Radiation Effects on the Performance of Proton Exchange Membranes in Electrochemical Cells

Abstract

Proton exchange membranes (PEMs) are being studied for tritium separation applications involving electrochemical processes. The effects of γ- and β-radiation on Nafion 112 membrane are discussed in this paper. The fluoride and sulfate release from Nafion 112 membrane increases with increase in γ-dose. Oxygen promotes the total organic carbon (TOC) release while hydrogen suppresses sulfur release. A β-radiation dose of 200 kGy from tritium causes minor damage to the membrane, comparable to the effect of γ-radiation at similar dose. The FTIR spectrum of tritium-exposed membranes is similar to that of the reference samples except for a weak peak of C=O stretch observed at 1740 cm-1. The conductivity and electrochemical performance of the tritium-exposed and reference membrane samples are not significantly different during the fuel cell and water electrolysis tests. It is believed that β-radiation is likely to attack the carbon chain in Nafion 112 membrane.