Conformations and thermal dynamics of graphene-based polymer nanocarpets

Abstract

We model possible mechanical conformations and thermal dynamics of the recently synthesized graphene-based polymer nanocarpets for advanced optoelectronics applications, made by homogeneous valence attachment (functionalization) to one side of the graphene sheet of polyethylene chains or benzene rings. It is shown that on a flat substrate, the anisotropic quasi-two-dimensional nanocarpets always preserve a flat shape with the inner side bound to the substrate and with the attached polymer molecules at the outer side orthogonal to the plane of the graphene sheet. The flat shape of the nanocarpet bound to the substrate is resistant to thermal vibrations. The heat capacity of the nanocarpet increases monotonically with temperature in the equipartition limit. Most strong growth of heat capacity occurs for the graphene sheets with attached polyethylene chains at T⩾450 K, when the disordering of the lattice of the attached polymer chains starts to occur from the edges of the nanocarpet.