Enhanced dielectric constant and suppressed dielectric loss of ternary composites based on Ag-P(VDF-HFP) matrix and TiO2 nanowires

In this study, TiO 2 nanowires with various aspect ratios were prepared via a precursor-controlled hydrothermal process. Ternary composite films comprised of P(VDF-HFP) polymer, Ag particles and the as-synthesized TiO 2 nanowires were then fabricated. The results reveal that TiO 2 NWs with high aspect ratios (i.e., pa-TiO 2 ) exhibit superiority in enhancing the dielectric constants of composites in comparison with their low-aspect-ratio counterparts (i.e., pr-TiO 2 ). For instance, the dielectric constant of the Ag/pa-TiO 2 /P(VDF-HFP) composite with 30   vol% TiO 2 NWs reaches 33.4 at 100   Hz, which is 42.1% larger than that of Ag/pr-TiO 2 /P(VDF-HFP) sample and 227% higher than pristine P(VDF-HFP). In addition, TiO 2 nanowires also serve as physical obstacles to avoid aggregation of Ag particles. As a consequence, the ternary composites filled with high-aspect-ratio TiO 2 NWs exhibit suppressed dielectric losses (e.g., 0.023 at 100   Hz) and low conductivities, making them promising candidates for applications in integrated capacitors and energy storage devices.