Nano-clip based composites with a low percolation threshold and high dielectric constant

An all-organic composite system using newly developed PPy nanoclips is developed. The composites have a uniform microstructure due to the unique preparation process. The composites have a very low percolation threshold (< 8 wt%) and exhibit a high dielectric constant. At room temperature, the composites exhibit a dielectric constant of more than 1000. At temperatures higher than 98 C, the composites exhibit a dielectric constant of about 2000. More interestingly, the high dielectric constant reported here is associated with a loss much smaller than the loss reported for other CDCs using 1-D fillers. It is indicated that a new dielectric relaxation process is induced due to the mixture of PPy with P(VDF-TrFE), whose relaxation time decreases with increasing PPy content. The loss observed in the composites at low temperature including room temperature is mainly determined by this relaxation process rather than the conductivity. If this relaxation process has a strong contribution to the dielectric constant, the widely used percolation formula describing relationship between the dielectric constant and the composite cannot be used. (C) 2016 Elsevier Ltd. All rights reserved.