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

Fuente: arXiv
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Main Author: Mukherji, Debashish
Format: Preprint
Published: 2024
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author Mukherji, Debashish
author_facet Mukherji, Debashish
contents Thermal transport coefficient $κ$ 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 $κ$ than the experimentally measured $κ^{\rm exp}$ 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 $κ$ by using the exact vibrational density of states $g(ν)$. The first approach is based within the framework of the minimum thermal conductivity model, while the second uses computed quantum heat capacity to scale $κ$. Computed $κ$ of a set of commodity polymers compares quantitatively with $κ^{\rm exp}$.
format Preprint
id arxiv_https___arxiv_org_abs_2405_18811
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle Computing the thermal transport coefficient of neutral amorphous polymers using exact vibrational density of states: Comparison with experiments
Mukherji, Debashish
Soft Condensed Matter
Materials Science
Statistical Mechanics
Thermal transport coefficient $κ$ 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 $κ$ than the experimentally measured $κ^{\rm exp}$ 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 $κ$ by using the exact vibrational density of states $g(ν)$. The first approach is based within the framework of the minimum thermal conductivity model, while the second uses computed quantum heat capacity to scale $κ$. Computed $κ$ of a set of commodity polymers compares quantitatively with $κ^{\rm exp}$.
title Computing the thermal transport coefficient of neutral amorphous polymers using exact vibrational density of states: Comparison with experiments
topic Soft Condensed Matter
Materials Science
Statistical Mechanics
url https://arxiv.org/abs/2405.18811