Dependence of Potential and Ion Distribution on Electrokinetic Radius in Infinite and Finite-length Nano-channels

J. Schiffbauer[1], J. Fernandez[2], W. Booth[1], K. Kelly[3], A. Timperman[3], and B. Edwards[1]
[1]Physics Dept. West Virginia University, Morgantown, WV, USA
[2]Chemical Engineering Dept,West Virginia University, Morgantown, WV, USA
[3]Dept. of Chemistry, West Virginia University, Morgantown, WV, USA
Published in 2008

A site-binding/dissociation model is used to determine surface charge in numerical studies of the equilibrium potential and ion distributions inside infinite and finite-length nano-channels. This COMSOL model allows us to investigate the response of surface (zeta) potential to environmental parameters such as reservoir salt concentration, solution pH and wall separation. The resulting ion and potential distributions in the electric double-layer (EDL) are used to calculate near-equilibrium charge and fluid transport through a nano-channel, demonstrating the possibility of flow-reversal at low salt concentration.

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