Yu Wei, Zhang Guang, Liu Changhong, Fan Shoushan
Tsinghua-Foxconn Nanotechnology Research Center and Department of Physics, Tsinghua University, Beijing 100084, China.
Department of Space Sciences, Qian Xuesen Laboratory of Space Technology, China Academy of Space Technology, Beijing 100094, China.
ACS Nano. 2020 Oct 27;14(10):14091-14099. doi: 10.1021/acsnano.0c06748. Epub 2020 Oct 12.
Heat dissipation is a serious limitation for increasingly miniaturized and functionalized electronics, resulting in the continuous need for developing highly efficient cooling methods. Here, utilizing the strong van der Waals force between super-aligned carbon nanotubes (SACNTs), a self-supported three-dimensional (3D) CNT/CaCl radiator with a more outstanding cooling performance than Al cooling fins was designed. Unlike the soft CNT sponges, these 3D structures could sustain a high pressure of 4.5 MPa with a small compression of 10% and thus are defined as hard CNT sponges. Hard CNT sponges show a 44.3% higher cooling efficiency than commercial Al cooling fins at a humidity of 50% due to the massive latent heat of water combining with the high thermal conductivity of CNTs and the high emissivity of the composites. The self-adjusting moisture absorption-desorption process could dissipate heat by water evaporation when electronics work at high power and spontaneously absorb moisture to regenerate the sponges at the standby mode of electronics. Besides, hard CNT sponges possess a much lower density (0.98-1.70 g cm) than aluminum (2.7 g cm). This high-performance cooler provides an alternative thermal management method for electronics.
散热是日益小型化和功能化电子设备面临的一个严重限制，这使得不断需要开发高效的冷却方法。在此，利用超对齐碳纳米管（SACNTs）之间强大的范德华力，设计了一种自支撑三维（3D）碳纳米管/氯化钙散热器，其冷却性能比铝制散热片更出色。与柔软的碳纳米管海绵不同，这些3D结构能够承受4.5兆帕的高压，压缩率仅为10%，因此被定义为硬质碳纳米管海绵。在50%的湿度条件下，由于水的大量潜热与碳纳米管的高导热性以及复合材料的高发射率相结合，硬质碳纳米管海绵的冷却效率比商用铝制散热片高出44.3%。当电子设备高功率运行时，自我调节的吸湿 - 解吸过程可通过水蒸发散热，而在电子设备待机模式下则自发吸收水分使海绵再生。此外，硬质碳纳米管海绵的密度（0.98 - 1.70克/立方厘米）远低于铝（2.7克/立方厘米）。这种高性能散热器为电子设备提供了一种替代的热管理方法。
