Kinetics of nanopore transport

TL;DR

This paper presents a nonlinear kinetic model to analyze osmosis and flow through nanopores, revealing flux maxima and deriving temperature-dependent permeabilities consistent with experiments.

Contribution

It introduces a nonlinear kinetic exclusion model for nanopore transport, providing new insights into flux behavior and temperature dependence in single-file pores.

Findings

Identification of two flux maxima as a function of pore affinity.

Derivation of Arrhenius temperature dependences for transport rates.

Transport rates align with experimental data.

Abstract

A nonlinear kinetic exclusion model is used to study osmosis and pressure driven flows through nearly single file pores such as antibiotic channels, aquaporins, zeolites and nanotubules. Two possible maxima in the steady state flux as a function of pore-solvent affinity are found. For small driving forces, the linear macroscopic osmotic and hydraulic permeabilities $P_{os}$ and $L_{p}$, are defined in terms of microscopic kinetic parameters. The dependences of the flux on activation energies, pore length and radius, and driving forces are explored and Arrhenius temperature dependences derived. Reasonable values for the physical parameters used in the analyses yield transport rates consistent with experimental measurements. Experimental consequences and interpretations are examined, and a straightforward extension to osmosis through disordered pores is given.