Berlin 2015 – wissenschaftliches Programm
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DS: Fachverband Dünne Schichten
DS 35: Graphen
DS 35.11: Vortrag
Donnerstag, 19. März 2015, 12:15–12:30, H 0111
hydration of bilayered graphene oxide — •bita rezania1, nikolai severin1, alexandr v talyzin2, and jürgen p rabe1 — 1Humboldt University, Berlin, Germany — 2Umeå University, Umeå, Sweden
Recently, it has been shown that graphene oxide (GO) membranes show remarkable selectivity in permeation of water molecules. This was attributed to the hydration of the membranes - the key to understand the water permeation mechanism. We investigated the change of the interlayer distance in bilayer GO as function of humidity and in liquid water using SFM [1]. The increase of relative humidity from 2 to *80% results in gradual expansion of interlayer distance by approximately 1 Å. The immersion into liquid water results in increase of the interlayer distance by another 3 Å. Our results are in good agreement with the averaged distance measured by X-ray diffraction on multilayered graphite oxides, which is commonly explained with an interstratification model. However, our experimental design excludes effects connected to interstratification. We find that the hydration is a continuous process of incorporation of water molecules into various sites within the GO layers, while liquid water inserts as a monolayer. The similarity of hydration for our bilayer and previously reported multilayered materials implies GO few and even bilayers to be suitable for selective water transport.
[1] Rezania, B., et al. Nano Lett. 2014, 14, 3993.