1. POLYMAT, Department of Polymer Science and Technology; Faculty of Chemistry, University of the Basque Country UPV/EHU; Donostia Spain
2. POLYMAT, Department of Mining-Metallurgy Engineering and Materials Science; University of the Basque Country UPV/EHU; Bilbao Spain
3. Departamento de Física de Materiales; Universidad Complutense de Madrid; Madrid Spain