Dresden 2017 – wissenschaftliches Programm
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CPP: Fachverband Chemische Physik und Polymerphysik
CPP 69: Thin Films, Nanostructures and Nanoparticles II
CPP 69.2: Vortrag
Freitag, 24. März 2017, 10:30–10:45, ZEU 114
Gas permeation through free-standing carbon nanomembranes — •Petr Dementyev1, Polina Angelova2, Henning Vieker2, Daniel Emmrich1, and Armin Gölzhäuser1 — 1Universität Bielefeld, Fakultät für Physik, Universitätsstr. 25, Bielefeld — 2CNM Technologies GmbH, Herforder Str. 155a, Bielefeld
Despite membranes-based gas separation can provide lower operation costs compared to distillation and sorption methods, membranes of superior permeance and selectivity are still under development. 2D materials seem to be promising in this context, as nanoporous membranes with the least thickness and no tortuosity would provide the ultimate permeation rate and could potentially work as molecular sieves.
Herein we employ a newly developed high vacuum permeation setup to study mass transport through free-standing carbon nanomembranes (CNMs). CNMs are formed out of self-assembled monolayers of molecules and are mechanically stable. Furthermore, CNMs can be fabricated on a large scale, and their properties are widely tunable depending on the preparation conditions.
Various CNMs were probed towards permeation of helium, neon, nitrogen, oxygen, argon and carbon dioxide. Mass-spectrometry detection enabled to determine the permeation rate and the membrane selectivity. Some of the samples were found to have defects with a characteristic size of 100 nm which was confirmed by helium ion microscopy. In turn, the intact samples were proved to be dense but highly selective to helium. We discuss the mechanism of gas separation as well as the origin of defects.