2000).

[29] A. Y. G. Fuh, W. K. Chen, K. T. Cheng, Y. C. Liu, C. K. Liu and Y. D. Chen, “Formation of holographic gratings in polymer-dispersed liquid crystals using off-resonant light,” Opt. Mater. Express 5, 774 (2015).

簡易檢索 / 詳目顯示

相關論文