Regensburg 2013 – wissenschaftliches Programm

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CPP: Fachverband Chemische Physik und Polymerphysik

CPP 2: Interfaces and Thin Films I (joint session with DECHEMA and VDI)

CPP 2.11: Vortrag

Montag, 11. März 2013, 12:30–12:45, H40

Structure of nano-phase separated monomolecularly thick water-ethanol layers confined between graphene and mica — •Nikolai Severin, Vitalij Scenev, Philipp Lange, Igor M. Sokolov, and Jürgen P. Rabe — Department of Physics, Humboldt-Universität zu Berlin, Newtonstr. 15, 12489 Berlin, Germany

Understanding and control of liquids confined to the nano-scale is of wide interest, e.g., for molecular assays and synthesis to be performed on small scales. We report in-situ scanning force microscopy imaging of graphenes replicating nano-phase separated ethanol-water monomolecular films on an atomically flat mica surface. Graphenes conform to the film topography bending at the boundaries between domains of water and the larger ethanol molecules. The lateral size of molecular domains becomes larger with the graphene thickness, which we attribute to the graphene bending energy. Ethanol and water molecules have been demonstrated to dope graphene negatively and positively, respectively [1]. Consequently, we account for stabilization of the heterogeneity by the counteraction of electrostatic repulsion of the doped charges and line tension controlled by the bending energy of the graphene layers. 1. Schedin, F., et al., Nature Materials, 6 (2007) 652.