Thermal Transport in Graphene and Graphene-based Composites

We theoretically and experimentally studied the thermal transport properties in various graphene-based systems. Firstly, we review our previous works of molecular dynamics simulations to study the thermal transport in graphene nanoribbons (GNRs). We also studied negative differential thermal conductance (NDTC) at large temperature biases in GNRs. We extended our study of NDTC in the diffusive limit into general one-dimensional thermal transport and found that NDTC is possible if thermal junctions are introduced. These findings are useful for future applications of controlling heat at nanoscale. Secondly, we describe our experimental work of synthesized graphene-based composites with fillers of reduced graphene oxide and polymers. We used 3 omega method to measure the thermal conductivity and found that the thermal conductivity can be tuned dramatically by the graphene filler concentration. Graphene-based composites are potentially promising as thermal interface materials, which have become increasingly important in modern heat management in many industrial applications.