Tailoring the electrical conductivity of Poly(vinylidene fluoride) by blending with poly (3,4-ethylenedioxythiophene) Polystyrene sulfonate (PEDOT:PSS) and ionic liquids

Abstract

In order to tailor dielectric response and electrical conductivity, novel polymer blends based on poly(vinylidene fluoride (PVDF) and different fillers composed by poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT:PSS), and PEDOT:PSS/ionic liquids (ILs): PEDOT:PSS/N-ethyl-N-methylpyrrolidinium bis(fluorosulfonyl)imide ([C2mpyr][FSI]) and PEDOT:PSS/N-ethyl-N-methylpyrrolidinium bis(trifluoromethanesulfonyl)imide ([C2mpyr][TFSI]), with different PEDOT:PSS/IL contents (10, 20 and 40 wt%) were prepared through solvent casting. The morphological, physical-chemical and thermal properties of the polymer blends were evaluated, together with the influence of PEDOT:PSS/IL on the PVDF crystallization kinetics, dielectric and electrical conductivity.

The incorporation of PEDOT:PSS/IL in the polymer matrix lead to a decrease of the PVDF spherulites. Furthermore, it was detected that both PEDOT:PSS and IL act as nucleation agents, promoting the homogeneous crystallization of PVDF as well as the crystallization into its b and g polar phases. The electrical conductivity formalism revealed significant contributions of PEDOT:PSS/IL to the electrical conductivity behavior of the blends, being thermally activated and described by the charge transport mechanism. Further, the dc conductivity increases due to the higher number of charge carriers of the PEDOT:PSS/IL content.

The tailorable electrical characteristics of the PVDF/PEDOT:PSS-IL blends demonstrate their potential for applications in areas such as ionic actuators and battery devices.