1. Empa, Swiss Federal Laboratories for Materials Science and Technology, 8600 Dübendorf, Switzerland
2. Department of Physics, University of Basel, 4056 Basel, Switzerland
3. Swiss Nanoscience Institute, University of Basel, 4056 Basel, Switzerland
4. Department of Physics, Applied Physics, and Astronomy, Rensselaer Polytechnic Institute, Troy, New York 12180, United States
5. Department of Chemistry and Biochemistry, University of Bern, 3012 Bern, Switzerland
6. Max Planck Institute for Polymer Research, 55128 Mainz, Germany
7. Institute of Physical Chemistry, Johannes Gutenberg-Universität Mainz, 55128 Mainz, Germany