复杂高分子/纳米粒子体系相结构、动力学及力学性能的模拟研究

Deep understanding of the complex coupling interaction between polymer and nanoparticle will not only help to explore new polymer functional nanomaterials, also to understand some biological macromolecular structure and its corresponding biological functions. This project is proposed based on coarse-grained molecular dynamics simulations to study the phase structure, dynamics behavior and mechanical properties of complex polymer/nanoparticle system. On the one hand, by studying the interface behavior of polymer/nanoparticle, polymer chain conformation, and particle aggregation and dispersion, a comprehensive understanding on the physical mechanism and the influence of chain rigid, polydispersity, particle orientation, and the coupling effect on polymer/nanoparticle system can be obtained; On the other hand, by studying the dynamics behavior and phase structure of complex polymer/nanoparticle system subjected to shear flow, and calculating the mechanical characteristic parameters, such as diffusion coefficient, stress-strain curve, shear modulus and viscosity, it is possible to establish the relationship between phase structure and macro performance. The above results will help people to understand complex self-assembled mechanism of polymer/nanoparticle system, and provide direct theoretical help to design high performance nanocomposites.

深入理解高分子与纳米粒子之间复杂的耦合相互作用机理不仅有助于探索新型高分子纳米功能材料，也对了解某些生物大分子的结构及其对应的生物功能具有指导意义。本项目拟采用基于粗粒化模型的分子动力学模拟方法研究复杂高分子/纳米粒子体系的相结构、动力学行为及力学性能。一方面，通过研究高分子/纳米粒子的界面行为、高分子链构型、及粒子的集聚与分散规律，全面了解链段的刚柔性、多分散性、粒子取向特性、及其耦合作用对高分子/纳米粒子体系影响的物理机制；另一方面，通过研究以上复杂高分子/纳米粒子体系在剪切外场下的动力学行为与微相结构，计算体系的扩散系数、应力-应变曲线、剪切模量及粘度系数等力学特性参数，进而建立纳米复合体系微相结构与宏观性能间的关系。研究成果将有助于人们深入了解复杂高分子/纳米粒子体系的自组装机理，并为设计高性能纳米复合材料提供直接的理论帮助。

本项目采用基于介观尺度上的粗粒化模型与分子动力学模拟方法，研究了高分子链的刚性、多分散性（如线形/环形链共混）、剪切场、粒子取向特性（如纳米棒）等参数的耦合效应对高分子/纳米粒子界面行为的影响，可以有效地控制纳米粒子在高分子基体中的集聚结构与分散行为，最终建立真实高分子纳米复合体系的微相结构与宏观力学性能之间的关系。研究成果将有助于人们深入了解复杂高分子/纳米粒子体系的自组装机理，并为设计高性能纳米复合材料提供直接的理论帮助。该项目的实施内容基本按照原计划书中执行，并按期完成了计划中的承诺成果。项目资助期间以第一作者或通讯作者发表SCI论文10余篇。