Enhanced dc conductivity and conductivity relaxation in PVDF/ionic liquid composites

To investigate the effects of 1-benzyl-3-methylimidazolium hexafluorophosphate on the crystal phase, morphology and dielectric relaxation behavior of poly(vinylidene fluoride) (PVDF), a series of PVDF/IL composites have been prepared using solution-cast method. The interaction between ILs and >CF2 groups of PVDF can facilitate the PVDF chains in amorphous area to form more polar phase for PVDF composites. In the frequency spectra of PVDF composites, MWS interfacial polarization, electrode polarization and dc conductivity resulted in high values of dielectric permittivity. The incorporation of ILs into the matrix can accelerate dc conductivity. The effect of IL on charge carrier movement mechanism was resulted from the increase of ion mobility induced by polar phase crystal and ion concentration.