含碳六十表面改質之單／雙苯酸之氫鍵彎曲型液晶混合物之 合成與研究

Abstract

以氫鍵之彎曲型液晶SiA-NBF14為主，本論文實驗成功合成出兩種含C60結構FIA與FIIA之混摻超分子液晶化合物，實驗結果藉由1H-NMR、13C-NMR、紅外線光譜儀、質譜以及元素分析鑑定其結構與純度，並透過DSC、POM、電性量測以及XRD來探討其液晶行為以及結構排列。研究結果顯示藉由混摻不同濃度C60分子(客)的複合材料，可改變其不同的液晶特性，使液晶相的溫寬提高，隨著所添加的C60分子的增加，其鐵電特性可由原本的反鐵電性轉為鐵電性，且其在高混摻濃度下仍具有鐵電液晶相。此外，實驗結果顯示透過微量的混摻含C60結構的FIA與FIIA可使此超分子液晶混合物的自發極化值(Ps值)與飽和電場達一最佳化值。

In this study we prepared novel composites materials from the hydrogen-bonded bent-core liquid crystal (LC) host and different mole ratios (0–90 mol%) of the surface-modified fullerenes(C60). The chemical structures of these compounds were characterized by 1H-NMR, 13C-NMR, IR spectra, MS as well as elemental analysis, and the liquid crystalline phases and mesomorphic behavior of all the compounds were identified from the results of DSC, POM, electro-optical measurement and XRD. The mesomorphic properties of the composites, including their mesophasic types and ranges, values of Ps, and saturated electric field were adjustable by varying the doping concentrations of fullerenes. By increasing the concentration of fullerenes, the polarity of the SmCP phase in the composite varied sequentially from anti-ferroelectricity to ferroelectricity. Futhermore, adding a little amount of surface-modified fullerenes make the mixtures possesses the best Ps value and saturated electric field.