Enhancing Thermal Conductivity Computation of Polymers via Machine Learning Techniques.

Accurate prediction of the thermal conductivity (κ) of polymers is generally challenging due to their complex structures. Currently available ab initio methods (e.g., DFT-BTE) are prohibitively expensive, and the classical force fields used in molecular dynamics lack accuracy. In this study, we combine ab initio hybrid machine learning (ML)/multipolar polarizable potential (i.e., PhyNEO) with ML-facilitated heat flux calculation. This approach provides reliable heat flux trajectories, which are then used to predict polymer κ quantitatively. Using poly(ethylene oxide) as an example, we compare our calculation results with reliable experimental reference obtained from time-domain thermoreflectance measurement, reaching excellent agreement. This work enables the quantitative prediction of bulk polymer κ starting from only small cluster quantum data, warranting broad applications in future.