Interfacial effects on the electrical behavior of elastomer nanoparticulate composites

摘要

Polymer nanocomposites exhibit unique effective properties that do not follow conventional effective mediaapproaches. The nanoparticle-polymer interphase has been shown to strongly influence the nanocomposites behavior dueto its significant volume when the particles are nano-sized, affording an opportunity to tune the dielectric response of theresulting nanocomposite. In this study, we investigate the effects of TiO2 nanoparticles on the electrical properties andthe charges distribution and transport in polydimethylsiloxane (PDMS) nanocomposites. Impedance spectroscopy showssuppression of interfacial Maxwell-Wagner-Sillars (MWS) polarization accompanied by a reduction in the lowfrequency dielectric permittivity and loss at high temperatures in the presence of the TiO2 nanoparticles. Thermallystimulated discharge current measurements confirm that the suppression of the interfacial polarization relaxationshappens by redistributing or depleting the charges through the composite and hindering their mobility, potentiallyresulting in lower electrical conduction and higher breakdown strength. Although the model materials investigated hereare TiO2 nanoparticles and Sylgard 184 PDMS, our findings can be extended to other nanoparticulate-filled elastomercomposites to design lightweight dielectrics, actuators and sensors with improved capabilities.