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Poly(vinyl alcohol)-potassium sodium niobate-poly(vinylpyrrolidone) composite films (PVA-KNN-PVP) were successfully fabricated via a solvent casting technique. The dependence of the dielectric and electric performances of the resultant PVA-KNN-PVP composites on different weight percentages of PVP and frequency was investigated. The composite surface morphology shows that KNN particles and PVP were uniformly distributed in the PVA matrix. The dielectric constant of the PVA-KNN-PVP composites is enhancing remarkably as 108 and loss value (1.04) about 12 wt% PVP at 102 Hz, which is 18 times greater than that of neat PVA. Thus, these PVA-KNN-PVP composites are suitable for high-energy storage applications. [ABSTRACT FROM AUTHOR]

In this report, a simple solution-casting technique was employed to prepare benzoxazine (BA) encapsulated BiFeO3; BFO particles (BA@BFO) usable as fillers filled poly(vinylidene fluoride) (PVDF) composite films. The effects of encapsulated BA@BFO particle on the electrical and mechanical performance of the composites were carefully investigated. The results suggested that the introduction of BA@BFO particles enhanced dielectric constant (ԑr) (≈ 62) and negligible loss (tan δ) (< 0.5) at 100 Hz. This may be due to the improved polarization, which is induced by relatively high dielectric constant ceramic particles. In addition, compared to untreated BFO particles, BA@BFO particles can be dispersed homogeneously in the poly (vinylidene fluoride) (PVDF) matrix, this might be the reason for the suppression of loss which makes them interesting for possible applications in electronic devices. Moreover, the interfacial interaction between PVDF chains and the BA@BFO particles were revealed, this interaction leads to the increase of the dielectric constant, tensile strength and relatively suppressed dielectric loss. Consequently, this study opens up the avenue for developmental analysis with respect to the use of BA in addition with BFO-PVDF composites with low dielectric loss and high dielectric constant for the next generation of high-performance dielectric capacitors. [ABSTRACT FROM AUTHOR]