State of water in nafion 117 proton exchange membranes studied by dielectric relaxation spectroscopy

Georgios Polizos; Zijie Lu; Digby D. Macdonald; Evangelos Manias

State of water in nafion 117 proton exchange membranes studied by dielectric relaxation spectroscopy

Georgios Polizos, Zijie Lu, Digby D. Macdonald, Evangelos Manias

Research output: Chapter in Book/Report/Conference proceeding › Conference contribution

Abstract

The dynamics and the nature of water environments in a fuel cell proton exchange membrane are studied experimentally. Specifically, the dynamics of water in Nafion 117 membranes, in the acid form, were investigated at two hydration levels and several temperatures by means of dielectric relaxation spectroscopy; two different dielectric spectroscopy experimental setups were employed for low (10^-2-10⁷ Hz, 25 to -80°C) and microwave (0.045-26 GHz, 35°C) frequency ranges. Three states of water were clearly identified: (a) water strongly bound to the sulfonic groups (in quantitative agreement with previous investigations) defining the first hydration layer; (b) loosely bound water, surrounding the first layer, and (c) free water, having similar dynamics as in the bulk/liquid water. This is the first time that the dynamics of loosely bound water are experimentally observed.

Original language	English (US)
Title of host publication	Solid-State Ionics-2006
Pages	131-136
Number of pages	6
State	Published - 2007
Event	2006 MRS Fall Meeting - Boston, MA, United States Duration: Nov 27 2006 → Dec 1 2006

Publication series

Name	Materials Research Society Symposium Proceedings
Volume	972
ISSN (Print)	0272-9172

Other

Other	2006 MRS Fall Meeting
Country/Territory	United States
City	Boston, MA
Period	11/27/06 → 12/1/06

All Science Journal Classification (ASJC) codes

General Materials Science
Condensed Matter Physics
Mechanics of Materials
Mechanical Engineering

Cite this

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title = "State of water in nafion 117 proton exchange membranes studied by dielectric relaxation spectroscopy",

abstract = "The dynamics and the nature of water environments in a fuel cell proton exchange membrane are studied experimentally. Specifically, the dynamics of water in Nafion 117 membranes, in the acid form, were investigated at two hydration levels and several temperatures by means of dielectric relaxation spectroscopy; two different dielectric spectroscopy experimental setups were employed for low (10-2-107 Hz, 25 to -80°C) and microwave (0.045-26 GHz, 35°C) frequency ranges. Three states of water were clearly identified: (a) water strongly bound to the sulfonic groups (in quantitative agreement with previous investigations) defining the first hydration layer; (b) loosely bound water, surrounding the first layer, and (c) free water, having similar dynamics as in the bulk/liquid water. This is the first time that the dynamics of loosely bound water are experimentally observed.",

author = "Georgios Polizos and Zijie Lu and Macdonald, {Digby D.} and Evangelos Manias",

year = "2007",

language = "English (US)",

isbn = "1558999299",

series = "Materials Research Society Symposium Proceedings",

pages = "131--136",

booktitle = "Solid-State Ionics-2006",

note = "2006 MRS Fall Meeting ; Conference date: 27-11-2006 Through 01-12-2006",

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TY - GEN

T1 - State of water in nafion 117 proton exchange membranes studied by dielectric relaxation spectroscopy

AU - Polizos, Georgios

AU - Lu, Zijie

AU - Macdonald, Digby D.

AU - Manias, Evangelos

PY - 2007

Y1 - 2007

N2 - The dynamics and the nature of water environments in a fuel cell proton exchange membrane are studied experimentally. Specifically, the dynamics of water in Nafion 117 membranes, in the acid form, were investigated at two hydration levels and several temperatures by means of dielectric relaxation spectroscopy; two different dielectric spectroscopy experimental setups were employed for low (10-2-107 Hz, 25 to -80°C) and microwave (0.045-26 GHz, 35°C) frequency ranges. Three states of water were clearly identified: (a) water strongly bound to the sulfonic groups (in quantitative agreement with previous investigations) defining the first hydration layer; (b) loosely bound water, surrounding the first layer, and (c) free water, having similar dynamics as in the bulk/liquid water. This is the first time that the dynamics of loosely bound water are experimentally observed.

AB - The dynamics and the nature of water environments in a fuel cell proton exchange membrane are studied experimentally. Specifically, the dynamics of water in Nafion 117 membranes, in the acid form, were investigated at two hydration levels and several temperatures by means of dielectric relaxation spectroscopy; two different dielectric spectroscopy experimental setups were employed for low (10-2-107 Hz, 25 to -80°C) and microwave (0.045-26 GHz, 35°C) frequency ranges. Three states of water were clearly identified: (a) water strongly bound to the sulfonic groups (in quantitative agreement with previous investigations) defining the first hydration layer; (b) loosely bound water, surrounding the first layer, and (c) free water, having similar dynamics as in the bulk/liquid water. This is the first time that the dynamics of loosely bound water are experimentally observed.

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M3 - Conference contribution

AN - SCOPUS:34250854544

SN - 1558999299

SN - 9781558999299

T3 - Materials Research Society Symposium Proceedings

SP - 131

EP - 136

BT - Solid-State Ionics-2006

T2 - 2006 MRS Fall Meeting

Y2 - 27 November 2006 through 1 December 2006

ER -

State of water in nafion 117 proton exchange membranes studied by dielectric relaxation spectroscopy

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