Shenzhen Institute of Advanced Electronic Materials, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen 518055, China.
Nanoscale. 2023 May 18;15(19):8706-8715. doi: 10.1039/d3nr00627a.
Interfacial binding and phonon mismatch are two crucial parameters in determining thermal boundary conductance. However, it is difficult for polymer/metal interfaces to possess both significant interfacial binding and weak phonon mismatch to achieve enhanced thermal boundary conductance. Herein, we circumvent this inherent trade-off by synthesizing a polyurethane and thioctic acid (PU-TA) copolymer with multiple hydrogen bonds and dynamic disulfide bonds. Using PU-TA/aluminum (Al) as a model interface, we demonstrate that the thermal boundary conductance of the PU-TA/Al interfaces measured by transient thermoreflectance is 2-5 times higher than that of traditional polymer/Al interfaces, which is attributed to the highly matched and bonded interface. Furthermore, a correlation analysis is developed, which demonstrates that interfacial binding has a greater impact than phonon mismatch on thermal boundary conductance at a highly matched interface. This work provides a systematic understanding of the relative contributions of the two dominant mechanisms to thermal boundary conductance by tailoring the polymer structure, which has applications in thermal management materials.
界面结合和声子失配是决定热边界传导率的两个关键参数。然而，聚合物/金属界面很难同时具有显著的界面结合和较弱的声子失配，以实现增强的热边界传导率。在本文中，我们通过合成具有多个氢键和动态二硫键的聚氨酯和硫辛酸（PU-TA）共聚物来规避这种固有的权衡。使用 PU-TA/铝（Al）作为模型界面，我们证明通过瞬态热反射测量的 PU-TA/Al 界面的热边界传导率比传统的聚合物/Al 界面高 2-5 倍，这归因于高度匹配和键合的界面。此外，我们还开发了相关分析，表明在高度匹配的界面上，界面结合对热边界传导率的影响大于声子失配。这项工作通过调整聚合物结构，系统地了解了这两个主要机制对热边界传导率的相对贡献，这在热管理材料中有应用。
