[Enhancing antibodies and supressive cells in maternal anti-fetal immune reaction].

Abstract

<p>This paper reports pure and mixed gas CO<sub>2</sub>/H<sub>2</sub> and CO<sub>2</sub>/CH<sub>4</sub> membrane separation performance of a highly permeable poly(ethylene oxide) based multi-block copolymer. Permeation and sorption properties have been studied over a wide temperature (-10°C to +35°C) and pressure range (up to 25bar partial pressure of CO<sub>2</sub>). In particular, we address the effect of plasticization by CO<sub>2</sub>. A strong dependency of CO<sub>2</sub> permeability on CO<sub>2</sub> concentration in the polymer matrix was observed in pure and mixed gas experiments. Plasticization effects increased the permeability of H<sub>2</sub> and CH<sub>4</sub> in mixed gas experiments compared to their pure gas values. The H<sub>2</sub> permeability was less influenced by plasticization than the CH<sub>4</sub> permeability due to H<sub>2</sub>'s smaller kinetic diameter. As a result, mixed gas selectivities were systematically lower than pure gas selectivities. This difference between mixed and pure gas selectivity is exclusively dependent on the CO<sub>2</sub> concentration in the polymer matrix, which can change with temperature or CO<sub>2</sub> fugacity. Remarkably, the difference between ideal selectivity and mixed gas selectivity scales linearly with the CO<sub>2</sub> concentration in the polymer for all pressures and temperatures considered.</p>