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

Polymer dielectrics with synergistically large dielectric permittivity (e') 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 (MoO3) shell and insulating polystyrene (PS) shell on the Mo surface through high-temperature oxidation followed by suspension polymerization. The resulting core@double-shell Mo@MoO3@PS particles were compounded with PVDF to achieve high e' and E-b while minimizing the loss. The results reveal that the Mo@MoO3@PS/PVDF composites indicate simultaneously ameliorative e' and E-b along with restrained loss owing to the existence of the MoO3@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@MoO3@PS/PVDF with high e' and E-b yet exceptionally low loss exhibit potential applications in microelectronics and electrical industries.