1. National Technical University of Athens, School of Chemical Engineering, Zografou Campus, GR-15780 Athens, Greece
2. Dutch Polymer Institute (DPI), P.O. Box 902, 5600 AX Eindhoven, The Netherlands
3. Laboratoire de Chimie Physique, Université Paris-Sud 11, UMR 8000 CNRS, Orsay, France