1. Institute
of Physics, Poznan University of Technology, Piotrowo 3, PL-60965 Poznan, Poland
2. Materials
Science and Technology of Polymers, MESA+ Institute for
Nanotechnology, University of Twente, NL-7500 AE Enschede, The Netherlands
3. Max Planck Institute for Polymer Research, Ackermannweg 10, D-55128 Mainz, Germany