Thermal enhancement of graphene/polyethylene glycol (PEG) by interfacial crosslinking modification : molecular dynamics simulation

Wu, X. and Liu, M. and Du, Y. (2025) Thermal enhancement of graphene/polyethylene glycol (PEG) by interfacial crosslinking modification : molecular dynamics simulation. Journal of Energy Storage, 127: 117169. ISSN 2352-152X

Text (Clean_version_of_the_revised_Manuscript)
Clean_version_of_the_revised_Manuscript.pdf - Accepted Version
Available under License Creative Commons Attribution.
Download (892kB)

Abstract

Polyethylene glycol (PEG) phase change materials (PCMs) are widely used in energy storage applications due to their excellent thermal properties. This study investigates, at the molecular level, the effects of graphene (GN) functionalization and the number of graphene layers on the interfacial thermal conductivity of composite phase change materials (CPCM) using the velocity rescaling method. By calculating the phonon density of states (PDOS), the study elucidates the mechanism through which functional groups enhance the interfacial thermal conductivity of GN/PEG composites. Additionally, the radial distribution function of carbon atoms in graphene with varying numbers of layers and PEG is analyzed. Finally, the thermal conductivity of the composite material is predicted using the effective medium theory. The results show that crosslinking modification significantly improves the thermal conductivity of the composite material, with -C7H15GN demonstrating the most notable enhancement in the GN/PEG interfacial thermal conductivity. When the filler volume fraction is 15 %, the thermal conductivities of the graphene based CPCM achieves 6.17 W/(m·K) or more, which is 643 % higher than the corresponding values of composite phase change materials with 1 % volume fraction of graphene.