构筑三维弹性相变导热网络降低界面热阻的实验和理论研究

The thermal interface materials (TIMs) have broad and important applications in thermal management fields. In order to reduce the whole thermal interface resistance, this project intends to study the key factors that affect the thermal resistance of the thermal interface material. The two key factors include the volume thermal resistance of the interface material and the boundary thermal resistance formed by the upper and lower ends of the interface material and the rough surface. Therefore, a three-dimensional elastic phase change thermal conductive network is proposed, which can reduce the thermal interface. Combined with the experimental and theoretical approaches, the effects of three-dimensional elastic phase change thermal conductivity network on the interface thermal resistance are investigated comprehensively. Taking full advantage of low-dimensional nanomaterials (especially high aspect ratio nanomaterials) in the heat transfer, three-dimensional thermal networks are fabricated with low-dimensional materials (one-dimensional or two-dimensional), leading to enhanced thermal conductivity of the interface material. Good elasticity is obtained by the design and formation of the three-dimensional aggregate, which can effectively solve the reduced thermal resistance of the interface material problem induced by the microcracks generated during the alternative hot and cold process. The wetting performance between the solid surface and phase change material is improved, and the air heat resistance between the thermal resistance is extruded if a small amount of the phase change material added into the base material is melted. This projet will provide the fundamental scientific basis for design of TIMs with excellent heat transfer properties.

热界面材料在热管理领域有广泛且重要的应用。本项目从分析影响热界面材料热阻的关键要素入手，以降低整体界面热阻为目标，综合考虑了界面材料自身的容积热阻和其上下端与粗糙表面形成的边界热阻两个关键因素，提出了“构筑三维弹性相变导热网络降低界面热阻”的思路。本项目将采用实验为主、理论为辅的方法系统研究三维弹性相变导热网络对界面热阻的影响。以低维材料（一维或二维）构筑三维导热网络，充分发挥低维纳米结构（特别是大长径比纳米材料）在强化传热方面的独特优势，大幅提高界面材料的热导率；通过三维聚集体的结构设计，赋予该导热体系良好的弹性，可有效解决因冷热交变过程中产生的微裂纹而造成界面材料失效问题，降低界面热阻；在基体材料中加入少量的相变材料，相变材料在融化后，将与固体表面之间有良好的润湿性，并挤出界面间的空气，进一步降低热阻。这些将为设计具有优异传热性能的界面材料提供必要的基础性科学依据。

本项目以降低整体界面热阻为目标，综合考虑了界面材料自身的容积热阻和其上下端与粗糙表面形成的边界热阻两个关键因素，提出了“构筑三维弹性相变导热网络降低界面热阻”的思路。通过三维聚集体的结构设计，赋予该导热体系良好的弹性，可有效解决因冷热交变过程中产生的微裂纹而造成界面材料失效问题，降低界面热阻；在基体材料中加入少量的相变材料，相变材料在融化后，将与固体表面之间有良好的润湿性，进一步降低热阻。.研究目标完成情况包括：.（1）完善了高导热低热阻TIMs制备平台，从实验方面确定影响TIMs热量输运和界面热阻的关键因素，构筑三维弹性相变导热网络，充分发挥低维纳米材料的特异性。.（2）建立了三维弹性相变导热网络结构与热物理性能间的有机联系，探索适用于预测TIMs热导率和界面热阻的模型和理论分析方法。.（3）在工程热物理与能源利用主流刊物上发表46篇学术论文，其中 SCI收录论文45 篇，EI收录1篇，第一标注论文26篇，第二标注论文17篇，第三标注论文3篇，中科院一区的代表性论文达到17篇，两篇文章入选ESI高被引论文，他引760次。申请发明专利10项，其中2项获得授权。 .（4）建立和完善了一支人员结构合理、知识覆盖面广、具有良好团队精神的科研梯队，培养研究生15名，培养年轻人才 3 名。在项目研究期间，参加国内相关会议5次，国际会议3次，作为主办方主办学术会议2次，积极开展了同行专家间的学术交流活动。