Nacre-inspired nanocomposite papers of graphene fluoride integrated 3D aramid nanofibers towards heat-dissipating applications

Abstract

Heat dissipation is a critical requirement for the innovation of fifth-generation (5G) electronics, and in turn, for the unceasing development of highly efficient heat-dissipating materials (HDMs). In 5G electronics, high thermoconductive yet electrically insulating HDMs with lightweight, excellent flexibility, and outstanding thermal properties have a high demand. In this study, we developed a fabulous HDM with superior mechanical properties, high thermal conductivity, and electrical insulation. The underlying principle involves taking advantage of graphene fluoride (GF), which is an emerging two-dimensional (2D) material that is highly thermally conductive, along with an electrically insulating material. By integrating a 2D GF sheet in a three-dimensional (3D) interconnected aramid nanofiber (ANF) network, a paper was successfully fabricated via a scalable process of sol-hydrogel-paper transformation. The resultant GF/ANF paper showed excellent mechanical properties with a remarkable strength of 188 MPa and toughness of 107 MJ m−3. These exceptional results are attributed to the formation of a nacre-inspired structure with strong hydrogen bonding between the GF sheet and ANF matrix and the extensive elongation of the entangled 3D ANF. Notably, the GF/ANF nacre-inspired paper with 40 wt% GF content achieved a thermal conductivity and volume resistivity as high as 48.2 W m−1 K−1 and 2.7 × 1015 Ω m, respectively. Moreover, the vibrational properties of GF and ANF were extensively investigated via ab initio calculations. The paper exhibited excellent thermal stability, non-flammability, and high efficiency in heat dissipation in an organic light-emitting diode system. It demonstrated the best overall performance among the representative HDMs analyzed, representing a critical breakthrough in the fabrication of HDMs toward practical applications in wearable electronic devices.