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Dr. Anna Guliakova

Wissenschaftliche Mitarbeiterin


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Beitrag in Sammelwerk/Tagungsband

  • A. Rychkov
  • Kuznetsov, A.
  • Anna Gulyakova
  • Dmitry Rychkov

Electret Properties of Layered Structures Based on Low Density Polyethylene Films

pg. 565-568.

IEEE

  • (2022)

DOI: 10.1109/ICD53806.2022.9863559

  • TSZ Weißenburg
  • NACHHALTIG
Zeitschriftenartikel

  • Anna Gulyakova
  • M. Galikhanov
  • X. Ma
  • X. Zhang
  • P. Fang

The Peculiarities of Electret Effect in Corona Electrets Based on Nonpolar and Polar Polymers With Dispersed Montmorillonite

In: IEEE Transactions on Dielectrics and Electrical Insulation vol. 29 pg. 840-844.

  • (2022)

DOI: 10.1109/TDEI.2022.3178093

  • TSZ Weißenburg
  • NACHHALTIG
Zeitschriftenartikel

  • A. Rychkov
  • Kuznetsov, A.
  • Anna Gulyakova
  • Dmitry Rychkov

Surface Potential Decay of Corona Charged Polyethylene Films: Influence of Deep Surface Traps

In: IEEE Transactions on Dielectrics and Electrical Insulation vol. 28 pg. 1933-1937.

  • (2021)

DOI: 10.1109/TDEI.2021.009698

Electret properties of low-density polyethylene (LDPE) films are investigated in the range of relatively low (up to 10 7 V/m) electrical fields. Thermally stimulated surface potential decay and thermally stimulated surface potential recovery reveal that LDPE films show no “cross-over” phenomenon and space charge accumulation in the polymer volume. The deepest traps with an energy of 1.1–1.2 eV are localized in the thin near-surface polymer layers. During poling (independent of the initial surface potential value), a part of the charge is captured in the deep traps that have limited concentration. Moreover, such deep traps can be filled also via the sequence of trapping and release events from the shallower traps located in the near-surface layer.
  • TSZ Weißenburg
  • Maschinenbau und Mechatronik
  • NACHHALTIG
Monographie

  • N. Anisimova
  • Y. Gorokhovatsky
  • Anna Gulyakova
  • et al.

General physics. Electricity and magnetism. Teaching package for Bachelor students [in Russian] . .

The A.I. Herzen State Pedagogical University of Russia, St. Petersburg Herzen University Publishing St. Petersburg, Russia

  • (2021)
  • TSZ Weißenburg
  • NACHHALTIG
Beitrag in Sammelwerk/Tagungsband

  • A. Rychkov
  • Kuznetsov, A.
  • Anna Gulyakova
  • Dmitry Rychkov

Surface potential decay of corona charged polyethylene films: Influence of poling time

pg. 51.

  • (2021)
  • TSZ Weißenburg
  • NACHHALTIG
Beitrag in Sammelwerk/Tagungsband

  • Anna Gulyakova
  • M. Galikhanov
  • X. Ma
  • X. Zhang
  • P. Fang

The peculiarities of electret effect in corona electrets based on nonpolar and polar polymers with dispersed montmorillonite

pg. 22.

  • (2021)
  • TSZ Weißenburg
  • NACHHALTIG
Beitrag in Sammelwerk/Tagungsband

  • Y. Gorokhovatsky
  • Anna Gulyakova
  • Y. Sotova
  • D. Temnov
  • V. Shabanov

Effect of stretching rate on charge relaxation in PVDF films

pg. 030004.

AIP Publishing

  • (2020)

DOI: 10.1063/5.0033478

  • TSZ Weißenburg
  • NACHHALTIG
Zeitschriftenartikel

  • T. Venkatesan
  • Anna Gulyakova
  • Gerhard, R.

Influence of film stretching on crystalline phases and dielectric properties of a 70/30 mol% poly(vinylidenefluoride-tetrafluoroethylene) copolymer

In: Journal of Advanced Dielectrics vol. 10 pg. 2050023.

  • (2020)

