1. Ernst-Berl-Institute of Technical and Macromolecular Chemistry, Laboratory for Macromolecular Chemistry and Paper Chemistry, Darmstadt University of Technology, Petersenstrasse 22, D-64278 Darmstadt, Germany
2. Department of Microsystems Engineering (IMTEK), Laboratory of Chemistry and Physics of Interfaces, University of Freiburg, D-79110 Freiburg, Germany