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Title: Concentration-Polarization-Induced Precipitation and Ionic Current Oscillations with Tunable Frequency

Abstract

At the nanoscale, charges present at the surfaces of liquid–solid interfaces greatly influence the properties of ions and molecules present in the solution, and can lead to nanoscale effects such as ion selectivity, ion current rectification, and modulation of local ionic concentrations. Concentration polarization is another nanoscale phenomenon whereby ion concentrations are enriched at one opening of an ion-selective nanopore and depleted at the other. We demonstrate that when a nanopore is in contact with a weakly soluble salt present at a concentration below its solubility product, concentration polarization can lead to locally enhanced ionic concentrations and precipitation of the salt. Formed precipitates partially or fully occlude the nanopore’s opening as indicated by a measured transient decrease of the nanopore’s conductance. We have confirmed experimental conditions at which the locally created precipitate is either pushed through or dissolved, clearing the pore entrance and allowing the precipitation reaction to occur again. The dynamic process of precipitate formation and dissolution is observed as ion current fluctuations and oscillations with frequencies reaching 200 Hz. The frequency of the system operation exceeds other nanopore-based oscillators by 2 orders of magnitude, which we believe stems from the 30 nm length of the pores examined here,more » versus ~10 μm long pores reported before.« less

Authors:
 [1];  [2]; ORCiD logo [1]
  1. Univ. of California, Irvine, CA (United States); Istanbul Univ. (Turkey)
  2. Univ. of California, Irvine, CA (United States)
Publication Date:
Research Org.:
Univ. of Maryland, College Park, MD (United States). Energy Frontier Research Center (EFRC) Nanostructures for Electrical Energy Storage (NEES)
Sponsoring Org.:
USDOE Office of Science (SC), Basic Energy Sciences (BES)
OSTI Identifier:
1470234
Grant/Contract Number:  
SC0001160
Resource Type:
Journal Article: Accepted Manuscript
Journal Name:
Journal of Physical Chemistry. C
Additional Journal Information:
Journal Volume: 122; Journal Issue: 6; Related Information: NEES partners with University of Maryland (lead); University of California, Irvine; University of Florida; Los Alamos National Laboratory; Sandia National Laboratories; Yale University; Journal ID: ISSN 1932-7447
Publisher:
American Chemical Society
Country of Publication:
United States
Language:
English
Subject:
77 NANOSCIENCE AND NANOTECHNOLOGY; 37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY

Citation Formats

Acar, Elif Turker, Hinkle, Preston, and Siwy, Zuzanna S. Concentration-Polarization-Induced Precipitation and Ionic Current Oscillations with Tunable Frequency. United States: N. p., 2018. Web. doi:10.1021/acs.jpcc.7b12265.
Acar, Elif Turker, Hinkle, Preston, & Siwy, Zuzanna S. Concentration-Polarization-Induced Precipitation and Ionic Current Oscillations with Tunable Frequency. United States. https://doi.org/10.1021/acs.jpcc.7b12265
Acar, Elif Turker, Hinkle, Preston, and Siwy, Zuzanna S. Wed . "Concentration-Polarization-Induced Precipitation and Ionic Current Oscillations with Tunable Frequency". United States. https://doi.org/10.1021/acs.jpcc.7b12265. https://www.osti.gov/servlets/purl/1470234.
@article{osti_1470234,
title = {Concentration-Polarization-Induced Precipitation and Ionic Current Oscillations with Tunable Frequency},
author = {Acar, Elif Turker and Hinkle, Preston and Siwy, Zuzanna S.},
abstractNote = {At the nanoscale, charges present at the surfaces of liquid–solid interfaces greatly influence the properties of ions and molecules present in the solution, and can lead to nanoscale effects such as ion selectivity, ion current rectification, and modulation of local ionic concentrations. Concentration polarization is another nanoscale phenomenon whereby ion concentrations are enriched at one opening of an ion-selective nanopore and depleted at the other. We demonstrate that when a nanopore is in contact with a weakly soluble salt present at a concentration below its solubility product, concentration polarization can lead to locally enhanced ionic concentrations and precipitation of the salt. Formed precipitates partially or fully occlude the nanopore’s opening as indicated by a measured transient decrease of the nanopore’s conductance. We have confirmed experimental conditions at which the locally created precipitate is either pushed through or dissolved, clearing the pore entrance and allowing the precipitation reaction to occur again. The dynamic process of precipitate formation and dissolution is observed as ion current fluctuations and oscillations with frequencies reaching 200 Hz. The frequency of the system operation exceeds other nanopore-based oscillators by 2 orders of magnitude, which we believe stems from the 30 nm length of the pores examined here, versus ~10 μm long pores reported before.},
doi = {10.1021/acs.jpcc.7b12265},
url = {https://www.osti.gov/biblio/1470234}, journal = {Journal of Physical Chemistry. C},
issn = {1932-7447},
number = 6,
volume = 122,
place = {United States},
year = {2018},
month = {1}
}

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Cited by: 10 works
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