FERROELECTRIC PVDF-BASED POLYMER THIN FILMS AND NANOSTRUCTURES

Abstract

The poly(vinylidene fluoride) (PVDF)-based materials are one of the most technically important and extensively studied ferroelectric polymers because of their relatively high remnant polarization, large piezoelectric coefficient, high dielectric constant, and low dielectric loss, making them promising dielectrics for wide applications including sensors, high energy density dielectric capacitors, and electromechanical transducers. In this work, ferroelectric PVDF copolymer P(VDF-TrFE) thin films and nanotubes are investigated. Further more, beta-phase PVDF homopolymer thin films and nanotubes have been fabricated using various approaches, such as incorporation of hydrated salt, Langmuir-Blodgett (LB) deposition and solution deposition in anodic aluminum oxide membrane (AAM) template. The mechanism of beta-phase formation in PVDF homopolymer has been studied. Compare to thin films, the PVDF-based nanotubes showed much enhanced capacitance and energy harvesting property. By using modified chemical solution deposition approach, we are able to fabricate ferroelectric polymer thin films and nanostructures with low-cost, scalable and convenient methods.