Naberezhnyi Daniil, Gölzhäuser Armin, Dementyev Petr
Physics of Supramolecular Systems and Surfaces, Faculty of Physics , Bielefeld University , 33615 Bielefeld , Germany.
J Phys Chem Lett. 2019 Sep 19;10(18):5598-5601. doi: 10.1021/acs.jpclett.9b02321. Epub 2019 Sep 6.
Planar nanomaterials finished with transverse ducts represent an intriguing avenue for exploring interfacial phenomena. Due to their small thickness, the kinetics of molecular diffusion across the channels is likely to be dominated by entrance events. Therefore, measuring transport rates in freestanding films can yield valuable information on surface processes. In this work, we study permeation of gases in carbon nanomembranes (CNMs) when accompanied by saturated water vapor. The experimental data reveal a manifold increase in transmembrane fluxes compared to dry conditions. Gas molecules are found to be trapped in adsorbed water, which enhances their translocation likelihood. We demonstrate that the permeance correlates with the vapor relative pressure and discuss the observed crossing mechanism in terms of water condensation and Henry's law. Our findings provide guidance for designing gas separation membranes upon two-dimensional materials.
具有横向通道的平面纳米材料是探索界面现象的一个有趣途径。由于其厚度小，分子跨通道扩散的动力学可能由入口事件主导。因此，测量独立薄膜中的传输速率可以获得有关表面过程的有价值信息。在这项工作中，我们研究了碳纳米膜（CNM）在伴有饱和水蒸气时的气体渗透情况。实验数据表明，与干燥条件相比，跨膜通量有显著增加。发现气体分子被困在吸附水中，这增加了它们的迁移可能性。我们证明渗透率与蒸汽相对压力相关，并根据水的凝结和亨利定律讨论了观察到的穿越机制。我们的研究结果为二维材料气体分离膜的设计提供了指导。
