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

Abstract Phonon engineering focuses on heat transport modulation in 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, the thermal conductivities of poly(vinylidene fluoride) array can be enhanced by a factor of 3.25 along the polarization direction by simulation. The thermal conductivities of semi-crystalline poly(vinylidene fluoride) film can be also enhanced by a factor of 1.5 which is shown by both simulation and measurement. The mechanism is analyzed by morphology and phonon properties. It is found 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.