    ISSN: 2010-135X

DOI: 10.1142/S2010135X2050023X

Polyvinylidene fluoride (PVDF)-based copolymers with tetrafluoroethylene (P(VDF-TFE)), trifluoroethylene (P(VDF-TrFE)) or hexafluoropropylene (P(VDF-HFP)) are of strong interest due to the underlying fundamental mechanisms and the potential ferro-, pyro- and piezo-electrical applications. Their flexibility and their adaptability to various shapes are advantageous in comparison to inorganic ferroelectrics. Here, we study the influence of stretching temperature on the crystalline phases and the dielectric properties in P(VDF-TFE) films by means of Dielectric Relaxation Spectroscopy (DRS), Fourier-Transform InfraRed spectroscopy (FTIR), Wide-Angle X-ray Diffraction (WAXD), Differential Scanning Calorimetry (DSC) and Dynamic Mechanical Analysis (DMA). Especially, the effect of stretching and the influence of the temperature of stretching on the mid-temperature (Tmid) transition are studied in detail. The results show that stretching has a similar effect as that on PVDF, and we observe an increase in the fraction of ferroelectric β-phase with a simultaneous increment in both melting point (Tm) and crystallinity (χc) of the copolymer. While an increase in the stretching temperature does not have a profound impact on the amount of ferroelectric phase, the stability of the ferroelectric phase seems to improve — as seen in the reduction of the Full Width at Half Maximum (FWHM) of the WAXD peaks in both parallel and perpendicular directions to the molecular chain axis. The observation is also supported by the reduction of dissipation losses with an increase in stretching temperature — as seen in DRS measurements. Finally, both stretching itself and the temperature of stretching affect the various molecular processes taking place in the temperature range of the Tmid transition.
  • TSZ Weißenburg
  • NACHHALTIG
Zeitschriftenartikel

  • Anna Gulyakova
  • M. Galikhanov
  • L. Galeeva
  • S. Gilfanova
  • P. Fang

Investigation of electret and filtering properties of polypropylene-based nonwoven fabrics and its composites with 2 vol% of silicon dioxide inclusions

In: IEEE Transactions on Dielectrics and Electrical Insulation vol. 27 pg. 1656-1661.

  • (2020)

DOI: 10.1109/TDEI.2020.008454

The electret characteristics of polypropylene (PP) nonwoven fabrics processed by melt-blowing and its composites with 2 vol% of silicon dioxide (SiO 2 ) are studied in this work. The surface potential V e , effective surface charge density a ef and electric field strengths E as well as their filtration efficiency are reported. Improvement of electret properties of PP filled with SiO 2 in comparison with the samples without filler is observed. It is seen that PP samples poled in a corona discharge show lower filtration rate than the non-poled ones. The electret nonwoven fabrics with improved filtration characteristics are obtained on the basis of PP with SiO 2 inclusions.
  • TSZ Weißenburg
  • NACHHALTIG
Beitrag in Sammelwerk/Tagungsband

  • M. Wübbenhorst
  • Anna Gulyakova
  • T. Putzeys

Polarization profiles inP(VDF-TFE) copolymer films stretched at different temperatures

pg. 116.

  • (2019)
  • TSZ Weißenburg
  • NACHHALTIG
Zeitschriftenartikel

  • Anna Gulyakova
  • Y. Gorokhovatsky
  • M. Galikhanov
  • P. Fruebing

Thermoactivational spectroscopy of the high impact polystyrene based composite films

In: St. Petersburg Polytechnic University Journal, Physics and Mathematics vol. 12 pg. 9-16.

St. Petersburg State Polytechnical University Journal. Physics and Mathematics

  • 2019 (2019)

DOI: 10.18721/JPM.12401

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 (α-relaxation peak) appeared at about 93 °C and represented the glass transition. The second peak ρ was a high-temperature part of the first one and overlapped it. The ρ 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 °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.
  • TSZ Weißenburg
  • NACHHALTIG
Zeitschriftenartikel

  • T. Venkatesan
  • Anna Gulyakova
  • P. Frübing
  • Gerhard, R.

Electrical polarization phenomena, dielectric relaxations and structural transitions in a relaxor-ferroelectric terpolymer investigated with electrical probing techniques

In: Materials Research Express vol. 6 pg. 125301.

  • (2019)

DOI: 10.1088/2053-1591/ab5352

Dielectric Relaxation Spectroscopy (DRS) and Thermally Stimulated Depolarization Current (TSDC) measurements were employed to study dielectric-relaxation processes, structural transitions and electric-polarization phenomena in poly(vinylidenefluoride-trifluoroethylene-chlorofluoroethylene) (P(VDF-TrFE-CFE)) terpolymer films. Results from DRS confirm the existence of two separate dispersion regions related to a para-to-ferroelectric phase transition and to the glass transition. The dipolar TSDC peak correlates with the loss peak of the α relaxation that represents the glass transition. The electric polarization calculated from the dipolar TSDC peak (glass transition) shows a non-linear electric-field dependence and saturates at high electric poling fields. As the observed behaviour is essentially the same as that of the electric polarization obtained from direct polarization-versus-electric-field hysteresis measurements, TSDC experiments are also suitable for studying the polarization in relaxor-ferroelectric polymers. A saturation polarization of 44 mC m−2 was found for an electric field of 190 MV m−1.
  • TSZ Weißenburg
  • NACHHALTIG
Beitrag in Sammelwerk/Tagungsband

  • Anna Gulyakova
  • M. Galikhanov
  • L. Galeeva
  • S. Gilfanova
  • P. Fang

Electret and filtering properties of non-woven fabrics based on polypropylene and its composites with SiO2 inclusions

pg. 47.

