热致相分离法制备聚(偏氟乙烯-六氟丙烯)/离子液体凝胶膜及 气体渗透性能

采用热致相分离（TIPS）法制备p(VDF-HFP)/BMIM]PF6凝胶膜，对该膜的内部结构及机械性能进行表征，探讨了BMIM]PF6添加量对凝胶膜的CO2/N2渗透性能影响。结果表明：随着BMIM]PF6添加量的增加，p(VDF-HFP)/BMIM]PF6体系的凝胶温度逐渐降低，凝胶膜的聚合物骨架结构由致密变成疏松的球晶结构；同时BMIM]PF6的添加降低了凝胶膜的结晶度，改善了p(VDF-HFP)链段的柔韧性，因而膜的CO2和N2渗透系数显著增加，CO2/N2渗透选择性则先升高后降低；凝胶膜受扩散过程控制，当BMIM]PF6添加量（质量分数）由0增加到60%时，凝胶膜的CO2渗透性系数从0.2 Barrer增加到94.3 Barrer。

Preparation of p(VDF-HFP)/IL gel membranes by thermally induced phase separation and gas permeation performances

p(VDF-HFP)/BMIM]PF6 gel membranes were prepared by thermally induced phase separation (TIPS) process. The Internal structure and mechanical properties of the gel membranes were characterized. The effects of the BMIM]PF6 contents on gas permeation performances of the gel membranes were discussed. The results showed a gradual decrease of the gel temperature and the dense polymer backbone structure of gel membrane into loose spherulitic structure with increasing BMIM]PF6 content. Meanwhile，the presence of the BMIM]PF6 reduced the overall crystallinity，improving the flexibility of p(VDF-HFP) segment，thereby CO2 and N2 permeability coefficient of the gel membranes significantly increased，whereas the permeability selectivity of CO2/N2 showed an initial increase and then a gradual decrease. When the BMIM]PF6 content increased from 0 to 60% (wt)，the CO2 permeability coefficient improved from 0.2Barrer to 94.3 Barrer. .