Electric-field-induced modulation of thermal conductivity in poly(vinylidene fluoride)

TL;DR

This study demonstrates that electric fields can significantly modulate the thermal conductivity of poly(vinylidene fluoride), a ferroelectric polymer, through changes in molecular order and phonon transport, offering a rapid, filler-free control method.

Contribution

It introduces a novel electric-field-based approach to modulate heat transport in ferroelectric polymers, supported by both simulation and experimental validation.

Findings

Thermal conductivity can be increased by up to 3.25 times along polarization direction.

Polymer film thermal conductivity enhancement factor is 1.5, confirmed by experiments.

Enhancement is due to increased lattice order, phonon velocity, and reduced scattering.

Abstract

Phonon engineering focuses on heat transport modulation on atomic-scale. Different from reported methods, it is shown that electric field can also modulate heat transport in ferroelectric polymers, poly(vinylidene fluoride), by both simulation and measurement. Interestingly, thermal conductivities of poly(vinylidene fluoride) array can be enhanced by a factor of 3.25 along the polarization direction by simulation. The semi-crystalline poly(vinylidene fluoride) film can be also enhanced by a factor of 1.5 which is found by both simulation and measurement. The morphology and phonon property analysis reveal that the enhancement arises from the higher inter-chain lattice order, stronger inter-chain interaction, higher phonon group velocity and suppressed phonon scattering. This study offers a new modulation strategy with quick response and without fillers.