Phase diagrams, mechanisms and unique characteristics of alternating-structured polymer self-assembly via simulations

• 来源期刊: 中国科学:化学（英文版）
• 年，卷（期）: 2019,（2）
• 页码范围: 226-237
• 页数: 12页
• 语种: 英文

摘要

Alternating-structured polymers (ASPs),like alternating copolymers,regular multiblock copolymers and polycondensates,are very important polymer structures with broad applications in photoelectric materials.However,their self-assembly behaviors,especially the self-assembly of alternating copolymers,have not been clearly studied up to now.Meanwhile,the unique characteristics therein have not been systematically disclosed yet by both experiments and theories.Herein,we have performed a systematic simulation study on the self-assembly of ASPs with two coil alternating segments in solution through dissipative particle dynamics (DPD) simulations.Several morphological phase diagrams were constructed as functions of different impact parameters.Diverse self-assemblies were observed,including spherical micelles,micelle networks,worm-like micelles,disklike micelles,multimicelle aggregates,bicontinuous micelles,vesicles,nanotubes and channelized micelles.Furthermore,a morphological evolutionary roadmap for all these self-assemblies was constructed,along with which the detailed molecular packing models and self-assembly mechanisms for each aggregate were disclosed.The ASPs were found to adopt a folded-chain mechanism in the self-assemblies.Finally,the unique characteristics for the self-assembly of alternating copolymers were revealed especially,including (1) ultra-fine and uniform feature sizes of the aggregates;(2) independence of self-assembled structures from molecular weight and molecular weight distribution;(3) ultra-small unimolecular aggregates.We believe the current work is beneficial for understanding the self-assembly of alternating structured polymers in solution and can serve as a guide for the further experiments.