Oriented rGO framework induced hBN confined network in PDMS for absorption enhanced EMI shielding and through-plane thermal conductivity

Abstract

Herein, inspired by the highly matched phonon spectra between reduced graphene oxide (rGO) and hexagonal boron nitride (hBN), and the good complementarity of the conductive loss of rGO and dielectric loss of hBN in dissipating microwaves, we construct an oriented rGO framework induced hBN confined network in bulk polydimethylsiloxane (PDMS) for electromagnetic interference (EMI) shielding and through-plane thermoconductive properties. A prefabricated three-dimensional (3D) rGO aerogel with a vertically oriented porous structure serving as an electrically conductive framework provides EMI shielding properties, and hBN distributed in the oriented rGO pores constructs a confined through-plane thermoconductive network. The introduction of hBN induces absorption-enhanced EMI shielding through dielectric loss, and the highly matched phonon spectra of rGO and hBN provide more abundant thermal conduction paths and enhance the thermal conductivity of the rGO/hBN/PDMS composites. The synergy of this rGO-hBN dual-network structure gives the composites an excellent EMI shielding effectiveness of 43.1 dB and a good through-plane thermal conductivity of 1.2 W m−1 K−1 at a thickness of 4 mm. This work provides a feasible strategy for realizing shielding and thermoconductive composites with potential applications in next-generation flexible packaging materials.