Structure and gas permeability of asymmetric polyimide membranes made by dry–wet phase inversion: Influence of alcohol as casting solution
Structure and gas permeability of asymmetric polyimide membranes made by dry–wet phase inversion: Influence of alcohol as casting solution
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DOI：
10.1002/polb.21290
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发表时间：
2007-10
期刊：
影响因子：
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通讯作者：
M. Mikawa;N. Seki;S. Nagaoka;H. Kawakami
中科院分区：
文献类型：
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作者：
M. Mikawa;N. Seki;S. Nagaoka;H. Kawakami
在本文中，我们报道了乙醇作为浇铸溶液对干湿相转化制备的不对称聚酰亚胺膜的结构和透气性的影响。非对称膜的表观皮层厚度随着醇分子量的增加而减小，由甲醇、乙醇、丙醇和丁醇制成的膜的厚度分别为250、120、61和31 nm。我们发现χ 12 作为溶剂-非溶剂的相互作用参数对混凝介质中发生的相转化有显着影响。另一方面，非对称膜的气体渗透性和气体选择性随着醇分子量的增加而增加。我们认为，具有更薄表面皮层的不对称聚酰亚胺膜中形成的更堆积的结构也是本研究中获得的气体选择性的厚度依赖性的原因。
In this article, we have reported the influence of alcohol as a casting solution on the structure and the gas permeability of asymmetric polyimide membranes made by dry-wet phase inversion. The apparent skin layer thickness of the asymmetric membrane decreased with an increase in molecular weight of the alcohol, and the thicknesses of the membranes made from methanol, ethanol, propanol, and butanol were 250, 120, 61, and 31 nm, respectively. We found that χ 12 as an interaction parameter of solvent-nonsolvent had a significant influence on the phase inversion occurring in the coagulant medium. On the other hand, the gas permeance and the gas selectivity in the asymmetric membranes increased with the increasing molecular weight of the alcohol. We believe that a more packed structure formed in the asymmetric polyimide membrane with a thinner surface skin layer is also responsible for the thickness-dependence of the gas selectivity obtained in this study.