Polymer Nanofibers with Outstanding Thermal Conductivity and Thermal Stability: Fundamental Linkage between Molecular Characteristics and Macroscopic Thermal Properties

摘要: Polymer nanofibers with high thermal conductivities and outstanding stabilities are highly desirable in heat transfer-critical applications such as management, exchangers energy storage. In this work, we unlock the fundamental relations between conductivity stability of polymer their molecular characteristics by studying temperature-induced phase transitions transport a series nanofibers. Ten different systematically chosen structures studied using large scale dynamics simulations. We found that good can be achieved polymers rigid backbones, exemplified {\pi}-conjugated polymers, due to suppressed segmental rotations phonon group velocities. The low probability rotation does not only prevent transition but also enables long mean free paths reduced disorder scattering. Although stronger inter-chain interactions improve stability, feature usually have heavier atoms, weaker backbone bonds, segments vulnerable random rotations, which lead conductivities. This work elucidates underlying linkage nature macroscopic properties nanofibers, is instrumental design thermally conductive temperature stabilities.