Polypropylene/Polyaniline Nanofiber/Reduced Graphene Oxide Nanocomposite with Enhanced Electrical, Dielectric, and Ferroelectric Properties for a High Energy Density Capacitor

This work demonstrates a ternary nanocomposite system, composed of polypropylene (PP), redoped PANI (r-PANI) nanofibers, and reduced graphene oxides (RGOs), for use in a high energy density capacitor. r-PANI nanofibers were fabricated by the combination methods of chemical oxidation polymerization and secondary doping processes, resulting in higher conductivity (sigma approximate to 156 S cm(-1)) than that of the primarily doped PANI nanofibers (sigma approximate to 16 S cm(-1)). RGO sheets with high electron mobility and thermal stability can enhance the conductivity of r-PANI/RGO (sigma approximate to 220 S cm(-1)) and thermal stability of PP matrix. These findings could be extended to combine the advantages of r-PANI nanofibers and RGO sheets for developing an efficient means of preparing PP/r-PANI/RGO nanocomposite. When the r-PANI/RGO cofillers (10 vol %) were added to PP matrix, the resulting PP/r-PANI/RGO nanocomposite exhibited high dielectric constant (epsilon' approximate to 51.8) with small dielectric loss (epsilon '' approximate to 9.3 x 10(-3)). Furthermore, the PP/r-PANI/RGO nanocomposite was used for an energy-harvesting device, which demonstrated high energy density (U-e approximate to 12.6 J cm(-3)) and breakdown strength (E approximate to 5.86 x 10(3) kV cm(-1)).