Abstract The high-pressure permeation and sorption behavior of supercritical carbon dioxide (sc-CO2) in glassy Matrimid® 5218 polymer membranes were extensively investigated. The effect of pressure (0–120 bar) and temperature (25–55 °C) was examined. The observations were related to the intrinsic membrane properties, plasticization phenomena and the CO2 fluid properties. The phase transition from gaseous (-like sc) CO2 to liquid (-like sc) CO2 has the largest influence on the CO2 fluid properties and therefore was found to have the most influence on the CO2 sorption and CO2 permeability. The CO2 sorption was directly dependent on the CO2 density in the liquid (-like sc) regime. The CO2 permeability of Matrimid® 5218 showed typical CO2-induced plasticization behavior in the gaseous (-like sc) CO2 regime. When entering the liquid (-like sc) CO2 regime, the extent of plasticization was found to be independent of the applied feed pressure in this regime. The membranes showed strong hysteresis with pressure. The permeation history of the membrane thus has a large influence on the time-dependent permeability behavior. Clearly, the CO2 permeability behavior at these high pressures in glassy Matrimid® 5218 is determined by a combination of the CO2 fluid density and plasticization phenomena.

中文翻译：

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玻璃状聚酰亚胺膜中的超临界 CO2 渗透

摘要 对超临界二氧化碳 (sc-CO2) 在玻璃质 Matrimid® 5218 聚合物膜中的高压渗透和吸附行为进行了广泛研究。检查了压力（0–120 bar）和温度（25–55 °C）的影响。观察结果与固有的膜特性、塑化现象和 CO2 流体特性有关。从气态 (-like sc) CO2 到液态 (-like sc) CO2 的相变对 CO2 流体性质的影响最大，因此发现对 CO2 吸附和 CO2 渗透率的影响最大。CO 2 吸附直接取决于液体（类似sc）状态中的CO 2 密度。Matrimid® 5218 的 CO2 渗透性在气态（类 sc）CO2 状态下显示出典型的 CO2 诱导的塑化行为。当进入液态（类似 sc）CO2 状态时，发现塑化程度与该状态下施加的进料压力无关。膜显示出强烈的压力滞后。因此，膜的渗透历史对随时间变化的渗透行为有很大影响。显然，玻璃质 Matrimid® 5218 在这些高压下的 CO2 渗透行为是由 CO2 流体密度和塑化现象的组合决定的。