Preparation and properties of highly birefringent liquid crystalline materials: styrene monomers with acetylenes, naphthyl, and isothiocyanate groups
Preparation and properties of highly birefringent liquid crystalline materials: styrene monomers with acetylenes, naphthyl, and isothiocyanate groups
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DOI：
10.1080/02678291003653641
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发表时间：
2010-04
期刊：
影响因子：
2.2
通讯作者：
Lanying Zhang;Xiao-Lin Guan;Zhen-Lin Zhang;Xiaofang Chen;Zhihao Shen;Xinghe Fan;Qifeng Zhou
中科院分区：
文献类型：
--
作者：
Lanying Zhang;Xiao-Lin Guan;Zhen-Lin Zhang;Xiaofang Chen;Zhihao Shen;Xinghe Fan;Qifeng Zhou
成功地合成了两个不同烷基链长的苯乙烯单体系列。合成中间体和单体的化学结构经傅里叶变换红外光谱、核磁共振氢谱、质谱和元素分析确证。通过偏光显微镜、热重分析、差示扫描量热法和一维广角X射线衍射研究了它们的热稳定性、转变温度和相序列。用阿贝折射仪和荧光仪测试了其双折射和光电性能、紫外-可见光谱和荧光光谱。结果表明，所有单体在较高温度下均呈现液晶相，双折射值在0.4 ~ 0.7之间，且具有良好的光致发光性能。随着烷基链长的增加，分子的偏振性降低，同系分子的光学各向异性也随之降低。此外，还发现了化学结构对光致发光性能的显著影响，并根据π共轭长度进行了讨论。
Two new series of styrene monomers with different alkyl chain length were successfully synthesised. The chemical structures of synthetic intermediates and monomers were confirmed by Fourier transform infrared spectroscopy, 1H nuclear magnetic resonance spectroscopy, mass spectrometry and elemental analysis. Their thermal stability, transition temperatures and phase sequences were investigated by polarised light microscopy, thermogravimetric analysis, differential scanning calorimetry and one-dimensional wide-angle X-ray diffraction. The birefringent and photoelectric properties, UV–vis and fluorescence spectroscopy were also measured using Abbe refractometer and fluorescent apparatus. The results indicated that all the monomers exhibited a liquid crystalline phase at higher temperature, high birefringence values between 0.4 and 0.7, and good photoluminescence properties. Optical anisotropy of homologous molecules was reduced with the increase of alkyl chain length due to the decrease of molecular polarisation. Moreover, a significant effect of the chemical structure on the photoluminescence properties was also found and discussed according to the length of π-conjugation.