ABA 型梳状三嵌段共聚物的自组装行为：布朗动力学模拟方法。

Self-assembly behavior of ABA coil-rod-coil triblock copolymers: a Brownian dynamics simulation approach.

机构信息

Shanghai Key Laboratory of Advanced Polymeric Materials, School of Materials Science and Engineering, East China University of Science and Technology, Shanghai 200237, China.

出版信息

J Chem Phys. 2011 Jul 7;135(1):014102. doi: 10.1063/1.3606396.

DOI:10.1063/1.3606396

PMID:21744883

Abstract

The self-assembly behavior of ABA coil-rod-coil triblock copolymers in a selective solvent was studied by a Brownian molecular dynamics simulation method. It was found that the rod midblock plays an important role in the self-assembly of the copolymers. With a decrease in the segregation strength, ɛ(RR), of rod pairs, the aggregate structure first varies from a smecticlike disk shape to a long twisted string micelle and then to small aggregates. The influence of the block length and the asymmetry of the triblock copolymer on the phase behavior were studied and the corresponding phase diagrams were mapped. It was revealed that the variation of these parameters has a profound effect on microstructure. The simulation results are consistent with experimental results. Compared to rod-coil diblock copolymers, the coil-rod-coil triblock copolymers has a larger entropy penalty associated with the interfacial grafting density of the aggregate, leading to a higher ɛ(RR) value for structural transitions.

摘要

采用布朗分子动力学模拟方法研究了 ABA 型梳状接枝共聚物在选择性溶剂中的自组装行为。结果表明，棒状嵌段在共聚物的自组装中起着重要作用。随着棒状分子间相互作用强度参数ε（RR）的降低，聚合物的聚集结构先是由近晶盘状变为长扭曲串状胶束，然后变为小的聚集物。研究了嵌段长度和三嵌段共聚物的不对称性对相行为的影响，并绘制了相应的相图。结果表明，这些参数的变化对微结构有深远的影响。模拟结果与实验结果一致。与棒状-线团两嵌段共聚物相比，梳状接枝三嵌段共聚物的聚集态的界面接枝密度的熵惩罚更大，导致结构转变的ε（RR）值更高。