Uniaxially aligned nucleation of vinylidene fluoride oligomer single-crystals on highly ordered ultrathin films of poly(vinylidene fluoride-trifluoroethylene) copolymer

Uniaxially aligned single-crystals of ferroelectric vinylidene fluoride (VDF) oligomer were obtained on a highly-oriented ultra-thin film of vinylidene fluoride-trifluoroethylene copolymer P(VDF/TrFE). Trapezoidal shaped plate-like VDF oligomer crystals with 20 nm thickness were selectively grown perpendicularly on P(VDF/TrFE) lamella crystals as a structural template. Fourier transform infrared reflection absorption spectroscopy (FTIR-RAS) and synchrotron two-dimensional grazing incidence X-ray diffraction (2D-GIXD) revealed that the molecular chain axis (c-axis) of P(VDF/TrFE) oriented to the friction transfer direction with the a-axis perpendicular to the film surface, and the friction-transferred P(VDF/TrFE) film induced the uniaxially aligned nucleation of the VDF oligomer with an epitaxial relationship (010)[001]VDF-oligomer//(100)[001]P(VDF/TrFE) in initial crystal growth of VDF oligomer.