1. Empa, Swiss Federal Laboratories for Materials Science and Technology, nanotech@surfaces Laboratory, 8600 Dübendorf, Switzerland
2. Max Planck Institute for Polymer Research, 55128 Mainz, Germany
3. Department of Chemistry, University of Zürich, 8057 Zürich, Switzerland
4. Department of Chemistry and Biochemistry, University of Bern, 3012 Bern, Switzerland