From tanghulu-like to cattail-like SiC nanowire architectures: interfacial design of nanocellulose composites toward high thermal conductivity

Abstract

The development of polymer-based thermal management materials (TMMs) is crucial to address the frequency reduction or overheating damage of modern electronics caused by inadequate thermal conductivity of substrates. However, high interfacial thermal resistance between filler and filler or between filler and matrix creates paramount bottlenecks for the prominent thermal conduction in polymer-based composites. Herein, novel tanghulu-like MoS₂–SiC nanowire (L-MoS₂–SiCNW) and cattail-like H-MoS₂–SiCNW hybrids are successfully fabricated via a facile hydrothermal method, and then incorporated into a green cellulose nanofiber (CNF) matrix by a vacuum-assisted filtration approach. MoS₂ nanosheets tightly rooted to the surface of SiCNWs can bridge the gap between SiCNWs and increase the contact area between them, which consequently leads to the large reduction of interfacial thermal resistance. As a result, the maximum in-plane TC of 19.76 W m⁻¹ K⁻¹ is attained for the flexible CNF/H-MoS₂–SiCNW film at a relatively low filler content of 22.5 vol%, which has an enhancement of 1408% in contrast to that of the pure CNF film. In addition, the volume resistivity of the flexible CNF/H-MoS₂–SiCNW film is two orders of magnitude higher than that of pure CNF, which is far above the required resistance for electrical insulation. In the real TMM application measurement of CNF/H-MoS₂–SiCNWs, the temperature of the CPU core with the CNF/H-MoS₂–SiCNW heat spreader is elevated more slowly than that of the bare case (e.g.: Δ = 4.9 °C at 980 s). Thus, this investigation provides a valuable insight into the design and fabrication of favorable polymer-based TMMs for potential applications in microelectronics and advanced energy.