In‐situ fabrication of barium titanate@polyvinyl pyrrolidone in polyvinylidene fluoride polymer nanocomposites for dielectric capacitor applications

Abstract

We have demonstrated an in situ route to design barium titanate (BT)@polyvinyl pyrrolidone (PVP) nanoparticles (NPs) in PVP/polyvinylidene fluoride (PVDF) blends. Thus, the PVP simultaneously acted as a linker and a part of the polymer matrix. We have hydrothermally synthesized the tetragonal phase of BT NPs (~150 nm). The BT NPs content was varied from 0 to 15 vol%. The resulting polymer nanocomposites generated enormous interfaces because of homogeneously dispersed BT@PVP NPs. Furthermore, the PVP simultaneously tailored the interfacial properties surrounding the BT NPs and bulk of the polymer matrix. Therefore, we achieved an enhanced maximum polarization (P max ) and energy density (U d ) of 27.9 μC cm À2 and 13.4 J cm À3 (2261 kV cm À1 ), respectively, at 7.5 vol% BT NPs loadings. At the same time, PVP/PVDF blends showed P max and U d of only 3.9 μC cm À2 and 4.6 J cm À3 (3369 kV cm À1 ), respectively. This simple approach of in situ nanomaterials modification will lead to development of lowcost and time-efficient dielectric capacitors.

The Effects of Humidity on Dielectric Permittivity of Surface-Modified TiO₂- and MgO-Based Polypropylene Nanocomposites

“…For example, in dry and humid conditions, the magnitude dielectric loss at low frequency (1 mHz) is 0.04 and 0.02, respectively. This high magnitude in dry TiO2 systems is likely due to interfacial polarization of charge trapped at the interfaces [23] [24]. In humid conditions, the maximum magnitude of dielectric loss occurs during the relaxation peak at 1 Hz.…”

Core–Shell Engineering of Conductive Fillers toward Enhanced Dielectric Properties: A Universal Polarization Mechanism in Polymer Conductor Composites

“…[9][10][11] The percolative composite approach requires much fewer filler loadings (less than 10 vol%) than when high k ceramic fillers are employed (e.g., more than 50 vol%), and could largely preserve the thermomechanical properties of polymers and facilitate manufacturing practices. [12][13][14][15][16] However, for percolative composites, a sharp increase in dielectric loss is always accompanied by the enhanced k, which would incur various issues to the devices made of such materials, e.g., overheating or attenuation of signals, especially at high repetition rates. [17] Currently, the mechanism to explain the significant increase in k is the microcapacitor network and interfacial polarization theory.…”

Improved Energy Density and Energy Efficiency of Poly(vinylidene difluoride) Nanocomposite Dielectrics Using 0.93Na0.5Bi0.5TiO3-0.07BaTiO3 Nanofibers

“…Combining the advantages of ceramic nanofiller with high permittivity and polymer with high breakdown strength, ceramic/polymer composites demonstrate the capability to yield excellent dielectric and energy storage performances. − Therefore, intensive research studies have been focused on a range of strategies to achieve high energy density of ceramic/polymer composites. Therefore, in this case, increasing the permittivity of the composites by introducing high loading of zero-dimensional (0D) ceramic nanoparticles is often at the cost of sacrificing the breakdown electric field, which also limits the increase of energy density. − …”