氧在甲基丙烯酸辛酯-乙烯基咪唑共聚物/钴卟啉复合膜中的溶解和扩散过程

讨论了氧在甲基丙烯酸辛酯 乙烯基咪唑共聚物 钴卟啉复合膜中的溶解和扩散过程,用二元输送模型分析了间α,α,α,α-四(邻三甲基乙酰胺苯基)钴卟啉(CoP)作为氧载体的复合膜氧输送性能.研究发现,固定在聚合物中的CoP与氧可逆地络合和解络合,其络合平衡常数K为14mol- 1 L ,根据吸附实验结果计算出氧在基体聚合物中的物理溶解度系数kD 为4 4×10 - 5cm3(STP)cm- 3Pa- 1 .聚合物 载体复合膜除了物理渗透外,氧还可通过与载体的络合和解络合而扩散,从而促进氧的输送.氧通过载体的扩散系数(DC)和通过基体聚合物的物理扩散系数(DD)的比值为0 0 8.

DISSOLUTION AND DIFFUSION OF OXYGEN IN AND THROUGHPOLY(OCTYL METHACRYLATE- co - VINYLIMIDAZOLE ) / COBALTPORPHYRIN COMPLEXED MEMBRANES

The dissolution and diffusion processes of oxygen in and through poly(octyl meth acrylate-co-vinylimidazole)(OIm)/cobaltporphyrin complexed membranes were d iscussed.Facilitated oxygen transport through a polymer membrane containing me so-α,α,α,α-tetrakis(o-pivalamidophenyl) porphyrinatocobalt ( CoP) as a fixed oxyge n carrier was analyzed by a dual-mode transport model.It was found that CoP fix e d in the solid membrane rapidly and reversibly bound with oxygen and the oxygen - binding equilibrium constants of CoP (K) was 14 mol -1L.The oxygen abso rption f or the CoP-OIm membrane obeyed a Langmuir-type isotherm,while the nitrogen abs or ption showed a proportional increase with nitrogen pressure according to Henry's law.The physical solubility coefficient of oxygen (k D) in the polymer mat rix was calculated to be 4.4×10 -5 cm3(STP) cm -3 Pa -1 according to the adsorption res ults.Oxygen permeability coefficients (P O 2) of the OIm-CoP membrane s steeply in creased with a decrease in the pressure difference (p O 2),while P O 2 for the cont rol membrane composed of inactive (oxidized) Co(Ⅲ)P was small and independe nt of p O 2,indicating that the CoP carrier fixed in the membrane intera cts with ox ygen and facilitates oxygen transport.The facilitation factor (G) that indic at es the degree of facilitated transport was 9.The ratio of the diffusion coeffici ent of oxygen for hopping between the fixed carriers (D C) to the physical diffusion coefficient of oxygen through the matric polymer (D D) was 0.08.