Measurement of water content in polymer electrolyte membranes using high resolution neutron imaging [electronic resource]

• Ngôn ngữ: eng
• Ký hiệu phân loại: 541.39 Chemical reactions
• Thông tin xuất bản: Los Alamos, N.M. : Oak Ridge, Tenn. : Los Alamos National Laboratory ; Distributed by the Office of Scientific and Technical Information, U.S. Dept. of Energy, 2010
• Mô tả vật lý: Medium: ED : , digital, PDF file.
• Bộ sưu tập: Metadata
• ID: 257025
• Chủ đề: 1. 30; 2. Diffusion; 3. Electrolytes; 4. Et al; 5. Fuel cells; 6. Hydration; 7. Ionic conductivity; 8. Membranes; 9. Neutron detectors; 10. Neutrons; 11. Polymers

Tóm tắt

Sufficient water content within a polymer electrolyte membrane (PEM) is necessary for adequate ionic conductivity. Membrane hydration is therefore a fundamental requirement for fuel cell operation. The hydration state of the membrane affects the water transport within, as both the diffusion coefficient and electro-osmotic drag depend on the water content. Membrane's water uptake is conventionally measured ex situ by weighing free-swelling samples equilibrated at controlled water activity. In the present study, water profiles in Nafion{reg_sign} membranes were measured using the high-resolution neutron imaging. The state-of-the-art, 10 {micro}m resolution neutron detector is capable of resolving water distributions across N1120, N1110 and N117 membranes. It provides a means to measure the water uptake and transport properties of fuel cell membranes in situ.