Enhanced dielectric properties induced by hematite nanoparticles in poly(vinylidene fluoride) composites

Polymer-based materials with a high dielectric constant have attracted considerable attention for energy storage applications. A new class of polymer-based composites composted of hematite nanoparticles and polyvinylidene fluoride (PVDF) has been fabricated by simply mixing method followed by melt compression. Hematite nanoparticles were mixed into neat PVDF with filler volume fraction of 5, 10, 12, 15, 18, 20 and 25%. Characterization of the nanocomposites indicates that hematite nanoparticles with diameter around 80nm and length up to 200nm were uniformly embedded into PVDF matrix. The dielectric properties of the hematite/PVDF composites as a function of the frequency and the volume fraction of hematite nanoparticles were investigated. The hematite/PVDF composites had dielectric constant of 210 with a dielectric loss below 1.5 at the volume fraction of hematite nanoparticles is 0.18 and 100Hz. Compared to the pristine PVDF, improved dielectric properties are achieved in the hematite/PVDF composites. It is believed that the hematite nanoparticles play an important role in realizing the high dielectric performances of the composites. The results indicate that hematite nanoparticles are promising filler to enhance the dielectric properties of polymer matrix.