Poly (ethylene-oxide) (PEO)-based membranes have attracted much attention recently for CO₂ separation because CO₂ is highly soluble into PEO and shows high selectivity over other gases such as CH₄ and N₂. Unfortunately, those membranes are not strong enough mechanically and highly crystalline, which hinders their broader applications for separation membranes. In this review discussions are made, as much in detail as possible, on the strategies to improve gas separation performance of PEO-based membranes. Some of techniques such as synthesis of graft copolymers that contain PEO, cross-linking of polymers and blending with long chains polymers contributed significantly to improvement of membrane. Incorporation of ionic liquids/nanoparticles has also been found effective. However, surface modification of nanoparticles has been done chemically or physically to enhance their compatibility with polymer matrix. As a result of all such efforts, an excellent performance, i.e., CO₂ permeability up to 200 Barrer, CO₂/N₂ selectivity up to 200 and CO₂/CH₄ selectivity up to 70, could be achieved. Another method is to introduce functional groups into PEO-based polymers which boosted CO₂ permeability up to 200 Barrer with CO₂/CH₄ selectivity between 40 and 50. The CO₂ permeability of PEO-based membranes increases, without much change in selectivity, when the length of ethylene oxide is increased.

基于聚环氧乙烷（PEO）的膜最近在CO ₂分离方面引起了广泛关注，因为CO ₂高度可溶于PEO并显示出对其他气体（例如CH ₄和N _2）的高选择性。不幸的是，这些膜的机械强度和结晶性不够强，这阻碍了它们在分离膜上的广泛应用。在这篇综述中，对改善基于PEO的膜的气体分离性能的策略进行了尽可能详细的讨论。某些技术（例如包含PEO的接枝共聚物的合成，聚合物的交联以及与长链聚合物的共混）显着改善了膜。还发现掺入离子液体/纳米颗粒是有效的。然而，已经化学或物理地对纳米颗粒进行了表面改性以增强其与聚合物基质的相容性。所有这些努力的结果是出色的性能，即高达200 Barrer，CO的CO ₂渗透性可以实现高达200的₂ / N ₂选择性和高达70的CO ₂ / CH ₄选择性。另一种方法是将官能团引入PEO基聚合物中，从而将CO ₂渗透率提高至200 Barrer，CO ₂ / CH ₄选择性在40至50之间。PEO基膜的CO ₂渗透率增加，而选择性没有太大变化，当环氧乙烷的长度增加时。