1. Fraunhofer Institute for Applied Polymer Research, Science Center Golm, 14476 Potsdam, Geiselbergstr. 69, Germany
2. Department of Organic Chemistry, Instituto de Ciencia de Materiales de Aragón, University of Zaragoza-CSIC, Pedro Cerbuna 12, 50009 Zaragoza, Spain
3. Philips Research, Prof. Holstlaan 4, 5656 AA Eindhoven, The Netherlands