Model-Based Dielectric Constant Estimation of Polymeric Nanocomposite

Abstract

The interphase region widely exists in polymer-based nanocomposites, which affects the dielectric properties of the nanocomposites. General models, such as the Knott model, are often used to predict the dielectric constant of nanocomposites, while the model does not take the existence of interphase into account, which leads to a large deviation between the predicted results and the experimental values. In this study, a developed Knott model is proposed by introducing the interphase region and appropriately assuming the properties of the interphase. The modeling results based on the developed model are in good agreement with the experimental data, which verifies the high accuracy of the development model. The influence of nanoparticle loading on the effective volume fraction is further studied. In addition, the effects of the polymer matrix, nanoparticles, interphase dielectric and thickness, nanoparticle size and volume fraction on the dielectric properties of the nanocomposites are also investigated. The results show that polymer matrix or nanoparticles with a high dielectric and thick interphase can effectively improve the dielectric properties of the materials. Small size nanoparticles with high concentrations are more conducive to improving the dielectric properties of the nanocomposites. This study demonstrates that the interphase properties have an important impact on the dielectric properties of nanocomposites, and the developed model is helpful to accurately predict the dielectric constant of polymer-based nanocomposites.

A Novel Vibration Piezoelectric Generator Based on Flexible Piezoelectric Film Composed of PZT and PI Layer

“…Moreover, mechanical-vibration-based generator has the advantages of relative high-power density, higher potential and longer lifespan [ 6 , 7 , 8 , 9 ]. Consequently, several strategies, such as piezoelectric mechanism, electromagnetic mechanism and electrostatic mechanism, have been introduced to develop a mechanical-vibration-based energy harvester [ 10 , 11 , 12 , 13 ]. The piezoelectric generator is based on the piezoelectric mechanism, which has been extensively investigated and is understood to be related to mechanical–electrical energy conversion.…”