@article{GuliakovaGorokhovatskyGalikhanovetal.2019,
  author    = {Guliakova, A. A. and Gorokhovatsky, Yu. A. and Galikhanov, M. F. and Fr{\"u}bing, Peter},
  title     = {Thermoactivational spectroscopy of the high impact polystyrene based composite films},
  series = {St. Petersburg Polytechnic University Journal : Physics and Mathematics},
  volume    = {12},
  journal   = {St. Petersburg Polytechnic University Journal : Physics and Mathematics},
  number    = {4},
  publisher = {Elsevier},
  address   = {Amsterdam},
  issn      = {2405-7223},
  doi       = {10.18721/JPM.12401},
  pages     = {9 -- 16},
  year      = {2019},
  abstract  = {The relaxation processes in the high impact polystyrene (HIPS) films filled with 2, 4, 6 vol.\% of titanium dioxide (TiO2) of the rutile modification have been studied using the thermally stimulated depolarization current (TSDC) technique. Three relaxation processes were observed in the composite HIPS films. The first one (a-relaxation peak) appeared at about 93 degrees C and represented the glass transition. The second peak p was a high-temperature part of the first one and overlapped it. The p peak was caused by the release and subsequent motion of excess charges deposited during the electret preparation or the polarization process. The third peak appeared at about 150 degrees C and occurred only in the spectra of the composite films. The overlapping peaks were separated by the thermal cleaning technique. The subsequent application of the numerical methods (the Tikhonov regularization technique) allowed to determine the activation energy of the second process and to compare the obtained value with the corresponding data on the dielectric relaxation.},
  language  = {ru}
}
@article{GulyakovaGorokhovatskyfruebingetal.2017,
  author    = {Gulyakova, Anna A. and Gorokhovatsky, Yuri A. and fr{\"u}bing, Peter and Gerhard, Reimund},
  title     = {Relaxation Processes Determining the Electret Stability of High-Impact Polystyrene/Titanium-Dioxide Composite Films},
  series = {IEEE transactions on dielectrics and electrical insulation},
  volume    = {24},
  journal   = {IEEE transactions on dielectrics and electrical insulation},
  publisher = {Inst. of Electr. and Electronics Engineers},
  address   = {Piscataway},
  issn      = {1070-9878},
  doi       = {10.1109/TDEI.2017.006587},
  pages     = {2541 -- 2548},
  year      = {2017},
  abstract  = {The influence of relaxation processes on the thermal electret stability of high-impact polystyrene (HIPS) free-standing films filled with titanium dioxide (TiO2) of the rutile modification are investigated by means of a combination of dielectric methods (dielectric relaxation spectroscopy (DRS), thermally stimulated depolarization current (TSDC) and thermally stimulated surface-potential decay (TSSPD)), supplemented by differential scanning calorimetry (DSC) and dynamic mechanical analysis (DMA). Films with 2, 4, 6 and 8 vol.\% TiO2 are compared to each other and to non-filled samples. Filling HIPS with up to 8 vol.\% of TiO2 enhances the elastic modulus below the glass transition and increases the thermal electret stability above the glass transition without significantly increasing the DC conductivity. The improvement of the electret stability is caused by the build-up of an interface polarization which decays only gradually if the glass transition is exceeded. Two kinds of Arrhenius processes are considered in order to explain the decay of the composite-polymer electrets: (1) charge release from chemical traps located at the phenyl rings of the polymer chain with an activation energy of E-a = 1.1 eV after passing the glass transition at about 100 degrees C and (2) charge release from traps formed by the TiO2 particles with E-a = 2.4 eV at temperatures above 130 degrees C. Finally, the activation energies are discussed with respect to their significance.},
  language  = {en}
}