Anomalous Diffusion Effects on the Electrical Impedance Response of Liquid-Crystalline Systems

Abstract

The electrical impedance response of six nematic liquid crystals samples is analyzed by means of an extension of the Poisson-Nernst-Planck diffusional model. This formulation includes fractional derivatives of distributed order governing the behavior of the bulk density of mobile charges, whose solutions are subjected to integro-differential equations accounting for the boundary conditions. The role of the intrinsic surface lengths involved in the adsorption-desorption phenomena at the electrodes is emphasized, in order to analyze the frequency dependence of the real and imaginary parts of the electrical impedance experimentally obtained.

Keywords:

• Impedance
• ionic conduction
• admittance

PACS::

• 84.37.+q
• 77.22.−d
• 66.10.Ed

Acknowledgment

This work was partially supported by the National Institutes of Science and Technology (INCT-CNPq) of Complex Systems (E. K. L.), Complex Fluids (L. R. E.).