教師資料查詢 | 類別: 期刊論文 | 教師: 余良杰 YU, LIANG-JYE (瀏覽個人網頁)

標題:Chirality in mixed nematic and cholesteric liquid crystals
學年61
學期1
出版(發表)日期1973/01/01
作品名稱Chirality in mixed nematic and cholesteric liquid crystals
作品名稱(其他語言)
著者余良杰; Yu, L. J.; Oron, N.
單位淡江大學化學學系
出版者Springer
著錄名稱、卷期、頁數Liquid crystals and ordered fluids 2, pp.403-410
摘要A mechanism is discussed explaining the different types of pitch-concentration dependences encountered in chiral mesophases. Addition of a low concentration of a chiral compound to a nematic produces a mesophase in which pitch is initially inversely proportional to concentration, but as the concentration increases, three different types of behavior occur: (a) the pitch slowly saturates as it approaches that of the pure chiral (cholesteric) compound; (b) the pitch decreases to a minimum pitch value (MPV) and then increases again to that of the pure cholesteric; (c) the pitch decreases to a MPV, increases to infinity and then decreases again to that of the pure cholesteric. This type of “compensation” which usually occurs only when a right-handed and left-handed cholesteric are mixed, is reported here for a mixture of choles-teryl-2(2-ethoxyethoxy) ethyl carbonate and the nematic N-p-methoxy-benzylidene-p-n-butylaniline. Thus, starting from a pure cholesteric, pitch may either increase or decrease upon adding a non-chiral solute. The common mechanism involves the induced circular dichroism (ICD) in the non-chiral compound caused by the helical arrangement of the chiral mesophase, which may be of the same or opposite sign as the ICD. The pitch of the pure cholesteric compound, the structure of the non-chiral compound and its affinity to ICD are important in determining which type of spectral behavior is observed.
關鍵字
語言英文
ISSN0146-5597
期刊性質國內
收錄於
產學合作
通訊作者
審稿制度
國別中華民國
公開徵稿
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