Interfacial insight of core@double‐shell Mo@MoO3@PS/PVDF composites towards prominently meliorative dielectric performances

Abstract Polymer dielectrics with synergistically large dielectric permittivity ( ε' ) and breakdown strength ( E b ) but prohibited loss is of crucial applications in the electronic devices and power equipment. In this study, we aim to elevate the integrated dielectric performances of molybdenum (Mo)/polyvinylidene fluoride (PVDF) by constructing a semiconducting molybdenum oxide (MoO 3 ) shell and insulating polystyrene (PS) shell on the Mo surface through high‐temperature oxidation followed by suspension polymerization. The resulting core@double‐shell Mo@MoO 3 @PS particles were compounded with PVDF to achieve high ε' and E b while minimizing the loss. The results reveal that the Mo@MoO 3 @PS/PVDF composites indicate simultaneously ameliorative ε' and E b along with restrained loss owing to the existence of the MoO 3 @PS double‐shell, which not only prominently enhances the interfacial compatibility and interactions between fillers and PVDF, but significantly inhibits the conductivity and loss through impeding the long‐distance motion of carrier charges. The dielectric capabilities could be improved by adjusting the thickness of the PS interlayer. The Havriliak‐Negami equation was used to fit the experimental results, which showed the impact of the PS shell on the polarization mechanism and how it inhibits carrier migration. The Mo@MoO 3 @PS/PVDF with high ε' and E b yet exceptionally low loss exhibit potential applications in microelectronics and electrical industries.