On the possible explanation of the reduced thermal conductivity in molecular forests

The heat propagation in quasi-one dimensional materials (Q1DMs) often appears paradoxical. For example, an isolated Q1DM, such as a nanowire, carbon nanotube, or polymer, can exhibit a high thermal conductivity κ, assemblies of the same materials show a reduction in κ. Here, the complex structures of these assemblies have hindered the emergence of a clear molecular picture of this intriguing phenomenon. We combine multiscale simulation with the concepts known from polymer physics and thermal transport to unveil a generic picture of κ reduction in molecular forests. We show that a delicate balance between the segment orientations, the persistence length of the Q1DM and the flexural vibrations govern the behavior of κ.

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