微纳尺度混合填充增强复合材料热导率的协同效应研究

微纳尺度混合填充有望通过协同效应显著提高复合材料的热导率，但目前的研究还不够深入，对于协同效应的强化机理缺乏科学认识。本项目采用理论与实验相结合的方法，研究微纳尺度混合填充条件下复合材料的传热强化机理。在实验获得混合填充的复合材料显微结构的基础上，通过对填料网络的合理简化，建立考虑界面热阻的复合材料等效热导率的计算模型，使用有限元方法数值求解并运用实验数据验证。在此基础上分析填料尺度、形状、数量配比等因素对复合材料热导率的影响规律，揭示多尺度混合填充提高复合材料热导率的协同效应的强化机理，建立运用多尺度填料混合填充增强复合材料热导率的调控机制，为复合材料传热强化提供指导和依据。

A remarkable thermal conductivity enhancement of polymer composite can be achieved by using hybrid fillers through synergistic effect. However, there is a lack of detailed study and very limited knowledge can be found about the mechanism of synergistic effect. This proposal aims to study the heat transfer enhancement mechanism in composites with micro/nanoscale hybrid fillers by means of theoretical analysis and experimental testing. Based on the experimental results of the distribution of hybrid fillers in the composite, a numerical model to calculate composite effective thermal conductivity was set up by reasonably simplifying the filler network. The thermal conductivities of the fillers were set to equivalent values which include the influence of the interfacial thermal resistance. The effective thermal conductivities of the composites were solved by finite element method and validated by experimental results. The numerical model was then used to analyze the influence of the new factors, which include filler type, dimension and shape difference, and quantity ratio, on composite thermal conductivity. With the results, the heat transfer enhancement mechanism of synergistic effect on composite thermal conductivity with micro/nanoscale hybrid fillers would be revealed and a regulation method to improve composite thermal conductivity by using hybrid fillers would be obtained. All these findings would provide guidance and reference for material engineering on how to improve composite thermal conductivity.