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O: Fachverband Oberflächenphysik
O 60: Poster Session IV (Solid/liquid interfaces; Semiconductors; Oxides and insulators; Graphene; Plasmonics and nanooptics; Electronic Structure; Surface chemical reactions; Heterogeneous catalysis)
O 60.57: Poster
Mittwoch, 16. März 2011, 17:30–21:00, P4
Gas permeation in graphenoid nanomembranes — •Nils Mellech1, Xianghui Zhang1, Elina Oberländer1, André Beyer1, Edgar Hansjosten2, Roland Dittmeyer2, and Armin Gölzhäuser1 — 1Faculty of Physics, Bielefeld University, Postfach 10 01 31, 33501 Bielefeld, Germany — 2Karlsruhe Institute of Technology, Institute for Micro Process Engineering (IMVT), Karlsruhe, Germany
Permeation and selectivity measurements with helium and argon are carried out on freestanding nanomembranes of cross-linked self-assembled mono- and multilayers. The monolayers of 1,1'-biphenyl-4-thiol and 4'-nitro-1,1'-biphenyl-4-thiol are prepared on gold on mica and cross-linked by electron irradiation which results in layer thicknesses of approximately 1 nm. Afterwards the nanomembranes are transferred either onto millimeter-sized polished sintered porous steel substrates or onto a micron-sized opening in a silicon nitride window on silicon substrates. The latter samples are investigated with an ultrahigh vacuum permeation measurement system based on a quadrupole mass spectrometer. The nanomembranes seal the UHV chamber from the high pressure feed gas side of the system and remain stable for days under pressures up to 30 kPa. The nanomembranes on the porous substrates are characterized by a gas flow measurement system. The membranes cover the pores and substantially reduce the gas flow. Permeation properties of the nanomembranes are discussed based on the measured data.