Interfacial effects of BaTiO3@TiO2 nanofibers on dielectric relaxation processes of P(VDF-TrFE-CFE) nanocomposites

Abstract TiO2 nanofibers embedded with BaTiO3 nanoparticles (BTO@TO_nfs) are prepared by electrospinning method. The interfacial effects of nanofibers on the dielectric relaxation processes of poly (vinylidene fluoride-trifluroethylene-chlorofluoroethylene) (P(VDF-TrFE-CFE)) are studied in a temperature range of −30 °C–96 °C. Two relaxation processes are investigated, i.e. space charge relaxation and α relaxation, which could be described by Arrhenius equation and Vogel-Fulcher-Tamman (VFT) equation, respectively. The results show that the addition of BTO@TO_nfs decreases the activation energy for space charge relaxation due to the shortened distance for charge motion, while the energy needed for α relaxation also decreases as a result of the suppressed intermolecular cooperativity by the BTO@TO_nfs. Homogeneous dispersion of the nanofibers in matrix also promotes the local homogeneity of polymer chains, resulting in a narrower distribution of relaxation times for α relaxation.