近年来，液晶器件的响应速度得到了很大的改善，响应时间已经从25 ms 减少到3 ms 甚至更短。虽然这种改善与液晶层厚度的变薄有关，但主要原因应该归因于新型液晶材料的发展和使用。色序液晶显示能产生更高质量的图像，但前提是必须有能快速工作的液晶材料。液晶材料的旋转黏度系数、双折射和液晶层的厚度是影响液晶器件响应时间的3个主要因素。本文以液晶双折射这一因素为主线，从液晶化合物结构的角度介绍了影响液晶双折射数值的若干因素，包括中心环结构、中心基团上的桥键、极性基团和侧位-F 对液晶双折射的影响等，延长分子的π电子共轭长度能有效提高液晶的双折射。本文列举了国内外已合成的高双折射向列相液晶的分子结构及双折射值，最后对高双折射液晶的研究进行了展望。
In recent years,the response speed of LCDs has been greatly improved.The response time has been reduced from 25 ms to 3 ms or less.Although this improvement related to reducing thickness of the liquid crystal layer,the main reason was attributed to the studying and using of novel liquid crystal mixtures.Sequential color LCDs can produce higher quality images,but prerequisite is to have fast response liquid crystal materials.The three main factors which influence the response time of the LCDs are the rotational viscosity coefficient of the liquid crystal,the birefringence and thickness of the liquid crystal layer.This paper focuses on the birefringence of liquid crystal and describes several fac-tors which influence the birefringence from the molecular structure of the liquid crystal compounds, including the central ring structure,the bridging groups on the center,the polar group and the “-F”on the lateral.Extending the length of π-electron conjugation of molecules can improve the birefrin-gence of liquid crystal.This paper lists the molecular structures and birefringence of several nematic liquid crystal compounds with high birefringence which has been synthesized.Finally,the research of high birefringence liquid crystal is prospected.
参考文献
| [1] | Demus D;Goodbye J W;Gray G W.Handbook of Liquid Crystals[M].Chichester:Wiley-VCH,1998 |
| [2] | 杨傅子.近期液晶研究中的几个新方向-液晶非显示应用基础研究中的进展[J].物理学进展,200828(02):107-129. |
| [3] | 曹召良;穆全全;胡立发.液晶波前校正器位相调制非线性及闭环校正研究[J].液晶与显示,200823(02):157-162. |
| [4] | Jakeman E;Raynes E P.Electro-optic response times in liquid crystals[J].Physics Letters A,197239(01):69-70. |
| [5] | 高鸿锦.液晶化学[M].北京:清华大学出版社,2011 |
| [6] | Gauza S;Parish A;Wu S T.Physical properties of laterally fluorinated isothiocyanato phenyl-tolane single liq-uid crystals components and mixtures[J].Molecular Crystals and Liquid Crystals,2008489(11):135-147. |
| [7] | 张然;彭增辉;刘永刚.高 Δn 低黏度液晶的合成与性能研究[J].液晶与显示,200924(06):789-793. |
| [8] | Chen Y;Sun J;Xianyu H Q.High birefringence fluoro-terphenyls for thin-cell-gap TFT-LCDs[J].J ournal of Display Technology,20117(09):478-481. |
| [9] | Gupta M D;Mukhopadhyay A;Roy S K.High birefringence liquid crystalline mixture:Optical properties and order parameter[J].J ournal of Applied Physics,2013113(0535 16):1-4. |
| [10] | Jia D;Yang C L;Peng Z H.Wide-angle switchable negative refraction in high birefringence nematic liquid crystals[J].Liquid Crystals,201340(05):599-604. |
| [11] | Pestov S M.Physical Properties of Liquid Crystals[M].Springer Berlin Heidebeng,2003 |
| [12] | Gauza S;Jiao M Z;Wu S T.High birefringence and negative dielectric anisotropy liquid crystal mixtures for vertical alignment applications[J].Liquid Crystals,200835(12):1401-1408. |
| [13] | Wu S T.Birefringence dispersions of liquid crystals[J].Physical Review A,198633:1270-1274. |
| [14] | Wu S T.High birefringence and wide nematic range bistolane liquid crystals[J].J ournal of Applied Physics,199973(03):344-346. |
