Regensburg 2010 – wissenschaftliches Programm

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O: Fachverband Oberflächenphysik

O 41: Poster Session I (Semiconductor Substrates: Epitaxy and growth; Semiconductor Substrates: Adsorbtion; Semiconductor Substrates: Solid-liquid interfaces; Semiconductor Substrates: Clean surfaces; Oxides and insulators: Epitaxy and growth; Oxides and insulators: Adsorption; Oxides and insulators: Clean surfaces; Organic, polymeric and biomolecular films - also with adsorbates; Organic electronics and photovoltaics, Surface chemical reactions; Heterogeneous catalysis; Phase transitions; Particles and clusters; Surface dynamics; Surface or interface magnetism; Electron and spin dynamics; Spin-Orbit Interaction at Surfaces; Electronic structure; Nanotribology; Solid/liquid interfaces; Graphene; Others)

O 41.112: Poster

Dienstag, 23. März 2010, 18:30–21:00, Poster B1

Gas permeation in graphenoid nanomembranes — •Nils Mellech, Elina Oberländer, Xianghui Zhang, André Beyer, and Armin Gölzhäuser — Universität Bielefeld, Postfach 10 01 31, 33501 Bielefeld, Germany

Permeation and selectivity measurements with Helium and Argon were carried out on freestanding nanomembranes of crosslinked self-assembled biphenylthiol and nitrobiphenylthiol monolayers. An ultrahigh vacuum permeation measurement system based on a quadrupole mass spectrometer was used to determine the permeation properties. The monolayers of biphenylthiol and nitrobiphenylthiol are prepared on gold on mica and crosslinked by electron irradiation. After preparation the nanomembranes which have a thickness of approximately 1 nm are transferred onto a micron-sized opening in a silicon nitride window of a silicon substrate. The nanomembrane seals the UHV chamber from the high pressure feed gas side of the system. Despite its thinness, the membranes remain stable under pressures of up to 30 kPa, even for days. The permeability of nitrobiphenylthiol nanomembranes was found to be substantially lower as compared to biphenylthiol membranes. This is accompanied by a significant increase in the permeation selectivity of He to Ar gas.