Adsorbate/absorbate interactions with organic ferroelectric polymers

Polarization of block textured films of ferroelectric copolymers of vinylidene fluoride with tetrafluoroethylene in an external field

“…These bonds, as new functional groups found on the surface after the polarization, can cause changes in the characteristics of the near electrode polarization. In addition, the presented data make it possible to esti mate the problem of water adsorption on the surface of the ferroelectric polymer stated in the literature [49,50]. For this purpose, the surfaces of the initial film and polarized film were investigated in the frequency range 3200-3600 cm -1 , where the copolymer does not have characteristic absorption bands and the water molecules absorb strongly.…”

Changing molecular band offsets in polymer blends of (P3HT/P(VDF–TrFE)) poly(3-hexylthiophene) and poly(vinylidene fluoride with trifluoroethylene) due to ferroelectric poling

“…Thus, the calculated density of states of PVDF-TrFE 70 : 30, by semiempirical methods, together with a rigid energy shi of 5.3 eV applied to the calculated electronic structure, provides a reasonable picture of the electronic structure that is in good agreement with the combined photoemission and inverse photoemission data from P(VDF-TrFE, 70 : 30). 30 The gap between the HOMO and the LUMO, derived from the combined photoemission and inverse photoemission spectra ( Fig. 5), indicates that P(VDF-TrFE, 70 : 30) has a band gap of 6 eV.…”

“…Calculations of the molecular orbitals, both occupied and unoccupied, of the polymer blend were performed for purposes of comparison with the density of states deduced from the UPS-IPES experiments. As in previous studies, 6,7,30,32,[45][46][47] the orbital energies of the single molecules (as in a gas phase experiment) were performed with the SPARTAN 10 package, based on density functional theory (DFT), using the conventional B3LYP hybrid functional and the 6-31 G(d,p) basis set, while the semiempirical calculations followed the PM3 methodology. The calculated density of states (DOS) were obtained by applying equal Gaussian envelopes of 1 eV full width halfmaximum to each molecular orbital energy to account for the solid state broadening in photoemission, followed by the summing of all envelopes to form the theoretical DOS spectra.…”

Isomeric effects with di-iodobenzene (C6H4I2) on adsorption on graphite

“…There is thus a need to invoke intermolecular interactions that can include intermolecular screening [11,42], chemical shifts due to intermolecular hybridization [43], as well as final state effects attributable to screening from the substrate [33,34].…”

“…For many large molecule adlayers, including a number of organic and metal-organic species, the energy level alignment of the adsorbate with respect to a conducting substrate Fermi level or adjacent layer chemical potential is dependent on the interfacial electronic structure and interfacial dipole layer, as has been demonstrated for a number of molecules [1][2][3], including metal (II) macrocyclic compounds (MPc) [4][5][6][7][8][9][10][11][12]. For metal (II) phthalocyanines adsorbed layers, the d-filling of the metal center atom is seen to alter the molecular band offsets [6][7][8][9], and in the case of the macrocyclic metal tetraazaannulenes (TMTAA), the d-filling of the metal center atom alters the preferential molecular orientation upon adsorption [12].…”