Dydek_2011

Summary

Overlimiting Current in a Microchannel. E.V. Dydek, B. Zaltzman, I. Rubinstein, D.S. Deng, A. Mani and M.Z. Bazant. Physical Review Letters, 107, 2011. (URL)

Abstract

We revisit the classical problem of diffusion-limited ion transport to a membrane (or electrode) by considering the effects of charged sidewalls. Using simple mathematical models and numerical simulations, we identify three basic mechanisms for overlimiting current in a microchannel: (i) surface conduction carried by excess counterions, which dominates for very thin channels, (ii) convection by electro-osmotic flow on the sidewalls, which dominates for thicker channels, and (iii) transitions to electro-osmotic instability on the membrane end in very thick channels. These intriguing electrokinetic phenomena may find applications in biological separations, water desalination, and electrochemical energy storage.

Bibtex entry

@ARTICLE { Dydek_2011, ABSTRACT = { We revisit the classical problem of diffusion-limited ion transport to a membrane (or electrode) by considering the effects of charged sidewalls. Using simple mathematical models and numerical simulations, we identify three basic mechanisms for overlimiting current in a microchannel: (i) surface conduction carried by excess counterions, which dominates for very thin channels, (ii) convection by electro-osmotic flow on the sidewalls, which dominates for thicker channels, and (iii) transitions to electro-osmotic instability on the membrane end in very thick channels. These intriguing electrokinetic phenomena may find applications in biological separations, water desalination, and electrochemical energy storage. }, AUTHOR = { E.V. Dydek and B. Zaltzman and I. Rubinstein and D.S. Deng and A. Mani and M.Z. Bazant }, JOURNAL = { Physical Review Letters }, TITLE = { Overlimiting Current in a Microchannel }, URL = { http://link.aps.org/doi/10.1103/PhysRevLett.107.118301 }, VOLUME = { 107 }, YEAR = { 2011 }, 1 = { http://link.aps.org/doi/10.1103/PhysRevLett.107.118301 }, }