Enhanced dielectric properties of the ZnO nanoparticles dispersed PU/PANI blend nanocomposites

Abstract

Dielectric systems composed of conductive polymers and metal oxide nanoparticles become the most frontier hybrid materials to be used in various electronics for their superior dielectric characteristics and easy processibility. In the present study, the effects of conducting polyaniline (PANI) and Zinc Oxide (ZnO) nanoparticles on the dielectric characteristics like dielectric constant (ε′), loss factor (ε″), current permitting ability (σac), both real and imaginary impedance (Z′ and Z″), Nyquist plots, etc., have been explored. The prime objective is to explore the effect of ultra-low loading levels of ZnO nanoparticles on the significant improvement in the dielectric relaxation behavior. Prior to the dielectric analysis, the dispersion pattern of ZnO nanoparticles in the bulk of TPU/PANI phases has been analyzed from the microphotographs obtained from the field emission scanning electron microscopy (FESEM) as well as high-resolution transmission electron microscopy (HRTEM) analysis. The analysis of the frequency of the applied electric field's effects (1 to 106 Hz) on the dielectric characteristics shows that the produced hybrid materials may be used in a variety of applications. The variation of the aforesaid parameters with change in temperature is also explored which informs the suitability of the hybrid system in the manufacturing of high-temperature sensing applications. Significant improvement in the dielectric properties at 0.1 wt% loading level of ZnO is the novelty of this present analysis. The predominance of ε′ over ε′′ after a certain frequency of the applied field ensures the electric energy storing ability of the systems rather than energy loss. The reduced area under the Nyquist plot informs the approach of the system from an insulator to a perfect dielectric material that can be used in a capacitor for electric energy storage purposes.