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Title: Proton Diffusion through Bilayer Pores

The transport of protons through channels in complex environments is important in biology and materials science. In this work, we use multistate empirical valence bond simulations to study proton transport within a well-defined bilayer pore in a lamellar L β phase lyotropic liquid crystal (LLC). The LLC is formed from the self-assembly of dicarboxylate gemini surfactants in water, and a bilayer-spanning pore of radius of approximately 3–5 Å results from the uneven partitioning of surfactants between the two leaflets of the lamella. Local proton diffusion within the pore is significantly faster than diffusion at the bilayer surface, which is due to the greater hydrophobicity of the surfactant/water interface within the pore. Proton diffusion proceeds by surface transport along exposed hydrophobic pockets at the surfactant/water interface and depends on the continuity of hydronium–water hydrogen bond networks. At the bilayer surface, there is a reduced fraction of the “Zundel” intermediates that are central to the Grotthuss transport mechanism, whereas the fraction of these species within the bilayer pore is similar to that in bulk water. Our results demonstrate that the chemical nature of the confining interface, in addition to confinement length scale, is an important determiner of local proton transport in nanoconfinedmore » aqueous environments.« less
Authors:
ORCiD logo [1] ; ORCiD logo [1]
  1. Univ. of Wisconsin, Madison, WI (United States). Dept. of Chemistry
Publication Date:
Grant/Contract Number:
SC0010328; CHE-0840494; TG-CHE090065
Type:
Accepted Manuscript
Journal Name:
Journal of Physical Chemistry. B, Condensed Matter, Materials, Surfaces, Interfaces and Biophysical Chemistry
Additional Journal Information:
Journal Volume: 121; Journal Issue: 39; Journal ID: ISSN 1520-6106
Publisher:
American Chemical Society
Research Org:
Univ. of Wisconsin, Madison, WI (United States)
Sponsoring Org:
USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22)
Contributing Orgs:
Center for High Throughput Computing (CHTC) at the University of Wisconsin and Extreme Science and Engineering Discovery Environment (XSEDE)
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; 59 BASIC BIOLOGICAL SCIENCES
OSTI Identifier:
1433958

McDaniel, Jesse G., and Yethiraj, Arun. Proton Diffusion through Bilayer Pores. United States: N. p., Web. doi:10.1021/acs.jpcb.7b07780.
McDaniel, Jesse G., & Yethiraj, Arun. Proton Diffusion through Bilayer Pores. United States. doi:10.1021/acs.jpcb.7b07780.
McDaniel, Jesse G., and Yethiraj, Arun. 2017. "Proton Diffusion through Bilayer Pores". United States. doi:10.1021/acs.jpcb.7b07780. https://www.osti.gov/servlets/purl/1433958.
@article{osti_1433958,
title = {Proton Diffusion through Bilayer Pores},
author = {McDaniel, Jesse G. and Yethiraj, Arun},
abstractNote = {The transport of protons through channels in complex environments is important in biology and materials science. In this work, we use multistate empirical valence bond simulations to study proton transport within a well-defined bilayer pore in a lamellar Lβ phase lyotropic liquid crystal (LLC). The LLC is formed from the self-assembly of dicarboxylate gemini surfactants in water, and a bilayer-spanning pore of radius of approximately 3–5 Å results from the uneven partitioning of surfactants between the two leaflets of the lamella. Local proton diffusion within the pore is significantly faster than diffusion at the bilayer surface, which is due to the greater hydrophobicity of the surfactant/water interface within the pore. Proton diffusion proceeds by surface transport along exposed hydrophobic pockets at the surfactant/water interface and depends on the continuity of hydronium–water hydrogen bond networks. At the bilayer surface, there is a reduced fraction of the “Zundel” intermediates that are central to the Grotthuss transport mechanism, whereas the fraction of these species within the bilayer pore is similar to that in bulk water. Our results demonstrate that the chemical nature of the confining interface, in addition to confinement length scale, is an important determiner of local proton transport in nanoconfined aqueous environments.},
doi = {10.1021/acs.jpcb.7b07780},
journal = {Journal of Physical Chemistry. B, Condensed Matter, Materials, Surfaces, Interfaces and Biophysical Chemistry},
number = 39,
volume = 121,
place = {United States},
year = {2017},
month = {9}
}