Conductive HNTs-PEDOT hybrid preparation and its application in enhancing the dielectric permittivity of HNTs-PEDOT/PVDF composites

Abstract A novel flexible dielectric composite with halloysite nanotube-poly(3,4-ethylenedioxythiophene) (HNTs-PEDOT) hybrid as conductive filler and poly(vinylidene fluoride) (PVDF) as polymer matrix were prepared via a blending and hot-pressing technique. HNTs-PEDOT hybrid, with PEDOT coated onto both the negatively charged inner and out surfaces of the HNTs tubes, were fabricated by chemical oxidative polymerization of EDOT with unmodified HNTs as templates. The conductivity of HNTs-PEDOT hybrid with 50 wt% HNTs is up to 12.89 S/cm, which is 100 times greater than that of pure PEDOT (about 0.12 S/cm) synthesized under the similar condition. With PEODT as outside organic layer, HNTs-PEDOT could be easily dispersed in PVDF matrix uniformly. In addition, with the introduction of HNTs-PEDOT into PVDF matrix, it makes a phase transformation of PVDF from α to electroactive β phase. HNTs-PEDOT/PVDF shows good dielectric performance. At close to the percolation threshold value (fHNTs-PEDOT = 0.11), the dielectric constant of HNTs-PEDOT/PVDF is up to 641 at 1000 Hz, which is attractive to prepare flexible materials.