Chaotic Behavior of Ionic Transportation Through Synthetic Ion Channels

Abstract

Selective ion transportation through synthetic ion channels in polymeric membranes (which mimic natural systems, e.g. excitable cell membranes) is being reported through this article. The synthetic ion channels have been created by swift heavy ion irradiation of polymeric membranes followed by chemical etching. Since, the transportation of sodium and potassium ions of aqueous electrolytes through synthetic ion channels in polyethylene terephthalate depends on the electrophoretic forces present in the electrolyte; these ion channels are referred to as “voltage activated channels”. For a particular range of applied voltage, these channels behave as K-channels while they act as Na-channels in another voltage range. The channels have been found to switch between high and low conduction states referred to as opening and closing of ion channels with applied potential. A mechanism is being proposed to explain the voltage dependent ion selectivity of the channels in both closed and open states. Nonlinear dynamical analysis of ion transportation and current oscillations confirm its chaotic behavior. Their possible applications as ionic switches and ionic flip-flops are discussed.