Anisotropic Percolation of SiC-Carbon Nanotube Hybrids: A New Route toward Thermally Conductive High-k Polymer Composites

作者：Yuan, Jinkai; Yao, Shenghong; Li, Weilong; Sylvestre, Alain; Bai, Jinbo^*

来源：Journal of Physical Chemistry C, 2017, 121(22): 12063-12070.

DOI：10.1021/acs.jpcc.7b03372

• HIGH DIELECTRIC-CONSTANT
• ENERGY-STORAGE
• ELECTRICAL-CONDUCTIVITY
• NANOCOMPOSITES
• PERMITTIVITY
• TEMPERATURE
• ALIGNMENT
• FLOW
• MATRIX

Percolation of carbon nanotubes (CNT) has been widely exploited in various polymer matrices to largely improve the dielectric constant or thermal conductivity of heterogeneous polymer composites. However, so far, it is still very challenging to simultaneously enhance both while maintaining the low losses of polymers. Herein, we demonstrate a thermally conductive high-k material with low losses by establishing anisotropic percolation of multiscale SiC-CNT hybrids within pcily(vinylidene fluoride) (PVDF) matrix, Indeed, the SiC-CNT/INDF composite exhibits a much lower electrical percolation threshold (1.23 wt %) along the in plane direction than that (1.89 wt %) perpendicular to it. By locating CNT content (1.5 wt %) between them, the composite displays unprecedented dielectric properties in the out-of-plane direction with a dielectric constant as high as 714 and the loss tangent of 0.49, while the thermal conductivity improved by 200% as compared with the virgin polymer along the in-plane direction. The true anisotropy in electrical, dielectric, and thermal properties is elucidated by invoking percolation theory on the basis of the rod geometry and spatial orientation of the hybrids.

• 出版日期2017-6-8
• 单位西北大学