Berlin 2008 – wissenschaftliches Programm
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CPP: Fachverband Chemische Physik und Polymerphysik
CPP 8: POSTERS Dynamics and Diffusion
CPP 8.3: Poster
Montag, 25. Februar 2008, 16:45–19:00, Poster A
Rectification in conical nanopores: a one-dimensional Poisson-Nernst-Planck modeling — •ilona kosinska1,2, igor goychuk1, marcin kostur1, gerhard schmid1, and peter hanggi1 — 1Institut fur Physik, Augsburg, Germany — 2M. Smoluchowski Institute of Physics, Krakow, Poland
The ion current rectification is studied within a reduced 1D Poisson-Nernst-Planck (PNP) model of synthetic nanopores. A conical channel of a few nm to a few hundred of nm in diameter, and of few µm long is considered in the limit where the channel length exceeds much the Debye screening length. The rigid channel wall is assumed to be weakly charged. A one-dimensional reduction of the three-dimensional problem in terms of corresponding entropic effects is put forward.
The ion transport is described by the non-equilibrium steady-state solution of the 1D Poisson-Nernst-Planck system within a singular perturbation treatment. The analytic formula for the approximate rectification current in the lowest order perturbation theory is given.
The crucial importance of the asymmetry in the potential jumps at the pore ends on the rectification effect is demonstrated. This so constructed 1D theory is shown to describe well the experimental data in the regime of small-to-moderate electric currents.