Designing BaTiO3/carbon nanotube core-shell hybrids to achieve polyvinylidene fluoride composites with high dielectric properties

The synthesized core-shell hybrids, BaTiO3 (shell) @ carbon nanotubes (core), (BT@CNT), can make the polyvinylidene fluoride (PVDF) matrix composite to exhibit high dielectric permittivity (epsilon') but low dielectric loss (tan delta) when approaching the percolation threshold. High epsilon' is attributed to BT coating which can strengthen the interfacial polarization in the composite. Low tan delta is attributed to the formation of the structure: CNT -> BT -> PVDF with the gradually decreasing dielectric properties from the centers of hybrid to the surrounding borders of PVDF. Additionally, AC conductivity of the composites can be deduced by the self-consistent effective medium (SCEM) approximation, which helps to understand the conductive behavior of CNT with a ceramic buffer layer in PVDF matrix more comprehensively.