Using normal modes to calculate and optimize thermal conductivity in functionalized macromolecules

The quest for high thermal conductivity materials has led to nanocomposites incorporating macromolecular materials with excellent thermal conductivity, such as carbon nanotubes and graphene nanoribbons, in a matrix of poorer thermal conductivity. To minimize the interface thermal resistance the stiff, incorporated materials can be chemically functionalized with various side chains. We report here an efficient theoretical method using normal modes to calculate the thermal conductivity of such systems and show how the participation ratio of these modes can be used to evaluate different choices for functionalization. We use this method to examine how effective different alkane chains improve the heat flux through a graphene nanosheet.