Tailoring Thermal Conductivity of Single-stranded Carbon-chain Polymers through Atomic Mass Modification

TL;DR

This study uses molecular dynamics simulations to show how atomic mass modifications in single-stranded carbon-chain polymers can effectively tune their thermal conductivity, revealing the dominant role of carbon chains and phonon band discrepancies.

Contribution

It provides the first detailed numerical analysis of how atomic mass modifications affect thermal conductivity in single-stranded carbon-chain polymers.

Findings

Heavy substituents do not enhance heat transport.

Trace heavy substituents can significantly hinder heat transfer.

Carbon chains contribute over 80% to thermal conduction.

Abstract

Tailoring the thermal conductivity of polymers is central to enlarge their applications in the thermal management of flexible integrated circuits. Progress has been made over the past decade by fabricating materials with various nanostructures, but a clear relationship between various functional groups and thermal properties of polymers remains to be established. Here, we numerically study the thermal conductivity of single-stranded carbon-chain polymers with multiple substituents of hydrogen atoms through atomic mass modification. We find that their thermal conductivity can be tuned by atomic mass modifications as revealed through molecular dynamics simulations. The simulation results suggest that heavy homogeneous substituents do not assist heat transport and trace amounts of heavy substituents can in fact hinder heat transport substantially. Our analysis indicates that carbon chain has the biggest contribution (over 80%) to the thermal conduction in single-stranded carbon-chain polymers. We further demonstrate that atomic mass modifications influence the phonon bands of bonding carbon atoms, and the discrepancies of phonon bands between carbon atoms are responsible for the remarkable drops in thermal conductivity and large thermal resistances in carbon chains. Our study provides fundamental insight into how to tailor the thermal conductivity of polymers through variable substituents.