Unusual Dielectric Loss Properties of Carbon Nanotube—Polyvinylidene Fluoride Composites in Low Frequency Region (100 Hz < f < 1 MHz)

Systematic investigations on the dielectric properties of multi-walled carbon nanotubes (MWNTs)-polyvinylidene fluoride (PVDF) composites with a wide MWNT concentration range (2 - 9 wt%) have been carried out. It is revealed that the dielectric constant is increased by the addition of an appropriate amount of MWNTs at room temperature. However, when the concentration of MWNTs in the composites reaches above 5 wt%, negative dielectric constants and large dielectric loss in the composites are observed in the low frequency range. The ferroelectric CNT-PVDF polymer composites containing more than 5 wt% MWNTs have a strong dielectric absorption, which has the potential for acoustic applications.