1. “Materials + Technologies” Group; Polytechnic School, Dpto. Ingeniería Química y M. Ambiente, Universidad País Vasco/Euskal Herriko Universitatea; Pza. Europa 1 20018 Donostia-San Sebastian Spain
2. Department of Materials Science Engineering; University of Ioannina; University Campus; Ioannina 45110 Greece
3. Laboratoire de Chimie des Polymères Organiques (LCPO); - UMR5629, Université Bordeaux, CNRS; IPB-ENSCBP, 16 Avenue Pey Berland 33607 Pessac Cedex France