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DS: Fachverband Dünne Schichten

DS 22: Interfaces and Thin Films III (joint session with CPP)

DS 22.3: Vortrag

Mittwoch, 18. März 2015, 10:00–10:15, C 243

Tailoring the mechanics of ultrathin carbon nanomembranes by molecular design — •Xianghui Zhang, Christof Neumann, Polina Angelova, André Beyer, and Armin Gölzhäuser — Fakultät für Physik, Universität Bielefeld, 33615 Bielefeld, Germany

Freestanding carbon nanomembranes (CNMs) with a thickness between 0.6 nm and 1.7 nm were prepared from self-assembled monolayers (SAMs) of diverse polyaromatic precursors via low energy electron induced cross-linking. The mechanical properties of CNMs were investigated by applying a pressure difference between the two sides of the membrane and by measuring the resulting deflection with atomic force microscopy. We found a correlation between the rigidity of the precursor molecules and the macroscopic mechanical stiffness of CNMs. While CNMs from rigid and condensed precursors like naphthalene and pyrene thiols prove to exhibit higher Young's moduli of 15~19 GPa, CNMs from non-fused oligophenyls possess lower Young's moduli of ~10 GPa. For CNMs from less densely packed SAMs, the presence of defects and nanopores plays an important role in determining their mechanical properties. The finite element method (FEM) was applied to examine the deformation profiles and simulate the pressure-deflection relationships.