有机高分子-无机粒子杂化材料介电机理及构效关系的多尺度模拟

Addition of particles with high dielectric constant to the polymer matrix can dramatically improve the dielectric constant of hybrid material. These composites have a wide application as smart materials and energy storage materials. However, as opinions vary, no unanimous conclusion can be drawn about the dielectric mechanism. Lack of systematic study limits the design of the structure of hybrid material. In this project, we combine the theoretical calculation and experimental characterization to systematically study the interfacial polarization model and the particle network, from micro-structure to macro-properties. Meanwhile, the relationship between micro-structure and dielectric performance is study. The static structure and dynamic performance in the interfacial region are studied on the molecular scale, and mechanism of the interfacial polarization is clarified. The formation of particle network and its influence on the dielectric properties are studied on the mesoscale. The dielectric properties of hybrid material are predicted, combined with the interfacial layer model (ILM). Surface modification of particle with polymer chains can prepare the special structure, such as core-shell structure and particle network. In this project, we use the multiscale dynamics simulations to clarify the dielectric mechanism of organic polymer-inorganic particle hybrid material, providing the scientific basis for the optimization of particle structure. The research aims to provide the theoretical guide for the hybrid material with low particle content, high dielectric constant and low dielectric loss.

在高分子基体掺杂高介电常数的粒子，可极大地提高材料的介电常数，广泛应用于智能材料、储能材料等领域。然而，关于介电机理众说纷纭，缺乏系统的研究，制约着杂化材料结构的设计。本项目以理论计算为主，实验表征为辅，从微观结构到宏观性能，对界面极化模型以及粒子网络结构进行系统的研究，并揭示其微观结构与介电性能之间的内在联系。在分子尺度下研究界面区域静态结构与动力学性质，阐明界面极化机理。在介观尺度下研究粒子网络结构的形成及其对介电性能的影响。结合界面层理论（ILM）公式预测杂化材料的介电性能。在粒子表面接枝分子链，制备特殊结构（如核壳结构和粒子三维网络结构），以提高介电性能。本项目通过多尺度模拟计算，阐明有机高分子-无机粒子杂化材料的介电机理，为粒子结构的优化提供科学依据；最终，为实验上制备低粒子含量、高介电常数、低介电损耗的杂化材料提供理论指导。

在高分子基体掺杂高介电常数的粒子，可极大地提高材料的介电常数，广泛应用于智能材料、储能材料等领域。然而，关于介电机理众说纷纭，缺乏系统的研究，制约着杂化材料结构的设计。本项目以理论计算为主，实验表征为辅，从微观结构到宏观性能，对界面极化模型以及粒子网络结构进行系统的研究，并揭示其微观结构与介电性能之间的内在联系。对于界面极化模型，本项目采用全原子分子动力学模拟与实验相结合的方法，发现界面区域中键合层与松散层合并，这有别于Tanaka提出的经典界面多核模型。松散层中密度较低，有利于取向极化，从而提高介电常数。另外，我们通过界面调控，构建BaTiO3核壳纳米粒子，提高杂化材料的介电常数和降低介电损耗。对于粒子网络结构的研究，本项目采用粗粒度分子动力学模拟，建立了介电常数的理论表征方法，研究了三种体系，包括粒子/均聚物、表面接枝粒子/均聚物、粒子/嵌段共聚物体系，提出对应的三种方法以在低粒子含量下构筑粒子网络结构，为实验室上制备低粒子含量、高介电常数的有机高分子–无机粒子杂化材料提供思路。