Probing the electrical and dielectric properties of polyaniline multi-walled carbon nanotubes nanocomposites doped in different protonic acids

Polymer nanocomposites with vital reinforcements of conductive fillers have evinced as next-generation high-performance materials with multi-functional applications. Herein, we report the facile synthesis of thermally stable, highly electrically conducting polyaniline multi-walled carbon nanotubes (PANI/MWCNT) nanocomposites doped in two different protonic acids, i.e. hydrochloric acid (HCl) and sulphuric acid (H2SO4). The doping acids significantly affect the electric and dielectric properties of conducting polymer nanocomposites. The paper probes in the synergistic effects of MWCNTs and the effect of doping acid on the thermal stability, conductivity and dielectric properties of the nanocomposites based on PANI nanofibres. The structural, morphological, optical, thermal and electrical properties were evaluated through X-ray diffraction, scanning electron microscopy, Raman spectroscopy, Fourier transform infrared spectroscopy, UV–Vis spectroscopy, thermogravimetric analysis and two-point probe technique. Ascribed to the high interfacial interaction between PANI and MWCNT, and considering the effect of doping acids, nanocomposites with high thermal stability, enhanced conductivity and high dielectric constant that can store large electrical charges have been synthesized by surfactant-assisted, in situ oxidative polymerization of aniline, in the presence of potassium persulfate as oxidant. The micellar structure of surfactant assists the dispersion of MWCNTs as well as the formation of PANI/MWCNT tubular structures. The effect of surfactant below and above critical micelle concentration was also studied. This complete study would affirm such a nanocomposite which procures excellent electrical and dielectric properties for microelectronic applications.