Needs of a material for thermal management in reduced-sized electronic devices drive single-walled carbon nanotubes (SWCNTs) to be one of the most promising candidates due to their excellent thermal properties. Many numerical and experimental studies have reported on understanding thermal properties of the SWCNT for thermal device applications. In the present study, thermal diffusivity and conductivity of SWCNT forests in the axial direction with various volume fractions of SWCNTs were measured by laser flash analysis technique and the same properties of an individual SWCNT were derived. The volume fraction was controlled up to 25 vol% by biaxial mechanical densification which maintains SWCNT alignment. While the thermal diffusivity of SWCNT forests was almost constant, it increased when the volume fraction was higher than 17 vol%, suggesting that some SWCNTs, which did not serve as a thermal path in the case of lower volume fraction, were connected with the other SWCNTs. Through the increase of inferred thermal conductivity equivalent to an individual SWCNT after 17 vol%, we also realized that the enhancement of volume fraction of SWCNT forest diminished thermal boundary resistance in good agreement with the tendency inferred from the reported numerical data.

尺寸减小的电子设备中对热管理材料的需求使单壁碳纳米管（SWCNT）由于其出色的热性能而成为最有前途的候选材料之一。已经报道了许多数值和实验研究，以了解用于热器件应用的SWCNT的热性能。在本研究中，通过激光闪光分析技术测量了具有不同体积分数的SWCNT森林在轴向上的热扩散率和电导率，并得出了单个SWCNT的相同特性。通过保持SWCNT排列的双轴机械致密化，将体积分数控制至25vol％。SWCNT森林的热扩散率几乎恒定，但当体积分数高于17 vol％时，其扩散率增加；这表明某些SWCNT与其他SWCNT连接，这些SWCNT在体积分数较低的情况下不用作热通道。通过增加相当于单个SWCNT的推断热导率，在17 vol％之后，我们还认识到，SWCNT森林体积分数的增加降低了热边界电阻，与从报告的数值数据推断出的趋势非常吻合。