Linking Electrostatic-Induced Chain Stiffening to Heat Flow in Amorphous Polymers

Area of Science:

• Materials Science
• Polymer Physics
• Computational Chemistry

Background:

• Amorphous polymers typically exhibit low thermal conductivity (κ < 0.40 W m⁻¹ K⁻¹) due to weak interchain interactions.
• Heat transport in these materials is primarily governed by nonbonded forces, limiting efficient thermal management applications.

Purpose of the Study:

• To investigate the impact of electrostatic modification (ionization) on the thermal transport coefficient (κ) in amorphous polymers.
• To elucidate the underlying mechanism responsible for enhanced thermal conductivity in charged polymer systems.

Main Methods:

• Utilized molecular-dynamics simulations employing a bead-spring polymer model.
• Simulated amorphous polymers across a range of ionization levels to quantify changes in thermal conductivity.

Main Results:

• Observed a significant enhancement in thermal conductivity (κ), exceeding 1.00 W m⁻¹ K⁻¹ in highly ionized systems, a >2.5-fold increase compared to uncharged polymers.
• Identified electrostatically induced local chain stiffening as the primary driver for the increased bonded contribution to thermal transport.

Conclusions:

• Electrostatic modification offers a viable strategy for tuning thermal conductivity in amorphous polymers.
• The findings reveal a generalizable mechanism for enhancing heat flow in a wide array of charged polymer systems.