Facilitated transport of oxygen in a solid Polymer membrane containing cobaltporphyrin (CoP) which carries oxygen specifically and reversibly, leads to permselectivity of oxygen against nitrogen in the membrane. The increase in concentration of the CoP carrier is expected to enhance the oxygen transport. The membranes of poly(octylmethacrylate-co-vinylimidazole) containing 0.8 ~ 10 wt% CoP were prepared, and the effects of the CoP-concentration on the transport and the diffusion constants of oxygen are studied. Although the induction period before the steady state of oxygen permeation was prolonged with the CoP concentration in the polymer membrane, the glass transition temperature (Tg) of the membrane was increased and the diffusion constants of oxygen were decreased with the CoP concentration to yield unexpected reduction of the oxygen permeation in the highly CoP loaded membrane. 相似文献
Facilitated or complexation-mediated transport of oxygen in the solid membrane containing a fixed carrier was described, by using the polymer-bound cobalt Schiff's base chelate (CoS) and cobaltporphyrin (CoP). α3 β-Substituted cobaltporphyrin derivatives were synthesized: The oxygen-binding reaction to cobalt was affected by the cavity structure on porphyrin, i.e., unbulky amido-substituted groups such as acetylamido- and acrylamido-substituents enhanced oxygen-binding and -dissociation rate constant or provided an oxygen-binding pathway. Oxygen transport through the membranes of these polymer-bound CoP derivatives was selectively augmented due to the rapid and reversible oxygen-binding. Diffusion constants via the fixed CoPs correlated to the characteristics of oxygen-binding reaction. 相似文献
Transport of molecular oxygen is facilitated in poly(butyl methacrylate) membranes containing the cobalt(II)-α,α′,α″,α′″-meso-tetrakis(o-pivalamidophenyl)porphyrin-1-methylimidazole (CoPIm) complex which forms oxygen adduct rapidly and reversibly. The facilitated transport of oxygen is studied by modifying a dual-mode transport model for gas permeation. The diffusion coefficient of oxygen via the fixed CoPIm complexes (Langmuir mode) is assumed to depend on oxygen concentration, and the modified dual-mode transport equation is described for the permeation steady state. The modified equation represents the effect of upstream oxygen pressure on the permeability. The oxygen permeation behavior through the macromolecular-metal complex membrane is discussed. 相似文献
An oxygen carrier, cobalt di-(salicylal)-3,3′-diimino-di-n-propylamine (Co(SalPr)), was added into a polycarbonate membrane for improving its oxygen/nitrogen selectivity. Both the oxygen permeability and oxygen/nitrogen selectivity increased when only 3 wt% of Co(SalPr) was added. The permeability kept increasing but the selectivity decreased when more than 3 wt% of Co(SalPr) was added. The oxygen to nitrogen solubility ratio decreased when 3 wt% of Co(SalPr) was added. Further increase in Co(SalPr) content led to an increase in oxygen/nitrogen solubility ratio. It was astonishing to know that the effect of Co(SalPr) content on the oxygen/nitrogen solubility ratio was totally opposite to that on the oxygen/nitrogen selectivity. A membrane gas transport model which combines the dual mobility model with pore model was adopted to explain the above phenomenon. The specific volume measurement implied that the pore diffusion was responsible for this behavior. The contribution of sorption-diffusion type transport was also investigated by examining the transport behavior of the 3 wt% Co(SalPr) containing membrane through which the pore diffusion is relatively low. The effect of upstream pressure on the oxygen permeability and solubility implied that the diffusivity of Henry's mode was much higher than that of Langmuir's mode. It was also found that the effects of upstream pressure and operating temperature on the oxygen/nitrogen selectivity were both in accordance with those on the Henry's mode solubility ratio. The above information suggested that in addition to the pore diffusion the ratio of Henry's mode diffusion dominated the O2/N2 separation instead of the overall O2 to N2 solubility ratio. 相似文献
Rubbery poly(organophosphazene)s were synthesized, and were combined with cobaltporphyrin (CoP) which binds molecular oxygen rapidly and reversibly. The apparent oxygen-binding equilibrium constant (Kapp) is in proportion to the physical solubility coefficient of oxygen in the polymer, although the reduced equilibrium and thermodynamic parameters are not dependent on the polymer matrix species. Diffusivity of oxygen via the fixed CoP(DC) is enhanced for poly(organophosphazene) membranes with a larger oxygen diffusion constant. Poly(organophosphazene) membranes with both a large Kapp and DC yield high oxygen permeability. 相似文献
Summary: A membrane of a cobalt tetraazaporphyrin polymer complex was prepared with a nanometer thickness and used as an oxygen‐facilitated transport membrane. Rapid and reversible oxygen binding to the cobalt tetraazaporphyrin complex with a polymeric imidazole ligand was observed at low temperature. Oxygen transport through the membrane was facilitated and a high (oxygen/nitrogen) permselectivity of 28 was obtained.
Oxygen‐facilitated transport through a cobalt tetraazaporphyrin complex‐polymer membrane of nanometer thickness. 相似文献