The presented contribution is centred on the area of condensed matter physics for investigation of the structure, dynamics, and macroscopic behaviour of materials which can be characterized as complex liquids (CL). CL is a very broad and general class of materials that include associated liquids, polymers, biomolecules, colloids, etc.) CL involves the appearance of a new ("mesoscopic") length scale, intermediate between molecular and macroscopic. The complete characterization of these relaxation behaviours requires the use of variety techniques in order to span the relevant ranges in frequency. To obtain this information, non-invasive methods such as Dielectric Spectroscopy (DS) are very advantageous. The unique technique with wide frequency (10-5 - 1012 Hz) and temperature (-170 °C +300 °C) ranges of that method is more then any others appropriate for such different scales of molecular motions.

The experimental results obtained by dielectric spectroscopy for complex liquids (microemulsions, lyposomes, cell suspensions etc.) with different level of dc conductivity are studied. Dynamic behavior at mesoscale in the vicinity to the percolation threshold was described in terms of two fractal models
a. Recursive fractal model
b. Statistical fractal model
The scaling in frequency and time domain allowed the construction of time - space models and the elaboration of the relationships for structural and dynamical properties at the mesoscale

 

Figure 2. Three-dimensional plots of the frequency and temperature dependence of the dielectric permittivity ε’ (a) and the three-dimensional plot of experimental dipole correlation function versus time and temperature (b). The dipole  correlation function (DCF);  The percolation threshold temperature Tp= 26.5°C