Formation, morphology and internal structure of one-dimensional nanostructures of the ferroelectric polymer P(VDF-TrFE)

We present an investigation of the formation, morphology, thermodynamic properties and crystal texture of P(VDF-TrFE) nanostructures obtained by wetting of porous anodic aluminum oxide templates, using electron microscopy, DSC and X-ray scattering. Wetting occurs initially via precursor film formation producing thin walled nanotubes. Formation of nanorods happens by subsequent thickening of the tube walls with thickness undulations occurring as a transient state. While crystallization within the one-dimensional nanostructures during cooling leads to the formation of highly oriented crystals in the high temperature paraelectric phase, the subsequent transition to the ferroelectric phase goes along with partial loss of orientation. Nevertheless, at room temperature the samples show a dominant orientation of the chains perpendicular to the long axis of the nanostructures. For narrow pores the size of crystalline domains is restricted by the strong confinement.