  • (2019)
  • TSZ Weißenburg
  • NACHHALTIG
Beitrag in Sammelwerk/Tagungsband

  • Anna Gulyakova
  • T. Venkatesan
  • M. Wübbenhorst
  • Gerhard, R.

Influence of stretching on crystalline phases and dielectric properties of a 70/30mol % P(VDF-TFE) copolymer

pg. 102.

  • (2019)
  • TSZ Weißenburg
  • NACHHALTIG
Beitrag in Sammelwerk/Tagungsband

  • T. Venkatesan
  • Anna Gulyakova
  • P. Frubing
  • Gerhard, R.

Origin of mid-temperature range transition(s) in vinylidenefluoride-based homo-, co- and ter-polymers: Can the puzzle be solved?

pg. 69.

  • (2019)
  • TSZ Weißenburg
  • NACHHALTIG
Zeitschriftenartikel

  • Thulasinath Venkatesan
  • Anna Gulyakova
  • Peter Frubing
  • Reimund Gerhard

Relaxation processes and structural transitions in Poly(vinylidene fluoride-trifluoroethylene-chlorofluoroethylene) relaxor-ferroelectric terpolymers as seen in dielectric spectroscopy

In: IEEE Transactions on Dielectrics and Electrical Insulation vol. 25 pg. 2229-2235.

  • (2018)

DOI: 10.1109/TDEI.2018.007440

Dielectric relaxation processes and structural transitions in Poly(vinylidenefluoride-trifluoroethylene-chlorofluoroethylene) (P(VDF-TrFE-CFE)) terpolymer films with two different monomer compositions were investigated in comparison with Poly(vinylidene-fluoride-trifluoroethylene) (P(VDF-TrFE)) copolymer films as reference material. Differential Scanning Calorimetry was employed to assess annealing effects on phase transitions and crystalline structure, while relaxation processes were investigated by means of Dielectric Relaxation Spectroscopy, the results of which indicate the existence of two separate dispersion regions, denoted as processes A and B, respectively. Process A appears at a certain temperature independent of frequency, but is strongly influenced by the crystallisation temperature and the CFE content, while peak B shows typical features of a relaxation process and is less influenced by crystallisation temperature and CFE content. Furthermore, peak B is related to the glass transition which is more pronounced in the terpolymer than in P(VDF-TrFE). A closer analysis indicates that the addition of CFE and thermal annealing gradually shift the ferro-to-paraelectric transition in P(VDF-TrFE) to lower temperatures, while the phase transition is transformed more and more into a relaxation.
  • TSZ Weißenburg
  • NACHHALTIG
Monographie

  • N. Anisimova
  • Y. Gorokhovatsky
  • Anna Gulyakova
  • et al.

General physics. Physics of the atomic nucleus and elementary particles. Teaching package for Bachelor students [in Russian]

The A.I. Herzen State Pedagogical University of Russia, St. Petersburg Herzen University Publishing St. Petersburg, Russia

  • (2018)
  • TSZ Weißenburg
  • NACHHALTIG
Monographie

  • N. Anisimova
  • Y. Gorokhovatsky
  • Anna Gulyakova
  • et al.

General physics. Mechanics. Teaching package for Bachelor students [in Russian]

The A.I. Herzen State Pedagogical University of Russia, St. Petersburg Herzen University Publishing St. Petersburg, Russia

  • (2017)
  • TSZ Weißenburg
  • NACHHALTIG
Beitrag in Sammelwerk/Tagungsband

  • Anna Gulyakova
  • Y. Gorokhovatsky
  • P. Frübing
  • Gerhard, R.

Investigation of relaxation processes in P(VDF-TrFE-CFE) terpolymer films by means of thermally stimulated depolarization and dielectric relaxation spectroscopy

pg. 67.

Leuven, Belgium

  • (2017)
  • TSZ Weißenburg
  • NACHHALTIG
Beitrag in Sammelwerk/Tagungsband

  • Anna Gulyakova
  • Y. Gorokhovatsky
  • P. Frübing
  • Gerhard, R.

Dielectric relaxation and thermoactivated processes in the relaxor ferroelectric terpolymer poly(vinylidene fluoride-trifluoroethylene-chlorofluoroethylene)

pg. 73-77.

  • (2017)
  • TSZ Weißenburg
  • NACHHALTIG
Beitrag in Sammelwerk/Tagungsband

  • Anna Gulyakova
  • Y. Gorokhovatsky
  • P. Frübing
  • Gerhard, R.

Dielectric relaxation processes in the relaxor ferroelectric terpolymer poly(vinylidene fluoridetrifluoroethylene-chlorofluoroethylene)

pg. 210-212.

