Synergistic enhancement in mechanical, thermal, and dielectric properties of PANI @ BT / PVDF composites by adding 2D nanoplatelets

Polymer-based dielectric composites with simultaneously improved dielectric constant and breakdown strength have great potential applications in energy storage. In this paper, polyaniline@BaTiO3 (PANI@BT) nanoparticles with core-shell structure are first fabricated by in-situ chemical oxidative polymerization, and deposited on the surface of two-dimensional nanoplatelets (graphene oxide [GO] and hexagonal boron nitride nanosheets [BNNS]), which are then utilized to prepare poly(vinylidene fluoride) (PVDF)-based composites. The presence of 2D nanoplatelets is found to significantly ameliorate the dispersion of PANI@BT particles in the PVDF matrix, and thus endowing the resultant PVDF composites with improved comprehensive performance. The dielectric constant of PANI@BT-GO/PVDF and PANI@BT-BNNS/PVDF composites with 50 wt% fillers increase to 124.9 and 169.5 at 100 Hz, accompanied with relatively low dielectric loss. When the filler content is 10 wt%, the breakdown strength of PANI@BT-BNNS/PVDF achieves 133.5 kV/mm, which is 9.7% and 71.8% higher than that of the pristine PVDF and PANI@BT/PVDF composites. Meanwhile, the tensile stress also reaches the highest value of 43.38 MPa. In addition, the PANI@BT-GO/PVDF and PANI@BT-BNNS/PVDF composites present higher thermal decomposition temperature in comparison with PANI@BT/PVDF composites.