Heat transfer through covalent versus non-covalent bonding: a case study in the crystalline π-conjugated P3HT polymer by approach-to-equilibrium molecular dynamics

Heat transport in a crystalline polymer, poly(3-hexylthiophene) (P3HT), is studied using molecular dynamics. The potential energy is described by density functional theory (DFT), to which a correction is added to account for van der Waals dispersion forces. Approach-to-equilibrium molecular dynamics (AEMD) method is used to create and analyse thermal transients and target transport along or between polymer chains. As expected, the approach leads to a length-dependent thermal conductivity of the system along the covalent polymer backbone. Less expectedly, we observe heat transfer between two polymers, i.e. along a non-covalent heat path, and quantify this transfer using a thermal conductance.