@article{WangFruebingWirgesetal.2010,
  author    = {Wang, Feipeng and Fr{\"u}bing, Peter and Wirges, Werner and Gerhard, Reimund and Wegener, Michael},
  title     = {Enhanced Polarization in Melt-quenched and Stretched Poly(vinylidene Fluoride-Hexafluoropropylene) Films},
  issn      = {1070-9878},
  doi       = {10.1109/TDEI.2010.5539679},
  year      = {2010},
  abstract  = {beta-phase poly(vinylidene fluoride-hexafluoropropylene) (P(VDF-HFP)) copolymer films were prepared by uniaxially stretching solution-cast or melt-quenched samples. Different preparation routes lead to different amounts of the crystalline alpha and beta phases in the films, as detected by means of Fourier-transform infrared spectroscopy and X-ray diffractometry. The beta phase is significantly enhanced in melt-quenched and stretched films in comparison to solution-cast and stretched films. This is particularly true for copolymer samples with higher HFP content. The beta- phase enhancement is also observed in ferroelectric-hysteresis experiments where a rather high polarization of 58 mC/ m(2) was found on melt-quenched and stretched samples after poling at electric fields of 140 MV/m. After poling at 160 MV/m, one of these samples exhibited a piezoelectric d(33) coefficient as high as 21 pC/N. An electric-field-induced partial transition from the alpha to the beta phase was also observed on the melt-quenched and stretched samples. This effect leads to a further increase in the applications-relevant dipole polarization. Uniaxially stretched ferroelectric- polymer films are highly anisotropic. Dielectric resonance spectroscopy reveals a strong increase of the transverse piezoelectric d(32) coefficient and a strong decrease of the transverse elastic modulus c(32) upon heating from 20 to 50 degrees C.},
  language  = {en}
}
@article{GrecoWangWegener2010,
  author    = {Greco, Tonino and Wang, Feipeng and Wegener, Michael},
  title     = {Multifunctional silver poly(vinylidene fluoride) nanocomposites : nanoparticle synthesis, film processing, and structural characterization},
  issn      = {0015-0193},
  doi       = {10.1080/00150193.2010.482896},
  year      = {2010},
  abstract  = {Scope of this work was the synthesis of homogeneously dispersed silver nanoparticles in the ferroelectric polymer poly(vinylidene fluoride) (PVDF) and the study of the resulting properties affecting both the electro-active matrix and the optically-active nanofiller. In the nanocomposites surface plasmon resonances can be tuned across the UV- vis to the NIR spectral range. From IR spectra and DSC measurements it is concluded that the - to -phase transformation is observed and no degradation of the polymer matrix occurs. Finally, electrical poling was performed in order to investigate the influence of the embedded silver particles on the polarization behavior of the ferroelectric polymer.},
  language  = {en}
}