Barium titanate@polyaniline core–shell semiconducting particles reinforced poly(vinylidene fluoride) flexible films with a percolation threshold and high dielectric constant

Barium titanate@polyaniline (BT@PANI) core–shell semiconducting particles were prepared by the introduction of polyacrylic acid onto the surface of BT via in-stiu polymerization. Polyvinylidene fluoride (PVDF) based composites filling BT@PANI particles with 3.336 × 10−2 S cm−1 presented positive multiple effect in enhancing dielectric constant of the three-phase composites. A percolation threshold appeared at a BT@PANI loading of 30 wt%, where the composite exhibited a high dielectric constant of 247 at 103 Hz, as well as winding and folding performance. The excellent dielectric behavior could be ascribed to the fact that the BT@PANI/PVDF composites realized multiple dielectric mechanisms, including the sufficient interfacial polarization, the effective BT polarization, and the microcapacitor mechanism. As a result, the novelty ceramic particles/polymer composite films presented a good balance of dielectric performance and mechanical property.