Yang Shuangqiao, Wang Qi, Wen Bianying
State Key Laboratory of Polymer Materials Engineering, Polymer Research Institute of Sichuan University, No. 24 South Section 1, Yihuan Road, Chengdu 610065, China.
Beijing Key Laboratory of Quality Evaluation Technology for Hygiene and Safety of Plastics, Beijing Technology and Business University, Beijing 100048, China.
ACS Appl Mater Interfaces. 2021 Jan 13;13(1):1511-1523. doi: 10.1021/acsami.0c18603. Epub 2020 Dec 21.
Polymer composites with highly thermally conductive and electrical insulation are urgently demanded for thermal management in modern electrical and energy applications. However, the incorporation of metal fillers in traditional polymeric composites usually fails to meet the requirements for simultaneously high thermal conductivity and high electrical insulation. Here, we successfully fabricated composites with high thermal conductivity and high electrical insulation by in situ thermal expansion of expandable graphite (EG) and in situ oxidation of aluminum (Al) nanoflakes in aluminum-plastic package waste (APPW). Due to the synergistic effect of the hybrid filler framework, the maximum thermal conductivity reached as high as 8.7 W m K for APPW/EG/Al-F composites. In addition, the formation of the nano AlO layer around the Al filler surface brings extremely low electrical conductivity (<10 S cm) and low dielectric loss (<0.06). Based on the results of finite element simulation, the heat flowed mainly along the effective filler framework and the high thermal conductivity is attributed to the interconnection of the high aspect ratio filler. Furthermore, the strong thermal management capability of the prepared composites was demonstrated in the heat dissipation experiment. The present work suggests that surface-oxidized Al nanoflakes demonstrate fascinating performance and show promising application as thermal management materials in emerging electrical systems and electronic devices.
在现代电气和能源应用的热管理中，迫切需要具有高导热性和电绝缘性的聚合物复合材料。然而，在传统聚合物复合材料中加入金属填料通常无法满足同时具有高导热性和高电绝缘性的要求。在此，我们通过对铝塑包装废弃物（APPW）中的可膨胀石墨（EG）进行原位热膨胀以及对铝（Al）纳米片进行原位氧化，成功制备了具有高导热性和高电绝缘性的复合材料。由于混合填料框架的协同效应，APPW/EG/Al-F复合材料的最大热导率高达8.7 W m⁻¹ K⁻¹。此外，在Al填料表面形成的纳米Al₂O₃层带来了极低的电导率（<10⁻⁹ S cm⁻¹）和低介电损耗（<0.06）。基于有限元模拟结果，热量主要沿着有效的填料框架流动，高导热性归因于高长径比填料的相互连接。此外，在散热实验中证明了所制备复合材料具有强大的热管理能力。目前的工作表明，表面氧化的Al纳米片表现出迷人的性能，并在新兴电气系统和电子设备中作为热管理材料显示出广阔的应用前景。
