Highly thermal conductivity of PVA-based nanocomposites by constructing MWCNT-BNNS conductive paths

The development of modern microelectronic devices and chip integration cause electronics devices to generate excessive heat. To overcome such challenges in the near future, designing thermally conductive composites with improved stability, conductivity, and excellent electric insulation properties is critical. In this study, a novel strategy was proposed to construct superior thermally conductive networks with boron nitride nanosheets-Multiwalled carbon nanotubes (BNNS-MWCNT)/ poly(vinyl alcohol) (PVA) nanocomposites through the electrospinning technique and hot-pressing process. BNNS and MWCNT are aligned along with the fiber orientation, and MWCNT, with high length-to-diameter ratio characteristics, can act as a bridging point for uncontacted BNNS. Interestingly, when the mass fraction of BNNS-MWCNT was 20 % and the mass ratio between the BNNS: MWCNT was maintained as 9:1, the resultant BNNS-MWCNT/PVA nanocomposites exhibited an excellent in-plane thermal conductivity of 11.49 W/(m·K) and observed a tremendous heat dissipation capacity than PVA and BNNS/PVA composites. Moreover, the BNNS-MWCNT/PVA recorded excellent electrical insulation properties. The present work provides inspiration for the preparation of composites with low fillers and high thermal conductivity.