Modeling of nematic electrolyte and nonlinear electroosmosis

TL;DR

This paper develops a mathematical model of nematic electrolytes to explore nonlinear electrokinetic effects, revealing how anisotropic properties enable sustained, polarity-independent flows useful for AC-driven devices.

Contribution

It introduces a novel mathematical model based on Leslie-Ericksen theory to analyze nonlinear electroosmotic flows in nematic electrolytes, highlighting effects not previously modeled.

Findings

Good agreement with laboratory experiments

Identification of quadratic flow dependence on electric field

Demonstration of sustained flows independent of electric polarity

Abstract

We derive a mathematical model of a nematic electrolyte based on the Leslie-Ericksen theory of liquid crystal flow. Our goal is to investigate the nonlinear electrokinetic effects that occur because the nematic matrix is anisotropic, in particular, transport of ions in a direction perpendicular to the electric field as well as quadratic dependence of the induced flow velocity on the electric field. The latter effect makes it possible to generate sustained flows in the nematic electrolyte that do not reverse their direction when the polarity of the applied electric field is reversed. From a practical perspective, this enables the design of AC-driven electrophoretic and electroosmotic devices. Our study of a special flow in a thin nematic film shows a very good agreement with laboratory experiments.