Vertically Oriented Carbon Nanotubes for Thermal Management

Efficient heat dissipation is an important technology to address the issues of overheating and increasing heat flux density for high-density integrated electronic devices toward miniaturization, multifunctionality, and high integration. Carbon nanotubes (CNTs) are considered as an ideal thermally conductive filler of polymeric encapsulation owing to its excellent thermal conductivity and unique linear structure but suffer from the random arrangement in the composites and extremely low thermal conductivity of the polymeric matrix. Here, we report vertically aligned carbon nanotubes (VACNTs) grown in situ by chemical vapor deposition, which were modified by polyethylene polyamine and covered with poly(vinyl alcohol) (PVA) to form the m-VACNTs/PVA thermally conductive composite film. The out-of-plane thermal conductivity of the m-VACNTs/PVA film reaches as high as 14.9 W m–1 K–1, which is approximately 53 times that of a pure PVA film. In addition, the m-VACNTs/PVA composites have excellent electrical conductivity and an outstanding electromagnetic shielding effect. This study provides a promising strategy for design of advanced composites with high thermal conductivity in the vertical direction.