Roberta R. Ribeiro de Almeida, Flávio S. Michels, V. Steffen, Ervin K. Lenzi, Rafael S. Zola e Luiz R. Evangelista

CHEMICAL PHYSICS LETTERS – Volume: 588; Pages: 87-90; DOI: 10.1016/j.cplett.2013.09.06

The electrical current profile in a liquid sample containing ionic impurities, submitted to a time-depen-dent external voltage, is determined in the framework of the Poisson–Nernst–Planck (PNP) diffusionalmodel. The boundary conditions at the limiting electrodes include the situations of blocking electrodes,generalized Chang–Jaffé (specific adsorption), and the adsorption–desorption of positive and negativeions at the interface, governed by a kinetic equation in the Langmuir’s approximation. The current–volt-age characteristics of the confined system are obtained in the presence of an arbitrary time-dependentapplied potential of small amplitude (linear approximation). The calculations are potentially useful formodeling and interpreting experimental situations found in biological cells and liquid crystals samples.