TY - JOUR
T1 - Interaction of water vapor with gamma-radiation-induced defects in proton conductive polymers
AU - Tsuchiya, B.
AU - Konishi, Y.
AU - Nagata, S.
AU - Shikama, Tatsuo
N1 - Funding Information:
This work was supported by a research grant from The MAZDA Foundation, Japan.
Copyright:
Copyright 2009 Elsevier B.V., All rights reserved.
PY - 2009/5/14
Y1 - 2009/5/14
N2 - The correlation between protonic conduction and the amount of radiation-induced defects in gamma-ray-irradiated perfluorosulfonic acid (PFSA) polymers (Aciplex-SF-1004®) has been investigated using a direct-current resistance method, transmission spectroscopy for the ultraviolet (UV) and visible (Vis) wavelength ranges and Fourier transform infrared (FTIR) spectroscopy with the attenuated total refraction (ATR) technique. The proton conductivity of the polymers, which are irradiated with a dose of up to 532 kGy under vacuum at room temperature and subsequently exposure to air, is enhanced by approximately three orders of magnitude as compared to that of the unirradiated polymer. The UV-Vis spectra of the irradiated polymers reveal the presence of fluorocarbon radicals, which increase with the irradiation dose. It is also observed in the UV-Vis and FTIR spectra that peroxy free radicals, unsaturated species (COF), and a carboxyl group (COOH) containing a carbon-oxygen double bond are formed by reactions of the fluorocarbon radicals with oxygen or water vapor in air. In addition, an increase in the hydrogen concentration is observed in the near-surface regions of the irradiated polymers by using an elastic recoil detection (ERD) technique. The production of charge carriers such as protons and oxonium ions (H3O+) by the interaction of water vapor with the activating-radiation-induced defects leads to the enhancement of the proton conductivity.
AB - The correlation between protonic conduction and the amount of radiation-induced defects in gamma-ray-irradiated perfluorosulfonic acid (PFSA) polymers (Aciplex-SF-1004®) has been investigated using a direct-current resistance method, transmission spectroscopy for the ultraviolet (UV) and visible (Vis) wavelength ranges and Fourier transform infrared (FTIR) spectroscopy with the attenuated total refraction (ATR) technique. The proton conductivity of the polymers, which are irradiated with a dose of up to 532 kGy under vacuum at room temperature and subsequently exposure to air, is enhanced by approximately three orders of magnitude as compared to that of the unirradiated polymer. The UV-Vis spectra of the irradiated polymers reveal the presence of fluorocarbon radicals, which increase with the irradiation dose. It is also observed in the UV-Vis and FTIR spectra that peroxy free radicals, unsaturated species (COF), and a carboxyl group (COOH) containing a carbon-oxygen double bond are formed by reactions of the fluorocarbon radicals with oxygen or water vapor in air. In addition, an increase in the hydrogen concentration is observed in the near-surface regions of the irradiated polymers by using an elastic recoil detection (ERD) technique. The production of charge carriers such as protons and oxonium ions (H3O+) by the interaction of water vapor with the activating-radiation-induced defects leads to the enhancement of the proton conductivity.
KW - Elastic recoil detection
KW - Gamma-ray irradiation
KW - Optical absorption
KW - Proton conductive polymers
KW - Proton conductivity
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U2 - 10.1016/j.ssi.2008.12.030
DO - 10.1016/j.ssi.2008.12.030
M3 - Article
AN - SCOPUS:67349157136
SN - 0167-2738
VL - 180
SP - 585
EP - 588
JO - Solid State Ionics
JF - Solid State Ionics
IS - 6-8
ER -