石墨烯粉末导热性能的研究

采用瞬态电热技术测量了5~6层纯石墨烯粉末中石墨烯的热扩散率,其值为1.15×10-5 m2/s,相应的导热系数为18.000 W/(m·K)。借助导热仪研究了不同密度下石墨烯粉末导热系数的变化情况,发现其导热系数与密度成正比。密度由0.02增加到0.22g/cm3时,导热系数总体提升了8.09%。另通过实验得到了含水率对石墨烯粉末导热性能的影响。实验结果显示,石墨烯粉末含水率由0.0%增加到99.8%的过程中,导热系数先是上升随后下降最终直线降至最低点(约为0.765~1.030 W/(m·K))。其中当含水率达到96.7%时,混合物(石墨烯与水)的导热系数提高了62.80%。该研究为石墨烯热应用及热管理提供了理论支撑。

Study of thermal conductivity of graphene powder

The thermal diffusivity of five-six layers of graphene is measured by the transient electro-thermal technique. The thermal diffusivity of graphene powder is 1.15×10-5 m2 /s, and the corresponding intrinsic thermal conductivity is 18.000 W/(m·K). The thermal conductivity of graphene powder under different density is measured by thermal conductivity instrument. It is found that the thermal conductivity of graphene powder increases with density. When the density of graphene powder increases from 0.02to 0.22g/cm3, the thermal conductivity increases by 8.09%. The influence of moisture content on the thermal conductivity of graphene powder is also examined with the moistrure content in from 0.0% to 99.8%. The results show that the thermal conductivity of graphene powder increases firstly and then declines, eventually falls to the lowest value with moisture content. When the moisture content of graphene powder increases to 96.7%, the thermal conductivity of graphene powder increases by 62.80%. This study provides a theoretical support for the thermal management and the thermal application of graphene.