EVA38/Tween20凝胶气体分离膜的制备及其性能

Preparation of EVA38/Tween20 gel gas separation membranes and their performances

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。

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/N2increased 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 CO2permeability coefficient of the gel membranes increased from 89.5 to 285 barrer,the CO2/N2ideal selectivity increased from 14.92 to 19.13.