Micelle formation of a rod-coil diblock copolymer in a solvent selective for the rod block
Micelle formation of a rod-coil diblock copolymer in a solvent selective for the rod block
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DOI：
10.1021/ma011502f
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发表时间：
2002-01
期刊：
影响因子：
5.5
通讯作者：
Jin Wu;E. Pearce;T. Kwei;A. A. Lefebvre-A.;N. Balsara
中科院分区：
文献类型：
--
作者：
Jin Wu;E. Pearce;T. Kwei;A. A. Lefebvre-A.;N. Balsara
使用光散射和偏光光学显微镜研究了两亲棒状线圈二嵌段共聚物聚（异氰酸正己酯）-b-聚（乙二醇）（PHIC-b-PEG）在甲苯（棒状 PHIC 嵌段的选择性溶剂）中的聚集。静态和动态光散射数据表明，在 25 °C 的极稀溶液（聚合物的重量分数，w，从 0.0002 到 0.008）中形成了流体动力学半径为 279 nm 的圆柱形胶束。根据实验数据与椭球体散射和自扩散理论的比较，确定圆柱形胶束为盘状（平面），直径为0.9 μm，厚度为20 nm。如果冠状棒块的向列相互作用占主导地位，则预计会出现平面聚集体。聚集体尺寸随着温度的升高而减小。由于 PHIC 块的光学各向异性，借助偏光光学显微镜可以在溶液中目视观察胶束。观察到直径在微米范围内的盘状物体在显微镜焦平面内和外进行平移和旋转运动。
Aggregation of an amphiphilic rod-coil diblock copolymer, poly(n-hexyl isocyanate)-b-poly(ethylene glycol) (PHIC-b-PEG), in toluene, a selective solvent for the rodlike PHIC block, was studied using light scattering and polarized optical microscopy. Static and dynamic light scattering data indicate the formation of cylindrical micelles with a hydrodynamic radius of 279 nm in very dilute solutions (weight fraction of polymer, w, from 0.0002 to 0.008) at 25 °C. The cylindrical micelles were determined to be disklike (planar), 0.9 μm in diameter and 20 nm in thickness, based on a comparison between the experimental data and the theory of scattering and self-diffusion of ellipsoids. Planar aggregates are expected if nematic interactions of the coronal rod block are dominant. The aggregate size decreases with increasing temperature. The micelles were observed visually in solution with the help of a polarized optical microscope due to the optical anisotropy of the PHIC block. Disklike objects with diameters in the micron range were observed to undergo translational and rotational motion in and out of the focal plane of the microscope.