The effects of TiC@AlOOH core–shell nanoparticles on the dielectric properties of PVDF based nanocomposites

Abstract

In this work, a novel titanium@boehmite (TiC@AlOOH) nanoparticle with a core–shell structure was prepared by coating the AlOOH layer which is about 10 nm on the surface of the titanium carbide (TiC) particle. Then a series of poly(vinylidene fluoride) (PVDF) based on nanocomposites were prepared by blending the TiC@AlOOH nanoparticles mechanically into the PVDF. Scanning Electron Microscopy (SEM) and Transmission Electron Microscopy (TEM) were used to investigate the surface morphology and core–shell structure of the TiC@AlOOH nanoparticles and their dispersed states in the PVDF matrix respectively. The influences of the TiC@AlOOH nanoparticles on the dielectric properties of the nanocomposites were studied according to a wide range of testing frequencies. The results showed that the dieletric constant of the nanocomposites increased sharply with the increase of filler contents. And it was as high as 1.8 × 10⁷ at 100 Hz when the content of TiC@AlOOH nanoparticles added was 41 wt%, which was about 1.8 million times higher than that of pure PVDF. Based on the percolation theory, the doped TiC@AlOOH nanoparticles can greatly induce the space-charge polarization in PVDF films through enhanced charged carrier generation.