SKM 2021 – wissenschaftliches Programm

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DS: Fachverband Dünne Schichten

DS 4: Poster

DS 4.13: Poster

Dienstag, 28. September 2021, 10:00–13:00, P

Molecular dynamics simulations of carbon nanomembranes (CNMs) — •Julian Ehrens, Levin Mihlan, and Jürgen Schnack — Universität Bielefeld, Universitätsstrasse 25, D-33615 Bielefeld

CNMs are made by electron-induced crosslinking of aromatic self-assembled monolayers (SAMs) [1,2]. Their supposedly irregular internal structure can not be adequately investigated by standard techniques, e.g. X-ray diffraction, which requires a characterization through physical quantities like solvent permeability and the Young's modulus. In order to propose possible internal molecular structures obtained from various initial configurations of the SAM and irradiation processes, we investigate the monolayers with respect to the Young's modulus in terms of classical molecular dynamics calculations using LAMMPS and use the experimental value of around 10 GPa for comparison. We present three distinct methods to calculate the Young's modulus: Global scaling of all coordinates (curvature of energy), stress-strain response from clamped straining and barostatted dynamics. Discrepancies among the methods with regard to vastly different outcomes of the Young's modulus will be discussed considering finite size effects and suitability of each method for this particular system.

[1] Dementyev, Petr, et al. ``Carbon Nanomembranes from Aromatic Carboxylate Precursors'' ChemPhysChem 21.10 (2020): 1006 [2] Ehrens, Julian, et al. ``Theoretical formation of carbon nanomembranes under realistic conditions using classical molecular dynamics'' Phys. Rev. B 103, 115416