Competitive permeation of gas and water vapour in high free volume polymeric membranes
Competitive permeation of gas and water vapour in high free volume polymeric membranes
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DOI：
10.1002/polb.23689
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发表时间：
2015-05
期刊：
影响因子：
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通讯作者：
C. Scholes;Jianyong Jin;G. Stevens;S. Kentish
中科院分区：
文献类型：
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作者：
C. Scholes;Jianyong Jin;G. Stevens;S. Kentish
研究了基于聚（1-三甲基硅基-1-丙炔）（PTMSP）和固有孔隙聚合物（PIM-1）的高渗透性玻璃状聚合物膜的吸水性、透水性以及在潮湿混合气体条件下从 N2 中分离 CO2 的性能。两种材料的吸水等温线都遵循表明微孔内多层吸附的行为，其中 PIM-1 在非常高的水活度下记录了显着的吸水量。使用考虑了这种多层效应的改进的双吸附模型对吸附等温线进行分析，使得朗缪尔亲和常数与较轻的气体比使用标准双模式方法更加一致。 PTMSP 和 PIM-1 的水渗透率与所研究的水活度相当，并且可以通过具有浓度依赖性扩散率的双模式吸附模型成功建模。还测量了两种膜的水渗透率与温度的关系，发现 PTMSP 的水渗透率在 80 °C 时最低，PIM-1 的水渗透率在 70 °C 时最低。这种温度依赖性是随着温度升高而降低两种膜中的水溶性的函数，而水扩散率的增加则抵消了这种影响。通过 PTMSP 和 PIM-1 的 CO2-N2 混合气体渗透率也通过双模式吸附理论进行了测量和建模。引入水蒸气进一步降低了二氧化碳和氮气的渗透性。测定了 PTMSP 中水的塑化电位，表明水使膜膨胀，增加了 CO2 和 N2 的扩散率，而对于 PIM-1，负电位意味着微孔中的水填充阻碍了 CO2 和 N2 通过膜的扩散。 © 2015 Wiley periodicals, Inc. J. Polym。科学，B 部分：聚合物。物理。 2015, 53, 719–728
Highly permeable glassy polymeric membranes based on poly (1‐trimethylsilyl‐1‐propyne) (PTMSP) and a polymer of intrinsic porosity (PIM‐1) were investigated for water sorption, water permeability and the separation of CO₂from N₂under humid mixed gas conditions. The water sorption isotherms for both materials followed behavior indicative of multilayer adsorption within the microvoids, with PIM‐1 registering a significant water uptake at very high water activities. Analysis of the sorption isotherms using a modified dual sorption model which accounts for such multilayer effects gave Langmuir affinity constants more consistent with lighter gases than the use of the standard dual mode approach. The water permeability through PTMSP and PIM‐1 was comparable over the water activities studied, and could be successfully modeled through a dual mode sorption model with a concentration dependent diffusivity. The water permeability through both membranes as a function of temperature was also measured, and found to be at a minimum at 80 °C for PTMSP and 70 °C for PIM‐1. This temperature dependence is a function of reducing water solubility in both membranes with increasing temperature countered by increasing water diffusivity. The CO₂‐ N₂mixed gas permeabilities through PTMSP and PIM‐1 were also measured and modeled through dual mode sorption theory. Introducing water vapour further reduced both the CO₂and N₂permeabilities. The plasticization potential of water in PTMSP was determined and indicated water swelled the membrane increasing CO₂and N₂diffusivity, while for PIM‐1 a negative potential implied that water filling of the microvoids hampered CO₂and N₂diffusion through the membrane. © 2015 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2015, 53, 719–728