| [15] | 史子谦;丰景义;贵丽红.高折射率液晶化合物与液晶混合物[J].液晶与显示,201328(03):310-314. |
| [16] | Hird M;Toyne K J;Goodby J W.Synthesis,mesomorphic behaviour and optical anisotropy of some novel materials for nematic mixtures of high birefringence[J].J ournal of Materials Chemistry,200414(11):1731-1743. |
| [17] | Zhang L Y;Guan X L;Zhang Z L.Preparation and properties of highly birefringent liquid crystalline materi-als:styrene monomers with acetylenes,naphthyl,and isothiocyanate groups[J].Liquid Crystals,201037(04):453-462. |
| [18] | Arakawa Y;Nakajma S;Kang S.Synthesis and evaluation of dinaphthylacetylene nematic liquid crystals for high-birefringence materials[J].Liquid Crystals,201239(09):1063-1069. |
| [19] | Dabrowski R;Kula P;Herman J.High birefringence liquid crystals[J].Crystals,20133(03):443-482. |
| [20] | Goto Y;Inukai T;Fujita A.New nematics with high birefringence[J].Molecular Crystal and Liquid Crystal,1995260(01):23-38. |
| [21] | Hsu C S;Shyu K F;Chuang Y Y.Synthesis of laterally substituted bistolane liquid crystals[J].Liquid Crys-tals,200027(02):283-287. |
| [22] | Kirsch P;Bremer M;Taugerbeck A.Difluorooxymethylene-bridged liquid crystals:A novel synthesis based on the oxxidative alkoxydifluoro desulfuration of dithianylium salts[J].Angew Chem Int Ed,200140(08):1480-1484. |
| [23] | Peng Z H;Liu Y G;Yao S L.Improvement of response performance of liquid crystal optical devices by using a low viscosity component[J].Chinese Physics Letters,201128(09):0942071-0942073. |
| [24] | Iwamatsu M;Kobayashi N;Ueda H .Liquid crystal composition and liquid crystal light modulating device using the liquid crystal composition[P].China,CN101193999B,2005. |
| [25] | 刘琦;谭玉东;张宏伟 等.包含 1,2-二氟乙烯和二氟亚甲基醚结构的化合物及其制备和应用[P].中国,CN102336634A,2012. |
| [26] | 杨世琰;李桂兰;李永杰 等.薄膜晶体管液晶显示器用的含氟液晶化合物及制备方法[P].中国,CN1710019,2005. |
| [27] | 何军;张然;鲁兴海.快速高双折射率向列相液晶的分子设计与模拟计算[J].液晶与显示,200924(01):15-21. |
| [28] | Liao Y M;Janarthanan N;Hsu C S.Synthesis and mesomorphic properties of fluoro and isothiocyanato bi-phenyl tolane liquid crystals[J].Liquid Crystals,200633(10):1199-1206. |
| [29] | 黄江涛 .二氟乙烯基氟二苯乙炔类液晶的合成与性能研究[D].武汉:武汉轻工大学,2013. |
| [30] | 王国华 .含氟异硫氰酸酯高双折射率液晶的合成研究[D].武汉:武汉轻工大学,2013. |
| [31] | Kitano K;Uchida M;Suzuki M et al.A liquid crystalline compound,Eurpoe0330216A2[P].A liquid crystalline compound,Eurpoe0330216A2,1990. |
| [32] | Haseba Y;Matsui S;Takeuchi H et al.Fluoro-substitued alkenyl compounds,liquid crystal compositions,and liq-uid crystal display elements[P].US,US20020015805A1,2002. |
| [33] | 张伟光;郑国钧.末端为二氟乙烯氧基类液晶分子的合成[J].化学试剂,20103(02):258-260. |
| [34] | 刘运 .新型二氟乙烯基二苯乙炔类液晶合成与性能研究[D].武汉:武汉轻工大学,2011. |
| [35] | 王勇丽 .二氟乙烯基氟二苯乙炔类液晶的合成及性能研究[D].武汉:武汉轻工大学,2013. |
| [36] | 金志龙;曾育南;郑功龙 等.高双折射率液晶化合物及其组合物[P].中国,CN1927856A,2007. |
| [37] | Guan X L;Zeng L Y;Zhang Z L.Synthesis and properties of novel liquid crystalline materials with super high birefringence:styrene monomers bearing diacetylenes,naphthyl,and nitrogen-containing groups[J].Tetrahedron,2009(65):3728-3732. |
| [38] | Arakawa Y;Kang S;Nakajima S.Synthesis of new wide nematic diaryl-diacetylenes containing thiophene-based heteromonocyclic and heterobicyclic structures,and their birefringence properties[J].Liquid Crystals,201441(05):624-651. |
- 下载量()
- 访问量()
- 您的评分：
-
10%
-
20%
-
30%
-
40%
-
50%