Formation of PVDF-g-HEMA/BaTiO₃ nanocomposites via in situ nanoparticle synthesis for high performance capacitor applications

PVDF-g-HEMA [poly(vinylidene fluoride)-graft-poly(2- hydroxyethylmethacrylate)]/Barium Titanate (BaTiO₃) nanocomposites were prepared successfully via an in situ synthesis method without any catalyst or initiator. The in situ synthesis approach enables the formation of oxide nanoparticles in the presence of the grafted polymer with a hydroxyl functionalization group for direct coupling with oxide nanofillers. This elegant in situ nanoparticle synthesis method provides a facile, cost-effective and void-free dispersion of the nanoparticles in the matrix. The dielectric nanoparticle (BaTiO₃) is well-attached onto the insulating polymer (PVDF) surface due to the surface anchoring linkage through hydrogen bonding between the two components, leading to the reduced aggregation in the resultant nanocomposites. The novel PVDF-g-HEMA/BaTiO₃ nanocomposites are investigated as high energy density capacitor materials, achieving highest dielectric constant reaching up to 333, and a dielectric loss of 0.73 at 30 wt% BaTiO₃ at 1 kHz.