Thermally conductive nanocomposite with silicon carbide nanowire-bridged boron nitride skeleton for multifunctional thermal interface materials

Abstract

Developing polymer-based thermal interface materials (TIMs) with multifunctional properties remains a severe challenge for modern electronic and optoelectronic devices. Herein, we demonstrate silicon carbide (SiC)-boron nitride nanosheet (BNNS) skeleton reinforced polydimethylsiloxane (PDMS) nanocomposite with comprehensive properties based on an interconnected and oriented SiC-BNNS skeleton through directional freeze-drying and in-situ growth methods. The SiC nanowire bridged oriented BNNS skeleton synergistically enhances overall thermal conduction of the nanocomposite. Notably, the SiC-BNNS/PDMS nanocomposite exhibits an unprecedented in-plane thermal conductivity of 2.09 W·m⁻¹·K⁻¹, and through-plane thermal conductivity of 1.39 W·m⁻¹·K⁻¹ at 9.70 vol% content. The SiC-BNNS/PDMS nanocomposite also shows an excellent breakdown strength of 37.78 kV/mm, and an improved flame resistance. Molecular dynamics simulations and finite element analysis were used to investigate the interfacial thermal transport behaviour of the SiC-BNNS/PDMS. The unique fabrication strategy provides a bright prospect to construct multifunctional TIMs with optimized comprehensive performance, promoting their applications in next-generation electronics.