1. Max Planck Institute for Polymer Research; Ackermannweg 10 55128 Mainz Germany
2. Graduate School Materials Science in Mainz; Staudinger Weg 9 55128 Mainz Germany
3. Department of Materials Science; University of Crete and IESL/FO.R.T.H; P.O. Box 1527 71110 Heraklion Greece