Regensburg 2022 – wissenschaftliches Programm

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CPP: Fachverband Chemische Physik und Polymerphysik

CPP 17: Poster 2

CPP 17.3: Poster

Dienstag, 6. September 2022, 11:00–13:00, P2

Selective Diffusion of CO2 and H2O through Carbon Nanomembranes in Aqueous Solution as Studied with Radioactive Tracers — Raphael Dalpke¹, Anna Dreyer², Riko Korzetz¹, •Lennart Schulte¹, André Beyer¹, and Karl Josef Diez² — ¹Faculty of Physics, Bielefeld University — ²Faculty of Biology, Bielefeld University

A well-known approach of improving membrane separation processes is the attempt to utilize 2D materials. In particular, carbon nanomem- branes (CNMs) are promising candidates due to their extremely high areal pore density. Specifically, CNMs made from terphenylthiol (TPT) exhibit a very high water permeance while blocking ions as well as many gases and vapours. Here, we present permeation measurements of TPT-CNMs utilizing radioactive tracer molecules to characterize diffusion of [³H]H2O, [¹⁴C]NaHCO3, and [³²P]H3 PO4 in aqueous solution. For full consideration of concentration polarization and outgassing effects a mathematical model was developed and verified using finite-element simulations. The experiment shows that water and carbonate can pass through the CNM while phosphate ions are completely blocked. Considering ion conductivity measurements, the obtained diffusion coefficients indicate that the permeation across the membrane primarily occurs by transport of neutral species.