Advances in Simulations of Thermal Transport in Carbon Nanotubes and Graphene Reinforced Polymer Composites: From Microscopic, Mesoscopic to Macroscopic

ABSTRACT As carbon‐based materials with exceptionally high thermal conductivity, graphene and carbon nanotube (CNT) are considered ideal fillers for the development of high thermal conductivity polymer composites. Over the past decade, graphene, carbon nanotubes, and their derivatives have been shown in numerous studies to significantly enhance the thermal conductivity of various polymers. This review summarizes the research progress on high thermal conductivity graphene/polymer and CNT/polymer composites. We first examine the effects of filler surface functionalization, defects/doping, and isotopic variations on the interfacial thermal conductivity at the microscopic scale. Next, we discuss the mechanisms of filler dispersion and the formation of thermal conductivity networks at the mesoscopic scale, which contribute to the improved thermal performance of the composites. Finally, we summarize the impact of filler size, synergistic effects between different fillers, and environmental factors on the overall thermal conductivity of the composites at the macroscopic scale. Through a discussion of the thermal conductivity of graphene/polymer and CNT/polymer composites across these three scales, we highlight the importance of multi‐scale simulations and identify challenges and opportunities for future research.