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https://tkuir.lib.tku.edu.tw/dspace/handle/987654321/32673
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| 題名: | 含4,4'-甲亞基,4,4'-乙亞基及4,4'-異丙亞基-二酚之彎曲形液晶分子 |
| 其他題名: | Banana mesogens derived from 4,4'-methylene, 4,4'-ethylidene and 4,4'-isopropylidene bisphenol |
| 作者: | 何惠珊;Ho, Hui-shan |
| 貢獻者: | 淡江大學化學學系碩士班
余良杰;Yu, Liang-jye |
| 關鍵詞: | 彎曲形液晶分子;banana;liquid crystals |
| 日期: | 2006 |
| 上傳時間: | 2010-01-11 02:32:29 (UTC+8) |
| 摘要: | 本研究目的為合成以4,4’-甲亞基,4,4’-乙亞基及4,4’-異丙亞基二酚為核心架構,兩翼皆以酯基連接苯環衍生出六環系統之彎曲形分子。探討隨著中間核心的變化、尾端烷氧鏈長度變化以及利用尾端烷氧鏈碳數不同與單邊側取代造成分子構形上的不對稱，對液晶相造成之影響。
系列一(CH3-CH3-nCl-nCl)以4,4’-異丙亞基二酚為中間核心之彎曲形分子。此系列都沒有液晶相的生成。
系列二(H-H-nCl-nCl)以4,4’-甲亞基二酚為中間核心之彎曲形液晶分子。此系列（n=8、10、12、14、16）液晶相皆為B1(ColreC)相，此系列液晶相溫度範圍83℃-111℃。此系列都沒有電場效應。
系列三(H-CH3-nCl-nCl)以4,4’-乙亞基二酚為中間核心之彎曲形液晶分子。在短碳鏈（n=8）時 , 液晶相為B1(ColreP)相 ; (n=10)時 , 液晶相為B1(ColreC)相。在長碳鏈（n=12、14、16）, 液晶相為B2相。此系列液晶相溫度範圍2℃-9℃。在正(負)向電場下，紋理圖中extinction crosses會有逆(順)時針偏轉和沒有偏轉，可觀察到三個穩定態，推測分子排列情況為SmCAPA和SmCSPA。
系列四(H-CH3-mCl-n) 以4,4’-乙亞基二酚為中間核心之彎曲形液晶分子，液晶相生成B2相，此系列液晶相溫度範圍為24℃-32℃。分子構形上的不對稱使得液晶相熔點下降及增加液晶相溫度範圍 , 主要是由尾端烷氧鏈碳數不同所造成。在外加電場下 , 紋理圖中extinction crosses不會偏轉 , 因而推測分子排列情況為SmCSPA。
New bent core mesogens derived from 4,4’-methylene , 4,4’-ethylidene and
4,4’-isopropylidene bisphenol were synthesized by esterification . The influences of mesogens were studied by altering centre cores , the length of the terminal alkoxy chain , and lateral substituents at the terminal rings .
Bent-shaped molecules derived from 4,4’- isopropylidene bisphenol as central core . Series I(CH3-CH3-nCl-nCl) doesn’t exist any mesophase .
Bent-shaped molecules derived from 4,4’-methylene bisphenol as the central unit. Series II(H-H-nCl-nCl) exhibited B1(ColreC) phase with tempature ranges 83℃-111℃. No electrooptical response had been found in the series .
Bent-shaped molecules derived from 4,4’-ethylidene bisphenol as the central unit .
Series III(H-CH3-nCl-nCl)with short terminal chain length (n=8)exhibited B1(ColreP) phase ; (n=10)exhibited B1(ColreC) phase . On increasing the terminal chain lengths(n=12, 14, 16)exhibited B2 phase.The temperature range of the series is 2℃-9℃. Under positive (or negative) electric field , some of the extinction crosses rotate counterclockwise (or clockwise) and some don’t rotate. Therefore , speculating SmCAPA and SmCSPA are the arrangement of the molecules.
Bent-shaped molecules derived from 4,4’-ethylidene bisphenol as the central unit.
SeriesIV(H-CH3-mCl-n)exhibited B2 phase . The temperature range of the serie is 24℃-32℃. Asymmetrical conformation can markedly lower melting point and expand temperature range of mesophase . It major results from the difference of terminal alkoxy chain . Under electric field , extinction crosses don’t rotate . So it may be speculated that molecular arrangement are SmCSPA . |
| 顯示於類別: | [化學學系暨研究所] 學位論文
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