Computing the thermal transport coefficient of neutral amorphous polymers using exact vibrational density of states: Comparison with experiments

Abstract

Thermal transport coefficient $\kappa$ is an important property that often dictates broad applications of a polymeric material, while at the same time its computation remains challenging. In particular, classical simulations overestimate $\kappa$ than the experimentally measured ${\kappa }^{\exp }$ and thus hinder their meaningful comparison. This is even when very careful simulations are performed using the most accurate empirical potentials. A key reason for such a discrepancy is because polymers have quantum--mechanical, nuclear degrees--of--freedom whose contribution to the heat balance is non--trivial. In this work, two semi--analytical approaches are considered to accurately compute $\kappa$ by using the exact vibrational density of states $g(\nu )$. The first approach is based within the framework of the minimum thermal conductivity model, while the second uses computed quantum heat capacity to scale $\kappa$. Computed $\kappa$ of a set of commodity polymers compares quantitatively with ${\kappa }^{\exp }$.

References in corpus (13)

• Canonical sampling through velocity-rescaling
• Depleted Depletion Drives Polymer Swelling in Poor Solvent Mixtures
• Semi-quantum approach to molecular dynamics simulation of thermal properties of low-dimensional nanostructures
• Explaining the specific heat of liquids based on instantaneous normal modes
• Comparing simulated specific heat of liquid polymers and oligomers to experiments
• Tuning morphology and thermal transport of asymmetric smart polymer blends by macromolecular engineering
• Identifying non-affine softening modes in glassy polymer networks: A pathway to chemical design
• Elastic Constants of Quantum Solids by Path Integral Simulations
• Elasticity and thermal transport of commodity plastics
• Reduced thermal conductivity in molecular forests
• Simulation of Material Properties Below the Debye Temperature: A Path-Integral Molecular Dynamics Case Study of Quartz
• Comparison of all atom and united atom models for thermal transport calculations of amorphous polyethylene
• Tuning thermal transport in highly cross-linked polymers by bond induced void engineering

Cited by in corpus (2)

• Thermal conductivity of polymers: A simple matter where complexity matters
• Thermal conductivity of commodity polymers under high pressures