Bridging boron nitride nanosheets with oriented carbon nanotubes by electrospinning for the fabrication of thermal conductivity enhanced flexible nanocomposites

Abstract With the rapidly growing power density of integrated circuits in modern electronic devices, how to construct efficient thermal conductive network achieving advanced heat conduction materials has attracted widespread attention. In this work, at an extremely low content of carbon nanotubes (CNTs), a synergistic hybrid structure of bridged boron nitride nanosheets (BNNSs) by CNTs was constructed along the polyvinyl alcohol (PVA) fibers by electrospinning, and simply resin transfer molding method was employed to produce Epoxy/PVA (BNNSs/CNTs) composite film. Fabricated Epoxy/PVA (BNNSs/CNTs) composite film not only presented great in-plane thermal conductivity (TC) 6.3 W/m·K at total filler loading of 27.5 wt%, higher than that of Epoxy/PVA (BNNSs) composite film without CNTs by 88%, but also exhibited excellent electrical insulating properties (6 × 10−13 S/cm). During the heating and cooling test, infrared thermal images showed that the synergistic hybrid composite has the highest surface temperature and the best heat dissipation capacity compared to other samples. The great TC enhancement is due to the bridging BNNSs by CNTs reducing interfacial thermal resistance between neighboring fillers. Additionally, good mechanical properties and stable TC provide more immense potential for the wide application of new generated flexible thermal management materials.