Ellipsopermeation - On the interplay of swelling and permeation of polymers with intrisicmicroporosity

椭圆渗透 - 具有固有微孔性的聚合物溶胀和渗透的相互作用

• 批准号: 397270430
• 负责人: Professor Dr.-Ing. Matthias Wessling
• 金额: --
• 依托单位: Lehrstuhl für Chemische Verfahrenstechnik (CVT)
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2017
• 资助国家: 德国
• 起止时间: 2016-12-31 至 2021-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/397270430?language=en
• 关键词: Ellipsopermeation; interplay; swelling; permeation; polymers

Polymer membranes have demonstrated over the past decades to be very valuable assets in separating molecular gas mixtures such as air, natural gas, biogas, ammonia reactor off-gas and propylene from drying of polypropylene. Classically, only few polymers are used in such membranes; they all work according to the solution-diffusion mechanism combining a dissolution of the permeating gas into the membrane material and subsequent diffusion into the direction of lower chemical potential. Currently, a new class of polymers with exceptional inverse selective properties emerges for gas separation applications: Polymers with Intrinsic Microporosity (PIM). They have remarkable mixed gas permeation properties as (a) they are glassy and (b) they permeate the larger species selectively over small inert gas molecules. The latter is coined inverse-selective. Their transport mechanism in gas mixtures however is very little explored nor understood. We propose to perform first-of-a-kind permeation experiments on such PIMs with varying feed and permeate gas activity while measuring simultaneously the swelling behaviour of the PIMs with in-situ ellipsometry. Our unique experimental system allows for unprecedented experimental analysis of the transport behaviour under controlled vapor gradients. Also, the PIM experiments will be compared to the most ideal membrane material silicone rubber (PDMS). For the first time ever, the experimental results will give fundamental insight into mass transport details of swollen PDMS and PIM membranes while measuring simultaneously the swelling degree. This rigorous experimental approach will shed light on long standing question to what extend permeate and feed activity and its corresponding concentration gradient affects the underlying mass transport phenomena in an ideal material such as PDMS as well as much more complex materials such as polymers with intrinsic porosity.

在过去的几十年中，聚合物膜已被证明是从聚丙烯干燥中分离分子气体混合物如空气、天然气、沼气、氨反应器废气和丙烯的非常有价值的资产。 传统上，在这种膜中仅使用少数聚合物;它们都根据溶解-扩散机制工作，该机制结合了渗透气体溶解到膜材料中以及随后扩散到较低化学势的方向。目前，一类新的聚合物具有特殊的反选择性的气体分离应用出现：聚合物与固有微孔（PIM）。它们具有显著的混合气体渗透性能，因为（a）它们是玻璃状的和（B）它们选择性地渗透较大的物质而不是小的惰性气体分子。后者被称为逆选择性。 然而，它们在气体混合物中的传输机制很少被探索或理解。我们建议进行第一个的一类渗透实验，这样的PIM与不同的进料和渗透气体的活动，同时测量的PIM的溶胀行为与原位椭圆偏振法。 我们独特的实验系统允许在受控蒸汽梯度下对传输行为进行前所未有的实验分析。 此外，PIM实验将与最理想的膜材料硅橡胶（PDMS）进行比较。有史以来第一次，实验结果将给出基本的洞察到溶胀PDMS和PIM膜的传质细节，同时测量溶胀度。这种严格的实验方法将阐明长期存在的问题，即渗透物和进料活性及其相应的浓度梯度会影响理想材料（如PDMS）以及更复杂的材料（如具有固有孔隙率的聚合物）中的潜在传质现象。