1. Max-Planck Institute for Polymer Research, 55128 Mainz, Germany
2. Department
of Materials Science and Nanotechnology Engineering, TOBB University of Economics and Technology, 06560 Ankara, Turkey
3. Institut
für Chemie neuer Materialien, Universität Osnabrück, D-49069 Osnabrück, Germany
4. Department
of Physics, University of Ioannina, 45110 Ioannina, Greece