Kinetics and thermodynamics across single-file pores: solute permeability and rectified osmosis

We study the effects of solute interactions on osmotic transport through pores. By extending single-file, single-species kinetic models to include entrance of solute into membrane pores, we model the statistical mechanics of competitive transport of two species across membrane pores. The results have direct applications to water transport across biomembrane pores and particle movement in zeolites, and can be extended to study ion channel transport. Reflection coefficients, the reduction of osmotic fluxes measured using different solutes, are computed in terms of the microscopic kinetic parameters. We find that a reduction in solvent flow due to solute-pore interactions can be modelled by a Langmuir adsorption isotherm. Osmosis experiments are discussed and proposed. Special cases and Onsager relations are presented in the Appendices.Comment: 15pp, 9 .eps figures. Accepted to J. Chem. Phys. 199

Interparticle gap distributions on one-dimensional lattices

We analyse the successive binding of two species of particles on a one-dimensional discrete lattice, where the second variety is deposited only after complete adsorption of the first. We consider the two extreme cases of a perfectly irreversible initial deposition, with non-sliding particles, and that of a fully equilibrated one. For the latter we construct the exact gap distribution from the Tonks gas partition function. This distribution is contrasted with that obtained from the random sequential adsorption process. We discuss implications for the kinetics of adsorption of the second species, as well as experimental relevance of our results