Surface-functionalized MWNTs with emeraldine base: preparation and improving dielectric properties of polymer nanocomposites.

A comparative study of the dielectric properties of poly(vinylidene fluoride) (PVDF) based nanocomposites with pristine multiwalled carbon nanotubes (MWNTs) and surface-modified MWNTs with core/shell structure (denoted as MEB) as fillers, was reported. Compared with MWNTs/PVDF composites, the MEB/PVDF composites exhibited lower loss tangent and higher dielectric permittivity. It is suggested that the conductive/nonconducting core/shell structure of the MEB filler is the main cause of the improved dielectric properties. Percolation based MWNTs networks is in charge of the improvement of dielectric permittivity, and the nonconducting emeraldine base layer of the MEB filler supports the low loss tangent and low conductivity in the MEB/PVDF composites.