TY - JOUR
T1 - Facilitated transport of molecular oxygen in cobalt-chelated copolymer membranes prepared by soap-free emulsion polymerization
AU - Wang, Cheng Chien
AU - Cheng, Mu Han
AU - Chen, Chuh Yean
AU - Chen, Chuh Yung
N1 - Funding Information:
The authors would like to thank the National Science Council of the Republic of China for financially supporting this research under Contract No. NSC89-2216-E-041-006
Copyright:
Copyright 2008 Elsevier B.V., All rights reserved.
PY - 2002/10/1
Y1 - 2002/10/1
N2 - Selectivity sorption and permeation of molecular oxygen are described for 2-methylacrylic acid 3-(bis-carboxymethylamino)-2-hydroxy-propyl ester cobalt(II) coordinated with rubbery copolymer membranes. Rubbery copolymers with different highly chelating group contents are prepared by using soap-free emulsion copolymerization. Amounts of cobalt(II) ion adsorbed by the rubbery copolymer membranes are in the range of 0.7-2.0wt.%, in other words, cobalt(II)-complex contents in membranes are up to ca. 12wt.%. The cobalt(II)-complex in membranes is a kind of highly oxygen-affinity material as well as rapid and reversible oxygen adsorption/desorption behavior showing. IR results of the oxygen-binding cobalt(II)-complexes show evidence for formation of mononuclear superoxo complexes. Sorption isotherms of oxygen for the membranes are analyzed with a dual-mode sorption model to give CC′ (the saturated amount of oxygen reversibly bound to the cobalt(II) sorption site) and K (the oxygen-affinity constant of cobalt(II)-complex). The oxygen permeability of the membrane containing cobalt(II)-complex increased with decreasing upstream oxygen pressure, which is in accordance with a dual-mode transport model. Moreover, the oxygen permeability/selectivity combinations are above and to the right of the "upper bound" line as the cobalt(II) contained as much as 1.7wt.% (cobalt(II)-complex 12.3wt.%) in membrane under high upstream oxygen pressure (Pu≤2atm), however, the best oxygen permeability and selectivity combinations in this study are as high as 11.2/10.3 under Pu=0.5atm, respectively.
AB - Selectivity sorption and permeation of molecular oxygen are described for 2-methylacrylic acid 3-(bis-carboxymethylamino)-2-hydroxy-propyl ester cobalt(II) coordinated with rubbery copolymer membranes. Rubbery copolymers with different highly chelating group contents are prepared by using soap-free emulsion copolymerization. Amounts of cobalt(II) ion adsorbed by the rubbery copolymer membranes are in the range of 0.7-2.0wt.%, in other words, cobalt(II)-complex contents in membranes are up to ca. 12wt.%. The cobalt(II)-complex in membranes is a kind of highly oxygen-affinity material as well as rapid and reversible oxygen adsorption/desorption behavior showing. IR results of the oxygen-binding cobalt(II)-complexes show evidence for formation of mononuclear superoxo complexes. Sorption isotherms of oxygen for the membranes are analyzed with a dual-mode sorption model to give CC′ (the saturated amount of oxygen reversibly bound to the cobalt(II) sorption site) and K (the oxygen-affinity constant of cobalt(II)-complex). The oxygen permeability of the membrane containing cobalt(II)-complex increased with decreasing upstream oxygen pressure, which is in accordance with a dual-mode transport model. Moreover, the oxygen permeability/selectivity combinations are above and to the right of the "upper bound" line as the cobalt(II) contained as much as 1.7wt.% (cobalt(II)-complex 12.3wt.%) in membrane under high upstream oxygen pressure (Pu≤2atm), however, the best oxygen permeability and selectivity combinations in this study are as high as 11.2/10.3 under Pu=0.5atm, respectively.
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U2 - 10.1016/S0376-7388(02)00205-3
DO - 10.1016/S0376-7388(02)00205-3
M3 - Article
AN - SCOPUS:0036808975
SN - 0376-7388
VL - 208
SP - 133
EP - 145
JO - Journal of Membrane Science
JF - Journal of Membrane Science
IS - 1-2
ER -