Nano silver-anchored reduced graphene oxide sheets for enhanced dielectric performance of polymer nanocomposites
Nano silver-anchored reduced graphene oxide (Ag–RGO) was prepared and used as the filler material for a polar polyvinylidene fluoride (PVDF) polymer. The percolation threshold of the Ag–RGO–PVDF composites was determined to be 1.52 vol%. The results showed that the dielectric performance of the composite system was greatly improved by incorporating Ag–RGO sheets. The dielectric permittivity of the composite system reached a value of about 97 at 1 kHz, while maintaining a relatively low loss tangent. The enhanced dielectric performance of the composites was attributed to the presence of silver nanoparticles. These particles separated the RGO sheets from aggregation, thus increasing the interfacial areas within the composites greatly. When the composites were exposed to an external electric field, intense Maxwell–Wagner–Sillars polarization occurred at the interfacial areas. This led to enhanced dielectric permittivity of the composites. Coupled with low loss tangent and electrical conductivity, the Ag–RGO–PVDF composite system shows great promise for use as dielectric material for electronic capacitors.