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On the Physics of Size Selectivity

Roland Roth·Dirk Gillespie
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Abstract

We demonstrate that two mechanisms used by biological ion channels to select particles by size are driven by entropy. With uncharged particles in an infinite cylinder, we show that a channel that attracts particles is small-particle selective and that a channel that repels water from the wall is large-particle selective. Comparing against extensive density-functional theory calculations of our model, we find that the main physics can be understood with surprisingly simple bulk models that neglect the confining geometry of the channel completely.

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Roland Roth, Dirk Gillespie. 2005-11-07. On the Physics of Size Selectivity. https://doi.org/10.1103/physrevlett.95.247801

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