Berlin 2018 – wissenschaftliches Programm
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O: Fachverband Oberflächenphysik
O 26: Organic-inorganic hybrid systems and organic films III
O 26.3: Vortrag
Dienstag, 13. März 2018, 11:00–11:15, MA 042
Mixed aliphatic self-assembled monolayers with embedded polar group — •Eric Sauter1, Jean-Francois Morin2, and Michael Zharnikov1 — 1Applied Physical Chemistry, Heidelberg University, 69120 Heidelberg, Germany — 2Departement de Chimie and Centre de Recherche sur les Materiaux Avancees (CERMA), Universite Laval, Quebec QC Canada G1 V 0A6
We studied structure, molecular orientation, morphology, and electrostatic properties of mixed self-assembled monolayers (SAMs) comprised of alkanethiolates with the dipolar ester group embedded into the alkyl backbone at two opposite orientations. The packing density and molecular orientation in these films were found to be similar to those of the "parent" single-component monolayers. Applying X-ray photoelectron spectroscopy (XPS) as a morphology tool, we could estimate that the mixed SAMs represent homogeneous intermolecular mixtures of both components, down to the molecular level, excluding existence of "hot spots" for charge injection. The analysis of the C 1s XPS spectra and the work function data suggests that the composition of the mixed SAMs fully mimicked the mixing ratio of both components in the solutions from which these SAMs were prepared, which suggests a minor role of the dipole-dipole interaction in the overall balance of the structure-building forces. Varying this composition, work function of the gold substrate could be tuned linearly, in controlled fashion within a 1.1 eV range, at the persistent chemical composition of the SAM-ambient interface.