کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
9587333 1393235 2005 8 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Membrane gas diffusion measurements with MRI
موضوعات مرتبط
مهندسی و علوم پایه شیمی شیمی تئوریک و عملی
پیش نمایش صفحه اول مقاله
Membrane gas diffusion measurements with MRI
چکیده انگلیسی
Gas transport across polymeric membranes is fundamental to many filtering and separation technologies. To elucidate transport mechanisms, and understand the behaviors of membrane materials, accurate measurement of transport properties is required. We report a new magnetic resonance imaging (MRI) methodology to measure membrane gas phase diffusion coefficients. The MRI challenges of low spin density and short gas phase relaxation times, especially for hydrogen gas, have been successfully overcome with a modified one-dimensional, single-point ramped imaging with T1 enhancement, measurement. We have measured the diffusion coefficients of both hydrogen gas and sulfur-hexafluoride in a model polymeric membrane of potential interest as a gas separator in metal hydride batteries. The experimental apparatus is a modified one-dimensional diaphragm cell which permits measurement of the diffusion coefficient in experimental times of less than 1 min. The H2 gas diffusion coefficient in the membrane was 0.54 ± 0.01 mm2/s, while that of sulfur-hexafluoride was 0.14 ± 0.01 mm2/s, at ambient conditions.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Journal of Magnetic Resonance - Volume 176, Issue 2, October 2005, Pages 215-222
نویسندگان
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