1. Department of Chemistry, Johannes Gutenberg University Mainz, Duesbergweg 10-14, 55128 Mainz, Germany
2. Institute of Fundamental Technological Research, Polish Academy of Sciences, Adolfa Pawińskiego 5b, 02-106 Warsaw, Poland
3. Max Planck Institute for Polymer Research, D-55125 Mainz, Germany
4. Department of Physics, University of Ioannina, P.O. Box 1186, 45110 Ioannina, Greece