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Laboratory of dielectric spectroscopy

Equipment:

  • Broadband dielectric spectroscopy system including high resolution dielectric analyzer
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Parameters:

Broadband dielectric spectroscopy system (Novocontrol) including: Dielectric analyzer: high resolution ALPHA-ANB (LF range: 3·10-6 Hz - 2·107 Hz) with active head sample cell ZGS, RF impedance analyzer: Agilent E4991 (HF range: 106 Hz - 3·109 Hz), RF sample cell BDS 2100 with gold plated electrodes, low loss RF extension line BDS 2201, Software: software package WinDETA-ALL, WinTEMP, WinPLOT and WinFIT, Temperature control: in range -160°C - +400°C with QUATRO Cryosystem.

The broadband dielectric spectroscopy laboratory, equipped with two spectrometers operating in a wide range of temperatures and frequencies, is used not only to determine the typical electrical properties of various materials (e.g. permittivity, loss tangent, conductivity) but, above all, to study their molecular dynamics and transitions phases in relation to their morphology or chemical structure. Using this technique, compounds in various forms can be tested: solids (powders, layers), liquids or gels, which in chemical terms can be classified as: low-molecular organic compounds or polymers of various chemical structure and morphology, ceramics or organic-inorganic composites.

 

Contact person: Lidia Okrasa

 

Applications of modern organic materials in advanced technologies require deep understanding of the structure/property relationships. The investigation of the molecular dynamics in new materials is one of the most important approaches allowing to characterize such relationships. Molecular dynamics of polymers, especially with complex architecture (i.e. hyperbranched polymers, dendrimers, polymer networks etc.) and their composites, is dependent on the synthesis methods, processing, presence of additives and impurities, aging, etc. In the case of many polymers, oligomers and low-mass materials the main goal is to understand of mechanism of phase transitions and relaxation processes, whose analysis can give important information about the intermolecular interactions and in consequence about supramolecular structure of investigated materials.
Broadband dielectric spectroscopy is excellent tool for investigations of electrical properties and molecular dynamics of low-mass as well as polymeric materials. The electrical properties of materials depend on many parameters like frequency, temperature, time, DC bias, voltage, which thanks to this equipment can be changed in wide range.

Publications:

  • Impact of oligoether chain lengths on the relaxation processes in poly(oligo(ethylene glycol) methyl ether methacrylate) networks that are synthesized by radiation-induced crosslinking polymerization (2020) https://doi.org/10.1016/j.jpcs.2020.109359
  • Effect of metal-ligand coordination complexes on molecular dynamics and structure of cross-linked poly(dimethylosiloxane) (2020) https://doi.org/10.3390/polym12081680
  • Influence of the La3+, Eu3+, and Er3+ Doping on Structural, Optical, and Electrical Properties of BiFeO3 Nanoparticles Synthesized by Microwave-Assisted Solution Combustion Method (2019) https://doi.org/10.1155/2019/5394325
  • Effect of zinc oxide modified silica particles on the molecular dynamics of carboxylated acrylonitrile-butadiene rubber composites (2017) https://doi.org/10.3390/polym9120645
  • Dielectric properties and characterisation of titanium dioxide obtained by different chemistry methods (2014) https://doi.org/10.1155/2014/124814
  • Impact of oligoether chain lengths on the relaxation processes in poly(oligo(ethylene glycol) methyl ether methacrylate) networks that are synthesized by radiation-induced crosslinking polymerization – A. Czaderna-Lekka, K. Piechocki, M. Kozanecki, L. Okrasa – J. Phys. Chem. Sol. 140, 109359 (2020)
  • Molecular dynamics of perfluoropolyethers with medium-low molecular weight; L. Okrasa, S. Karolczak; Journal of Non-Crystalline Solids, (2010)
    Thermal and electrical properties of copoly(1,3,4-oxadiazole-ether)s containing fluorene groups; C. Hamciuc, E. Hamciuc, A. M. Ipate, M. Cristea, L. Okrasa; J. Appl. Polym. Sci. 113 (2009) 383 - 391
  • Molecular dynamics in polyester- or polyether-urethane networks based on different diisocyanates; L. Okrasa, P. Czech, G. Boiteux, F. Méchin, J. Ulanski; Polymer 49 (2008) 2662-2668
  • Molecular relaxations in radiationally crosslinked poly(vinyl methyl ether) hydrogels; M. Pastorczak, S. Kadlubowska, L. Okrasa, M. Kozanecki, G. Boiteux, J. Rosiak, J. Ulanski; Journal of Non-Crystalline Solids 353 (2007) 4536-4540
  • Physical aging and structural recovery of polystyrene as seen by relaxational and low-frequency vibrational spectroscopy; A. Wypych, E. Duval, G. Boiteux, J. Ulanski, L. David, G. Seytre, A. Mermet, I. Stevenson, M. Kozanecki, L. Okrasa; Journal of Non-Crystalline Solids 351 (2005) 2593-2598
  • Liquid crystalline (cyanoethylpropyl)cellulose and its optically anisotropic composites with acrylic polymers; L. Okrasa, J. Ulanski, G. Boiteux; Polymer 43 (2002) 2417-2424