Dissolution and diffusion of oxygen in and through poly(octyl methacrylate-co-vinylimidazole)/cobaltporphyrin complexed membranes

Baoqing Shentu, Zhixue Weng, Hiroyuki Nishide

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The dissolution and diffusion processes of oxygen in and through poly (octyl methacrylate-co-vinylimidazole)(OIm)/cobaltporphyrin complexed membranes were discussed. Facilitated oxygen transport through a polymer membrane containing meso-α , α , α , α-tetrakis(o- pivalamidophenyl) porphyrinatocobalt (CoP) as a fixed oxygen carrier was analyzed by a dual-mode transport model. It was found that CoP fixed in the solid membrane rapidly and reversibly bound with oxygen and the oxygen-binding equilibrium constants of CoP (K) was 14 mol-1 L. The oxygen absorption for the CoP-OIm membrane obeyed a Langmuir-type isotherm, while the nitrogen absorption showed a proportional increase with nitrogen pressure according to Henry's law. The physical solubility coefficient of oxygen (k D) in the polymer matrix was calculated to be 4.4 × 10 -5 cm3 (STP) cm-3 Pa-1 according to the adsorption results. Oxygen permeability coefficients (Po2) of the OIm-CoP membranes steeply increased with a decrease in the pressure difference (po2), while Po2 for the control membrane composed of inactive (oxidized) Co(III)P was small and independent of po2, indicating that the CoP carrier fixed in the membrane interacts with oxygen and facilitates oxygen transport. The facilitation factor (G) that indicates the degree of facilitated transport was 9. The ratio of the diffusion coefficient of oxygen for hopping between the fixed carriers (Dc) to the physical diffusion coefficient of oxygen through the matric polymer (DD) was 0.08.

Original languageEnglish
Pages (from-to)345-349
Number of pages5
JournalActa Polymerica Sinica
Issue number3
Publication statusPublished - 2005 Jun
Externally publishedYes



  • Cobaltporphyrin
  • Complexed Membrane
  • Diffusion
  • Dissolution
  • Poly (octyl methacrylate-co-vinylimidazole)

ASJC Scopus subject areas

  • Materials Chemistry
  • Polymers and Plastics

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