Ion-specific Confined Water Dynamics in Convex Nanopores of Gemini Surfactant Lyotropic Liquid Crystals
Abstract
The impact of pore geometry and functionality on the dynamics of water nanoconfined in porous media are the subject of some debate. Here, we report the synthesis and small-angle X-ray scattering (SAXS) characterization of a series of perdeuterated gemini surfactant lyotropic liquid crystals (LLCs), in which convex, water-filled nanopores of well-defined dimensions are lined with carboxylate functionalities. Quasielastic neutron scattering (QENS) measurements of the translational water dynamics in these dicarboxylate LLC nanopores as functions of the surfactant hydration state and the charge compensating counterion (Na+, K+, NMe4+) reveal that the measured dynamics depend primarily on surfactant hydration, with an unexpected counterion dependence that varies with hydration number. We rationalize these trends in terms of a balance between counterion-water attractions and the nanopore volume excluded by the counterions. On the basis of electron density maps derived from SAXS analyses of these LLCs, we directly show that the volume excluded by the counterions depends on both their size and spatial distribution in the water-filled channels. The translational water dynamics in the convex pores of these LLCs are also slower than those reported in the concave pores of AOT reverse micelles, implying that water dynamics also depend on the nanopore curvature.
- Authors:
-
- Univ. of Wisconsin, Madison, WI (United States). Dept. of Chemistry
- Univ. of Minnesota, Minneapolis, MN (United States). Dept. of Chemical Engineering and Materials Science
- Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Chemical and Engineering Materials Division
- Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Neutron Scattering Science Division
- Univ. of Wisconsin, Madison, WI (United States). Dept. of Chemistry; Univ. of Minnesota, Minneapolis, MN (United States). Dept. of Chemical Engineering and Materials Science
- Publication Date:
- Research Org.:
- Univ. of Minnesota, Minneapolis, MN (United States); Argonne National Lab. (ANL), Argonne, IL (United States); Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
- Sponsoring Org.:
- USDOE Office of Science (SC), Basic Energy Sciences (BES); US Dept. of Defense (DOD); National Science Foundation (NSF); National Institutes of Health (NIH)
- OSTI Identifier:
- 1473701
- Grant/Contract Number:
- SC0010328; AC02-06CH11357; CHE-9974839; CHE-1048642; DMR-0832760; DMR-1121288; DMR-1420013; S10OD011952
- Resource Type:
- Accepted Manuscript
- Journal Name:
- Journal of Physical Chemistry. B, Condensed Matter, Materials, Surfaces, Interfaces and Biophysical Chemistry
- Additional Journal Information:
- Journal Volume: 122; Journal Issue: 43; Journal ID: ISSN 1520-6106
- Publisher:
- American Chemical Society
- Country of Publication:
- United States
- Language:
- English
- Subject:
- 37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY; 36 MATERIALS SCIENCE
Citation Formats
Jackson, Grayson L., Mantha, Sriteja, Kim, Sung A., Diallo, Souleymane O., Herwig, Kenneth W., Yethiraj, Arun, and Mahanthappa, Mahesh K. Ion-specific Confined Water Dynamics in Convex Nanopores of Gemini Surfactant Lyotropic Liquid Crystals. United States: N. p., 2018.
Web. doi:10.1021/acs.jpcb.8b05942.
Jackson, Grayson L., Mantha, Sriteja, Kim, Sung A., Diallo, Souleymane O., Herwig, Kenneth W., Yethiraj, Arun, & Mahanthappa, Mahesh K. Ion-specific Confined Water Dynamics in Convex Nanopores of Gemini Surfactant Lyotropic Liquid Crystals. United States. https://doi.org/10.1021/acs.jpcb.8b05942
Jackson, Grayson L., Mantha, Sriteja, Kim, Sung A., Diallo, Souleymane O., Herwig, Kenneth W., Yethiraj, Arun, and Mahanthappa, Mahesh K. Tue .
"Ion-specific Confined Water Dynamics in Convex Nanopores of Gemini Surfactant Lyotropic Liquid Crystals". United States. https://doi.org/10.1021/acs.jpcb.8b05942. https://www.osti.gov/servlets/purl/1473701.
@article{osti_1473701,
title = {Ion-specific Confined Water Dynamics in Convex Nanopores of Gemini Surfactant Lyotropic Liquid Crystals},
author = {Jackson, Grayson L. and Mantha, Sriteja and Kim, Sung A. and Diallo, Souleymane O. and Herwig, Kenneth W. and Yethiraj, Arun and Mahanthappa, Mahesh K.},
abstractNote = {The impact of pore geometry and functionality on the dynamics of water nanoconfined in porous media are the subject of some debate. Here, we report the synthesis and small-angle X-ray scattering (SAXS) characterization of a series of perdeuterated gemini surfactant lyotropic liquid crystals (LLCs), in which convex, water-filled nanopores of well-defined dimensions are lined with carboxylate functionalities. Quasielastic neutron scattering (QENS) measurements of the translational water dynamics in these dicarboxylate LLC nanopores as functions of the surfactant hydration state and the charge compensating counterion (Na+, K+, NMe4+) reveal that the measured dynamics depend primarily on surfactant hydration, with an unexpected counterion dependence that varies with hydration number. We rationalize these trends in terms of a balance between counterion-water attractions and the nanopore volume excluded by the counterions. On the basis of electron density maps derived from SAXS analyses of these LLCs, we directly show that the volume excluded by the counterions depends on both their size and spatial distribution in the water-filled channels. The translational water dynamics in the convex pores of these LLCs are also slower than those reported in the concave pores of AOT reverse micelles, implying that water dynamics also depend on the nanopore curvature.},
doi = {10.1021/acs.jpcb.8b05942},
journal = {Journal of Physical Chemistry. B, Condensed Matter, Materials, Surfaces, Interfaces and Biophysical Chemistry},
number = 43,
volume = 122,
place = {United States},
year = {2018},
month = {9}
}
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