Projects / Programmes
Dielectric Spectroscopy of Electroactive Polymer Composites
| Code |
Science |
Field |
Subfield |
| 1.02.00 |
Natural sciences and mathematics |
Physics |
|
| Code |
Science |
Field |
| P190 |
Natural sciences and mathematics |
Mathematical and general theoretical physics, classical mechanics, quantum mechanics, relativity, gravitation, statistical physics, thermodynamics |
| P250 |
Natural sciences and mathematics |
Condensed matter: structure, thermal and mechanical properties, crystallography, phase equilibria |
| P260 |
Natural sciences and mathematics |
Condensed matter: electronic structure, electrical, magnetic and optical properties, supraconductors, magnetic resonance, relaxation, spectroscopy |
dielectric spectroscopy, polymer, composite, relaxor, ferroelectric
Researchers (3)
| no. |
Code |
Name and surname |
Research area |
Role |
Period |
No. of publicationsNo. of publications |
| 1. |
15644 |
PhD Vid Bobnar |
Physics |
Head |
2004 - 2007 |
362 |
| 2. |
04347 |
PhD Cene Filipič |
Physics |
Researcher |
2004 - 2007 |
289 |
| 3. |
00199 |
PhD Adrijan Levstik |
Physics |
Researcher |
2004 - 2007 |
372 |
Organisations (1)
| no. |
Code |
Research organisation |
City |
Registration number |
No. of publicationsNo. of publications |
| 1. |
0106 |
Jožef Stefan Institute |
Ljubljana |
5051606000 |
90,742 |
Abstract
Dielectric spectroscopy is one of the basic experimental methods for studying the static and dynamic properties of relaxors, which exhibit large values of piezoelectric and dielectric constants in a broad temperature range. The fact that, contrary to inorganic systems, P(VDF-TrFE) copolymer-based organic relaxors can be easily prepared in a variety of shapes, makes them a very promising material for numerous applications.
Although electromechanical response of organic relaxors is much larger than that of inorganic, the dielectric constant of polymers is typically much smaller. As the input electric energy that can be converted into strain energy is proportional to the dielectric constant, high electric fields are required for the electromechanical operation of polymers. Therefore a big effort is put into the synthesis of new polymer-based materials with large dielectric constant.
We will investigate the linear and nonlinear dielectric response in polymer composites, where materials with high dielectric constant (relaxor ceramics, large organic molecules such as copper-phthalocyanine (CuPc)) or conductive particles (polyaniline, metals), which also enlarge the net dielectric constant, are embedded into the polymer matrix. As there is no chemical reaction between the admixture and the matrix, composites retain the electromechanical response of the polymer. Experimental results will reveal whether dielectric dynamics in composites is similar to those in relaxors and dipolar glasses, as well as how constituents contribute to the net properties of composites.
Relaxor-like polymer composites are the first materials with large simultaneous electromechanical and dielectric response. Dielectric investigations therefore seem to be very interesting as from the experimental as well as from the theoretical point of view. For the basic research, CuPc-polymer composite is particularly interesting. Here, completely delocalized electrons can move over large CuPc molecules, thus acting very much like dipoles, while hopping between separated localized states governs very interesting conductive properties.
Experimental results should reveal the microscopic origin of large electromechanical and dielectric response of these systems, which should result in their optimization and synthesis of new polymer-based composites.
