Abstract: EVA38 membrane and EVA38/Tween20 gel membranes were prepared by solvent evaporation method. The physical and chemical structures and gas permeation properties for the gel membranes were investigated as a function of Tween20 content. The results showed a good compatibility of EVA38 polymer with Tween20. With the addition of Tween20，the crystallinity and melting temperature of the membrane decreased obviously while the flexibility were improved remarkably，resulting in a dramatic increase in permeability coefficients for both CO2 and N2. Meanwhile，the ideal selectivity of CO2/N2 increased since the ethylene oxide groups in Tween20 have a strong affinity to CO2. As Tween20 loading increased from 0 to 100% (compared with the amount of EVA38)，the CO2 permeability coefficient of the gel membranes increased from 89.5 to 285 barrer，the CO2/N2 ideal selectivity increased from 14.92 to 19.13.

Key words: Tween20, gel membrane, permeation properties, gas separation membrane

摘要： 采用溶剂挥发法制备了EVA38/Tween20凝胶膜，研究了不同Tween20含量对凝胶膜物理化学结构和气体渗透性能的影响。结果表明，Tween20与EVA38具有良好的相容性。Tween20的引入降低了膜的结晶度和熔融温度，也明显改善了膜的柔顺性，因而膜的CO2和N2渗透系数显著增加。同时膜的CO2/N2选择性也增加，这可以归因于Tween20中的乙氧基团对CO2强的选择吸附作用。当Tween20添加量从0增加到100%（以EVA38质量为基准）时，凝胶膜的CO2渗透系数由EVA38膜的89.5 Barrer增加到285 Barrer，CO2/N2理想分离因子从14.92增加到19.13。

关键词: 吐温20, 凝胶膜, 渗透性能, 气体分离膜