【作者】 赵伟国；

【导师】 谢孔良；

【作者基本信息】 东华大学 ， 纺织化学与染整工程， 2011， 硕士

【摘要】 液晶材料在高新技术领域显示出越来越广阔的应用前景,因而倍受研究者的青睐。手性是自然界和生命体中普遍存在的现象。手性问题对生命科学、药物化学、(高分子)材料科学等相关学科的发展具有重要意义。将手性掺杂剂引入液晶中,大大促进了新型液晶材料及非线性光学材料的发展和应用。使液晶具有优良的热色效应,而且性能稳定,已在热谱图像中得到越来越多的应用。手性液晶材料已越来越受到人们的重视,这是由于它们具有独特的光电性能(如光的选择反射、热致变色、铁电、压电等),故在非线性光学、快速光开关、微电子等领域具有广阔的应用前景。本文分别以L-乳酸乙酯和异山梨醇为原料设计合成了两种手性掺杂剂,并分别以这两种掺杂剂为原料,再与液晶基元联苯二酚反应设计合成了两种新型小分子热致液晶,讨论了实验的影响因素,优化了合成路线和合成条件。通过IR、1HNMR表征化合物的结构。通过341型旋光仪、J-810型圆二色谱仪、热台偏光显微镜(POM)初步探讨了液晶分子结构与性能的关系。研究表明：合成的四种化合物均具有良好的旋光性能,手性基团与联苯二酚反应后生成的手性液晶,其旋光性能会发生变化；手性掺杂剂以1%的比例掺杂时可以获得良好的掺杂效果,并且基本不会影响液晶本身的性能,而且掺杂剂加入到联苯类液晶中后,液晶在达到清亮点后并没有明显的黑十字消光现象出现,降温过程中,液晶织构变化更多样。两种手性液晶化合物与液晶基元相比,熔点、清亮点都得到一定程度的提高,而且升温过程中更易出现明显的织构变化,降温过程中无明显的变化。更多还原

【Abstract】 LCD has wider application prospect in high-tech fields, so many researchers are paying great attention to it. Chiral is a common phenomenon in nature and living things. The problems of chiral have great significance for the development of life sciences, pharmaceutical chemistry, (polymer) materials science and other related subjects. The introduction of the chiral dopants in liquid crystal, which greatly promoted the development and applications of new liquid crystal materials and nonlinear optical materials. The LCD which has excellent thermal effects and stable performance has more and more applications in the thermal spectrum image. Chiral liquid crystal materials have been paid more and more attention, which are due to their unique optical properties (such as selective reflection of light, thermochromism, ferroelectric, piezoelectric, etc), so Chiral liquid crystal materials have broad application prospects in the nonlinear optics, rapid light switches, microelectronics and other fields.Two kinds of chiral dopants were synthesized based on L-lactate and Isosorbide respectively, on the basis of them, reacted with United hydroquinone respectively, two novel small molecule thermo tropic liquid crystals were synthesized, the more common routes of synthesis were compared, the experimental factors were discussed, and optimal synthetic route was selected. The structures of compounds were characterized by IR,1HNMR. The relationship between molecular structure and properties were discussed by 341 type polar meter、J-810type circular dichroism instrument and hot stage polarized optical microscopy (POM). The results show that:the four compounds synthesized have good optical properties, The optical properties of two novel chiral liquid crystals will change greatly; we not only get a good mixed results but also not affect the basic performance of the LCD itself when the concentration of chiral dopant was one percent, the chiral liquid crystals do not have black cross extinction phenomenon after reaching clearing point. During the cooling process, the texture of liquid crystal will change more; The properties of Chiral Liquid crystal compounds got improvement comparing with the liquid crystalline in melting point and clearing point, the texture get more changes during the heating process and without significant changes during the cooling process.更多还原