Caliskan Esra, Shishatskiy Sergey, Filiz Volkan
Institute of Membrane Research, Helmholtz-Zentrum Hereon, Max-Planck-Str. 1, 21502 Geesthacht, Germany.
Polymers (Basel). 2024 Oct 18;16(20):2932. doi: 10.3390/polym16202932.
This study assesses the gas and water vapor permeance of PIM-derivative thin-film composite (TFC) membranes using pervaporation and "pressure increase" methods, and provides a comparative view of "time lag" measurements of thick films obtained from our previous work. In this study, TFC membranes were prepared using PIM-1 and homopolymers that were modified with different side groups to explore their effects on gas and water vapor transport. Rigid and bulky aliphatic groups were used to increase the polymer's free volume and were evaluated for their impact on both gas and water transport. Aromatic side groups were specifically employed to assess water affinity. The permeance of CO, H, CH and water vapor through these membranes was analyzed using the 'pressure increase' method to determine the modifications' influence on transport efficiency and interaction with water molecules. Over a 20 h period, the aging and the permeance of the TFC membranes were analyzed using this method. In parallel, pervaporation experiments were conducted on samples taken independently from the same membrane roll to assess water flux, with particular attention paid to the liquid form on the feed side. The significantly higher water vapor transport rates observed in pervaporation experiments compared to those using the "pressure increase" method underline the efficiency of pervaporation. This efficiency suggests that membranes designed for pervaporation can serve as effective alternatives to conventional porous membranes used in distillation applications. Additionally, incorporating "time lag" results from a pioneering study into the comparison revealed that the trends observed in "time lag" and pervaporation results exhibited similar trends, whereas "pressure increase" data showed a different development. This discrepancy is attributed to the state of the polymer, which varies significantly depending on the operating conditions.
本研究采用渗透蒸发和“压力增加”方法评估了PIM衍生物薄膜复合（TFC）膜的气体和水蒸气渗透性能，并对我们之前工作中获得的厚膜“时间滞后”测量结果进行了比较。在本研究中，使用PIM-1和带有不同侧基修饰的均聚物制备了TFC膜，以探索它们对气体和水蒸气传输的影响。使用刚性和庞大的脂肪族基团来增加聚合物的自由体积，并评估它们对气体和水传输的影响。特别采用芳香族侧基来评估水亲和力。使用“压力增加”方法分析了CO、H、CH和水蒸气透过这些膜的渗透率，以确定修饰对传输效率和与水分子相互作用的影响。在20小时的时间内，使用该方法分析了TFC膜的老化和渗透率。同时，对从同一膜卷独立取出的样品进行了渗透蒸发实验，以评估水通量，特别关注进料侧的液体形式。与使用“压力增加”方法相比，渗透蒸发实验中观察到的水蒸气传输速率显著更高，这突出了渗透蒸发的效率。这种效率表明，为渗透蒸发设计的膜可以作为蒸馏应用中使用的传统多孔膜的有效替代品。此外，将一项开创性研究中的“时间滞后”结果纳入比较后发现，“时间滞后”和渗透蒸发结果中观察到的趋势呈现出相似的趋势，而“压力增加”数据则显示出不同的变化。这种差异归因于聚合物的状态，其根据操作条件有显著变化。
