Exploring the influence of ionic liquid and temperature on the dielectric properties and microwave absorption of SWCNT based PVDF/PANI blend nanocomposites

Abstract

This study reveals the electromagnetic shielding effectiveness (EMISE) and dielectric relaxation phenomena of single walled carbon nanotube (SWCNT) based poly (vinylidene fluoride) (PVDF)/poly aniline (PANI) blend nanocomposites. An imidazolium base salt which is a liquid at room temperature is introduced in the polymer blend for improved dispersion of SWCNT phase. The extent of dispersion of SWCNT phase at the interface and the improved dispersion in the ionic liquid (IL) incorporated systems are investigated with High resolution transmission electron microscopy (HRTEM). The qualitative morphology and interaction between the different phases are correlated the obtained dielectric and EMISE outcomes. Analysis of various properties of the fabricated nanocomposite systems like, AC conductivity (σac), impedance (real and imaginary part), dielectric permittivity (ε′) have been done in the frequency range of 1–106 Hz of the applied external electric field. Introduction of IL to the composite systems affects the dielectric properties which is also analysed and the observed significant high value of ε′ is a result of effortless polarization at the interface of SWCNT and PANI phase. Microwave absorption efficiency of the SWCNT incorporated composite systems are explored in X-band range of frequencies (8–12 GHz) and high absorbance with low transmittance as well as low reflectance of microwave is noticed for the developed PVDF/PANI/SWCNT nanocomposites. The absorbance is predominantly increased with increasing the SWCNT loading level.