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.

Automated summary

Polymer-based dielectric composites with improved dielectric constant and breakdown strength are achieved by fabricating core-shell structure nanoparticles and depositing them on 2D nanoplatelets, which are used to prepare PVDF-based composites. The presence of 2D nanoplatelets significantly enhances the dispersion of nanoparticles in the PVDF matrix, resulting in improved comprehensive performance of the composites. The composites exhibit high dielectric constant, low dielectric loss, high breakdown strength, and high tensile stress, as well as increased thermal decomposition temperature compared to the pristine PVDF composites.