基膜热处理对复合膜气体分离性能的影响

Effects of Heating Treatment of the Membrane Abstrate on the Separation Performance of Composite Hollow Fiber Membrane

制备了用于有机蒸汽正庚烷/氮气分离的PDMS/PVDF复合膜,研究了PVDF基膜热处理温度和时间对复合膜的分离性能的影响,用XPS和SEM对PVDF基膜表面结构的变化进行了研究。结果表明,393.2K、12min热处理后的PVDF基膜表面的C-O、C=O极性官能团增加,增强了表面极性,使得PDMS活性层和PVDF基膜能够紧密结合,而且复合膜的分离性能达到最佳值。在固定测试条件下,分离因子αC7H16/N2为445.7,渗透速率JC7H16和JN2为1.9×10-7、4.26×10-10mol/(m2.s.Pa)。

The PDMS/PVDF composite hollow fiber membrane for the separation of n-heptane/nitrogen was prepared. The effects of thermal treatment temperature and time on permeability of membranes were investigated. The surface structures of the base membrane were characterized using XPS and SEM. The results show that the polar functional groups of C-O and C = O increased and the surface polarity was enhanced when the base membrane was heated at 393.2K, for 12 minutes, accordingly the active layer PDMS and the base membrane PVDF were well-knit and the performance of the composite membrane was maximized. The separation factor was 445.7, and the permeabilities of n-heptane and nitrogen were 1.9×10^-7, 4.26 × 10^-10 mol/（m^2·s·Pa）, respectively.