Ricerc@Sapienza

This study presents a comparison of the piezoelectric properties of nanostructured thin films made of arrays of vertically oriented ZnO-nanorods (ZnO-NRs) over ITO-glass substrate and of ZnO-nanowalls (ZnO-NWs) over aluminium substrate. Both nanostructures were synthesized on a large area through chemical bath deposition. The morphological, structural, and chemical characteristics of the produced nanostructures were investigated in order to assess the crystal quality and purity.

In this work, we develop graphene-gold electrodes (GGEs) for flexible nanogenerators made of porous piezoelectric PVDF films. The bilayer electrode structure was conceived in order to avoid the short circuit between top and bottom electrodes produced through direct Au sputtering over the film surface. Gold was sputtered over chemical-vapor- deposition (CVD) grown graphene film, that was subsequently transferred onto a PVDF film.

The piezoelectric properties of Poly(vinylidene fluoride) (PVDF) mainly depend on its most polar ?-phase. In this work, we investigated through Piezoresponse Force Microscopy (PFM) the piezoelectric properties of PVDF composite films when we induce the formation of ?-phase crystals adding graphene nanoplatelets (GNPs) without any chemical modification or poling. At first, we fabricated GNP-filled PVDF composite films by the solution casting method.

The present work reports the development and the piezoelectric characterization of nano-engineered thin-films of Polyvinylidene Fluoride (PVDF) and vertical array of zinc oxide nanorods (ZnO-NRs). In particular, the piezoelectric response of the produced samples was investigated by evaluating the piezoelectric coefficient (d33), through Piezoresponse Force Microscopy (PFM). We compared the piezoelectric response of three different samples: a neat PVDF thin-film, an array of vertically oriented ZnO-NRs and an array of vertically oriented ZnO-NRs embedded in PVDF.

In the present work, poly(vinylidene fluoride) (PVDF) films were produced by spin-coating, and applying different conditions of quenching, in order to investigate the dominant mechanism of the β-phase formation. The influence of the polymer/solvent mass ratio of the solution, the rotational speed of the spin-coater and the crystallization temperature of the film on both the β-phase content and the piezoelectric coefficient (d33) were investigated.