Studies on reversal permanent charges and reversal potentials via classical Poisson-Nernst-Planck systems with boundary layers

Abstract

<p style='text-indent:20px;'>We consider a one-dimensional classical Poisson-Nernst-Planck model with two ion species, one positively charged and one negatively charged, and a simple profile of nonzero permanent charges. Of particular interest is to examine the effect from boundary layers on zero-current ionic flows in terms of reversal potentials and reversal permanent charges through membrane channels. This is important because boundary layers of charge are particularly likely to create artifacts over long distances, and this could dramatically affect the behavior of ionic flows. With boundary layers, the existence of reversal potentials and reversal permanent charges is established. Particularly, the reversal potentials are further compared with those identified under electroneutrality boundary conditions, and their orders are provided, which sensitively depends on the complicated nonlinear interaction among system parameters, particularly, boundary layers, boundary concentrations and channel geometry.</p>