Amphiphilic cholesteryl-bearing carboxymethylcellulose derivatives: self-assembly and rheological behaviour in aqueous solution
Amphiphilic cholesteryl-bearing carboxymethylcellulose derivatives: self-assembly and rheological behaviour in aqueous solution
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两亲性胆固醇羧甲基纤维素衍生物：水溶液中的自组装和流变行为
DOI：
10.1007/s10570-008-9218-4
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发表时间：
2008-10-01
期刊：
影响因子：
5.7
通讯作者：
Zhang, Li-Ming
中科院分区：
文献类型：
--
作者：
Yang, Liqun;Kuang, Jianliang;Zhang, Li-Ming
除了它们在水溶液中的流变行为之外，还研究了两亲性带有胆固醇的羧甲基纤维素衍生物（CCMC）从单个分子到自聚集体的自组装。使用静态和动态光散射分析以及稳定荧光技术对单个 CCMC 单个分子和自聚集体的构象以及 CCMC 自聚集体的微观结构进行了表征。结果表明，当疏水性胆固醇基团的数量增加时，各个CCMC链变得紧凑，并且氯化钠水溶液从近似溶剂变为不良溶剂。 CCMC 自聚集体表现为致密球体。微观结构表征表明，一种CCMC自聚集体由多个单独的CCMC分子和疏水性微域组成，并且多个胆固醇基团自缔合成一个疏水性微域。 CCMC自聚集体相模式的原子力显微镜图像显示，多个内部疏水相分离区域被亲水多糖链包围，为一个自聚集体中存在多个疏水微域提供了证据。流变学分析证明CCMC自聚集体是一种微凝胶，其中胆固醇基团的缔合在聚合物网络中提供了多个交联点。微凝胶溶液表现出独特的触变性和剪切稀化行为。
The self-assembly of amphiphilic cholesteryl-bearing carboxymethylcellulose derivatives (CCMCs) from individual molecules to self-aggregates, in addition to their rheological behaviour in aqueous solution were investigated. The conformations of the individual CCMC individual molecules and self-aggregates, and the microstructures of CCMC self-aggregates were characterized using the static and dynamic light scattering analyses, and the steady fluorescence technology. The results showed that the individual CCMC chains became compact, and aqueous NaCl solution changed from an approximateθsolvent to a bad one when the number of hydrophobic cholesteryl groups increased. The CCMC self-aggregates exhibited as compact spheres. The microstructural characterization indicated that one CCMC self-aggregate consisted of multiple individual CCMC molecules and hydrophobic microdomains, and multiple cholesteryl groups self-associated into one hydrophobic microdomain. The atomic force microscopy images of CCMC self-aggregates in phase mode showed that the multiple interior hydrophobic phase separation regions were surrounded by hydrophilic polysaccharide chains, providing an evidence for multiple hydrophobic microdomains in one self-aggregate. The rheological analysis proved that the CCMC self-aggregates were a microgel, in which the associations of cholesteryl groups provided multiple cross-linking points in the polymer network. The microgel solutions displayed a unique thixotropy and a shear thinning behaviour.