1. Leibniz-Institut of Poslymer Research Dresden, 01069 Dresden, Germany
2. Institute of Physics, University of Szczecin, Wielkopolska 15, 70451 Szczecin, Poland
3. Department of Materials Science and Engineering, Northwestern University, Evanston, Illinois 60208, USA
4. Institute for Physical Chemistry, Bulgarian Academy of Sciences, 1113 Sofia, Bulgaria
5. Max-Planck-Institute for Polymer Research, Ackermannweg 10, 55128 Mainz, Germany