Surface-Initiated Polymerization from Barium Titanate Nanoparticles for Hybrid Dielectric Capacitors

Abstract

A phosphonic acid is used as a surface initiator for the growth of polystyrene and polymethylmethacrylate (PMMA) from barium titanate (BTO) nanoparticles through atom transfer radical polymerization with activators regenerated by electron transfer. This results in the barium titanate cores embedded in the grafted polymer. The one-component system, PMMA-grafted-BTO, achieves a maximum extractable energy density of 2 J/cm(3) at a field strength of ∼220 V/μm, which exhibits a 2-fold increase compared to that of the composite without covalent attachment or the neat polymer. Such materials have potential applications in hybrid capacitors due to the high permittivity of the nanoparticles and the high breakdown strength, mechanical flexibility, and ease of processability due to the organic polymer. The synthesis, processing, characterization, and testing of the materials in capacitors are discussed.

A comparison between size dependent paraelectric and ferroelectric BaTiO3 nanoparticle doped nematic and ferroelectric liquid crystals

“…al. 49 Nevertheless, our investigations showed an even faster aggregation rate than that of the untreated nanoparticles, also with the use of an appropriate solvent, such as dichloromethane and application of extensive sonication. Especially when the solvent was evaporated, causing an isotropic to nematic transition, aggregation was enhanced strongly for the modified nanoparticles.…”

Polyarylene Ether Nitrile-Based High-k Composites for Dielectric Applications

“…Unfortunately, the loss tangent of the system increases simultaneously due to the incompatibility between the organic substrate and the inorganic additives. As a result, the micromorphology of fillers, the distribution mode of the additives in the polymeric substrate, surface treatment, and preparation methods of the fillers (i.e., "core-shell" nanoarchitectures) [43][44][45][46] are equal important as the kind of fillers that determines the properties of the obtained composites [47][48][49][50][51]. This article reviews the progress of PEN-based composites exhibiting high-k for electric applications.…”

Influence of ZnO and TiO2 Particle Sizes in the Mechanical and Dielectric Properties of Vulcanized Rubber

“…Therefore, it is important to highlight that in order to increase the dielectric properties homogeneous microstructures should be obtained. [19][20] Agglomerates usually increase the porosity of the material, thus increasing electron conduction and dielectric loss. Therefore, they tend to form conductive pathways which in turn increase dielectric loss and leakage current.…”