Kapitza resistance and thermal transport in knotted graphene nanoribbons

Resumo

Thermal transport in low-dimensional systems is central to nanoscale heat dissipation and phonon engineering applications, particularly in materials where geometry and structural distortions strongly influence scattering mechanisms. In this context, graphene nanoribbons constitute a well-defined platform for investigating thermal transport due to their quasi-one-dimensional character and tunable structural properties. In this work, we have investigated the effect of structural knots on the thermal transport of graphene nanoribbons using nonequilibrium molecular dynamics simulations (NEMD). Systems containing one, two, and three knots were considered. The temperature profiles exhibit localized temperature drops at the knot positions, indicating the emergence of thermal resistance in these regions. This behavior is analogous to Kapitza resistance observed at interfaces between dissimilar materials or in single materials containing defects or lattice distortions. The thermal resistance associated with an individual knot is approximately constant. The total thermal resistance increases almost linearly with the number of knots, consistent with a series arrangement of thermal resistances. In addition, variations in the relative positions of the knots along the nanoribbon do not significantly affect the heat current driven by the imposed temperature gradient, indicating a weak thermal rectification effect for the configurations investigated.

APPLIED SURFACE SCIENCE, 2026 · Fator de impacto 6,6.

DOI 10.1016/j.apsusc.2026.167187