Development of Poly (vinylidene fluoride) and Polyaniline blend with high dielectric permittivity, excellent electromagnetic shielding effectiveness and Ultra low optical energy band gap: Effect of ionic liquid and temperature

Electrically conductive polymer blends have attracted profound attention as dielectric materials. However, achieving isotropic behavior, electrical stability and low current leakage is still challenging. Here we have synthesized a conductive polymer blend of Polyaniline (PANI) and Poly (vinylidene fluoride) (PVDF) exhibiting relatively high dielectric permittivity (epsilon') together with low band gap. Ionic liquid (IL) has been incorporated and the effect of IL in the dielectric properties are explored. The interfacial adhesion, morphology and the dielectric polarization of the blends are investigated. The electromagnetic shielding effectiveness (EMISE) of the conductive blends is studied in X-band frequency range. The electrical stability and decrease in current loss of the blends has been analyzed through I-V characteristics. The findings reveal that with increase in PANI loading in the temperature range of 25-100 degrees C and IL incorporation results in excellent dielectric properties for charge storage applications. The high efficiency of absorption and low transmission of electromagnetic radiation by the conductive blends is the main reason for excellent EMISE possessed by the systems which can be used for shielding applications in electronics. The increase in electrical stability and decrease in current leakage ability appear in the form of narrow band gap.