A recently introduced real-space lattice methodology for solving the three-dimensional Poisson-Nernst-Planck equations is used to compute current-voltage relations for ion permeation through the gramicidin A ion channel embedded in membranes characterized by surface dipoles and/or surface charge. Comparisons to a variety of experimental results, presented herein, have proven largely successful....

We consider a one-dimensional steady-state Poisson-Nernst-Planck type model for ionic flow through membrane channels. Improving the classical Poisson-Nernst-Planck models where ion species are treated as point charges, this model includes ionic interaction due to finite sizes of ion species modeled by hard sphere potential from the Density Functional Theory. The resulting problem is a singularl...

High surface charges of polymer pore walls and applied electric fields can lead to the formation and subsequent dissolution of precipitates in nanopores. These precipitates block the pore, leading to current fluctuations. We present an extended Poisson-Nernst-Planck system which includes chemical reactions of precipitation and dissolution. We discuss the mathematical modeling and present 2D num...

A number of studies have shown that an electropotential difference, PD, of about 100 mv (interior negative), is present across plant cell membranes (2, 3, 7, 8, 10, 11, 13, 21), similar to that across animal celtl membranes. Thus, if minerals move through cell membranes as ions, they are subject not only to concentration gradients but also to electrical fields. For precise evaluation of the ene...