  • (2017)
  • TSZ Weißenburg
  • NACHHALTIG
Zeitschriftenartikel

  • Anna Gulyakova
  • Y. Gorokhovatsky
  • P. Frubing
  • Gerhard, R.

Relaxation processes determining the electret stability of high-impact polystyrene/titanium-dioxide composite films

In: IEEE Transactions on Dielectrics and Electrical Insulation vol. 24 pg. 2541-2548.

  • (2017)

DOI: 10.1109/TDEI.2017.006587

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 Ea = 1.1 eV after passing the glass transition at about 100 °C and (2) charge release from traps formed by the TiO2 particles with Ea = 2.4 eV at temperatures above 130 °C. Finally, the activation energies are discussed with respect to their significance.
  • TSZ Weißenburg
  • NACHHALTIG
Monographie

  • N. Anisimova
  • Y. Gorokhovatsky
  • Anna Gulyakova
  • et al.

General physics. Atomic physics. Teaching package for Bachelor students [in Russian]

The A.I. Herzen State Pedagogical University of Russia, St. Petersburg Herzen University Publishing St. Petersburg, Russia

  • (2016)
  • TSZ Weißenburg
  • NACHHALTIG
Zeitschriftenartikel

  • Y. Gorokhovatsky
  • Anna Gulyakova
  • P. Frübing

Electrical relaxation processes in composite polymer films based on high-impact polystyrene [in Russian]

In: Izvestiya RGPU: Scientific Journal (Herzen University Publishing, St. Petersburg, Russia) pg. 24-39.

  • (2015)
  • TSZ Weißenburg
  • NACHHALTIG
Beitrag in Sammelwerk/Tagungsband

  • Anna Gulyakova
  • P. Frübing
  • Y. Gorokhovatsky

Charge relaxation in titanium-dioxide filled high-impact polystyrene films

pg. 55.

  • (2015)
  • TSZ Weißenburg
  • NACHHALTIG
Monographie

  • M. Galikhanov
  • Y. Gorokhovatsky
  • Anna Gulyakova
  • Dmitry Rychkov
  • A. Rychkov
  • et al.

Production methods, research methods and electrophysical properties of composite polymer films [in Russian]

Fora-Print Publishing St. Petersburg, Russia

  • (2014)
  • TSZ Weißenburg
  • NACHHALTIG
Beitrag in Sammelwerk/Tagungsband

  • Anna Gulyakova
  • P. Frübing
  • Y. Gorokhovatsky

Dielectric relaxation in titanium-dioxide filled high-impact polystyrene (HIPS) films

pg. 263-266.

  • (2014)
  • TSZ Weißenburg
  • NACHHALTIG
Beitrag in Sammelwerk/Tagungsband

  • Anna Gulyakova
  • P. Frübing
  • Y. Gorokhovatsky

Relaxation processes in high-impact polystyrene films with titanium dioxide inclusions

pg. 56-59.

  • (2011)
  • TSZ Weißenburg
  • NACHHALTIG
Zeitschriftenartikel

  • Y. Gorokhovatsky
  • Anna Gulyakova

Investigation of charge relaxation in high-impact polystyrene films with titanium dioxide inclusions [in Russian]

In: Izvestiya RGPU: Scientific Journal (Herzen University Publishing, St. Petersburg, Russia) vol. 2011 pg. 25-33.

  • (2011)
  • TSZ Weißenburg
  • NACHHALTIG
Beitrag in Sammelwerk/Tagungsband

  • Anna Gulyakova
  • P. Frübing
  • Y. Gorokhovatsky

Relaxation processes and electret properties of titanium-dioxide filled high-impact polystyrene films

pg. 137-138.

IEEE Piscataway, NJ, USA

  • (2011)

DOI: 10.1109/ISE.2011.6085020

The influence of relaxation processes on electret properties of high-impact polystyrene (HIPS) free-standing films filled with titanium dioxide (TiO 2 ) of rutile modification are investigated by means of the combination of dynamic-mechanical and dielectric methods: thermally stimulated depolarization current (TSDC) measurements, thermally stimulated surface potential decay (TSSPD), dielectric relaxation spectroscopy (DRS), dynamic mechanical analysis (DMA) and differential scanning calorimetry (DSC). Films with 2, 4, 6 and 8 vol.% TiO 2 as well as the pure HIPS are compared.
  • TSZ Weißenburg
  • NACHHALTIG
Zeitschriftenartikel

  • M. Galikhanov
  • Y. Gorokhovatsky
  • Anna Gulyakova
  • et al.

Study of the electret state stability in composite polymer films with a dispersed filler [in Russian]

In: Izvestiya RGPU: Scientific Journal (Herzen University Publishing, St. Petersburg, Russia) vol. 2011 pg. 25-34.

  • (2011)
  • TSZ Weißenburg
  • NACHHALTIG