1. Max Planck Institute for Polymer Research, Postfach 3148, 55021 Mainz, Germany
2. Institute of General Botany, Johannes Gutenberg University Mainz, Müllerweg 6, 55099 Mainz, Germany
3. Laboratory for Physical Chemistry, ETH Zürich, Wolfgang-Pauli-Strasse 10, 8093 Zürich, Switzerland