1. Max-Planck-Institute for Polymer Research, Ackermannweg 10, 55128 Mainz, Germany
2. Department of Chemistry, Johannes Gutenberg-Universität, Duesbergweg 10-14, 55099 Mainz, Germany
3. Institute for Soldier Nanotechnologies, Department of Materials Science and Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139
4. Department of Materials Science & F.O.R.T.H., P.O. Box 1527, 71110 Heraklion, Greece