过渡层对Pebax/PAN复合膜孔渗现象的影响研究

Effect of gutter layer on pore penetration phenomenon of Pebax/PAN composite

选用聚丙烯腈(PAN)超滤膜作底膜,以乙醇/水混合液作为Pebax的溶剂,采用浸渍涂层(dip coating)的方法制备Pebax/PAN复合膜.发现直接在PAN底膜上涂覆Pebax制备Pebax/PAN复合膜会导致涂层液的孔渗.本文借助理论模型分析孔渗深度对Pebax/PAN复合膜渗透速率的影响.研究表明,微小的孔渗深度也会对复合膜的整体气体渗透速率造成显著的影响.引入氨基硅氧烷与PDMS共混过渡层来解决孔渗问题,结果证实,引入该过渡层后,Pebax/PAN复合膜的气体渗透速率明显提高,而CO_2/N_2选择性基本保持不变.

The dip coating method was adopted to prepare Pebax/PANcomposite membrane, with polyacrylonitrile（PAN） ultrafiltration membrane as substrate and ethanol-water mixture as solvent for Pebax. It was found that Pebax/PAN composite membrane, which was prepared by coating Pebax on PAN substrate directly, would lead to the permeation of coating solution. In this paper, the effect of penetration depth on the permeation rate of Pebax/PAN composite membrane was analyzed by the theory model, and the result showed that minute penetration depth would have a great influence on the overall gas permeation rate of the Pebax/PAN composite membrane. Transition layer, which was prepared by blending amino siloxane and PDMS, was applied to address the above permeation, and the result proved that there was a significant increase of gas permeation of Pebax/PAN composite membrane and its CO2/N2 selectivity was basically stable.