Effects of Sub-Micro Sized BaTiO3 Blocking Particles and Ag-Deposited Nano-Sized BaTiO3 Hybrid Particles on Dielectric Properties of Poly(vinylidene-fluoride) Polymer

This work provided an alternative route to balance the significantly increased dielectric permittivity (epsilon & PRIME;) and effectively retained tan delta using an effective two-step concept. Ag-deposited nano-sized BaTiO3 (Ag-nBT) hybrid particle was used as the first filler to increase the epsilon & PRIME; of the poly(vinylidene-fluoride) (PVDF) polymer via the strong interfacial polarization and a high permittivity of nBT and suppress the increased loss tangent (tan delta) owing to the discrete growth of Ag nanoparticles on the surface of nBT, preventing a continuous percolating path. The epsilon & PRIME; and tan delta values at 10(3) Hz of the Ag-nBT/PVDF composite with f(Ag-nBT)~0.29 were 61.7 and 0.036. The sub-micron-sized BaTiO3 (mu BT) particle was selected as the blocking particles to doubly reduce the tan delta with simultaneously enhanced epsilon & PRIME; due to the presence of the tetragonal BT phase. The mu BT blocking particles can effectively further inhibit the formation of conducting network and hence further reducing tan delta. By incorporation of mu BT clocking particles with f(mu)(BT) = 0.2, the epsilon & PRIME; value of the Ag-nBT/PVDF-mu BT composite (f(Ag-nBT) = 0.30) can significantly increase to 161.4, while the tan delta was reduced to 0.026. Furthermore, the tan delta was lower than 0.09 in the temperature range of -60-150 & DEG;C due to the blocking effect of mu BT particles.