Research Note pubs.acs.org/IECR
Reversible and Selective O2 Binding Using a New Thermoresponsive Cobalt(II)-Based Ionic Liquid Yuki Kohno,†,‡,§ Matthew G. Cowan,†,‡ Akiyoshi Okafuji,§,∇ Hiroyuki Ohno,§,∇ Douglas L. Gin,*,†,‡ and Richard D. Noble*,† †
Department of Chemical & Biological Engineering, and ‡Department of Chemistry & Biochemistry, University of Colorado, Boulder, Colorado 80309, United States § Functional Ionic Liquid Laboratories (FILL), Graduate School of Engineering, and ∇Department of Biotechnology, Tokyo University of Agriculture and Technology, Naka-cho, Koganei, Tokyo 184-8588, Japan S Supporting Information *
ABSTRACT: A new cobalt(II)-based metal-containing ionic liquid (MCIL), 1, has been prepared that reversibly and selectively absorbs O2 with an associated colorimetric change. This MCIL was impregnated into a porous PTFE polymer support, and the resulting supported membranes show higher O2 sorption over N2 with increasing loading levels of 1. The O2/N2 selectivity of these 1-impregnated membranes was determined to be as high as 26 ± 8 at 25 °C when ∼0.9 bar of feed gas pressure was applied. The absorbed O2 can be removed by moderate heating of the samples from 25 °C to 60 °C in vacuo. The high level of O2 sorption in these 1-impregnated membranes was maintained for at least five successive sorption/desorption cycles.
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Recently, ionic liquids (ILs, i.e., molten salts at ambient pressure and temperatures of
