Investigating thermal transport in knotted graphene nanoribbons using non-equilibrium molecular dynamics

TL;DR

This study uses non-equilibrium molecular dynamics to analyze how knots in graphene nanoribbons affect thermal transport, revealing that each knot adds a similar thermal resistance and that their position has minimal impact on heat flow.

Contribution

It demonstrates that knots in graphene nanoribbons act as series thermal resistances, with their number linearly increasing overall resistance, and shows weak thermal rectification effects.

Findings

Thermal resistance per knot is consistent and additive.

Number of knots linearly increases total thermal resistance.

Position of knots has minimal effect on thermal current.

Abstract

In this work, we investigated the effect of knots in the thermal transport of graphene nanoribbons through non-equilibrium molecular dynamics simulations. We considered the cases of one, two, and three knots are present. Temperature jumps appear in the temperature profile where the knots are located, which indicates that they introduce thermal resistances in the system, similar to interfacial Kapitza resistance present between two different materials and/or single materials with defects and/or lattice distortions. We found that the thermal resistance introduced by each individual knot is essentially the same as the overall resistance increase linearly with the number of knots, as they behave as thermal resistances associated in series. Also, the relative position between each knot in the arrangement does not strongly affect the thermal current produced by the temperature gradient, showing a weak thermal rectification effect.