1. Laboratory for Chemistry & Physics of Interfaces, Department of Microsystems Engineering (IMTEK), Albert-Ludwigs-Universität Freiburg, Freiburg 79110, Germany
2. Freiburg Institute for Interactive Materials and Bioinspired Technologies (FIT), Albert-Ludwigs-Universität Freiburg, Freiburg 79110, Germany
3. Macromolecular Chemistry & Paper Chemistry, Technical University of Darmstadt, Darmstadt 64287, Germany