Interfacial Thermal Transport in Boron Nitride-Polymer Nanocomposite

TL;DR

This study uses molecular dynamics simulations to investigate how electrostatic interactions influence interfacial thermal conductance in boron nitride-polymer nanocomposites, revealing that stronger electrostatic forces enhance heat transfer.

Contribution

It provides new insights into the role of electrostatic interactions in interfacial thermal transport in h-BN-polymer composites, guiding improved composite design.

Findings

Electrostatic interactions significantly affect interfacial thermal conductance.

Stronger electrostatic forces lead to closer interface distances and higher heat flux.

Systematic variation of polymer polarity alters thermal transport properties.

Abstract

Polymer composites with thermally conductive nanoscale filler particles, such as graphene and hexagonal boron nitride (h-BN), are promising for certain heat transfer applications. While graphene-polymer composites have been extensively investigated, studies on h-BN-polymer composites has been relatively rare. In this paper, we use molecular dynamics (MD) simulations to study the interfacial thermal conductance (ITC) involved in the h-BN-polymer composites. We first compare the ITC across h-BN/hexane (C6H14) interfaces to that of graphene/hexane interfaces, where we found that the electrostatic interaction due to the partial charge on h-BN atoms can play an important role in such interfacial thermal transport. Based this finding, we further explore the thermal transport across different h-BN interfaces, including h-BN/hexanamine (C6H13NH2), h-BN/hexanol (C6H13OH), h-BN/hexanoic acid (C5H11COOH), where the increasingly polar molecules lead to systematic changes in the electrostatic interactions between h-BN and polymers. Heat flux decomposition and atom number density calculations are performed to understand the role of electrostatic interaction in thermal transport across h-BN-polymer interfaces. It was observed that stronger electrostatic interactions across the interfaces can help attract the polymer molecules closer to h-BN, and the reduced interface distance leads to larger heat flux contributed from both van der Waals and electrostatic forces. These results may provide useful information to guide the design of thermally conductive h-BN-polymer nanocomposites.