A flexible carbon nanotube-pyrolytic carbon sandwich paper with a stable structure and high heat-dissipation capacity

A thin layer of pyrolytic carbon (PyC) was deposited on a carbon nanotube paper (CNP) by chemical vapor deposition from methane to improve its structural stability while maintaining its excellent mechanical and thermal conductivity performance. The resulting material consisted of layers of PyC carbon on the outer surfaces, a layer of bare CNTs in the center, and layers of CNTs infiltrated with PyC between the outer and inner layers. The resulting sandwich material could be cut into any size without breaking the surrounding material. The CNTs in the center layer were stretched after the CNP was bent 500 times around a cylindrical die, leading to an increase of tensile strength from 8.58 to 11.41 MPa. The outer PyC layers and the PyC-infiltrated layers retained their integrity. The thermal diffusivity and heat-dissipation capacity of the sandwich paper remain almost the same before and after bending, which is attributed to the undamaged CNTs and PyC layers. This paper has potential applications as a lightweight and flexible heat-dissipation material at high temperatures.