Synthesis and characterization of hydroxyethyl chitosan grafted by carboxyl ending DOVOB dendrimer: A novel liquid crystalline polymer

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• 作者：Yaqing Zhao ; Jian Chen ; Erman Zeng ; Xiaolan Hu ; Anhua Liu ; Yanming Dong
• 关键词：Chitosan ; Dendrimer ; Lyotropic cholesteric liquid crystal
• 刊名：Carbohydrate Polymers
• 出版年：2008
• 出版时间：21 November 2008
• 年：2008
• 卷：74
• 期：4
• 页码：828-833
• 全文大小：487 K

文摘

A novel chitosan derivative, hydroxyethyl chitosan grafted 3,4,5-tris[p-(n-dodecyloxy)-m-methoxybenzyloxy]benzoate (HECS-g-DOVOB) was prepared via grafting dendrimer 3,4,5-tris[p-(n-dodecyloxy)-m-methoxybenzyloxy]benzoic acid (DOVOB acid) onto hydroxyethyl chitosan (HECS). The structure of HECS-g-DOVOB was investigated by means of FTIR, ¹H NMR, UV and circular dichroism (CD). The degree of substitution was measured to be about 0.39 per glucose unit. The DOVOB acid was able to self-assemble into a thermotropic hexagonal columnar liquid crystalline phase showing fan-like texture, the aqueous HECS solution formed lyotropic cholesteric liquid crystal showing fingerprint texture. Whereas, HECS-g-DOVOB formed lyotropic cholesteric liquid crystal in concentrated DMSO solution with a planar texture, which was different to that of both DOVOB and HECS. The cholesteric pitch of HECS-g-DOVOB is much smaller than that of HECS. The fluorescence spectrum of HECS-g-DOVOB shows excimer fluorescence which is very similar to the dendrimer is a good indication for light-emitting polymeric material.