Topology-Directed Control on Thermal Stability: Micelles Formed from Linear and Cyclized Amphiphilic Block Copolymers
Topology-Directed Control on Thermal Stability: Micelles Formed from Linear and Cyclized Amphiphilic Block Copolymers
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DOI：
10.1021/ja104691j
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发表时间：
2010-08-04
影响因子：
15
通讯作者：
Tezuka, Yasuyuki
中科院分区：
文献类型：
--
作者：
Honda, Satoshi;Yamamoto, Takuya;Tezuka, Yasuyuki
拓扑效应显著提高了自组装胶束的热稳定性。线性聚（丙烯酸丁酯）-嵌段-聚（环氧乙烷）-嵌段-聚（丙烯酸丁酯）（1）和环化产物聚（丙烯酸丁酯）-嵌段-聚（环氧乙烷）（2）自组装形成花状胶束。通过粘度法测定，1和2的临界胶束浓度分别为0.13和0.14 mg/mL。动态光散射，原子力显微镜和透射电子显微镜的研究表明，这两种胶束是球形的，直径约20 nm。尽管胶束的化学组成或结构没有明显的变化，我们发现，通过聚合物两亲物的线性到环状的拓扑转化，浊点（T-C）升高了40摄氏度以上。此外，通过1和2的共组装来调谐T-c。
The thermal stability of a self-assembled micelle was remarkably enhanced by a topology effect. Linear poly(butyl acrylate)-block-poly(ethylene oxide)-block-poly(butyl acrylate) (1) and the cyclized product, poly(butyl acrylate)-block-poly(ethylene oxide) (2), were self-assembled to form flower-like micelles. By means of viscometry, the critical micelle concentrations were determined to be 0.13 and 0.14 mg/mL for 1 and 2, respectively. Dynamic light scattering, atomic force microscopy, and transmission electron microscopy studies revealed that both micelles are spherical and approximately 20 nm in diameter. Despite no distinctive change in the chemical composition or structure of the micelle, we found that the cloud point (T-c) was elevated by more than 40 degrees C through the linear-to-cyclic topological conversion of the polymer amphiphile. Furthermore, the T-c was tuned by coassembly of 1 and 2.