Interface modified Si@SiO₂/PVDF composite dielectrics with synchronously ameliorative dielectric and mechanical properties

Abstract

To efficaciously decrease dielectric loss while still synchronously harvesting a high dielectric constant (ε′) and breakdown strength (Eb), as well as good mechanical properties in silicon (Si)/poly(vinylidene fluoride) (PVDF), in this work, the core@shell structured Si@silicon dioxide (SiO2) particles were first prepared via a high temperature oxidation, and subsequently incorporated into the PVDF to generate morphology‐dependent composites with a high‐ε′ and Eb but low loss. The SiO2 shell effects on the morphology, dielectric, and mechanical properties of PVDF composites were explored. In comparison to pristine Si/PVDF, the Si@SiO2/PVDF presents significantly suppressed loss and boosted Eb because the SiO2 interlayer not only efficiently blocks the connection between the raw Si and greatly impedes the long‐range charges migration even at high filler loadings, but also obviously improves the compatibility between Si and PVDF at the interfaces which promotes fillers' uniform dispersion in host matrix, thus leading to enhanced dielectric and mechanical properties. The fitting result by the Havriliak–Negami equation theoretically elucidates the SiO2 interlayer's suppression effect on charge migration behavior in the composites. More importantly, dielectric properties can be efficiently turned via tailoring the SiO2 shell thickness. The Si@SiO2/PVDF with simultaneously enhanced dielectric and mechanical performances shows promising uses in the electrical and microelectronics industries.

A A Novel Poly (vinylidene) Fluoride/TiO2/Spent Bleaching Earth for Enhancing Hydrophilic Hollow Fibre Membrane

“…And the other hand, PVDF-TiO2 HF membrane without SBE addition show the low peak of Si-O-Si functional group. it proves with SBE addition, so the PVDF HF membrane strength characteristic can be improved by the presence of silica [31,32].…”

Energy Storage Performance of Polymer-Based Dielectric Composites with Two-Dimensional Fillers

“…Moreover, the existence of a substantial disparity in permittivity between the two phases gives rise to a profoundly non-uniform electric field, leading to the formation of a composite material with a much reduced effective breakdown strength. Due to these reasons, many metal oxides have been used as fillers to improve the energy storage performance, including TiO 2 [162][163][164][165], ZrO 2 [166][167][168], Al 2 O 3 [169], SiO 2 [170], Fe 3 O 4 [171], ZnO [172][173][174], and SnO 2 [175].…”

Morphological engineering of SiO2 interlayer towards meliorative dielectric and thermal properties in β‐SiCw@SiO2/PVDF composites

“…At a filler content below 12.2 vol%, the ε increases slowly with increasing β-SiC w -0 concentration because the β-SiC w -0 particles are separated by a large distance, and the charges isolation is thus vastly limited, resulting in decreased polarization as a result. 37 When the β-SiC w -0 loading approaches the f c , the ε is sharply enhanced, which implies the composite changes from an insulator to a conductor and the start of percolation phenomena, leading to a reduction in the distance between electrodes. When the electrons tunnel or hop across some adjoining conductive fillers, the charge closed in an individual filler can be greatly released, consistently boosting charge separation, which in turn vastly raises the ε.…”