Silver Nanoparticle-Enhanced Three-Dimensional Boron Nitride/Reduced Graphene Oxide Skeletons for Improving Thermal Conductivity of Polymer Composites

Abstract

The thermally conductive properties of polymer composites are hugely constrained by discontinuous filler networks and high thermal contact resistances in filler/filler interfaces. Herein, a silver nanoparticle-decorated boron nitride hybrid (BN@ AgNPs) is fabricated via in situ reduction of Ag + . Subsequently, the AgNP-enhanced three-dimensional BN/reduced graphene oxide (3D-BN/rGO) skeleton with continuous structures possessing "point-plane" connections is prepared via hydrothermally treating the aqueous slurry containing BN@AgNPs and GO followed by freeze-drying. It is established that rGO serves as a scaffold to assemble BN@AgNPs into 3D structures. Notably, the AgNP-enhanced 3D-BN/rGO skeleton makes the polydimethylsiloxane (PDMS) composite exhibit a high thermal conductivity of 2.34 W m −1 K −1 at a low filler loading of 23.8 wt %, which is 41.8 and 207.9% higher than that of the PDMS composite incorporated with the original 3D-BN/rGO skeleton and BN flakes at the same loading, respectively. Meanwhile, the composite also exhibits a high volume resistance of 6.9 × 10 13 Ω cm −1 . Thermal resistance analysis demonstrates that assembling BN flakes into 3D skeletons makes phonon transfer along BN flakes rather than BN/PDMS interfaces with larger resistances, and the introduction of AgNPs depresses the phonon scattering in BN/BN interfaces. Finite element simulation further reveals that the AgNPs on BN planes and BN edges elevate the heat transfer in BN planes and BN/BN interfaces, respectively. Our work provides a promising approach for fabricating thermally conductive and electrically insulating polymer composites utilized in electronics.

Anchoring modified polystyrene to boron nitride nanosheets as highly thermal conductive composites for heat dissipation

“…[7][8][9] It has been observed that polymer-based composites filled with thermally conductive fillers (e.g., carbon-based materials, [10] metal nanoparticles, [11] and ceramics particles [12] ) achieve desirable mechanical characteristics and superior TC. Hexagonal boron nitride (h-BN) nanosheets, as a promising 2D ceramic material, have several advantages over both carbon-based materials and metal nanoparticles, including high thermal stability, [13] excellent corrosion resistance, [6] outstanding oxidize resistance, [14] and excellent electrical insulation, [15] rendering it an exceptional thermal conductive filler for enhancing the heat transfer performance of polymers. [16,17] Nevertheless, the lack of active groups causes BN to clump together and distribute poorly in the polymer matrix, forming many interfacial thermal resistances (ITR) between the filler and the matrix, as well as the overlaps of fillers.…”

Carbon Aerogel with High Thermal Conductivity Enabled by Shrinkage Control

“…Graphene sheets can be turned into 3D skeleton structures through an ice template, , hydrothermal reduction, , or directly chemical vapor deposition method . In these cases, composites filled with a 3D graphene skeleton still exhibit limited thermal conductivity, despite their high thermal conductivity enhancement ratios.…”

Study on Preparation and Properties of Ultrahigh Molecular Weight Polyethylene Composites Filled with Different Carbon Materials

“…40% rGO addition can increase the thermal conductivity of aramid nanofibers by 1250%. Liu 35 et al added rGO to the silver nanoparticledecorated boron nitride hybrid to prepare a thermally conductive framework by hydrothermal treatment and then compounded it with PDMS to obtain a thermally conductive polymer. The thermal conductivity test results showed that the addition of rGO effectively enhanced the thermal conductivity and electrical conductivity of the composites.…”