Enhanced Dispersibility Induced by Core-Shell Cu@Crosslinked Polystyrene and Its Effect on Structure and Dielectric Properties of Polyvinylidene Fluoride Nanocomposites

The Cu@crosslinked polystyrene (Cu@cPS) core-shell nanoparticle was designed, and we found it is an effective way to suppress the formation of conductive networks, prevent oxidation of Cu nanoparticle, enhance compatibility with polymer matrix, and improve dispersity. Compared with the Cu nanoparticle, the outstanding performance of Cu@cPS can endow the nanocomposite films with excellent dielectric properties. When the temperature is 90°C, 20 vol% Cu@cPS/PVDF nanocomposite film ( ε r = 5998, tan δ = 0.49, at 100 Hz) possesses a higher relative dielectric constant ( ε r ) and a lower loss tangent (tan δ ) than 20 vol% Cu/PVDF nanocomposite film ( ε r = 445, tan δ = 1.08, at 100 Hz). The calculated conductivity activation energy ( E A ) proved that the Cu@cPS core/shell structure can effectively restrain charges spreading behavior. This novel inorganic@cPS core-shell nanoparticle not only opens a new avenue to fabricate high-performance dielectric nanocomposite but also is of great significance for the preparation of inorganic/polymer nanocomposites with excellent dispersity.