1. Max-Planck Institute for Polymer Research, 55128 Mainz, Germany
2. Department of Materials Science & 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