1. Department
of Physics, University of Siegen, Walter-Flex-Strasse 3, D-57072 Siegen, Germany
2. IM2NP,
Faculté des Sciences et Techniques, Aix-Marseille Université, Avenue Escadrille Normandie Niemen, Case 142, F-13397 Marseille, France
3. Macromolecular
Chemistry and Institute for Polymer Technology, Bergische Universität Wuppertal, Gauss-Strasse 20, 42119 Wuppertal, Germany