稀溶液中Rod-Coil-Rod三嵌段共聚物组装结构的耗散粒子动力学模拟

采用耗散粒子动力学方法模拟研究了rod-coil-rod 三嵌段共聚物在稀溶液中的聚集行为. 分别考察了rod-coil 嵌段的相互作用、溶剂性质、共聚物浓度以及coil 嵌段长度对聚集体形貌的影响. 模拟结果发现，随着rod-coil 相互排斥作用的增加，共聚物由球形转变成洋葱状、笼形和柱状结构. 随着coil 嵌段疏水性的增加，笼形转变成洋葱状和补丁状结构. 给出了聚集体形貌随共聚物浓度和coil 长度变化的相图. 当浓度较小和coil 嵌段较长时，共聚物形成笼状聚集体，反之，则有利于洋葱状结构的形成.

Dissipative Particle Dynamics Simulation on Aggregation of Rod-Coil-Rod Triblock Copolymer in Dilute Solution

The aggregate morphology of rod-coil-rod copolymers in a dilute solution was investigated by dissipative particle dynamics simulations. The influences of the mutual compatibility between rod and coil blocks, the solvent property, the coil length, and the copolymer concentration on the aggregate structure were studied in detail. The simulation results show that the increase of the mutual compatibility between rod and coil blocks induces transformation of the aggregate morphology from spherical, to onion-like, to cage-like, and ultimately to cylindrical. With the increase in the hydrophobicity of the coil block, the cagelike aggregate changes into an onion-like aggregate, then a patchy aggregate, and then an inverted onionlike aggregate. Finally, a phase diagram of the rod-coil-rod triblock copolymers as a function of the coil length and the copolymer concentration is presented. It shows that cage aggregates are easily formed when the coil length is long and the concentration is relatively low, whereas onion-like aggregates are preferred when the coil length is short and the concentration is moderately low.