Effect of Covalent Functionalisation on Thermal Transport Across Graphene-Polymer Interfaces

TL;DR

This study uses molecular dynamics simulations to show that covalent functionalisation of graphene, especially with butyl groups, significantly reduces interfacial thermal resistance in graphene-polymer composites, aiding thermal management.

Contribution

It reveals how different covalent functional groups and layer numbers influence interfacial thermal resistance, providing guidelines for optimizing graphene-based thermal interfaces.

Findings

Butyl functional groups most effectively reduce thermal resistance.

Layer number up to four has negligible effect on resistance.

Functionalisation effects are explained via vibrational density of states.

Abstract

This paper is concerned with the interfacial thermal resistance for polymer composites reinforced by various covalently functionalised graphene. By using molecular dynamics simulations, the obtained results show that the covalent functionalisation in graphene plays a significant role in reducing the graphene-paraffin interfacial thermal resistance. This reduction is dependent on the coverage and type of functional groups. Among the various functional groups, butyl is found to be the most effective in reducing the interfacial thermal resistance, followed by methyl, phenyl and formyl. The other functional groups under consideration such as carboxyl, hydroxyl and amines are found to produce negligible reduction in the interfacial thermal resistance. For multilayer graphene with a layer number up to four, the interfacial thermal resistance is insensitive to the layer number. The effects of the different functional groups and the layer number on the interfacial thermal resistance are also elaborated using the vibrational density of states of the graphene and the paraffin matrix. The present findings provide useful guidelines in the application of functionalised graphene for practical thermal management.